| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * Kernel-based Virtual Machine (KVM) Hypervisor |
| * |
| * Copyright (C) 2006 Qumranet, Inc. |
| * Copyright 2010 Red Hat, Inc. and/or its affiliates. |
| * |
| * Authors: |
| * Avi Kivity <avi@qumranet.com> |
| * Yaniv Kamay <yaniv@qumranet.com> |
| */ |
| |
| #include <kvm/iodev.h> |
| |
| #include <linux/kvm_host.h> |
| #include <linux/kvm.h> |
| #include <linux/module.h> |
| #include <linux/errno.h> |
| #include <linux/percpu.h> |
| #include <linux/mm.h> |
| #include <linux/miscdevice.h> |
| #include <linux/vmalloc.h> |
| #include <linux/reboot.h> |
| #include <linux/debugfs.h> |
| #include <linux/highmem.h> |
| #include <linux/file.h> |
| #include <linux/syscore_ops.h> |
| #include <linux/cpu.h> |
| #include <linux/sched/signal.h> |
| #include <linux/sched/mm.h> |
| #include <linux/sched/stat.h> |
| #include <linux/cpumask.h> |
| #include <linux/smp.h> |
| #include <linux/anon_inodes.h> |
| #include <linux/profile.h> |
| #include <linux/kvm_para.h> |
| #include <linux/pagemap.h> |
| #include <linux/mman.h> |
| #include <linux/swap.h> |
| #include <linux/bitops.h> |
| #include <linux/spinlock.h> |
| #include <linux/compat.h> |
| #include <linux/srcu.h> |
| #include <linux/hugetlb.h> |
| #include <linux/slab.h> |
| #include <linux/sort.h> |
| #include <linux/bsearch.h> |
| #include <linux/io.h> |
| #include <linux/lockdep.h> |
| #include <linux/kthread.h> |
| #include <linux/suspend.h> |
| |
| #include <asm/processor.h> |
| #include <asm/ioctl.h> |
| #include <linux/uaccess.h> |
| |
| #include "coalesced_mmio.h" |
| #include "async_pf.h" |
| #include "kvm_mm.h" |
| #include "vfio.h" |
| |
| #include <trace/events/ipi.h> |
| |
| #define CREATE_TRACE_POINTS |
| #include <trace/events/kvm.h> |
| |
| #include <linux/kvm_dirty_ring.h> |
| |
| |
| /* Worst case buffer size needed for holding an integer. */ |
| #define ITOA_MAX_LEN 12 |
| |
| MODULE_AUTHOR("Qumranet"); |
| MODULE_DESCRIPTION("Kernel-based Virtual Machine (KVM) Hypervisor"); |
| MODULE_LICENSE("GPL"); |
| |
| /* Architectures should define their poll value according to the halt latency */ |
| unsigned int halt_poll_ns = KVM_HALT_POLL_NS_DEFAULT; |
| module_param(halt_poll_ns, uint, 0644); |
| EXPORT_SYMBOL_GPL(halt_poll_ns); |
| |
| /* Default doubles per-vcpu halt_poll_ns. */ |
| unsigned int halt_poll_ns_grow = 2; |
| module_param(halt_poll_ns_grow, uint, 0644); |
| EXPORT_SYMBOL_GPL(halt_poll_ns_grow); |
| |
| /* The start value to grow halt_poll_ns from */ |
| unsigned int halt_poll_ns_grow_start = 10000; /* 10us */ |
| module_param(halt_poll_ns_grow_start, uint, 0644); |
| EXPORT_SYMBOL_GPL(halt_poll_ns_grow_start); |
| |
| /* Default halves per-vcpu halt_poll_ns. */ |
| unsigned int halt_poll_ns_shrink = 2; |
| module_param(halt_poll_ns_shrink, uint, 0644); |
| EXPORT_SYMBOL_GPL(halt_poll_ns_shrink); |
| |
| /* |
| * Ordering of locks: |
| * |
| * kvm->lock --> kvm->slots_lock --> kvm->irq_lock |
| */ |
| |
| DEFINE_MUTEX(kvm_lock); |
| LIST_HEAD(vm_list); |
| |
| static struct kmem_cache *kvm_vcpu_cache; |
| |
| static __read_mostly struct preempt_ops kvm_preempt_ops; |
| static DEFINE_PER_CPU(struct kvm_vcpu *, kvm_running_vcpu); |
| |
| static struct dentry *kvm_debugfs_dir; |
| |
| static const struct file_operations stat_fops_per_vm; |
| |
| static long kvm_vcpu_ioctl(struct file *file, unsigned int ioctl, |
| unsigned long arg); |
| #ifdef CONFIG_KVM_COMPAT |
| static long kvm_vcpu_compat_ioctl(struct file *file, unsigned int ioctl, |
| unsigned long arg); |
| #define KVM_COMPAT(c) .compat_ioctl = (c) |
| #else |
| /* |
| * For architectures that don't implement a compat infrastructure, |
| * adopt a double line of defense: |
| * - Prevent a compat task from opening /dev/kvm |
| * - If the open has been done by a 64bit task, and the KVM fd |
| * passed to a compat task, let the ioctls fail. |
| */ |
| static long kvm_no_compat_ioctl(struct file *file, unsigned int ioctl, |
| unsigned long arg) { return -EINVAL; } |
| |
| static int kvm_no_compat_open(struct inode *inode, struct file *file) |
| { |
| return is_compat_task() ? -ENODEV : 0; |
| } |
| #define KVM_COMPAT(c) .compat_ioctl = kvm_no_compat_ioctl, \ |
| .open = kvm_no_compat_open |
| #endif |
| static int hardware_enable_all(void); |
| static void hardware_disable_all(void); |
| |
| static void kvm_io_bus_destroy(struct kvm_io_bus *bus); |
| |
| #define KVM_EVENT_CREATE_VM 0 |
| #define KVM_EVENT_DESTROY_VM 1 |
| static void kvm_uevent_notify_change(unsigned int type, struct kvm *kvm); |
| static unsigned long long kvm_createvm_count; |
| static unsigned long long kvm_active_vms; |
| |
| static DEFINE_PER_CPU(cpumask_var_t, cpu_kick_mask); |
| |
| __weak void kvm_arch_guest_memory_reclaimed(struct kvm *kvm) |
| { |
| } |
| |
| bool kvm_is_zone_device_page(struct page *page) |
| { |
| /* |
| * The metadata used by is_zone_device_page() to determine whether or |
| * not a page is ZONE_DEVICE is guaranteed to be valid if and only if |
| * the device has been pinned, e.g. by get_user_pages(). WARN if the |
| * page_count() is zero to help detect bad usage of this helper. |
| */ |
| if (WARN_ON_ONCE(!page_count(page))) |
| return false; |
| |
| return is_zone_device_page(page); |
| } |
| |
| /* |
| * Returns a 'struct page' if the pfn is "valid" and backed by a refcounted |
| * page, NULL otherwise. Note, the list of refcounted PG_reserved page types |
| * is likely incomplete, it has been compiled purely through people wanting to |
| * back guest with a certain type of memory and encountering issues. |
| */ |
| struct page *kvm_pfn_to_refcounted_page(kvm_pfn_t pfn) |
| { |
| struct page *page; |
| |
| if (!pfn_valid(pfn)) |
| return NULL; |
| |
| page = pfn_to_page(pfn); |
| if (!PageReserved(page)) |
| return page; |
| |
| /* The ZERO_PAGE(s) is marked PG_reserved, but is refcounted. */ |
| if (is_zero_pfn(pfn)) |
| return page; |
| |
| /* |
| * ZONE_DEVICE pages currently set PG_reserved, but from a refcounting |
| * perspective they are "normal" pages, albeit with slightly different |
| * usage rules. |
| */ |
| if (kvm_is_zone_device_page(page)) |
| return page; |
| |
| return NULL; |
| } |
| |
| /* |
| * Switches to specified vcpu, until a matching vcpu_put() |
| */ |
| void vcpu_load(struct kvm_vcpu *vcpu) |
| { |
| int cpu = get_cpu(); |
| |
| __this_cpu_write(kvm_running_vcpu, vcpu); |
| preempt_notifier_register(&vcpu->preempt_notifier); |
| kvm_arch_vcpu_load(vcpu, cpu); |
| put_cpu(); |
| } |
| EXPORT_SYMBOL_GPL(vcpu_load); |
| |
| void vcpu_put(struct kvm_vcpu *vcpu) |
| { |
| preempt_disable(); |
| kvm_arch_vcpu_put(vcpu); |
| preempt_notifier_unregister(&vcpu->preempt_notifier); |
| __this_cpu_write(kvm_running_vcpu, NULL); |
| preempt_enable(); |
| } |
| EXPORT_SYMBOL_GPL(vcpu_put); |
| |
| /* TODO: merge with kvm_arch_vcpu_should_kick */ |
| static bool kvm_request_needs_ipi(struct kvm_vcpu *vcpu, unsigned req) |
| { |
| int mode = kvm_vcpu_exiting_guest_mode(vcpu); |
| |
| /* |
| * We need to wait for the VCPU to reenable interrupts and get out of |
| * READING_SHADOW_PAGE_TABLES mode. |
| */ |
| if (req & KVM_REQUEST_WAIT) |
| return mode != OUTSIDE_GUEST_MODE; |
| |
| /* |
| * Need to kick a running VCPU, but otherwise there is nothing to do. |
| */ |
| return mode == IN_GUEST_MODE; |
| } |
| |
| static void ack_kick(void *_completed) |
| { |
| } |
| |
| static inline bool kvm_kick_many_cpus(struct cpumask *cpus, bool wait) |
| { |
| if (cpumask_empty(cpus)) |
| return false; |
| |
| smp_call_function_many(cpus, ack_kick, NULL, wait); |
| return true; |
| } |
| |
| static void kvm_make_vcpu_request(struct kvm_vcpu *vcpu, unsigned int req, |
| struct cpumask *tmp, int current_cpu) |
| { |
| int cpu; |
| |
| if (likely(!(req & KVM_REQUEST_NO_ACTION))) |
| __kvm_make_request(req, vcpu); |
| |
| if (!(req & KVM_REQUEST_NO_WAKEUP) && kvm_vcpu_wake_up(vcpu)) |
| return; |
| |
| /* |
| * Note, the vCPU could get migrated to a different pCPU at any point |
| * after kvm_request_needs_ipi(), which could result in sending an IPI |
| * to the previous pCPU. But, that's OK because the purpose of the IPI |
| * is to ensure the vCPU returns to OUTSIDE_GUEST_MODE, which is |
| * satisfied if the vCPU migrates. Entering READING_SHADOW_PAGE_TABLES |
| * after this point is also OK, as the requirement is only that KVM wait |
| * for vCPUs that were reading SPTEs _before_ any changes were |
| * finalized. See kvm_vcpu_kick() for more details on handling requests. |
| */ |
| if (kvm_request_needs_ipi(vcpu, req)) { |
| cpu = READ_ONCE(vcpu->cpu); |
| if (cpu != -1 && cpu != current_cpu) |
| __cpumask_set_cpu(cpu, tmp); |
| } |
| } |
| |
| bool kvm_make_vcpus_request_mask(struct kvm *kvm, unsigned int req, |
| unsigned long *vcpu_bitmap) |
| { |
| struct kvm_vcpu *vcpu; |
| struct cpumask *cpus; |
| int i, me; |
| bool called; |
| |
| me = get_cpu(); |
| |
| cpus = this_cpu_cpumask_var_ptr(cpu_kick_mask); |
| cpumask_clear(cpus); |
| |
| for_each_set_bit(i, vcpu_bitmap, KVM_MAX_VCPUS) { |
| vcpu = kvm_get_vcpu(kvm, i); |
| if (!vcpu) |
| continue; |
| kvm_make_vcpu_request(vcpu, req, cpus, me); |
| } |
| |
| called = kvm_kick_many_cpus(cpus, !!(req & KVM_REQUEST_WAIT)); |
| put_cpu(); |
| |
| return called; |
| } |
| |
| bool kvm_make_all_cpus_request(struct kvm *kvm, unsigned int req) |
| { |
| struct kvm_vcpu *vcpu; |
| struct cpumask *cpus; |
| unsigned long i; |
| bool called; |
| int me; |
| |
| me = get_cpu(); |
| |
| cpus = this_cpu_cpumask_var_ptr(cpu_kick_mask); |
| cpumask_clear(cpus); |
| |
| kvm_for_each_vcpu(i, vcpu, kvm) |
| kvm_make_vcpu_request(vcpu, req, cpus, me); |
| |
| called = kvm_kick_many_cpus(cpus, !!(req & KVM_REQUEST_WAIT)); |
| put_cpu(); |
| |
| return called; |
| } |
| EXPORT_SYMBOL_GPL(kvm_make_all_cpus_request); |
| |
| void kvm_flush_remote_tlbs(struct kvm *kvm) |
| { |
| ++kvm->stat.generic.remote_tlb_flush_requests; |
| |
| /* |
| * We want to publish modifications to the page tables before reading |
| * mode. Pairs with a memory barrier in arch-specific code. |
| * - x86: smp_mb__after_srcu_read_unlock in vcpu_enter_guest |
| * and smp_mb in walk_shadow_page_lockless_begin/end. |
| * - powerpc: smp_mb in kvmppc_prepare_to_enter. |
| * |
| * There is already an smp_mb__after_atomic() before |
| * kvm_make_all_cpus_request() reads vcpu->mode. We reuse that |
| * barrier here. |
| */ |
| if (!kvm_arch_flush_remote_tlbs(kvm) |
| || kvm_make_all_cpus_request(kvm, KVM_REQ_TLB_FLUSH)) |
| ++kvm->stat.generic.remote_tlb_flush; |
| } |
| EXPORT_SYMBOL_GPL(kvm_flush_remote_tlbs); |
| |
| void kvm_flush_remote_tlbs_range(struct kvm *kvm, gfn_t gfn, u64 nr_pages) |
| { |
| if (!kvm_arch_flush_remote_tlbs_range(kvm, gfn, nr_pages)) |
| return; |
| |
| /* |
| * Fall back to a flushing entire TLBs if the architecture range-based |
| * TLB invalidation is unsupported or can't be performed for whatever |
| * reason. |
| */ |
| kvm_flush_remote_tlbs(kvm); |
| } |
| |
| void kvm_flush_remote_tlbs_memslot(struct kvm *kvm, |
| const struct kvm_memory_slot *memslot) |
| { |
| /* |
| * All current use cases for flushing the TLBs for a specific memslot |
| * are related to dirty logging, and many do the TLB flush out of |
| * mmu_lock. The interaction between the various operations on memslot |
| * must be serialized by slots_locks to ensure the TLB flush from one |
| * operation is observed by any other operation on the same memslot. |
| */ |
| lockdep_assert_held(&kvm->slots_lock); |
| kvm_flush_remote_tlbs_range(kvm, memslot->base_gfn, memslot->npages); |
| } |
| |
| static void kvm_flush_shadow_all(struct kvm *kvm) |
| { |
| kvm_arch_flush_shadow_all(kvm); |
| kvm_arch_guest_memory_reclaimed(kvm); |
| } |
| |
| #ifdef KVM_ARCH_NR_OBJS_PER_MEMORY_CACHE |
| static inline void *mmu_memory_cache_alloc_obj(struct kvm_mmu_memory_cache *mc, |
| gfp_t gfp_flags) |
| { |
| void *page; |
| |
| gfp_flags |= mc->gfp_zero; |
| |
| if (mc->kmem_cache) |
| return kmem_cache_alloc(mc->kmem_cache, gfp_flags); |
| |
| page = (void *)__get_free_page(gfp_flags); |
| if (page && mc->init_value) |
| memset64(page, mc->init_value, PAGE_SIZE / sizeof(u64)); |
| return page; |
| } |
| |
| int __kvm_mmu_topup_memory_cache(struct kvm_mmu_memory_cache *mc, int capacity, int min) |
| { |
| gfp_t gfp = mc->gfp_custom ? mc->gfp_custom : GFP_KERNEL_ACCOUNT; |
| void *obj; |
| |
| if (mc->nobjs >= min) |
| return 0; |
| |
| if (unlikely(!mc->objects)) { |
| if (WARN_ON_ONCE(!capacity)) |
| return -EIO; |
| |
| /* |
| * Custom init values can be used only for page allocations, |
| * and obviously conflict with __GFP_ZERO. |
| */ |
| if (WARN_ON_ONCE(mc->init_value && (mc->kmem_cache || mc->gfp_zero))) |
| return -EIO; |
| |
| mc->objects = kvmalloc_array(capacity, sizeof(void *), gfp); |
| if (!mc->objects) |
| return -ENOMEM; |
| |
| mc->capacity = capacity; |
| } |
| |
| /* It is illegal to request a different capacity across topups. */ |
| if (WARN_ON_ONCE(mc->capacity != capacity)) |
| return -EIO; |
| |
| while (mc->nobjs < mc->capacity) { |
| obj = mmu_memory_cache_alloc_obj(mc, gfp); |
| if (!obj) |
| return mc->nobjs >= min ? 0 : -ENOMEM; |
| mc->objects[mc->nobjs++] = obj; |
| } |
| return 0; |
| } |
| |
| int kvm_mmu_topup_memory_cache(struct kvm_mmu_memory_cache *mc, int min) |
| { |
| return __kvm_mmu_topup_memory_cache(mc, KVM_ARCH_NR_OBJS_PER_MEMORY_CACHE, min); |
| } |
| |
| int kvm_mmu_memory_cache_nr_free_objects(struct kvm_mmu_memory_cache *mc) |
| { |
| return mc->nobjs; |
| } |
| |
| void kvm_mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc) |
| { |
| while (mc->nobjs) { |
| if (mc->kmem_cache) |
| kmem_cache_free(mc->kmem_cache, mc->objects[--mc->nobjs]); |
| else |
| free_page((unsigned long)mc->objects[--mc->nobjs]); |
| } |
| |
| kvfree(mc->objects); |
| |
| mc->objects = NULL; |
| mc->capacity = 0; |
| } |
| |
| void *kvm_mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc) |
| { |
| void *p; |
| |
| if (WARN_ON(!mc->nobjs)) |
| p = mmu_memory_cache_alloc_obj(mc, GFP_ATOMIC | __GFP_ACCOUNT); |
| else |
| p = mc->objects[--mc->nobjs]; |
| BUG_ON(!p); |
| return p; |
| } |
| #endif |
| |
| static void kvm_vcpu_init(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned id) |
| { |
| mutex_init(&vcpu->mutex); |
| vcpu->cpu = -1; |
| vcpu->kvm = kvm; |
| vcpu->vcpu_id = id; |
| vcpu->pid = NULL; |
| #ifndef __KVM_HAVE_ARCH_WQP |
| rcuwait_init(&vcpu->wait); |
| #endif |
| kvm_async_pf_vcpu_init(vcpu); |
| |
| kvm_vcpu_set_in_spin_loop(vcpu, false); |
| kvm_vcpu_set_dy_eligible(vcpu, false); |
| vcpu->preempted = false; |
| vcpu->ready = false; |
| preempt_notifier_init(&vcpu->preempt_notifier, &kvm_preempt_ops); |
| vcpu->last_used_slot = NULL; |
| |
| /* Fill the stats id string for the vcpu */ |
| snprintf(vcpu->stats_id, sizeof(vcpu->stats_id), "kvm-%d/vcpu-%d", |
| task_pid_nr(current), id); |
| } |
| |
| static void kvm_vcpu_destroy(struct kvm_vcpu *vcpu) |
| { |
| kvm_arch_vcpu_destroy(vcpu); |
| kvm_dirty_ring_free(&vcpu->dirty_ring); |
| |
| /* |
| * No need for rcu_read_lock as VCPU_RUN is the only place that changes |
| * the vcpu->pid pointer, and at destruction time all file descriptors |
| * are already gone. |
| */ |
| put_pid(rcu_dereference_protected(vcpu->pid, 1)); |
| |
| free_page((unsigned long)vcpu->run); |
| kmem_cache_free(kvm_vcpu_cache, vcpu); |
| } |
| |
| void kvm_destroy_vcpus(struct kvm *kvm) |
| { |
| unsigned long i; |
| struct kvm_vcpu *vcpu; |
| |
| kvm_for_each_vcpu(i, vcpu, kvm) { |
| kvm_vcpu_destroy(vcpu); |
| xa_erase(&kvm->vcpu_array, i); |
| } |
| |
| atomic_set(&kvm->online_vcpus, 0); |
| } |
| EXPORT_SYMBOL_GPL(kvm_destroy_vcpus); |
| |
| #ifdef CONFIG_KVM_GENERIC_MMU_NOTIFIER |
| static inline struct kvm *mmu_notifier_to_kvm(struct mmu_notifier *mn) |
| { |
| return container_of(mn, struct kvm, mmu_notifier); |
| } |
| |
| typedef bool (*gfn_handler_t)(struct kvm *kvm, struct kvm_gfn_range *range); |
| |
| typedef void (*on_lock_fn_t)(struct kvm *kvm); |
| |
| struct kvm_mmu_notifier_range { |
| /* |
| * 64-bit addresses, as KVM notifiers can operate on host virtual |
| * addresses (unsigned long) and guest physical addresses (64-bit). |
| */ |
| u64 start; |
| u64 end; |
| union kvm_mmu_notifier_arg arg; |
| gfn_handler_t handler; |
| on_lock_fn_t on_lock; |
| bool flush_on_ret; |
| bool may_block; |
| }; |
| |
| /* |
| * The inner-most helper returns a tuple containing the return value from the |
| * arch- and action-specific handler, plus a flag indicating whether or not at |
| * least one memslot was found, i.e. if the handler found guest memory. |
| * |
| * Note, most notifiers are averse to booleans, so even though KVM tracks the |
| * return from arch code as a bool, outer helpers will cast it to an int. :-( |
| */ |
| typedef struct kvm_mmu_notifier_return { |
| bool ret; |
| bool found_memslot; |
| } kvm_mn_ret_t; |
| |
| /* |
| * Use a dedicated stub instead of NULL to indicate that there is no callback |
| * function/handler. The compiler technically can't guarantee that a real |
| * function will have a non-zero address, and so it will generate code to |
| * check for !NULL, whereas comparing against a stub will be elided at compile |
| * time (unless the compiler is getting long in the tooth, e.g. gcc 4.9). |
| */ |
| static void kvm_null_fn(void) |
| { |
| |
| } |
| #define IS_KVM_NULL_FN(fn) ((fn) == (void *)kvm_null_fn) |
| |
| /* Iterate over each memslot intersecting [start, last] (inclusive) range */ |
| #define kvm_for_each_memslot_in_hva_range(node, slots, start, last) \ |
| for (node = interval_tree_iter_first(&slots->hva_tree, start, last); \ |
| node; \ |
| node = interval_tree_iter_next(node, start, last)) \ |
| |
| static __always_inline kvm_mn_ret_t __kvm_handle_hva_range(struct kvm *kvm, |
| const struct kvm_mmu_notifier_range *range) |
| { |
| struct kvm_mmu_notifier_return r = { |
| .ret = false, |
| .found_memslot = false, |
| }; |
| struct kvm_gfn_range gfn_range; |
| struct kvm_memory_slot *slot; |
| struct kvm_memslots *slots; |
| int i, idx; |
| |
| if (WARN_ON_ONCE(range->end <= range->start)) |
| return r; |
| |
| /* A null handler is allowed if and only if on_lock() is provided. */ |
| if (WARN_ON_ONCE(IS_KVM_NULL_FN(range->on_lock) && |
| IS_KVM_NULL_FN(range->handler))) |
| return r; |
| |
| idx = srcu_read_lock(&kvm->srcu); |
| |
| for (i = 0; i < kvm_arch_nr_memslot_as_ids(kvm); i++) { |
| struct interval_tree_node *node; |
| |
| slots = __kvm_memslots(kvm, i); |
| kvm_for_each_memslot_in_hva_range(node, slots, |
| range->start, range->end - 1) { |
| unsigned long hva_start, hva_end; |
| |
| slot = container_of(node, struct kvm_memory_slot, hva_node[slots->node_idx]); |
| hva_start = max_t(unsigned long, range->start, slot->userspace_addr); |
| hva_end = min_t(unsigned long, range->end, |
| slot->userspace_addr + (slot->npages << PAGE_SHIFT)); |
| |
| /* |
| * To optimize for the likely case where the address |
| * range is covered by zero or one memslots, don't |
| * bother making these conditional (to avoid writes on |
| * the second or later invocation of the handler). |
| */ |
| gfn_range.arg = range->arg; |
| gfn_range.may_block = range->may_block; |
| |
| /* |
| * {gfn(page) | page intersects with [hva_start, hva_end)} = |
| * {gfn_start, gfn_start+1, ..., gfn_end-1}. |
| */ |
| gfn_range.start = hva_to_gfn_memslot(hva_start, slot); |
| gfn_range.end = hva_to_gfn_memslot(hva_end + PAGE_SIZE - 1, slot); |
| gfn_range.slot = slot; |
| |
| if (!r.found_memslot) { |
| r.found_memslot = true; |
| KVM_MMU_LOCK(kvm); |
| if (!IS_KVM_NULL_FN(range->on_lock)) |
| range->on_lock(kvm); |
| |
| if (IS_KVM_NULL_FN(range->handler)) |
| goto mmu_unlock; |
| } |
| r.ret |= range->handler(kvm, &gfn_range); |
| } |
| } |
| |
| if (range->flush_on_ret && r.ret) |
| kvm_flush_remote_tlbs(kvm); |
| |
| mmu_unlock: |
| if (r.found_memslot) |
| KVM_MMU_UNLOCK(kvm); |
| |
| srcu_read_unlock(&kvm->srcu, idx); |
| |
| return r; |
| } |
| |
| static __always_inline int kvm_handle_hva_range(struct mmu_notifier *mn, |
| unsigned long start, |
| unsigned long end, |
| gfn_handler_t handler) |
| { |
| struct kvm *kvm = mmu_notifier_to_kvm(mn); |
| const struct kvm_mmu_notifier_range range = { |
| .start = start, |
| .end = end, |
| .handler = handler, |
| .on_lock = (void *)kvm_null_fn, |
| .flush_on_ret = true, |
| .may_block = false, |
| }; |
| |
| return __kvm_handle_hva_range(kvm, &range).ret; |
| } |
| |
| static __always_inline int kvm_handle_hva_range_no_flush(struct mmu_notifier *mn, |
| unsigned long start, |
| unsigned long end, |
| gfn_handler_t handler) |
| { |
| struct kvm *kvm = mmu_notifier_to_kvm(mn); |
| const struct kvm_mmu_notifier_range range = { |
| .start = start, |
| .end = end, |
| .handler = handler, |
| .on_lock = (void *)kvm_null_fn, |
| .flush_on_ret = false, |
| .may_block = false, |
| }; |
| |
| return __kvm_handle_hva_range(kvm, &range).ret; |
| } |
| |
| void kvm_mmu_invalidate_begin(struct kvm *kvm) |
| { |
| lockdep_assert_held_write(&kvm->mmu_lock); |
| /* |
| * The count increase must become visible at unlock time as no |
| * spte can be established without taking the mmu_lock and |
| * count is also read inside the mmu_lock critical section. |
| */ |
| kvm->mmu_invalidate_in_progress++; |
| |
| if (likely(kvm->mmu_invalidate_in_progress == 1)) { |
| kvm->mmu_invalidate_range_start = INVALID_GPA; |
| kvm->mmu_invalidate_range_end = INVALID_GPA; |
| } |
| } |
| |
| void kvm_mmu_invalidate_range_add(struct kvm *kvm, gfn_t start, gfn_t end) |
| { |
| lockdep_assert_held_write(&kvm->mmu_lock); |
| |
| WARN_ON_ONCE(!kvm->mmu_invalidate_in_progress); |
| |
| if (likely(kvm->mmu_invalidate_range_start == INVALID_GPA)) { |
| kvm->mmu_invalidate_range_start = start; |
| kvm->mmu_invalidate_range_end = end; |
| } else { |
| /* |
| * Fully tracking multiple concurrent ranges has diminishing |
| * returns. Keep things simple and just find the minimal range |
| * which includes the current and new ranges. As there won't be |
| * enough information to subtract a range after its invalidate |
| * completes, any ranges invalidated concurrently will |
| * accumulate and persist until all outstanding invalidates |
| * complete. |
| */ |
| kvm->mmu_invalidate_range_start = |
| min(kvm->mmu_invalidate_range_start, start); |
| kvm->mmu_invalidate_range_end = |
| max(kvm->mmu_invalidate_range_end, end); |
| } |
| } |
| |
| bool kvm_mmu_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range) |
| { |
| kvm_mmu_invalidate_range_add(kvm, range->start, range->end); |
| return kvm_unmap_gfn_range(kvm, range); |
| } |
| |
| static int kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn, |
| const struct mmu_notifier_range *range) |
| { |
| struct kvm *kvm = mmu_notifier_to_kvm(mn); |
| const struct kvm_mmu_notifier_range hva_range = { |
| .start = range->start, |
| .end = range->end, |
| .handler = kvm_mmu_unmap_gfn_range, |
| .on_lock = kvm_mmu_invalidate_begin, |
| .flush_on_ret = true, |
| .may_block = mmu_notifier_range_blockable(range), |
| }; |
| |
| trace_kvm_unmap_hva_range(range->start, range->end); |
| |
| /* |
| * Prevent memslot modification between range_start() and range_end() |
| * so that conditionally locking provides the same result in both |
| * functions. Without that guarantee, the mmu_invalidate_in_progress |
| * adjustments will be imbalanced. |
| * |
| * Pairs with the decrement in range_end(). |
| */ |
| spin_lock(&kvm->mn_invalidate_lock); |
| kvm->mn_active_invalidate_count++; |
| spin_unlock(&kvm->mn_invalidate_lock); |
| |
| /* |
| * Invalidate pfn caches _before_ invalidating the secondary MMUs, i.e. |
| * before acquiring mmu_lock, to avoid holding mmu_lock while acquiring |
| * each cache's lock. There are relatively few caches in existence at |
| * any given time, and the caches themselves can check for hva overlap, |
| * i.e. don't need to rely on memslot overlap checks for performance. |
| * Because this runs without holding mmu_lock, the pfn caches must use |
| * mn_active_invalidate_count (see above) instead of |
| * mmu_invalidate_in_progress. |
| */ |
| gfn_to_pfn_cache_invalidate_start(kvm, range->start, range->end); |
| |
| /* |
| * If one or more memslots were found and thus zapped, notify arch code |
| * that guest memory has been reclaimed. This needs to be done *after* |
| * dropping mmu_lock, as x86's reclaim path is slooooow. |
| */ |
| if (__kvm_handle_hva_range(kvm, &hva_range).found_memslot) |
| kvm_arch_guest_memory_reclaimed(kvm); |
| |
| return 0; |
| } |
| |
| void kvm_mmu_invalidate_end(struct kvm *kvm) |
| { |
| lockdep_assert_held_write(&kvm->mmu_lock); |
| |
| /* |
| * This sequence increase will notify the kvm page fault that |
| * the page that is going to be mapped in the spte could have |
| * been freed. |
| */ |
| kvm->mmu_invalidate_seq++; |
| smp_wmb(); |
| /* |
| * The above sequence increase must be visible before the |
| * below count decrease, which is ensured by the smp_wmb above |
| * in conjunction with the smp_rmb in mmu_invalidate_retry(). |
| */ |
| kvm->mmu_invalidate_in_progress--; |
| KVM_BUG_ON(kvm->mmu_invalidate_in_progress < 0, kvm); |
| |
| /* |
| * Assert that at least one range was added between start() and end(). |
| * Not adding a range isn't fatal, but it is a KVM bug. |
| */ |
| WARN_ON_ONCE(kvm->mmu_invalidate_range_start == INVALID_GPA); |
| } |
| |
| static void kvm_mmu_notifier_invalidate_range_end(struct mmu_notifier *mn, |
| const struct mmu_notifier_range *range) |
| { |
| struct kvm *kvm = mmu_notifier_to_kvm(mn); |
| const struct kvm_mmu_notifier_range hva_range = { |
| .start = range->start, |
| .end = range->end, |
| .handler = (void *)kvm_null_fn, |
| .on_lock = kvm_mmu_invalidate_end, |
| .flush_on_ret = false, |
| .may_block = mmu_notifier_range_blockable(range), |
| }; |
| bool wake; |
| |
| __kvm_handle_hva_range(kvm, &hva_range); |
| |
| /* Pairs with the increment in range_start(). */ |
| spin_lock(&kvm->mn_invalidate_lock); |
| if (!WARN_ON_ONCE(!kvm->mn_active_invalidate_count)) |
| --kvm->mn_active_invalidate_count; |
| wake = !kvm->mn_active_invalidate_count; |
| spin_unlock(&kvm->mn_invalidate_lock); |
| |
| /* |
| * There can only be one waiter, since the wait happens under |
| * slots_lock. |
| */ |
| if (wake) |
| rcuwait_wake_up(&kvm->mn_memslots_update_rcuwait); |
| } |
| |
| static int kvm_mmu_notifier_clear_flush_young(struct mmu_notifier *mn, |
| struct mm_struct *mm, |
| unsigned long start, |
| unsigned long end) |
| { |
| trace_kvm_age_hva(start, end); |
| |
| return kvm_handle_hva_range(mn, start, end, kvm_age_gfn); |
| } |
| |
| static int kvm_mmu_notifier_clear_young(struct mmu_notifier *mn, |
| struct mm_struct *mm, |
| unsigned long start, |
| unsigned long end) |
| { |
| trace_kvm_age_hva(start, end); |
| |
| /* |
| * Even though we do not flush TLB, this will still adversely |
| * affect performance on pre-Haswell Intel EPT, where there is |
| * no EPT Access Bit to clear so that we have to tear down EPT |
| * tables instead. If we find this unacceptable, we can always |
| * add a parameter to kvm_age_hva so that it effectively doesn't |
| * do anything on clear_young. |
| * |
| * Also note that currently we never issue secondary TLB flushes |
| * from clear_young, leaving this job up to the regular system |
| * cadence. If we find this inaccurate, we might come up with a |
| * more sophisticated heuristic later. |
| */ |
| return kvm_handle_hva_range_no_flush(mn, start, end, kvm_age_gfn); |
| } |
| |
| static int kvm_mmu_notifier_test_young(struct mmu_notifier *mn, |
| struct mm_struct *mm, |
| unsigned long address) |
| { |
| trace_kvm_test_age_hva(address); |
| |
| return kvm_handle_hva_range_no_flush(mn, address, address + 1, |
| kvm_test_age_gfn); |
| } |
| |
| static void kvm_mmu_notifier_release(struct mmu_notifier *mn, |
| struct mm_struct *mm) |
| { |
| struct kvm *kvm = mmu_notifier_to_kvm(mn); |
| int idx; |
| |
| idx = srcu_read_lock(&kvm->srcu); |
| kvm_flush_shadow_all(kvm); |
| srcu_read_unlock(&kvm->srcu, idx); |
| } |
| |
| static const struct mmu_notifier_ops kvm_mmu_notifier_ops = { |
| .invalidate_range_start = kvm_mmu_notifier_invalidate_range_start, |
| .invalidate_range_end = kvm_mmu_notifier_invalidate_range_end, |
| .clear_flush_young = kvm_mmu_notifier_clear_flush_young, |
| .clear_young = kvm_mmu_notifier_clear_young, |
| .test_young = kvm_mmu_notifier_test_young, |
| .release = kvm_mmu_notifier_release, |
| }; |
| |
| static int kvm_init_mmu_notifier(struct kvm *kvm) |
| { |
| kvm->mmu_notifier.ops = &kvm_mmu_notifier_ops; |
| return mmu_notifier_register(&kvm->mmu_notifier, current->mm); |
| } |
| |
| #else /* !CONFIG_KVM_GENERIC_MMU_NOTIFIER */ |
| |
| static int kvm_init_mmu_notifier(struct kvm *kvm) |
| { |
| return 0; |
| } |
| |
| #endif /* CONFIG_KVM_GENERIC_MMU_NOTIFIER */ |
| |
| #ifdef CONFIG_HAVE_KVM_PM_NOTIFIER |
| static int kvm_pm_notifier_call(struct notifier_block *bl, |
| unsigned long state, |
| void *unused) |
| { |
| struct kvm *kvm = container_of(bl, struct kvm, pm_notifier); |
| |
| return kvm_arch_pm_notifier(kvm, state); |
| } |
| |
| static void kvm_init_pm_notifier(struct kvm *kvm) |
| { |
| kvm->pm_notifier.notifier_call = kvm_pm_notifier_call; |
| /* Suspend KVM before we suspend ftrace, RCU, etc. */ |
| kvm->pm_notifier.priority = INT_MAX; |
| register_pm_notifier(&kvm->pm_notifier); |
| } |
| |
| static void kvm_destroy_pm_notifier(struct kvm *kvm) |
| { |
| unregister_pm_notifier(&kvm->pm_notifier); |
| } |
| #else /* !CONFIG_HAVE_KVM_PM_NOTIFIER */ |
| static void kvm_init_pm_notifier(struct kvm *kvm) |
| { |
| } |
| |
| static void kvm_destroy_pm_notifier(struct kvm *kvm) |
| { |
| } |
| #endif /* CONFIG_HAVE_KVM_PM_NOTIFIER */ |
| |
| static void kvm_destroy_dirty_bitmap(struct kvm_memory_slot *memslot) |
| { |
| if (!memslot->dirty_bitmap) |
| return; |
| |
| vfree(memslot->dirty_bitmap); |
| memslot->dirty_bitmap = NULL; |
| } |
| |
| /* This does not remove the slot from struct kvm_memslots data structures */ |
| static void kvm_free_memslot(struct kvm *kvm, struct kvm_memory_slot *slot) |
| { |
| if (slot->flags & KVM_MEM_GUEST_MEMFD) |
| kvm_gmem_unbind(slot); |
| |
| kvm_destroy_dirty_bitmap(slot); |
| |
| kvm_arch_free_memslot(kvm, slot); |
| |
| kfree(slot); |
| } |
| |
| static void kvm_free_memslots(struct kvm *kvm, struct kvm_memslots *slots) |
| { |
| struct hlist_node *idnode; |
| struct kvm_memory_slot *memslot; |
| int bkt; |
| |
| /* |
| * The same memslot objects live in both active and inactive sets, |
| * arbitrarily free using index '1' so the second invocation of this |
| * function isn't operating over a structure with dangling pointers |
| * (even though this function isn't actually touching them). |
| */ |
| if (!slots->node_idx) |
| return; |
| |
| hash_for_each_safe(slots->id_hash, bkt, idnode, memslot, id_node[1]) |
| kvm_free_memslot(kvm, memslot); |
| } |
| |
| static umode_t kvm_stats_debugfs_mode(const struct _kvm_stats_desc *pdesc) |
| { |
| switch (pdesc->desc.flags & KVM_STATS_TYPE_MASK) { |
| case KVM_STATS_TYPE_INSTANT: |
| return 0444; |
| case KVM_STATS_TYPE_CUMULATIVE: |
| case KVM_STATS_TYPE_PEAK: |
| default: |
| return 0644; |
| } |
| } |
| |
| |
| static void kvm_destroy_vm_debugfs(struct kvm *kvm) |
| { |
| int i; |
| int kvm_debugfs_num_entries = kvm_vm_stats_header.num_desc + |
| kvm_vcpu_stats_header.num_desc; |
| |
| if (IS_ERR(kvm->debugfs_dentry)) |
| return; |
| |
| debugfs_remove_recursive(kvm->debugfs_dentry); |
| |
| if (kvm->debugfs_stat_data) { |
| for (i = 0; i < kvm_debugfs_num_entries; i++) |
| kfree(kvm->debugfs_stat_data[i]); |
| kfree(kvm->debugfs_stat_data); |
| } |
| } |
| |
| static int kvm_create_vm_debugfs(struct kvm *kvm, const char *fdname) |
| { |
| static DEFINE_MUTEX(kvm_debugfs_lock); |
| struct dentry *dent; |
| char dir_name[ITOA_MAX_LEN * 2]; |
| struct kvm_stat_data *stat_data; |
| const struct _kvm_stats_desc *pdesc; |
| int i, ret = -ENOMEM; |
| int kvm_debugfs_num_entries = kvm_vm_stats_header.num_desc + |
| kvm_vcpu_stats_header.num_desc; |
| |
| if (!debugfs_initialized()) |
| return 0; |
| |
| snprintf(dir_name, sizeof(dir_name), "%d-%s", task_pid_nr(current), fdname); |
| mutex_lock(&kvm_debugfs_lock); |
| dent = debugfs_lookup(dir_name, kvm_debugfs_dir); |
| if (dent) { |
| pr_warn_ratelimited("KVM: debugfs: duplicate directory %s\n", dir_name); |
| dput(dent); |
| mutex_unlock(&kvm_debugfs_lock); |
| return 0; |
| } |
| dent = debugfs_create_dir(dir_name, kvm_debugfs_dir); |
| mutex_unlock(&kvm_debugfs_lock); |
| if (IS_ERR(dent)) |
| return 0; |
| |
| kvm->debugfs_dentry = dent; |
| kvm->debugfs_stat_data = kcalloc(kvm_debugfs_num_entries, |
| sizeof(*kvm->debugfs_stat_data), |
| GFP_KERNEL_ACCOUNT); |
| if (!kvm->debugfs_stat_data) |
| goto out_err; |
| |
| for (i = 0; i < kvm_vm_stats_header.num_desc; ++i) { |
| pdesc = &kvm_vm_stats_desc[i]; |
| stat_data = kzalloc(sizeof(*stat_data), GFP_KERNEL_ACCOUNT); |
| if (!stat_data) |
| goto out_err; |
| |
| stat_data->kvm = kvm; |
| stat_data->desc = pdesc; |
| stat_data->kind = KVM_STAT_VM; |
| kvm->debugfs_stat_data[i] = stat_data; |
| debugfs_create_file(pdesc->name, kvm_stats_debugfs_mode(pdesc), |
| kvm->debugfs_dentry, stat_data, |
| &stat_fops_per_vm); |
| } |
| |
| for (i = 0; i < kvm_vcpu_stats_header.num_desc; ++i) { |
| pdesc = &kvm_vcpu_stats_desc[i]; |
| stat_data = kzalloc(sizeof(*stat_data), GFP_KERNEL_ACCOUNT); |
| if (!stat_data) |
| goto out_err; |
| |
| stat_data->kvm = kvm; |
| stat_data->desc = pdesc; |
| stat_data->kind = KVM_STAT_VCPU; |
| kvm->debugfs_stat_data[i + kvm_vm_stats_header.num_desc] = stat_data; |
| debugfs_create_file(pdesc->name, kvm_stats_debugfs_mode(pdesc), |
| kvm->debugfs_dentry, stat_data, |
| &stat_fops_per_vm); |
| } |
| |
| kvm_arch_create_vm_debugfs(kvm); |
| return 0; |
| out_err: |
| kvm_destroy_vm_debugfs(kvm); |
| return ret; |
| } |
| |
| /* |
| * Called after the VM is otherwise initialized, but just before adding it to |
| * the vm_list. |
| */ |
| int __weak kvm_arch_post_init_vm(struct kvm *kvm) |
| { |
| return 0; |
| } |
| |
| /* |
| * Called just after removing the VM from the vm_list, but before doing any |
| * other destruction. |
| */ |
| void __weak kvm_arch_pre_destroy_vm(struct kvm *kvm) |
| { |
| } |
| |
| /* |
| * Called after per-vm debugfs created. When called kvm->debugfs_dentry should |
| * be setup already, so we can create arch-specific debugfs entries under it. |
| * Cleanup should be automatic done in kvm_destroy_vm_debugfs() recursively, so |
| * a per-arch destroy interface is not needed. |
| */ |
| void __weak kvm_arch_create_vm_debugfs(struct kvm *kvm) |
| { |
| } |
| |
| static struct kvm *kvm_create_vm(unsigned long type, const char *fdname) |
| { |
| struct kvm *kvm = kvm_arch_alloc_vm(); |
| struct kvm_memslots *slots; |
| int r, i, j; |
| |
| if (!kvm) |
| return ERR_PTR(-ENOMEM); |
| |
| KVM_MMU_LOCK_INIT(kvm); |
| mmgrab(current->mm); |
| kvm->mm = current->mm; |
| kvm_eventfd_init(kvm); |
| mutex_init(&kvm->lock); |
| mutex_init(&kvm->irq_lock); |
| mutex_init(&kvm->slots_lock); |
| mutex_init(&kvm->slots_arch_lock); |
| spin_lock_init(&kvm->mn_invalidate_lock); |
| rcuwait_init(&kvm->mn_memslots_update_rcuwait); |
| xa_init(&kvm->vcpu_array); |
| #ifdef CONFIG_KVM_GENERIC_MEMORY_ATTRIBUTES |
| xa_init(&kvm->mem_attr_array); |
| #endif |
| |
| INIT_LIST_HEAD(&kvm->gpc_list); |
| spin_lock_init(&kvm->gpc_lock); |
| |
| INIT_LIST_HEAD(&kvm->devices); |
| kvm->max_vcpus = KVM_MAX_VCPUS; |
| |
| BUILD_BUG_ON(KVM_MEM_SLOTS_NUM > SHRT_MAX); |
| |
| /* |
| * Force subsequent debugfs file creations to fail if the VM directory |
| * is not created (by kvm_create_vm_debugfs()). |
| */ |
| kvm->debugfs_dentry = ERR_PTR(-ENOENT); |
| |
| snprintf(kvm->stats_id, sizeof(kvm->stats_id), "kvm-%d", |
| task_pid_nr(current)); |
| |
| r = -ENOMEM; |
| if (init_srcu_struct(&kvm->srcu)) |
| goto out_err_no_srcu; |
| if (init_srcu_struct(&kvm->irq_srcu)) |
| goto out_err_no_irq_srcu; |
| |
| r = kvm_init_irq_routing(kvm); |
| if (r) |
| goto out_err_no_irq_routing; |
| |
| refcount_set(&kvm->users_count, 1); |
| |
| for (i = 0; i < kvm_arch_nr_memslot_as_ids(kvm); i++) { |
| for (j = 0; j < 2; j++) { |
| slots = &kvm->__memslots[i][j]; |
| |
| atomic_long_set(&slots->last_used_slot, (unsigned long)NULL); |
| slots->hva_tree = RB_ROOT_CACHED; |
| slots->gfn_tree = RB_ROOT; |
| hash_init(slots->id_hash); |
| slots->node_idx = j; |
| |
| /* Generations must be different for each address space. */ |
| slots->generation = i; |
| } |
| |
| rcu_assign_pointer(kvm->memslots[i], &kvm->__memslots[i][0]); |
| } |
| |
| r = -ENOMEM; |
| for (i = 0; i < KVM_NR_BUSES; i++) { |
| rcu_assign_pointer(kvm->buses[i], |
| kzalloc(sizeof(struct kvm_io_bus), GFP_KERNEL_ACCOUNT)); |
| if (!kvm->buses[i]) |
| goto out_err_no_arch_destroy_vm; |
| } |
| |
| r = kvm_arch_init_vm(kvm, type); |
| if (r) |
| goto out_err_no_arch_destroy_vm; |
| |
| r = hardware_enable_all(); |
| if (r) |
| goto out_err_no_disable; |
| |
| #ifdef CONFIG_HAVE_KVM_IRQCHIP |
| INIT_HLIST_HEAD(&kvm->irq_ack_notifier_list); |
| #endif |
| |
| r = kvm_init_mmu_notifier(kvm); |
| if (r) |
| goto out_err_no_mmu_notifier; |
| |
| r = kvm_coalesced_mmio_init(kvm); |
| if (r < 0) |
| goto out_no_coalesced_mmio; |
| |
| r = kvm_create_vm_debugfs(kvm, fdname); |
| if (r) |
| goto out_err_no_debugfs; |
| |
| r = kvm_arch_post_init_vm(kvm); |
| if (r) |
| goto out_err; |
| |
| mutex_lock(&kvm_lock); |
| list_add(&kvm->vm_list, &vm_list); |
| mutex_unlock(&kvm_lock); |
| |
| preempt_notifier_inc(); |
| kvm_init_pm_notifier(kvm); |
| |
| return kvm; |
| |
| out_err: |
| kvm_destroy_vm_debugfs(kvm); |
| out_err_no_debugfs: |
| kvm_coalesced_mmio_free(kvm); |
| out_no_coalesced_mmio: |
| #ifdef CONFIG_KVM_GENERIC_MMU_NOTIFIER |
| if (kvm->mmu_notifier.ops) |
| mmu_notifier_unregister(&kvm->mmu_notifier, current->mm); |
| #endif |
| out_err_no_mmu_notifier: |
| hardware_disable_all(); |
| out_err_no_disable: |
| kvm_arch_destroy_vm(kvm); |
| out_err_no_arch_destroy_vm: |
| WARN_ON_ONCE(!refcount_dec_and_test(&kvm->users_count)); |
| for (i = 0; i < KVM_NR_BUSES; i++) |
| kfree(kvm_get_bus(kvm, i)); |
| kvm_free_irq_routing(kvm); |
| out_err_no_irq_routing: |
| cleanup_srcu_struct(&kvm->irq_srcu); |
| out_err_no_irq_srcu: |
| cleanup_srcu_struct(&kvm->srcu); |
| out_err_no_srcu: |
| kvm_arch_free_vm(kvm); |
| mmdrop(current->mm); |
| return ERR_PTR(r); |
| } |
| |
| static void kvm_destroy_devices(struct kvm *kvm) |
| { |
| struct kvm_device *dev, *tmp; |
| |
| /* |
| * We do not need to take the kvm->lock here, because nobody else |
| * has a reference to the struct kvm at this point and therefore |
| * cannot access the devices list anyhow. |
| * |
| * The device list is generally managed as an rculist, but list_del() |
| * is used intentionally here. If a bug in KVM introduced a reader that |
| * was not backed by a reference on the kvm struct, the hope is that |
| * it'd consume the poisoned forward pointer instead of suffering a |
| * use-after-free, even though this cannot be guaranteed. |
| */ |
| list_for_each_entry_safe(dev, tmp, &kvm->devices, vm_node) { |
| list_del(&dev->vm_node); |
| dev->ops->destroy(dev); |
| } |
| } |
| |
| static void kvm_destroy_vm(struct kvm *kvm) |
| { |
| int i; |
| struct mm_struct *mm = kvm->mm; |
| |
| kvm_destroy_pm_notifier(kvm); |
| kvm_uevent_notify_change(KVM_EVENT_DESTROY_VM, kvm); |
| kvm_destroy_vm_debugfs(kvm); |
| kvm_arch_sync_events(kvm); |
| mutex_lock(&kvm_lock); |
| list_del(&kvm->vm_list); |
| mutex_unlock(&kvm_lock); |
| kvm_arch_pre_destroy_vm(kvm); |
| |
| kvm_free_irq_routing(kvm); |
| for (i = 0; i < KVM_NR_BUSES; i++) { |
| struct kvm_io_bus *bus = kvm_get_bus(kvm, i); |
| |
| if (bus) |
| kvm_io_bus_destroy(bus); |
| kvm->buses[i] = NULL; |
| } |
| kvm_coalesced_mmio_free(kvm); |
| #ifdef CONFIG_KVM_GENERIC_MMU_NOTIFIER |
| mmu_notifier_unregister(&kvm->mmu_notifier, kvm->mm); |
| /* |
| * At this point, pending calls to invalidate_range_start() |
| * have completed but no more MMU notifiers will run, so |
| * mn_active_invalidate_count may remain unbalanced. |
| * No threads can be waiting in kvm_swap_active_memslots() as the |
| * last reference on KVM has been dropped, but freeing |
| * memslots would deadlock without this manual intervention. |
| * |
| * If the count isn't unbalanced, i.e. KVM did NOT unregister its MMU |
| * notifier between a start() and end(), then there shouldn't be any |
| * in-progress invalidations. |
| */ |
| WARN_ON(rcuwait_active(&kvm->mn_memslots_update_rcuwait)); |
| if (kvm->mn_active_invalidate_count) |
| kvm->mn_active_invalidate_count = 0; |
| else |
| WARN_ON(kvm->mmu_invalidate_in_progress); |
| #else |
| kvm_flush_shadow_all(kvm); |
| #endif |
| kvm_arch_destroy_vm(kvm); |
| kvm_destroy_devices(kvm); |
| for (i = 0; i < kvm_arch_nr_memslot_as_ids(kvm); i++) { |
| kvm_free_memslots(kvm, &kvm->__memslots[i][0]); |
| kvm_free_memslots(kvm, &kvm->__memslots[i][1]); |
| } |
| cleanup_srcu_struct(&kvm->irq_srcu); |
| cleanup_srcu_struct(&kvm->srcu); |
| #ifdef CONFIG_KVM_GENERIC_MEMORY_ATTRIBUTES |
| xa_destroy(&kvm->mem_attr_array); |
| #endif |
| kvm_arch_free_vm(kvm); |
| preempt_notifier_dec(); |
| hardware_disable_all(); |
| mmdrop(mm); |
| } |
| |
| void kvm_get_kvm(struct kvm *kvm) |
| { |
| refcount_inc(&kvm->users_count); |
| } |
| EXPORT_SYMBOL_GPL(kvm_get_kvm); |
| |
| /* |
| * Make sure the vm is not during destruction, which is a safe version of |
| * kvm_get_kvm(). Return true if kvm referenced successfully, false otherwise. |
| */ |
| bool kvm_get_kvm_safe(struct kvm *kvm) |
| { |
| return refcount_inc_not_zero(&kvm->users_count); |
| } |
| EXPORT_SYMBOL_GPL(kvm_get_kvm_safe); |
| |
| void kvm_put_kvm(struct kvm *kvm) |
| { |
| if (refcount_dec_and_test(&kvm->users_count)) |
| kvm_destroy_vm(kvm); |
| } |
| EXPORT_SYMBOL_GPL(kvm_put_kvm); |
| |
| /* |
| * Used to put a reference that was taken on behalf of an object associated |
| * with a user-visible file descriptor, e.g. a vcpu or device, if installation |
| * of the new file descriptor fails and the reference cannot be transferred to |
| * its final owner. In such cases, the caller is still actively using @kvm and |
| * will fail miserably if the refcount unexpectedly hits zero. |
| */ |
| void kvm_put_kvm_no_destroy(struct kvm *kvm) |
| { |
| WARN_ON(refcount_dec_and_test(&kvm->users_count)); |
| } |
| EXPORT_SYMBOL_GPL(kvm_put_kvm_no_destroy); |
| |
| static int kvm_vm_release(struct inode *inode, struct file *filp) |
| { |
| struct kvm *kvm = filp->private_data; |
| |
| kvm_irqfd_release(kvm); |
| |
| kvm_put_kvm(kvm); |
| return 0; |
| } |
| |
| /* |
| * Allocation size is twice as large as the actual dirty bitmap size. |
| * See kvm_vm_ioctl_get_dirty_log() why this is needed. |
| */ |
| static int kvm_alloc_dirty_bitmap(struct kvm_memory_slot *memslot) |
| { |
| unsigned long dirty_bytes = kvm_dirty_bitmap_bytes(memslot); |
| |
| memslot->dirty_bitmap = __vcalloc(2, dirty_bytes, GFP_KERNEL_ACCOUNT); |
| if (!memslot->dirty_bitmap) |
| return -ENOMEM; |
| |
| return 0; |
| } |
| |
| static struct kvm_memslots *kvm_get_inactive_memslots(struct kvm *kvm, int as_id) |
| { |
| struct kvm_memslots *active = __kvm_memslots(kvm, as_id); |
| int node_idx_inactive = active->node_idx ^ 1; |
| |
| return &kvm->__memslots[as_id][node_idx_inactive]; |
| } |
| |
| /* |
| * Helper to get the address space ID when one of memslot pointers may be NULL. |
| * This also serves as a sanity that at least one of the pointers is non-NULL, |
| * and that their address space IDs don't diverge. |
| */ |
| static int kvm_memslots_get_as_id(struct kvm_memory_slot *a, |
| struct kvm_memory_slot *b) |
| { |
| if (WARN_ON_ONCE(!a && !b)) |
| return 0; |
| |
| if (!a) |
| return b->as_id; |
| if (!b) |
| return a->as_id; |
| |
| WARN_ON_ONCE(a->as_id != b->as_id); |
| return a->as_id; |
| } |
| |
| static void kvm_insert_gfn_node(struct kvm_memslots *slots, |
| struct kvm_memory_slot *slot) |
| { |
| struct rb_root *gfn_tree = &slots->gfn_tree; |
| struct rb_node **node, *parent; |
| int idx = slots->node_idx; |
| |
| parent = NULL; |
| for (node = &gfn_tree->rb_node; *node; ) { |
| struct kvm_memory_slot *tmp; |
| |
| tmp = container_of(*node, struct kvm_memory_slot, gfn_node[idx]); |
| parent = *node; |
| if (slot->base_gfn < tmp->base_gfn) |
| node = &(*node)->rb_left; |
| else if (slot->base_gfn > tmp->base_gfn) |
| node = &(*node)->rb_right; |
| else |
| BUG(); |
| } |
| |
| rb_link_node(&slot->gfn_node[idx], parent, node); |
| rb_insert_color(&slot->gfn_node[idx], gfn_tree); |
| } |
| |
| static void kvm_erase_gfn_node(struct kvm_memslots *slots, |
| struct kvm_memory_slot *slot) |
| { |
| rb_erase(&slot->gfn_node[slots->node_idx], &slots->gfn_tree); |
| } |
| |
| static void kvm_replace_gfn_node(struct kvm_memslots *slots, |
| struct kvm_memory_slot *old, |
| struct kvm_memory_slot *new) |
| { |
| int idx = slots->node_idx; |
| |
| WARN_ON_ONCE(old->base_gfn != new->base_gfn); |
| |
| rb_replace_node(&old->gfn_node[idx], &new->gfn_node[idx], |
| &slots->gfn_tree); |
| } |
| |
| /* |
| * Replace @old with @new in the inactive memslots. |
| * |
| * With NULL @old this simply adds @new. |
| * With NULL @new this simply removes @old. |
| * |
| * If @new is non-NULL its hva_node[slots_idx] range has to be set |
| * appropriately. |
| */ |
| static void kvm_replace_memslot(struct kvm *kvm, |
| struct kvm_memory_slot *old, |
| struct kvm_memory_slot *new) |
| { |
| int as_id = kvm_memslots_get_as_id(old, new); |
| struct kvm_memslots *slots = kvm_get_inactive_memslots(kvm, as_id); |
| int idx = slots->node_idx; |
| |
| if (old) { |
| hash_del(&old->id_node[idx]); |
| interval_tree_remove(&old->hva_node[idx], &slots->hva_tree); |
| |
| if ((long)old == atomic_long_read(&slots->last_used_slot)) |
| atomic_long_set(&slots->last_used_slot, (long)new); |
| |
| if (!new) { |
| kvm_erase_gfn_node(slots, old); |
| return; |
| } |
| } |
| |
| /* |
| * Initialize @new's hva range. Do this even when replacing an @old |
| * slot, kvm_copy_memslot() deliberately does not touch node data. |
| */ |
| new->hva_node[idx].start = new->userspace_addr; |
| new->hva_node[idx].last = new->userspace_addr + |
| (new->npages << PAGE_SHIFT) - 1; |
| |
| /* |
| * (Re)Add the new memslot. There is no O(1) interval_tree_replace(), |
| * hva_node needs to be swapped with remove+insert even though hva can't |
| * change when replacing an existing slot. |
| */ |
| hash_add(slots->id_hash, &new->id_node[idx], new->id); |
| interval_tree_insert(&new->hva_node[idx], &slots->hva_tree); |
| |
| /* |
| * If the memslot gfn is unchanged, rb_replace_node() can be used to |
| * switch the node in the gfn tree instead of removing the old and |
| * inserting the new as two separate operations. Replacement is a |
| * single O(1) operation versus two O(log(n)) operations for |
| * remove+insert. |
| */ |
| if (old && old->base_gfn == new->base_gfn) { |
| kvm_replace_gfn_node(slots, old, new); |
| } else { |
| if (old) |
| kvm_erase_gfn_node(slots, old); |
| kvm_insert_gfn_node(slots, new); |
| } |
| } |
| |
| /* |
| * Flags that do not access any of the extra space of struct |
| * kvm_userspace_memory_region2. KVM_SET_USER_MEMORY_REGION_V1_FLAGS |
| * only allows these. |
| */ |
| #define KVM_SET_USER_MEMORY_REGION_V1_FLAGS \ |
| (KVM_MEM_LOG_DIRTY_PAGES | KVM_MEM_READONLY) |
| |
| static int check_memory_region_flags(struct kvm *kvm, |
| const struct kvm_userspace_memory_region2 *mem) |
| { |
| u32 valid_flags = KVM_MEM_LOG_DIRTY_PAGES; |
| |
| if (kvm_arch_has_private_mem(kvm)) |
| valid_flags |= KVM_MEM_GUEST_MEMFD; |
| |
| /* Dirty logging private memory is not currently supported. */ |
| if (mem->flags & KVM_MEM_GUEST_MEMFD) |
| valid_flags &= ~KVM_MEM_LOG_DIRTY_PAGES; |
| |
| #ifdef CONFIG_HAVE_KVM_READONLY_MEM |
| /* |
| * GUEST_MEMFD is incompatible with read-only memslots, as writes to |
| * read-only memslots have emulated MMIO, not page fault, semantics, |
| * and KVM doesn't allow emulated MMIO for private memory. |
| */ |
| if (!(mem->flags & KVM_MEM_GUEST_MEMFD)) |
| valid_flags |= KVM_MEM_READONLY; |
| #endif |
| |
| if (mem->flags & ~valid_flags) |
| return -EINVAL; |
| |
| return 0; |
| } |
| |
| static void kvm_swap_active_memslots(struct kvm *kvm, int as_id) |
| { |
| struct kvm_memslots *slots = kvm_get_inactive_memslots(kvm, as_id); |
| |
| /* Grab the generation from the activate memslots. */ |
| u64 gen = __kvm_memslots(kvm, as_id)->generation; |
| |
| WARN_ON(gen & KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS); |
| slots->generation = gen | KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS; |
| |
| /* |
| * Do not store the new memslots while there are invalidations in |
| * progress, otherwise the locking in invalidate_range_start and |
| * invalidate_range_end will be unbalanced. |
| */ |
| spin_lock(&kvm->mn_invalidate_lock); |
| prepare_to_rcuwait(&kvm->mn_memslots_update_rcuwait); |
| while (kvm->mn_active_invalidate_count) { |
| set_current_state(TASK_UNINTERRUPTIBLE); |
| spin_unlock(&kvm->mn_invalidate_lock); |
| schedule(); |
| spin_lock(&kvm->mn_invalidate_lock); |
| } |
| finish_rcuwait(&kvm->mn_memslots_update_rcuwait); |
| rcu_assign_pointer(kvm->memslots[as_id], slots); |
| spin_unlock(&kvm->mn_invalidate_lock); |
| |
| /* |
| * Acquired in kvm_set_memslot. Must be released before synchronize |
| * SRCU below in order to avoid deadlock with another thread |
| * acquiring the slots_arch_lock in an srcu critical section. |
| */ |
| mutex_unlock(&kvm->slots_arch_lock); |
| |
| synchronize_srcu_expedited(&kvm->srcu); |
| |
| /* |
| * Increment the new memslot generation a second time, dropping the |
| * update in-progress flag and incrementing the generation based on |
| * the number of address spaces. This provides a unique and easily |
| * identifiable generation number while the memslots are in flux. |
| */ |
| gen = slots->generation & ~KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS; |
| |
| /* |
| * Generations must be unique even across address spaces. We do not need |
| * a global counter for that, instead the generation space is evenly split |
| * across address spaces. For example, with two address spaces, address |
| * space 0 will use generations 0, 2, 4, ... while address space 1 will |
| * use generations 1, 3, 5, ... |
| */ |
| gen += kvm_arch_nr_memslot_as_ids(kvm); |
| |
| kvm_arch_memslots_updated(kvm, gen); |
| |
| slots->generation = gen; |
| } |
| |
| static int kvm_prepare_memory_region(struct kvm *kvm, |
| const struct kvm_memory_slot *old, |
| struct kvm_memory_slot *new, |
| enum kvm_mr_change change) |
| { |
| int r; |
| |
| /* |
| * If dirty logging is disabled, nullify the bitmap; the old bitmap |
| * will be freed on "commit". If logging is enabled in both old and |
| * new, reuse the existing bitmap. If logging is enabled only in the |
| * new and KVM isn't using a ring buffer, allocate and initialize a |
| * new bitmap. |
| */ |
| if (change != KVM_MR_DELETE) { |
| if (!(new->flags & KVM_MEM_LOG_DIRTY_PAGES)) |
| new->dirty_bitmap = NULL; |
| else if (old && old->dirty_bitmap) |
| new->dirty_bitmap = old->dirty_bitmap; |
| else if (kvm_use_dirty_bitmap(kvm)) { |
| r = kvm_alloc_dirty_bitmap(new); |
| if (r) |
| return r; |
| |
| if (kvm_dirty_log_manual_protect_and_init_set(kvm)) |
| bitmap_set(new->dirty_bitmap, 0, new->npages); |
| } |
| } |
| |
| r = kvm_arch_prepare_memory_region(kvm, old, new, change); |
| |
| /* Free the bitmap on failure if it was allocated above. */ |
| if (r && new && new->dirty_bitmap && (!old || !old->dirty_bitmap)) |
| kvm_destroy_dirty_bitmap(new); |
| |
| return r; |
| } |
| |
| static void kvm_commit_memory_region(struct kvm *kvm, |
| struct kvm_memory_slot *old, |
| const struct kvm_memory_slot *new, |
| enum kvm_mr_change change) |
| { |
| int old_flags = old ? old->flags : 0; |
| int new_flags = new ? new->flags : 0; |
| /* |
| * Update the total number of memslot pages before calling the arch |
| * hook so that architectures can consume the result directly. |
| */ |
| if (change == KVM_MR_DELETE) |
| kvm->nr_memslot_pages -= old->npages; |
| else if (change == KVM_MR_CREATE) |
| kvm->nr_memslot_pages += new->npages; |
| |
| if ((old_flags ^ new_flags) & KVM_MEM_LOG_DIRTY_PAGES) { |
| int change = (new_flags & KVM_MEM_LOG_DIRTY_PAGES) ? 1 : -1; |
| atomic_set(&kvm->nr_memslots_dirty_logging, |
| atomic_read(&kvm->nr_memslots_dirty_logging) + change); |
| } |
| |
| kvm_arch_commit_memory_region(kvm, old, new, change); |
| |
| switch (change) { |
| case KVM_MR_CREATE: |
| /* Nothing more to do. */ |
| break; |
| case KVM_MR_DELETE: |
| /* Free the old memslot and all its metadata. */ |
| kvm_free_memslot(kvm, old); |
| break; |
| case KVM_MR_MOVE: |
| case KVM_MR_FLAGS_ONLY: |
| /* |
| * Free the dirty bitmap as needed; the below check encompasses |
| * both the flags and whether a ring buffer is being used) |
| */ |
| if (old->dirty_bitmap && !new->dirty_bitmap) |
| kvm_destroy_dirty_bitmap(old); |
| |
| /* |
| * The final quirk. Free the detached, old slot, but only its |
| * memory, not any metadata. Metadata, including arch specific |
| * data, may be reused by @new. |
| */ |
| kfree(old); |
| break; |
| default: |
| BUG(); |
| } |
| } |
| |
| /* |
| * Activate @new, which must be installed in the inactive slots by the caller, |
| * by swapping the active slots and then propagating @new to @old once @old is |
| * unreachable and can be safely modified. |
| * |
| * With NULL @old this simply adds @new to @active (while swapping the sets). |
| * With NULL @new this simply removes @old from @active and frees it |
| * (while also swapping the sets). |
| */ |
| static void kvm_activate_memslot(struct kvm *kvm, |
| struct kvm_memory_slot *old, |
| struct kvm_memory_slot *new) |
| { |
| int as_id = kvm_memslots_get_as_id(old, new); |
| |
| kvm_swap_active_memslots(kvm, as_id); |
| |
| /* Propagate the new memslot to the now inactive memslots. */ |
| kvm_replace_memslot(kvm, old, new); |
| } |
| |
| static void kvm_copy_memslot(struct kvm_memory_slot *dest, |
| const struct kvm_memory_slot *src) |
| { |
| dest->base_gfn = src->base_gfn; |
| dest->npages = src->npages; |
| dest->dirty_bitmap = src->dirty_bitmap; |
| dest->arch = src->arch; |
| dest->userspace_addr = src->userspace_addr; |
| dest->flags = src->flags; |
| dest->id = src->id; |
| dest->as_id = src->as_id; |
| } |
| |
| static void kvm_invalidate_memslot(struct kvm *kvm, |
| struct kvm_memory_slot *old, |
| struct kvm_memory_slot *invalid_slot) |
| { |
| /* |
| * Mark the current slot INVALID. As with all memslot modifications, |
| * this must be done on an unreachable slot to avoid modifying the |
| * current slot in the active tree. |
| */ |
| kvm_copy_memslot(invalid_slot, old); |
| invalid_slot->flags |= KVM_MEMSLOT_INVALID; |
| kvm_replace_memslot(kvm, old, invalid_slot); |
| |
| /* |
| * Activate the slot that is now marked INVALID, but don't propagate |
| * the slot to the now inactive slots. The slot is either going to be |
| * deleted or recreated as a new slot. |
| */ |
| kvm_swap_active_memslots(kvm, old->as_id); |
| |
| /* |
| * From this point no new shadow pages pointing to a deleted, or moved, |
| * memslot will be created. Validation of sp->gfn happens in: |
| * - gfn_to_hva (kvm_read_guest, gfn_to_pfn) |
| * - kvm_is_visible_gfn (mmu_check_root) |
| */ |
| kvm_arch_flush_shadow_memslot(kvm, old); |
| kvm_arch_guest_memory_reclaimed(kvm); |
| |
| /* Was released by kvm_swap_active_memslots(), reacquire. */ |
| mutex_lock(&kvm->slots_arch_lock); |
| |
| /* |
| * Copy the arch-specific field of the newly-installed slot back to the |
| * old slot as the arch data could have changed between releasing |
| * slots_arch_lock in kvm_swap_active_memslots() and re-acquiring the lock |
| * above. Writers are required to retrieve memslots *after* acquiring |
| * slots_arch_lock, thus the active slot's data is guaranteed to be fresh. |
| */ |
| old->arch = invalid_slot->arch; |
| } |
| |
| static void kvm_create_memslot(struct kvm *kvm, |
| struct kvm_memory_slot *new) |
| { |
| /* Add the new memslot to the inactive set and activate. */ |
| kvm_replace_memslot(kvm, NULL, new); |
| kvm_activate_memslot(kvm, NULL, new); |
| } |
| |
| static void kvm_delete_memslot(struct kvm *kvm, |
| struct kvm_memory_slot *old, |
| struct kvm_memory_slot *invalid_slot) |
| { |
| /* |
| * Remove the old memslot (in the inactive memslots) by passing NULL as |
| * the "new" slot, and for the invalid version in the active slots. |
| */ |
| kvm_replace_memslot(kvm, old, NULL); |
| kvm_activate_memslot(kvm, invalid_slot, NULL); |
| } |
| |
| static void kvm_move_memslot(struct kvm *kvm, |
| struct kvm_memory_slot *old, |
| struct kvm_memory_slot *new, |
| struct kvm_memory_slot *invalid_slot) |
| { |
| /* |
| * Replace the old memslot in the inactive slots, and then swap slots |
| * and replace the current INVALID with the new as well. |
| */ |
| kvm_replace_memslot(kvm, old, new); |
| kvm_activate_memslot(kvm, invalid_slot, new); |
| } |
| |
| static void kvm_update_flags_memslot(struct kvm *kvm, |
| struct kvm_memory_slot *old, |
| struct kvm_memory_slot *new) |
| { |
| /* |
| * Similar to the MOVE case, but the slot doesn't need to be zapped as |
| * an intermediate step. Instead, the old memslot is simply replaced |
| * with a new, updated copy in both memslot sets. |
| */ |
| kvm_replace_memslot(kvm, old, new); |
| kvm_activate_memslot(kvm, old, new); |
| } |
| |
| static int kvm_set_memslot(struct kvm *kvm, |
| struct kvm_memory_slot *old, |
| struct kvm_memory_slot *new, |
| enum kvm_mr_change change) |
| { |
| struct kvm_memory_slot *invalid_slot; |
| int r; |
| |
| /* |
| * Released in kvm_swap_active_memslots(). |
| * |
| * Must be held from before the current memslots are copied until after |
| * the new memslots are installed with rcu_assign_pointer, then |
| * released before the synchronize srcu in kvm_swap_active_memslots(). |
| * |
| * When modifying memslots outside of the slots_lock, must be held |
| * before reading the pointer to the current memslots until after all |
| * changes to those memslots are complete. |
| * |
| * These rules ensure that installing new memslots does not lose |
| * changes made to the previous memslots. |
| */ |
| mutex_lock(&kvm->slots_arch_lock); |
| |
| /* |
| * Invalidate the old slot if it's being deleted or moved. This is |
| * done prior to actually deleting/moving the memslot to allow vCPUs to |
| * continue running by ensuring there are no mappings or shadow pages |
| * for the memslot when it is deleted/moved. Without pre-invalidation |
| * (and without a lock), a window would exist between effecting the |
| * delete/move and committing the changes in arch code where KVM or a |
| * guest could access a non-existent memslot. |
| * |
| * Modifications are done on a temporary, unreachable slot. The old |
| * slot needs to be preserved in case a later step fails and the |
| * invalidation needs to be reverted. |
| */ |
| if (change == KVM_MR_DELETE || change == KVM_MR_MOVE) { |
| invalid_slot = kzalloc(sizeof(*invalid_slot), GFP_KERNEL_ACCOUNT); |
| if (!invalid_slot) { |
| mutex_unlock(&kvm->slots_arch_lock); |
| return -ENOMEM; |
| } |
| kvm_invalidate_memslot(kvm, old, invalid_slot); |
| } |
| |
| r = kvm_prepare_memory_region(kvm, old, new, change); |
| if (r) { |
| /* |
| * For DELETE/MOVE, revert the above INVALID change. No |
| * modifications required since the original slot was preserved |
| * in the inactive slots. Changing the active memslots also |
| * release slots_arch_lock. |
| */ |
| if (change == KVM_MR_DELETE || change == KVM_MR_MOVE) { |
| kvm_activate_memslot(kvm, invalid_slot, old); |
| kfree(invalid_slot); |
| } else { |
| mutex_unlock(&kvm->slots_arch_lock); |
| } |
| return r; |
| } |
| |
| /* |
| * For DELETE and MOVE, the working slot is now active as the INVALID |
| * version of the old slot. MOVE is particularly special as it reuses |
| * the old slot and returns a copy of the old slot (in working_slot). |
| * For CREATE, there is no old slot. For DELETE and FLAGS_ONLY, the |
| * old slot is detached but otherwise preserved. |
| */ |
| if (change == KVM_MR_CREATE) |
| kvm_create_memslot(kvm, new); |
| else if (change == KVM_MR_DELETE) |
| kvm_delete_memslot(kvm, old, invalid_slot); |
| else if (change == KVM_MR_MOVE) |
| kvm_move_memslot(kvm, old, new, invalid_slot); |
| else if (change == KVM_MR_FLAGS_ONLY) |
| kvm_update_flags_memslot(kvm, old, new); |
| else |
| BUG(); |
| |
| /* Free the temporary INVALID slot used for DELETE and MOVE. */ |
| if (change == KVM_MR_DELETE || change == KVM_MR_MOVE) |
| kfree(invalid_slot); |
| |
| /* |
| * No need to refresh new->arch, changes after dropping slots_arch_lock |
| * will directly hit the final, active memslot. Architectures are |
| * responsible for knowing that new->arch may be stale. |
| */ |
| kvm_commit_memory_region(kvm, old, new, change); |
| |
| return 0; |
| } |
| |
| static bool kvm_check_memslot_overlap(struct kvm_memslots *slots, int id, |
| gfn_t start, gfn_t end) |
| { |
| struct kvm_memslot_iter iter; |
| |
| kvm_for_each_memslot_in_gfn_range(&iter, slots, start, end) { |
| if (iter.slot->id != id) |
| return true; |
| } |
| |
| return false; |
| } |
| |
| /* |
| * Allocate some memory and give it an address in the guest physical address |
| * space. |
| * |
| * Discontiguous memory is allowed, mostly for framebuffers. |
| * |
| * Must be called holding kvm->slots_lock for write. |
| */ |
| int __kvm_set_memory_region(struct kvm *kvm, |
| const struct kvm_userspace_memory_region2 *mem) |
| { |
| struct kvm_memory_slot *old, *new; |
| struct kvm_memslots *slots; |
| enum kvm_mr_change change; |
| unsigned long npages; |
| gfn_t base_gfn; |
| int as_id, id; |
| int r; |
| |
| r = check_memory_region_flags(kvm, mem); |
| if (r) |
| return r; |
| |
| as_id = mem->slot >> 16; |
| id = (u16)mem->slot; |
| |
| /* General sanity checks */ |
| if ((mem->memory_size & (PAGE_SIZE - 1)) || |
| (mem->memory_size != (unsigned long)mem->memory_size)) |
| return -EINVAL; |
| if (mem->guest_phys_addr & (PAGE_SIZE - 1)) |
| return -EINVAL; |
| /* We can read the guest memory with __xxx_user() later on. */ |
| if ((mem->userspace_addr & (PAGE_SIZE - 1)) || |
| (mem->userspace_addr != untagged_addr(mem->userspace_addr)) || |
| !access_ok((void __user *)(unsigned long)mem->userspace_addr, |
| mem->memory_size)) |
| return -EINVAL; |
| if (mem->flags & KVM_MEM_GUEST_MEMFD && |
| (mem->guest_memfd_offset & (PAGE_SIZE - 1) || |
| mem->guest_memfd_offset + mem->memory_size < mem->guest_memfd_offset)) |
| return -EINVAL; |
| if (as_id >= kvm_arch_nr_memslot_as_ids(kvm) || id >= KVM_MEM_SLOTS_NUM) |
| return -EINVAL; |
| if (mem->guest_phys_addr + mem->memory_size < mem->guest_phys_addr) |
| return -EINVAL; |
| if ((mem->memory_size >> PAGE_SHIFT) > KVM_MEM_MAX_NR_PAGES) |
| return -EINVAL; |
| |
| slots = __kvm_memslots(kvm, as_id); |
| |
| /* |
| * Note, the old memslot (and the pointer itself!) may be invalidated |
| * and/or destroyed by kvm_set_memslot(). |
| */ |
| old = id_to_memslot(slots, id); |
| |
| if (!mem->memory_size) { |
| if (!old || !old->npages) |
| return -EINVAL; |
| |
| if (WARN_ON_ONCE(kvm->nr_memslot_pages < old->npages)) |
| return -EIO; |
| |
| return kvm_set_memslot(kvm, old, NULL, KVM_MR_DELETE); |
| } |
| |
| base_gfn = (mem->guest_phys_addr >> PAGE_SHIFT); |
| npages = (mem->memory_size >> PAGE_SHIFT); |
| |
| if (!old || !old->npages) { |
| change = KVM_MR_CREATE; |
| |
| /* |
| * To simplify KVM internals, the total number of pages across |
| * all memslots must fit in an unsigned long. |
| */ |
| if ((kvm->nr_memslot_pages + npages) < kvm->nr_memslot_pages) |
| return -EINVAL; |
| } else { /* Modify an existing slot. */ |
| /* Private memslots are immutable, they can only be deleted. */ |
| if (mem->flags & KVM_MEM_GUEST_MEMFD) |
| return -EINVAL; |
| if ((mem->userspace_addr != old->userspace_addr) || |
| (npages != old->npages) || |
| ((mem->flags ^ old->flags) & KVM_MEM_READONLY)) |
| return -EINVAL; |
| |
| if (base_gfn != old->base_gfn) |
| change = KVM_MR_MOVE; |
| else if (mem->flags != old->flags) |
| change = KVM_MR_FLAGS_ONLY; |
| else /* Nothing to change. */ |
| return 0; |
| } |
| |
| if ((change == KVM_MR_CREATE || change == KVM_MR_MOVE) && |
| kvm_check_memslot_overlap(slots, id, base_gfn, base_gfn + npages)) |
| return -EEXIST; |
| |
| /* Allocate a slot that will persist in the memslot. */ |
| new = kzalloc(sizeof(*new), GFP_KERNEL_ACCOUNT); |
| if (!new) |
| return -ENOMEM; |
| |
| new->as_id = as_id; |
| new->id = id; |
| new->base_gfn = base_gfn; |
| new->npages = npages; |
| new->flags = mem->flags; |
| new->userspace_addr = mem->userspace_addr; |
| if (mem->flags & KVM_MEM_GUEST_MEMFD) { |
| r = kvm_gmem_bind(kvm, new, mem->guest_memfd, mem->guest_memfd_offset); |
| if (r) |
| goto out; |
| } |
| |
| r = kvm_set_memslot(kvm, old, new, change); |
| if (r) |
| goto out_unbind; |
| |
| return 0; |
| |
| out_unbind: |
| if (mem->flags & KVM_MEM_GUEST_MEMFD) |
| kvm_gmem_unbind(new); |
| out: |
| kfree(new); |
| return r; |
| } |
| EXPORT_SYMBOL_GPL(__kvm_set_memory_region); |
| |
| int kvm_set_memory_region(struct kvm *kvm, |
| const struct kvm_userspace_memory_region2 *mem) |
| { |
| int r; |
| |
| mutex_lock(&kvm->slots_lock); |
| r = __kvm_set_memory_region(kvm, mem); |
| mutex_unlock(&kvm->slots_lock); |
| return r; |
| } |
| EXPORT_SYMBOL_GPL(kvm_set_memory_region); |
| |
| static int kvm_vm_ioctl_set_memory_region(struct kvm *kvm, |
| struct kvm_userspace_memory_region2 *mem) |
| { |
| if ((u16)mem->slot >= KVM_USER_MEM_SLOTS) |
| return -EINVAL; |
| |
| return kvm_set_memory_region(kvm, mem); |
| } |
| |
| #ifndef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT |
| /** |
| * kvm_get_dirty_log - get a snapshot of dirty pages |
| * @kvm: pointer to kvm instance |
| * @log: slot id and address to which we copy the log |
| * @is_dirty: set to '1' if any dirty pages were found |
| * @memslot: set to the associated memslot, always valid on success |
| */ |
| int kvm_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log, |
| int *is_dirty, struct kvm_memory_slot **memslot) |
| { |
| struct kvm_memslots *slots; |
| int i, as_id, id; |
| unsigned long n; |
| unsigned long any = 0; |
| |
| /* Dirty ring tracking may be exclusive to dirty log tracking */ |
| if (!kvm_use_dirty_bitmap(kvm)) |
| return -ENXIO; |
| |
| *memslot = NULL; |
| *is_dirty = 0; |
| |
| as_id = log->slot >> 16; |
| id = (u16)log->slot; |
| if (as_id >= kvm_arch_nr_memslot_as_ids(kvm) || id >= KVM_USER_MEM_SLOTS) |
| return -EINVAL; |
| |
| slots = __kvm_memslots(kvm, as_id); |
| *memslot = id_to_memslot(slots, id); |
| if (!(*memslot) || !(*memslot)->dirty_bitmap) |
| return -ENOENT; |
| |
| kvm_arch_sync_dirty_log(kvm, *memslot); |
| |
| n = kvm_dirty_bitmap_bytes(*memslot); |
| |
| for (i = 0; !any && i < n/sizeof(long); ++i) |
| any = (*memslot)->dirty_bitmap[i]; |
| |
| if (copy_to_user(log->dirty_bitmap, (*memslot)->dirty_bitmap, n)) |
| return -EFAULT; |
| |
| if (any) |
| *is_dirty = 1; |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(kvm_get_dirty_log); |
| |
| #else /* CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT */ |
| /** |
| * kvm_get_dirty_log_protect - get a snapshot of dirty pages |
| * and reenable dirty page tracking for the corresponding pages. |
| * @kvm: pointer to kvm instance |
| * @log: slot id and address to which we copy the log |
| * |
| * We need to keep it in mind that VCPU threads can write to the bitmap |
| * concurrently. So, to avoid losing track of dirty pages we keep the |
| * following order: |
| * |
| * 1. Take a snapshot of the bit and clear it if needed. |
| * 2. Write protect the corresponding page. |
| * 3. Copy the snapshot to the userspace. |
| * 4. Upon return caller flushes TLB's if needed. |
| * |
| * Between 2 and 4, the guest may write to the page using the remaining TLB |
| * entry. This is not a problem because the page is reported dirty using |
| * the snapshot taken before and step 4 ensures that writes done after |
| * exiting to userspace will be logged for the next call. |
| * |
| */ |
| static int kvm_get_dirty_log_protect(struct kvm *kvm, struct kvm_dirty_log *log) |
| { |
| struct kvm_memslots *slots; |
| struct kvm_memory_slot *memslot; |
| int i, as_id, id; |
| unsigned long n; |
| unsigned long *dirty_bitmap; |
| unsigned long *dirty_bitmap_buffer; |
| bool flush; |
| |
| /* Dirty ring tracking may be exclusive to dirty log tracking */ |
| if (!kvm_use_dirty_bitmap(kvm)) |
| return -ENXIO; |
| |
| as_id = log->slot >> 16; |
| id = (u16)log->slot; |
| if (as_id >= kvm_arch_nr_memslot_as_ids(kvm) || id >= KVM_USER_MEM_SLOTS) |
| return -EINVAL; |
| |
| slots = __kvm_memslots(kvm, as_id); |
| memslot = id_to_memslot(slots, id); |
| if (!memslot || !memslot->dirty_bitmap) |
| return -ENOENT; |
| |
| dirty_bitmap = memslot->dirty_bitmap; |
| |
| kvm_arch_sync_dirty_log(kvm, memslot); |
| |
| n = kvm_dirty_bitmap_bytes(memslot); |
| flush = false; |
| if (kvm->manual_dirty_log_protect) { |
| /* |
| * Unlike kvm_get_dirty_log, we always return false in *flush, |
| * because no flush is needed until KVM_CLEAR_DIRTY_LOG. There |
| * is some code duplication between this function and |
| * kvm_get_dirty_log, but hopefully all architecture |
| * transition to kvm_get_dirty_log_protect and kvm_get_dirty_log |
| * can be eliminated. |
| */ |
| dirty_bitmap_buffer = dirty_bitmap; |
| } else { |
| dirty_bitmap_buffer = kvm_second_dirty_bitmap(memslot); |
| memset(dirty_bitmap_buffer, 0, n); |
| |
| KVM_MMU_LOCK(kvm); |
| for (i = 0; i < n / sizeof(long); i++) { |
| unsigned long mask; |
| gfn_t offset; |
| |
| if (!dirty_bitmap[i]) |
| continue; |
| |
| flush = true; |
| mask = xchg(&dirty_bitmap[i], 0); |
| dirty_bitmap_buffer[i] = mask; |
| |
| offset = i * BITS_PER_LONG; |
| kvm_arch_mmu_enable_log_dirty_pt_masked(kvm, memslot, |
| offset, mask); |
| } |
| KVM_MMU_UNLOCK(kvm); |
| } |
| |
| if (flush) |
| kvm_flush_remote_tlbs_memslot(kvm, memslot); |
| |
| if (copy_to_user(log->dirty_bitmap, dirty_bitmap_buffer, n)) |
| return -EFAULT; |
| return 0; |
| } |
| |
| |
| /** |
| * kvm_vm_ioctl_get_dirty_log - get and clear the log of dirty pages in a slot |
| * @kvm: kvm instance |
| * @log: slot id and address to which we copy the log |
| * |
| * Steps 1-4 below provide general overview of dirty page logging. See |
| * kvm_get_dirty_log_protect() function description for additional details. |
| * |
| * We call kvm_get_dirty_log_protect() to handle steps 1-3, upon return we |
| * always flush the TLB (step 4) even if previous step failed and the dirty |
| * bitmap may be corrupt. Regardless of previous outcome the KVM logging API |
| * does not preclude user space subsequent dirty log read. Flushing TLB ensures |
| * writes will be marked dirty for next log read. |
| * |
| * 1. Take a snapshot of the bit and clear it if needed. |
| * 2. Write protect the corresponding page. |
| * 3. Copy the snapshot to the userspace. |
| * 4. Flush TLB's if needed. |
| */ |
| static int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, |
| struct kvm_dirty_log *log) |
| { |
| int r; |
| |
| mutex_lock(&kvm->slots_lock); |
| |
| r = kvm_get_dirty_log_protect(kvm, log); |
| |
| mutex_unlock(&kvm->slots_lock); |
| return r; |
| } |
| |
| /** |
| * kvm_clear_dirty_log_protect - clear dirty bits in the bitmap |
| * and reenable dirty page tracking for the corresponding pages. |
| * @kvm: pointer to kvm instance |
| * @log: slot id and address from which to fetch the bitmap of dirty pages |
| */ |
| static int kvm_clear_dirty_log_protect(struct kvm *kvm, |
| struct kvm_clear_dirty_log *log) |
| { |
| struct kvm_memslots *slots; |
| struct kvm_memory_slot *memslot; |
| int as_id, id; |
| gfn_t offset; |
| unsigned long i, n; |
| unsigned long *dirty_bitmap; |
| unsigned long *dirty_bitmap_buffer; |
| bool flush; |
| |
| /* Dirty ring tracking may be exclusive to dirty log tracking */ |
| if (!kvm_use_dirty_bitmap(kvm)) |
| return -ENXIO; |
| |
| as_id = log->slot >> 16; |
| id = (u16)log->slot; |
| if (as_id >= kvm_arch_nr_memslot_as_ids(kvm) || id >= KVM_USER_MEM_SLOTS) |
| return -EINVAL; |
| |
| if (log->first_page & 63) |
| return -EINVAL; |
| |
| slots = __kvm_memslots(kvm, as_id); |
| memslot = id_to_memslot(slots, id); |
| if (!memslot || !memslot->dirty_bitmap) |
| return -ENOENT; |
| |
| dirty_bitmap = memslot->dirty_bitmap; |
| |
| n = ALIGN(log->num_pages, BITS_PER_LONG) / 8; |
| |
| if (log->first_page > memslot->npages || |
| log->num_pages > memslot->npages - log->first_page || |
| (log->num_pages < memslot->npages - log->first_page && (log->num_pages & 63))) |
| return -EINVAL; |
| |
| kvm_arch_sync_dirty_log(kvm, memslot); |
| |
| flush = false; |
| dirty_bitmap_buffer = kvm_second_dirty_bitmap(memslot); |
| if (copy_from_user(dirty_bitmap_buffer, log->dirty_bitmap, n)) |
| return -EFAULT; |
| |
| KVM_MMU_LOCK(kvm); |
| for (offset = log->first_page, i = offset / BITS_PER_LONG, |
| n = DIV_ROUND_UP(log->num_pages, BITS_PER_LONG); n--; |
| i++, offset += BITS_PER_LONG) { |
| unsigned long mask = *dirty_bitmap_buffer++; |
| atomic_long_t *p = (atomic_long_t *) &dirty_bitmap[i]; |
| if (!mask) |
| continue; |
| |
| mask &= atomic_long_fetch_andnot(mask, p); |
| |
| /* |
| * mask contains the bits that really have been cleared. This |
| * never includes any bits beyond the length of the memslot (if |
| * the length is not aligned to 64 pages), therefore it is not |
| * a problem if userspace sets them in log->dirty_bitmap. |
| */ |
| if (mask) { |
| flush = true; |
| kvm_arch_mmu_enable_log_dirty_pt_masked(kvm, memslot, |
| offset, mask); |
| } |
| } |
| KVM_MMU_UNLOCK(kvm); |
| |
| if (flush) |
| kvm_flush_remote_tlbs_memslot(kvm, memslot); |
| |
| return 0; |
| } |
| |
| static int kvm_vm_ioctl_clear_dirty_log(struct kvm *kvm, |
| struct kvm_clear_dirty_log *log) |
| { |
| int r; |
| |
| mutex_lock(&kvm->slots_lock); |
| |
| r = kvm_clear_dirty_log_protect(kvm, log); |
| |
| mutex_unlock(&kvm->slots_lock); |
| return r; |
| } |
| #endif /* CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT */ |
| |
| #ifdef CONFIG_KVM_GENERIC_MEMORY_ATTRIBUTES |
| /* |
| * Returns true if _all_ gfns in the range [@start, @end) have attributes |
| * matching @attrs. |
| */ |
| bool kvm_range_has_memory_attributes(struct kvm *kvm, gfn_t start, gfn_t end, |
| unsigned long attrs) |
| { |
| XA_STATE(xas, &kvm->mem_attr_array, start); |
| unsigned long index; |
| bool has_attrs; |
| void *entry; |
| |
| rcu_read_lock(); |
| |
| if (!attrs) { |
| has_attrs = !xas_find(&xas, end - 1); |
| goto out; |
| } |
| |
| has_attrs = true; |
| for (index = start; index < end; index++) { |
| do { |
| entry = xas_next(&xas); |
| } while (xas_retry(&xas, entry)); |
| |
| if (xas.xa_index != index || xa_to_value(entry) != attrs) { |
| has_attrs = false; |
| break; |
| } |
| } |
| |
| out: |
| rcu_read_unlock(); |
| return has_attrs; |
| } |
| |
| static u64 kvm_supported_mem_attributes(struct kvm *kvm) |
| { |
| if (!kvm || kvm_arch_has_private_mem(kvm)) |
| return KVM_MEMORY_ATTRIBUTE_PRIVATE; |
| |
| return 0; |
| } |
| |
| static __always_inline void kvm_handle_gfn_range(struct kvm *kvm, |
| struct kvm_mmu_notifier_range *range) |
| { |
| struct kvm_gfn_range gfn_range; |
| struct kvm_memory_slot *slot; |
| struct kvm_memslots *slots; |
| struct kvm_memslot_iter iter; |
| bool found_memslot = false; |
| bool ret = false; |
| int i; |
| |
| gfn_range.arg = range->arg; |
| gfn_range.may_block = range->may_block; |
| |
| for (i = 0; i < kvm_arch_nr_memslot_as_ids(kvm); i++) { |
| slots = __kvm_memslots(kvm, i); |
| |
| kvm_for_each_memslot_in_gfn_range(&iter, slots, range->start, range->end) { |
| slot = iter.slot; |
| gfn_range.slot = slot; |
| |
| gfn_range.start = max(range->start, slot->base_gfn); |
| gfn_range.end = min(range->end, slot->base_gfn + slot->npages); |
| if (gfn_range.start >= gfn_range.end) |
| continue; |
| |
| if (!found_memslot) { |
| found_memslot = true; |
| KVM_MMU_LOCK(kvm); |
| if (!IS_KVM_NULL_FN(range->on_lock)) |
| range->on_lock(kvm); |
| } |
| |
| ret |= range->handler(kvm, &gfn_range); |
| } |
| } |
| |
| if (range->flush_on_ret && ret) |
| kvm_flush_remote_tlbs(kvm); |
| |
| if (found_memslot) |
| KVM_MMU_UNLOCK(kvm); |
| } |
| |
| static bool kvm_pre_set_memory_attributes(struct kvm *kvm, |
| struct kvm_gfn_range *range) |
| { |
| /* |
| * Unconditionally add the range to the invalidation set, regardless of |
| * whether or not the arch callback actually needs to zap SPTEs. E.g. |
| * if KVM supports RWX attributes in the future and the attributes are |
| * going from R=>RW, zapping isn't strictly necessary. Unconditionally |
| * adding the range allows KVM to require that MMU invalidations add at |
| * least one range between begin() and end(), e.g. allows KVM to detect |
| * bugs where the add() is missed. Relaxing the rule *might* be safe, |
| * but it's not obvious that allowing new mappings while the attributes |
| * are in flux is desirable or worth the complexity. |
| */ |
| kvm_mmu_invalidate_range_add(kvm, range->start, range->end); |
| |
| return kvm_arch_pre_set_memory_attributes(kvm, range); |
| } |
| |
| /* Set @attributes for the gfn range [@start, @end). */ |
| static int kvm_vm_set_mem_attributes(struct kvm *kvm, gfn_t start, gfn_t end, |
| unsigned long attributes) |
| { |
| struct kvm_mmu_notifier_range pre_set_range = { |
| .start = start, |
| .end = end, |
| .handler = kvm_pre_set_memory_attributes, |
| .on_lock = kvm_mmu_invalidate_begin, |
| .flush_on_ret = true, |
| .may_block = true, |
| }; |
| struct kvm_mmu_notifier_range post_set_range = { |
| .start = start, |
| .end = end, |
| .arg.attributes = attributes, |
| .handler = kvm_arch_post_set_memory_attributes, |
| .on_lock = kvm_mmu_invalidate_end, |
| .may_block = true, |
| }; |
| unsigned long i; |
| void *entry; |
| int r = 0; |
| |
| entry = attributes ? xa_mk_value(attributes) : NULL; |
| |
| mutex_lock(&kvm->slots_lock); |
| |
| /* Nothing to do if the entire range as the desired attributes. */ |
| if (kvm_range_has_memory_attributes(kvm, start, end, attributes)) |
| goto out_unlock; |
| |
| /* |
| * Reserve memory ahead of time to avoid having to deal with failures |
| * partway through setting the new attributes. |
| */ |
| for (i = start; i < end; i++) { |
| r = xa_reserve(&kvm->mem_attr_array, i, GFP_KERNEL_ACCOUNT); |
| if (r) |
| goto out_unlock; |
| } |
| |
| kvm_handle_gfn_range(kvm, &pre_set_range); |
| |
| for (i = start; i < end; i++) { |
| r = xa_err(xa_store(&kvm->mem_attr_array, i, entry, |
| GFP_KERNEL_ACCOUNT)); |
| KVM_BUG_ON(r, kvm); |
| } |
| |
| kvm_handle_gfn_range(kvm, &post_set_range); |
| |
| out_unlock: |
| mutex_unlock(&kvm->slots_lock); |
| |
| return r; |
| } |
| static int kvm_vm_ioctl_set_mem_attributes(struct kvm *kvm, |
| struct kvm_memory_attributes *attrs) |
| { |
| gfn_t start, end; |
| |
| /* flags is currently not used. */ |
| if (attrs->flags) |
| return -EINVAL; |
| if (attrs->attributes & ~kvm_supported_mem_attributes(kvm)) |
| return -EINVAL; |
| if (attrs->size == 0 || attrs->address + attrs->size < attrs->address) |
| return -EINVAL; |
| if (!PAGE_ALIGNED(attrs->address) || !PAGE_ALIGNED(attrs->size)) |
| return -EINVAL; |
| |
| start = attrs->address >> PAGE_SHIFT; |
| end = (attrs->address + attrs->size) >> PAGE_SHIFT; |
| |
| /* |
| * xarray tracks data using "unsigned long", and as a result so does |
| * KVM. For simplicity, supports generic attributes only on 64-bit |
| * architectures. |
| */ |
| BUILD_BUG_ON(sizeof(attrs->attributes) != sizeof(unsigned long)); |
| |
| return kvm_vm_set_mem_attributes(kvm, start, end, attrs->attributes); |
| } |
| #endif /* CONFIG_KVM_GENERIC_MEMORY_ATTRIBUTES */ |
| |
| struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn) |
| { |
| return __gfn_to_memslot(kvm_memslots(kvm), gfn); |
| } |
| EXPORT_SYMBOL_GPL(gfn_to_memslot); |
| |
| struct kvm_memory_slot *kvm_vcpu_gfn_to_memslot(struct kvm_vcpu *vcpu, gfn_t gfn) |
| { |
| struct kvm_memslots *slots = kvm_vcpu_memslots(vcpu); |
| u64 gen = slots->generation; |
| struct kvm_memory_slot *slot; |
| |
| /* |
| * This also protects against using a memslot from a different address space, |
| * since different address spaces have different generation numbers. |
| */ |
| if (unlikely(gen != vcpu->last_used_slot_gen)) { |
| vcpu->last_used_slot = NULL; |
| vcpu->last_used_slot_gen = gen; |
| } |
| |
| slot = try_get_memslot(vcpu->last_used_slot, gfn); |
| if (slot) |
| return slot; |
| |
| /* |
| * Fall back to searching all memslots. We purposely use |
| * search_memslots() instead of __gfn_to_memslot() to avoid |
| * thrashing the VM-wide last_used_slot in kvm_memslots. |
| */ |
| slot = search_memslots(slots, gfn, false); |
| if (slot) { |
| vcpu->last_used_slot = slot; |
| return slot; |
| } |
| |
| return NULL; |
| } |
| |
| bool kvm_is_visible_gfn(struct kvm *kvm, gfn_t gfn) |
| { |
| struct kvm_memory_slot *memslot = gfn_to_memslot(kvm, gfn); |
| |
| return kvm_is_visible_memslot(memslot); |
| } |
| EXPORT_SYMBOL_GPL(kvm_is_visible_gfn); |
| |
| bool kvm_vcpu_is_visible_gfn(struct kvm_vcpu *vcpu, gfn_t gfn) |
| { |
| struct kvm_memory_slot *memslot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); |
| |
| return kvm_is_visible_memslot(memslot); |
| } |
| EXPORT_SYMBOL_GPL(kvm_vcpu_is_visible_gfn); |
| |
| unsigned long kvm_host_page_size(struct kvm_vcpu *vcpu, gfn_t gfn) |
| { |
| struct vm_area_struct *vma; |
| unsigned long addr, size; |
| |
| size = PAGE_SIZE; |
| |
| addr = kvm_vcpu_gfn_to_hva_prot(vcpu, gfn, NULL); |
| if (kvm_is_error_hva(addr)) |
| return PAGE_SIZE; |
| |
| mmap_read_lock(current->mm); |
| vma = find_vma(current->mm, addr); |
| if (!vma) |
| goto out; |
| |
| size = vma_kernel_pagesize(vma); |
| |
| out: |
| mmap_read_unlock(current->mm); |
| |
| return size; |
| } |
| |
| static bool memslot_is_readonly(const struct kvm_memory_slot *slot) |
| { |
| return slot->flags & KVM_MEM_READONLY; |
| } |
| |
| static unsigned long __gfn_to_hva_many(const struct kvm_memory_slot *slot, gfn_t gfn, |
| gfn_t *nr_pages, bool write) |
| { |
| if (!slot || slot->flags & KVM_MEMSLOT_INVALID) |
| return KVM_HVA_ERR_BAD; |
| |
| if (memslot_is_readonly(slot) && write) |
| return KVM_HVA_ERR_RO_BAD; |
| |
| if (nr_pages) |
| *nr_pages = slot->npages - (gfn - slot->base_gfn); |
| |
| return __gfn_to_hva_memslot(slot, gfn); |
| } |
| |
| static unsigned long gfn_to_hva_many(struct kvm_memory_slot *slot, gfn_t gfn, |
| gfn_t *nr_pages) |
| { |
| return __gfn_to_hva_many(slot, gfn, nr_pages, true); |
| } |
| |
| unsigned long gfn_to_hva_memslot(struct kvm_memory_slot *slot, |
| gfn_t gfn) |
| { |
| return gfn_to_hva_many(slot, gfn, NULL); |
| } |
| EXPORT_SYMBOL_GPL(gfn_to_hva_memslot); |
| |
| unsigned long gfn_to_hva(struct kvm *kvm, gfn_t gfn) |
| { |
| return gfn_to_hva_many(gfn_to_memslot(kvm, gfn), gfn, NULL); |
| } |
| EXPORT_SYMBOL_GPL(gfn_to_hva); |
| |
| unsigned long kvm_vcpu_gfn_to_hva(struct kvm_vcpu *vcpu, gfn_t gfn) |
| { |
| return gfn_to_hva_many(kvm_vcpu_gfn_to_memslot(vcpu, gfn), gfn, NULL); |
| } |
| EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_hva); |
| |
| /* |
| * Return the hva of a @gfn and the R/W attribute if possible. |
| * |
| * @slot: the kvm_memory_slot which contains @gfn |
| * @gfn: the gfn to be translated |
| * @writable: used to return the read/write attribute of the @slot if the hva |
| * is valid and @writable is not NULL |
| */ |
| unsigned long gfn_to_hva_memslot_prot(struct kvm_memory_slot *slot, |
| gfn_t gfn, bool *writable) |
| { |
| unsigned long hva = __gfn_to_hva_many(slot, gfn, NULL, false); |
| |
| if (!kvm_is_error_hva(hva) && writable) |
| *writable = !memslot_is_readonly(slot); |
| |
| return hva; |
| } |
| |
| unsigned long gfn_to_hva_prot(struct kvm *kvm, gfn_t gfn, bool *writable) |
| { |
| struct kvm_memory_slot *slot = gfn_to_memslot(kvm, gfn); |
| |
| return gfn_to_hva_memslot_prot(slot, gfn, writable); |
| } |
| |
| unsigned long kvm_vcpu_gfn_to_hva_prot(struct kvm_vcpu *vcpu, gfn_t gfn, bool *writable) |
| { |
| struct kvm_memory_slot *slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); |
| |
| return gfn_to_hva_memslot_prot(slot, gfn, writable); |
| } |
| |
| static inline int check_user_page_hwpoison(unsigned long addr) |
| { |
| int rc, flags = FOLL_HWPOISON | FOLL_WRITE; |
| |
| rc = get_user_pages(addr, 1, flags, NULL); |
| return rc == -EHWPOISON; |
| } |
| |
| /* |
| * The fast path to get the writable pfn which will be stored in @pfn, |
| * true indicates success, otherwise false is returned. It's also the |
| * only part that runs if we can in atomic context. |
| */ |
| static bool hva_to_pfn_fast(unsigned long addr, bool write_fault, |
| bool *writable, kvm_pfn_t *pfn) |
| { |
| struct page *page[1]; |
| |
| /* |
| * Fast pin a writable pfn only if it is a write fault request |
| * or the caller allows to map a writable pfn for a read fault |
| * request. |
| */ |
| if (!(write_fault || writable)) |
| return false; |
| |
| if (get_user_page_fast_only(addr, FOLL_WRITE, page)) { |
| *pfn = page_to_pfn(page[0]); |
| |
| if (writable) |
| *writable = true; |
| return true; |
| } |
| |
| return false; |
| } |
| |
| /* |
| * The slow path to get the pfn of the specified host virtual address, |
| * 1 indicates success, -errno is returned if error is detected. |
| */ |
| static int hva_to_pfn_slow(unsigned long addr, bool *async, bool write_fault, |
| bool interruptible, bool *writable, kvm_pfn_t *pfn) |
| { |
| /* |
| * When a VCPU accesses a page that is not mapped into the secondary |
| * MMU, we lookup the page using GUP to map it, so the guest VCPU can |
| * make progress. We always want to honor NUMA hinting faults in that |
| * case, because GUP usage corresponds to memory accesses from the VCPU. |
| * Otherwise, we'd not trigger NUMA hinting faults once a page is |
| * mapped into the secondary MMU and gets accessed by a VCPU. |
| * |
| * Note that get_user_page_fast_only() and FOLL_WRITE for now |
| * implicitly honor NUMA hinting faults and don't need this flag. |
| */ |
| unsigned int flags = FOLL_HWPOISON | FOLL_HONOR_NUMA_FAULT; |
| struct page *page; |
| int npages; |
| |
| might_sleep(); |
| |
| if (writable) |
| *writable = write_fault; |
| |
| if (write_fault) |
| flags |= FOLL_WRITE; |
| if (async) |
| flags |= FOLL_NOWAIT; |
| if (interruptible) |
| flags |= FOLL_INTERRUPTIBLE; |
| |
| npages = get_user_pages_unlocked(addr, 1, &page, flags); |
| if (npages != 1) |
| return npages; |
| |
| /* map read fault as writable if possible */ |
| if (unlikely(!write_fault) && writable) { |
| struct page *wpage; |
| |
| if (get_user_page_fast_only(addr, FOLL_WRITE, &wpage)) { |
| *writable = true; |
| put_page(page); |
| page = wpage; |
| } |
| } |
| *pfn = page_to_pfn(page); |
| return npages; |
| } |
| |
| static bool vma_is_valid(struct vm_area_struct *vma, bool write_fault) |
| { |
| if (unlikely(!(vma->vm_flags & VM_READ))) |
| return false; |
| |
| if (write_fault && (unlikely(!(vma->vm_flags & VM_WRITE)))) |
| return false; |
| |
| return true; |
| } |
| |
| static int kvm_try_get_pfn(kvm_pfn_t pfn) |
| { |
| struct page *page = kvm_pfn_to_refcounted_page(pfn); |
| |
| if (!page) |
| return 1; |
| |
| return get_page_unless_zero(page); |
| } |
| |
| static int hva_to_pfn_remapped(struct vm_area_struct *vma, |
| unsigned long addr, bool write_fault, |
| bool *writable, kvm_pfn_t *p_pfn) |
| { |
| kvm_pfn_t pfn; |
| pte_t *ptep; |
| pte_t pte; |
| spinlock_t *ptl; |
| int r; |
| |
| r = follow_pte(vma, addr, &ptep, &ptl); |
| if (r) { |
| /* |
| * get_user_pages fails for VM_IO and VM_PFNMAP vmas and does |
| * not call the fault handler, so do it here. |
| */ |
| bool unlocked = false; |
| r = fixup_user_fault(current->mm, addr, |
| (write_fault ? FAULT_FLAG_WRITE : 0), |
| &unlocked); |
| if (unlocked) |
| return -EAGAIN; |
| if (r) |
| return r; |
| |
| r = follow_pte(vma, addr, &ptep, &ptl); |
| if (r) |
| return r; |
| } |
| |
| pte = ptep_get(ptep); |
| |
| if (write_fault && !pte_write(pte)) { |
| pfn = KVM_PFN_ERR_RO_FAULT; |
| goto out; |
| } |
| |
| if (writable) |
| *writable = pte_write(pte); |
| pfn = pte_pfn(pte); |
| |
| /* |
| * Get a reference here because callers of *hva_to_pfn* and |
| * *gfn_to_pfn* ultimately call kvm_release_pfn_clean on the |
| * returned pfn. This is only needed if the VMA has VM_MIXEDMAP |
| * set, but the kvm_try_get_pfn/kvm_release_pfn_clean pair will |
| * simply do nothing for reserved pfns. |
| * |
| * Whoever called remap_pfn_range is also going to call e.g. |
| * unmap_mapping_range before the underlying pages are freed, |
| * causing a call to our MMU notifier. |
| * |
| * Certain IO or PFNMAP mappings can be backed with valid |
| * struct pages, but be allocated without refcounting e.g., |
| * tail pages of non-compound higher order allocations, which |
| * would then underflow the refcount when the caller does the |
| * required put_page. Don't allow those pages here. |
| */ |
| if (!kvm_try_get_pfn(pfn)) |
| r = -EFAULT; |
| |
| out: |
| pte_unmap_unlock(ptep, ptl); |
| *p_pfn = pfn; |
| |
| return r; |
| } |
| |
| /* |
| * Pin guest page in memory and return its pfn. |
| * @addr: host virtual address which maps memory to the guest |
| * @atomic: whether this function is forbidden from sleeping |
| * @interruptible: whether the process can be interrupted by non-fatal signals |
| * @async: whether this function need to wait IO complete if the |
| * host page is not in the memory |
| * @write_fault: whether we should get a writable host page |
| * @writable: whether it allows to map a writable host page for !@write_fault |
| * |
| * The function will map a writable host page for these two cases: |
| * 1): @write_fault = true |
| * 2): @write_fault = false && @writable, @writable will tell the caller |
| * whether the mapping is writable. |
| */ |
| kvm_pfn_t hva_to_pfn(unsigned long addr, bool atomic, bool interruptible, |
| bool *async, bool write_fault, bool *writable) |
| { |
| struct vm_area_struct *vma; |
| kvm_pfn_t pfn; |
| int npages, r; |
| |
| /* we can do it either atomically or asynchronously, not both */ |
| BUG_ON(atomic && async); |
| |
| if (hva_to_pfn_fast(addr, write_fault, writable, &pfn)) |
| return pfn; |
| |
| if (atomic) |
| return KVM_PFN_ERR_FAULT; |
| |
| npages = hva_to_pfn_slow(addr, async, write_fault, interruptible, |
| writable, &pfn); |
| if (npages == 1) |
| return pfn; |
| if (npages == -EINTR) |
| return KVM_PFN_ERR_SIGPENDING; |
| |
| mmap_read_lock(current->mm); |
| if (npages == -EHWPOISON || |
| (!async && check_user_page_hwpoison(addr))) { |
| pfn = KVM_PFN_ERR_HWPOISON; |
| goto exit; |
| } |
| |
| retry: |
| vma = vma_lookup(current->mm, addr); |
| |
| if (vma == NULL) |
| pfn = KVM_PFN_ERR_FAULT; |
| else if (vma->vm_flags & (VM_IO | VM_PFNMAP)) { |
| r = hva_to_pfn_remapped(vma, addr, write_fault, writable, &pfn); |
| if (r == -EAGAIN) |
| goto retry; |
| if (r < 0) |
| pfn = KVM_PFN_ERR_FAULT; |
| } else { |
| if (async && vma_is_valid(vma, write_fault)) |
| *async = true; |
| pfn = KVM_PFN_ERR_FAULT; |
| } |
| exit: |
| mmap_read_unlock(current->mm); |
| return pfn; |
| } |
| |
| kvm_pfn_t __gfn_to_pfn_memslot(const struct kvm_memory_slot *slot, gfn_t gfn, |
| bool atomic, bool interruptible, bool *async, |
| bool write_fault, bool *writable, hva_t *hva) |
| { |
| unsigned long addr = __gfn_to_hva_many(slot, gfn, NULL, write_fault); |
| |
| if (hva) |
| *hva = addr; |
| |
| if (kvm_is_error_hva(addr)) { |
| if (writable) |
| *writable = false; |
| |
| return addr == KVM_HVA_ERR_RO_BAD ? KVM_PFN_ERR_RO_FAULT : |
| KVM_PFN_NOSLOT; |
| } |
| |
| /* Do not map writable pfn in the readonly memslot. */ |
| if (writable && memslot_is_readonly(slot)) { |
| *writable = false; |
| writable = NULL; |
| } |
| |
| return hva_to_pfn(addr, atomic, interruptible, async, write_fault, |
| writable); |
| } |
| EXPORT_SYMBOL_GPL(__gfn_to_pfn_memslot); |
| |
| kvm_pfn_t gfn_to_pfn_prot(struct kvm *kvm, gfn_t gfn, bool write_fault, |
| bool *writable) |
| { |
| return __gfn_to_pfn_memslot(gfn_to_memslot(kvm, gfn), gfn, false, false, |
| NULL, write_fault, writable, NULL); |
| } |
| EXPORT_SYMBOL_GPL(gfn_to_pfn_prot); |
| |
| kvm_pfn_t gfn_to_pfn_memslot(const struct kvm_memory_slot *slot, gfn_t gfn) |
| { |
| return __gfn_to_pfn_memslot(slot, gfn, false, false, NULL, true, |
| NULL, NULL); |
| } |
| EXPORT_SYMBOL_GPL(gfn_to_pfn_memslot); |
| |
| kvm_pfn_t gfn_to_pfn_memslot_atomic(const struct kvm_memory_slot *slot, gfn_t gfn) |
| { |
| return __gfn_to_pfn_memslot(slot, gfn, true, false, NULL, true, |
| NULL, NULL); |
| } |
| EXPORT_SYMBOL_GPL(gfn_to_pfn_memslot_atomic); |
| |
| kvm_pfn_t kvm_vcpu_gfn_to_pfn_atomic(struct kvm_vcpu *vcpu, gfn_t gfn) |
| { |
| return gfn_to_pfn_memslot_atomic(kvm_vcpu_gfn_to_memslot(vcpu, gfn), gfn); |
| } |
| EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_pfn_atomic); |
| |
| kvm_pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn) |
| { |
| return gfn_to_pfn_memslot(gfn_to_memslot(kvm, gfn), gfn); |
| } |
| EXPORT_SYMBOL_GPL(gfn_to_pfn); |
| |
| kvm_pfn_t kvm_vcpu_gfn_to_pfn(struct kvm_vcpu *vcpu, gfn_t gfn) |
| { |
| return gfn_to_pfn_memslot(kvm_vcpu_gfn_to_memslot(vcpu, gfn), gfn); |
| } |
| EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_pfn); |
| |
| int gfn_to_page_many_atomic(struct kvm_memory_slot *slot, gfn_t gfn, |
| struct page **pages, int nr_pages) |
| { |
| unsigned long addr; |
| gfn_t entry = 0; |
| |
| addr = gfn_to_hva_many(slot, gfn, &entry); |
| if (kvm_is_error_hva(addr)) |
| return -1; |
| |
| if (entry < nr_pages) |
| return 0; |
| |
| return get_user_pages_fast_only(addr, nr_pages, FOLL_WRITE, pages); |
| } |
| EXPORT_SYMBOL_GPL(gfn_to_page_many_atomic); |
| |
| /* |
| * Do not use this helper unless you are absolutely certain the gfn _must_ be |
| * backed by 'struct page'. A valid example is if the backing memslot is |
| * controlled by KVM. Note, if the returned page is valid, it's refcount has |
| * been elevated by gfn_to_pfn(). |
| */ |
| struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn) |
| { |
| struct page *page; |
| kvm_pfn_t pfn; |
| |
| pfn = gfn_to_pfn(kvm, gfn); |
| |
| if (is_error_noslot_pfn(pfn)) |
| return KVM_ERR_PTR_BAD_PAGE; |
| |
| page = kvm_pfn_to_refcounted_page(pfn); |
| if (!page) |
| return KVM_ERR_PTR_BAD_PAGE; |
| |
| return page; |
| } |
| EXPORT_SYMBOL_GPL(gfn_to_page); |
| |
| void kvm_release_pfn(kvm_pfn_t pfn, bool dirty) |
| { |
| if (dirty) |
| kvm_release_pfn_dirty(pfn); |
| else |
| kvm_release_pfn_clean(pfn); |
| } |
| |
| int kvm_vcpu_map(struct kvm_vcpu *vcpu, gfn_t gfn, struct kvm_host_map *map) |
| { |
| kvm_pfn_t pfn; |
| void *hva = NULL; |
| struct page *page = KVM_UNMAPPED_PAGE; |
| |
| if (!map) |
| return -EINVAL; |
| |
| pfn = gfn_to_pfn(vcpu->kvm, gfn); |
| if (is_error_noslot_pfn(pfn)) |
| return -EINVAL; |
| |
| if (pfn_valid(pfn)) { |
| page = pfn_to_page(pfn); |
| hva = kmap(page); |
| #ifdef CONFIG_HAS_IOMEM |
| } else { |
| hva = memremap(pfn_to_hpa(pfn), PAGE_SIZE, MEMREMAP_WB); |
| #endif |
| } |
| |
| if (!hva) |
| return -EFAULT; |
| |
| map->page = page; |
| map->hva = hva; |
| map->pfn = pfn; |
| map->gfn = gfn; |
| |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(kvm_vcpu_map); |
| |
| void kvm_vcpu_unmap(struct kvm_vcpu *vcpu, struct kvm_host_map *map, bool dirty) |
| { |
| if (!map) |
| return; |
| |
| if (!map->hva) |
| return; |
| |
| if (map->page != KVM_UNMAPPED_PAGE) |
| kunmap(map->page); |
| #ifdef CONFIG_HAS_IOMEM |
| else |
| memunmap(map->hva); |
| #endif |
| |
| if (dirty) |
| kvm_vcpu_mark_page_dirty(vcpu, map->gfn); |
| |
| kvm_release_pfn(map->pfn, dirty); |
| |
| map->hva = NULL; |
| map->page = NULL; |
| } |
| EXPORT_SYMBOL_GPL(kvm_vcpu_unmap); |
| |
| static bool kvm_is_ad_tracked_page(struct page *page) |
| { |
| /* |
| * Per page-flags.h, pages tagged PG_reserved "should in general not be |
| * touched (e.g. set dirty) except by its owner". |
| */ |
| return !PageReserved(page); |
| } |
| |
| static void kvm_set_page_dirty(struct page *page) |
| { |
| if (kvm_is_ad_tracked_page(page)) |
| SetPageDirty(page); |
| } |
| |
| static void kvm_set_page_accessed(struct page *page) |
| { |
| if (kvm_is_ad_tracked_page(page)) |
| mark_page_accessed(page); |
| } |
| |
| void kvm_release_page_clean(struct page *page) |
| { |
| WARN_ON(is_error_page(page)); |
| |
| kvm_set_page_accessed(page); |
| put_page(page); |
| } |
| EXPORT_SYMBOL_GPL(kvm_release_page_clean); |
| |
| void kvm_release_pfn_clean(kvm_pfn_t pfn) |
| { |
| struct page *page; |
| |
| if (is_error_noslot_pfn(pfn)) |
| return; |
| |
| page = kvm_pfn_to_refcounted_page(pfn); |
| if (!page) |
| return; |
| |
| kvm_release_page_clean(page); |
| } |
| EXPORT_SYMBOL_GPL(kvm_release_pfn_clean); |
| |
| void kvm_release_page_dirty(struct page *page) |
| { |
| WARN_ON(is_error_page(page)); |
| |
| kvm_set_page_dirty(page); |
| kvm_release_page_clean(page); |
| } |
| EXPORT_SYMBOL_GPL(kvm_release_page_dirty); |
| |
| void kvm_release_pfn_dirty(kvm_pfn_t pfn) |
| { |
| struct page *page; |
| |
| if (is_error_noslot_pfn(pfn)) |
| return; |
| |
| page = kvm_pfn_to_refcounted_page(pfn); |
| if (!page) |
| return; |
| |
| kvm_release_page_dirty(page); |
| } |
| EXPORT_SYMBOL_GPL(kvm_release_pfn_dirty); |
| |
| /* |
| * Note, checking for an error/noslot pfn is the caller's responsibility when |
| * directly marking a page dirty/accessed. Unlike the "release" helpers, the |
| * "set" helpers are not to be used when the pfn might point at garbage. |
| */ |
| void kvm_set_pfn_dirty(kvm_pfn_t pfn) |
| { |
| if (WARN_ON(is_error_noslot_pfn(pfn))) |
| return; |
| |
| if (pfn_valid(pfn)) |
| kvm_set_page_dirty(pfn_to_page(pfn)); |
| } |
| EXPORT_SYMBOL_GPL(kvm_set_pfn_dirty); |
| |
| void kvm_set_pfn_accessed(kvm_pfn_t pfn) |
| { |
| if (WARN_ON(is_error_noslot_pfn(pfn))) |
| return; |
| |
| if (pfn_valid(pfn)) |
| kvm_set_page_accessed(pfn_to_page(pfn)); |
| } |
| EXPORT_SYMBOL_GPL(kvm_set_pfn_accessed); |
| |
| static int next_segment(unsigned long len, int offset) |
| { |
| if (len > PAGE_SIZE - offset) |
| return PAGE_SIZE - offset; |
| else |
| return len; |
| } |
| |
| /* Copy @len bytes from guest memory at '(@gfn * PAGE_SIZE) + @offset' to @data */ |
| static int __kvm_read_guest_page(struct kvm_memory_slot *slot, gfn_t gfn, |
| void *data, int offset, int len) |
| { |
| int r; |
| unsigned long addr; |
| |
| addr = gfn_to_hva_memslot_prot(slot, gfn, NULL); |
| if (kvm_is_error_hva(addr)) |
| return -EFAULT; |
| r = __copy_from_user(data, (void __user *)addr + offset, len); |
| if (r) |
| return -EFAULT; |
| return 0; |
| } |
| |
| int kvm_read_guest_page(struct kvm *kvm, gfn_t gfn, void *data, int offset, |
| int len) |
| { |
| struct kvm_memory_slot *slot = gfn_to_memslot(kvm, gfn); |
| |
| return __kvm_read_guest_page(slot, gfn, data, offset, len); |
| } |
| EXPORT_SYMBOL_GPL(kvm_read_guest_page); |
| |
| int kvm_vcpu_read_guest_page(struct kvm_vcpu *vcpu, gfn_t gfn, void *data, |
| int offset, int len) |
| { |
| struct kvm_memory_slot *slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); |
| |
| return __kvm_read_guest_page(slot, gfn, data, offset, len); |
| } |
| EXPORT_SYMBOL_GPL(kvm_vcpu_read_guest_page); |
| |
| int kvm_read_guest(struct kvm *kvm, gpa_t gpa, void *data, unsigned long len) |
| { |
| gfn_t gfn = gpa >> PAGE_SHIFT; |
| int seg; |
| int offset = offset_in_page(gpa); |
| int ret; |
| |
| while ((seg = next_segment(len, offset)) != 0) { |
| ret = kvm_read_guest_page(kvm, gfn, data, offset, seg); |
| if (ret < 0) |
| return ret; |
| offset = 0; |
| len -= seg; |
| data += seg; |
| ++gfn; |
| } |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(kvm_read_guest); |
| |
| int kvm_vcpu_read_guest(struct kvm_vcpu *vcpu, gpa_t gpa, void *data, unsigned long len) |
| { |
| gfn_t gfn = gpa >> PAGE_SHIFT; |
| int seg; |
| int offset = offset_in_page(gpa); |
| int ret; |
| |
| while ((seg = next_segment(len, offset)) != 0) { |
| ret = kvm_vcpu_read_guest_page(vcpu, gfn, data, offset, seg); |
| if (ret < 0) |
| return ret; |
| offset = 0; |
| len -= seg; |
| data += seg; |
| ++gfn; |
| } |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(kvm_vcpu_read_guest); |
| |
| static int __kvm_read_guest_atomic(struct kvm_memory_slot *slot, gfn_t gfn, |
| void *data, int offset, unsigned long len) |
| { |
| int r; |
| unsigned long addr; |
| |
| addr = gfn_to_hva_memslot_prot(slot, gfn, NULL); |
| if (kvm_is_error_hva(addr)) |
| return -EFAULT; |
| pagefault_disable(); |
| r = __copy_from_user_inatomic(data, (void __user *)addr + offset, len); |
| pagefault_enable(); |
| if (r) |
| return -EFAULT; |
| return 0; |
| } |
| |
| int kvm_vcpu_read_guest_atomic(struct kvm_vcpu *vcpu, gpa_t gpa, |
| void *data, unsigned long len) |
| { |
| gfn_t gfn = gpa >> PAGE_SHIFT; |
| struct kvm_memory_slot *slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); |
| int offset = offset_in_page(gpa); |
| |
| return __kvm_read_guest_atomic(slot, gfn, data, offset, len); |
| } |
| EXPORT_SYMBOL_GPL(kvm_vcpu_read_guest_atomic); |
| |
| /* Copy @len bytes from @data into guest memory at '(@gfn * PAGE_SIZE) + @offset' */ |
| static int __kvm_write_guest_page(struct kvm *kvm, |
| struct kvm_memory_slot *memslot, gfn_t gfn, |
| const void *data, int offset, int len) |
| { |
| int r; |
| unsigned long addr; |
| |
| addr = gfn_to_hva_memslot(memslot, gfn); |
| if (kvm_is_error_hva(addr)) |
| return -EFAULT; |
| r = __copy_to_user((void __user *)addr + offset, data, len); |
| if (r) |
| return -EFAULT; |
| mark_page_dirty_in_slot(kvm, memslot, gfn); |
| return 0; |
| } |
| |
| int kvm_write_guest_page(struct kvm *kvm, gfn_t gfn, |
| const void *data, int offset, int len) |
| { |
| struct kvm_memory_slot *slot = gfn_to_memslot(kvm, gfn); |
| |
| return __kvm_write_guest_page(kvm, slot, gfn, data, offset, len); |
| } |
| EXPORT_SYMBOL_GPL(kvm_write_guest_page); |
| |
| int kvm_vcpu_write_guest_page(struct kvm_vcpu *vcpu, gfn_t gfn, |
| const void *data, int offset, int len) |
| { |
| struct kvm_memory_slot *slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); |
| |
| return __kvm_write_guest_page(vcpu->kvm, slot, gfn, data, offset, len); |
| } |
| EXPORT_SYMBOL_GPL(kvm_vcpu_write_guest_page); |
| |
| int kvm_write_guest(struct kvm *kvm, gpa_t gpa, const void *data, |
| unsigned long len) |
| { |
| gfn_t gfn = gpa >> PAGE_SHIFT; |
| int seg; |
| int offset = offset_in_page(gpa); |
| int ret; |
| |
| while ((seg = next_segment(len, offset)) != 0) { |
| ret = kvm_write_guest_page(kvm, gfn, data, offset, seg); |
| if (ret < 0) |
| return ret; |
| offset = 0; |
| len -= seg; |
| data += seg; |
| ++gfn; |
| } |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(kvm_write_guest); |
| |
| int kvm_vcpu_write_guest(struct kvm_vcpu *vcpu, gpa_t gpa, const void *data, |
| unsigned long len) |
| { |
| gfn_t gfn = gpa >> PAGE_SHIFT; |
| int seg; |
| int offset = offset_in_page(gpa); |
| int ret; |
| |
| while ((seg = next_segment(len, offset)) != 0) { |
| ret = kvm_vcpu_write_guest_page(vcpu, gfn, data, offset, seg); |
| if (ret < 0) |
| return ret; |
| offset = 0; |
| len -= seg; |
| data += seg; |
| ++gfn; |
| } |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(kvm_vcpu_write_guest); |
| |
| static int __kvm_gfn_to_hva_cache_init(struct kvm_memslots *slots, |
| struct gfn_to_hva_cache *ghc, |
| gpa_t gpa, unsigned long len) |
| { |
| int offset = offset_in_page(gpa); |
| gfn_t start_gfn = gpa >> PAGE_SHIFT; |
| gfn_t end_gfn = (gpa + len - 1) >> PAGE_SHIFT; |
| gfn_t nr_pages_needed = end_gfn - start_gfn + 1; |
| gfn_t nr_pages_avail; |
| |
| /* Update ghc->generation before performing any error checks. */ |
| ghc->generation = slots->generation; |
| |
| if (start_gfn > end_gfn) { |
| ghc->hva = KVM_HVA_ERR_BAD; |
| return -EINVAL; |
| } |
| |
| /* |
| * If the requested region crosses two memslots, we still |
| * verify that the entire region is valid here. |
| */ |
| for ( ; start_gfn <= end_gfn; start_gfn += nr_pages_avail) { |
| ghc->memslot = __gfn_to_memslot(slots, start_gfn); |
| ghc->hva = gfn_to_hva_many(ghc->memslot, start_gfn, |
| &nr_pages_avail); |
| if (kvm_is_error_hva(ghc->hva)) |
| return -EFAULT; |
| } |
| |
| /* Use the slow path for cross page reads and writes. */ |
| if (nr_pages_needed == 1) |
| ghc->hva += offset; |
| else |
| ghc->memslot = NULL; |
| |
| ghc->gpa = gpa; |
| ghc->len = len; |
| return 0; |
| } |
| |
| int kvm_gfn_to_hva_cache_init(struct kvm *kvm, struct gfn_to_hva_cache *ghc, |
| gpa_t gpa, unsigned long len) |
| { |
| struct kvm_memslots *slots = kvm_memslots(kvm); |
| return __kvm_gfn_to_hva_cache_init(slots, ghc, gpa, len); |
| } |
| EXPORT_SYMBOL_GPL(kvm_gfn_to_hva_cache_init); |
| |
| int kvm_write_guest_offset_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc, |
| void *data, unsigned int offset, |
| unsigned long len) |
| { |
| struct kvm_memslots *slots = kvm_memslots(kvm); |
| int r; |
| gpa_t gpa = ghc->gpa + offset; |
| |
| if (WARN_ON_ONCE(len + offset > ghc->len)) |
| return -EINVAL; |
| |
| if (slots->generation != ghc->generation) { |
| if (__kvm_gfn_to_hva_cache_init(slots, ghc, ghc->gpa, ghc->len)) |
| return -EFAULT; |
| } |
| |
| if (kvm_is_error_hva(ghc->hva)) |
| return -EFAULT; |
| |
| if (unlikely(!ghc->memslot)) |
| return kvm_write_guest(kvm, gpa, data, len); |
| |
| r = __copy_to_user((void __user *)ghc->hva + offset, data, len); |
| if (r) |
| return -EFAULT; |
| mark_page_dirty_in_slot(kvm, ghc->memslot, gpa >> PAGE_SHIFT); |
| |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(kvm_write_guest_offset_cached); |
| |
| int kvm_write_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc, |
| void *data, unsigned long len) |
| { |
| return kvm_write_guest_offset_cached(kvm, ghc, data, 0, len); |
| } |
| EXPORT_SYMBOL_GPL(kvm_write_guest_cached); |
| |
| int kvm_read_guest_offset_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc, |
| void *data, unsigned int offset, |
| unsigned long len) |
| { |
| struct kvm_memslots *slots = kvm_memslots(kvm); |
| int r; |
| gpa_t gpa = ghc->gpa + offset; |
| |
| if (WARN_ON_ONCE(len + offset > ghc->len)) |
| return -EINVAL; |
| |
| if (slots->generation != ghc->generation) { |
| if (__kvm_gfn_to_hva_cache_init(slots, ghc, ghc->gpa, ghc->len)) |
| return -EFAULT; |
| } |
| |
| if (kvm_is_error_hva(ghc->hva)) |
| return -EFAULT; |
| |
| if (unlikely(!ghc->memslot)) |
| return kvm_read_guest(kvm, gpa, data, len); |
| |
| r = __copy_from_user(data, (void __user *)ghc->hva + offset, len); |
| if (r) |
| return -EFAULT; |
| |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(kvm_read_guest_offset_cached); |
| |
| int kvm_read_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc, |
| void *data, unsigned long len) |
| { |
| return kvm_read_guest_offset_cached(kvm, ghc, data, 0, len); |
| } |
| EXPORT_SYMBOL_GPL(kvm_read_guest_cached); |
| |
| int kvm_clear_guest(struct kvm *kvm, gpa_t gpa, unsigned long len) |
| { |
| const void *zero_page = (const void *) __va(page_to_phys(ZERO_PAGE(0))); |
| gfn_t gfn = gpa >> PAGE_SHIFT; |
| int seg; |
| int offset = offset_in_page(gpa); |
| int ret; |
| |
| while ((seg = next_segment(len, offset)) != 0) { |
| ret = kvm_write_guest_page(kvm, gfn, zero_page, offset, len); |
| if (ret < 0) |
| return ret; |
| offset = 0; |
| len -= seg; |
| ++gfn; |
| } |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(kvm_clear_guest); |
| |
| void mark_page_dirty_in_slot(struct kvm *kvm, |
| const struct kvm_memory_slot *memslot, |
| gfn_t gfn) |
| { |
| struct kvm_vcpu *vcpu = kvm_get_running_vcpu(); |
| |
| #ifdef CONFIG_HAVE_KVM_DIRTY_RING |
| if (WARN_ON_ONCE(vcpu && vcpu->kvm != kvm)) |
| return; |
| |
| WARN_ON_ONCE(!vcpu && !kvm_arch_allow_write_without_running_vcpu(kvm)); |
| #endif |
| |
| if (memslot && kvm_slot_dirty_track_enabled(memslot)) { |
| unsigned long rel_gfn = gfn - memslot->base_gfn; |
| u32 slot = (memslot->as_id << 16) | memslot->id; |
| |
| if (kvm->dirty_ring_size && vcpu) |
| kvm_dirty_ring_push(vcpu, slot, rel_gfn); |
| else if (memslot->dirty_bitmap) |
| set_bit_le(rel_gfn, memslot->dirty_bitmap); |
| } |
| } |
| EXPORT_SYMBOL_GPL(mark_page_dirty_in_slot); |
| |
| void mark_page_dirty(struct kvm *kvm, gfn_t gfn) |
| { |
| struct kvm_memory_slot *memslot; |
| |
| memslot = gfn_to_memslot(kvm, gfn); |
| mark_page_dirty_in_slot(kvm, memslot, gfn); |
| } |
| EXPORT_SYMBOL_GPL(mark_page_dirty); |
| |
| void kvm_vcpu_mark_page_dirty(struct kvm_vcpu *vcpu, gfn_t gfn) |
| { |
| struct kvm_memory_slot *memslot; |
| |
| memslot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); |
| mark_page_dirty_in_slot(vcpu->kvm, memslot, gfn); |
| } |
| EXPORT_SYMBOL_GPL(kvm_vcpu_mark_page_dirty); |
| |
| void kvm_sigset_activate(struct kvm_vcpu *vcpu) |
| { |
| if (!vcpu->sigset_active) |
| return; |
| |
| /* |
| * This does a lockless modification of ->real_blocked, which is fine |
| * because, only current can change ->real_blocked and all readers of |
| * ->real_blocked don't care as long ->real_blocked is always a subset |
| * of ->blocked. |
| */ |
| sigprocmask(SIG_SETMASK, &vcpu->sigset, ¤t->real_blocked); |
| } |
| |
| void kvm_sigset_deactivate(struct kvm_vcpu *vcpu) |
| { |
| if (!vcpu->sigset_active) |
| return; |
| |
| sigprocmask(SIG_SETMASK, ¤t->real_blocked, NULL); |
| sigemptyset(¤t->real_blocked); |
| } |
| |
| static void grow_halt_poll_ns(struct kvm_vcpu *vcpu) |
| { |
| unsigned int old, val, grow, grow_start; |
| |
| old = val = vcpu->halt_poll_ns; |
| grow_start = READ_ONCE(halt_poll_ns_grow_start); |
| grow = READ_ONCE(halt_poll_ns_grow); |
| if (!grow) |
| goto out; |
| |
| val *= grow; |
| if (val < grow_start) |
| val = grow_start; |
| |
| vcpu->halt_poll_ns = val; |
| out: |
| trace_kvm_halt_poll_ns_grow(vcpu->vcpu_id, val, old); |
| } |
| |
| static void shrink_halt_poll_ns(struct kvm_vcpu *vcpu) |
| { |
| unsigned int old, val, shrink, grow_start; |
| |
| old = val = vcpu->halt_poll_ns; |
| shrink = READ_ONCE(halt_poll_ns_shrink); |
| grow_start = READ_ONCE(halt_poll_ns_grow_start); |
| if (shrink == 0) |
| val = 0; |
| else |
| val /= shrink; |
| |
| if (val < grow_start) |
| val = 0; |
| |
| vcpu->halt_poll_ns = val; |
| trace_kvm_halt_poll_ns_shrink(vcpu->vcpu_id, val, old); |
| } |
| |
| static int kvm_vcpu_check_block(struct kvm_vcpu *vcpu) |
| { |
| int ret = -EINTR; |
| int idx = srcu_read_lock(&vcpu->kvm->srcu); |
| |
| if (kvm_arch_vcpu_runnable(vcpu)) |
| goto out; |
| if (kvm_cpu_has_pending_timer(vcpu)) |
| goto out; |
| if (signal_pending(current)) |
| goto out; |
| if (kvm_check_request(KVM_REQ_UNBLOCK, vcpu)) |
| goto out; |
| |
| ret = 0; |
| out: |
| srcu_read_unlock(&vcpu->kvm->srcu, idx); |
| return ret; |
| } |
| |
| /* |
| * Block the vCPU until the vCPU is runnable, an event arrives, or a signal is |
| * pending. This is mostly used when halting a vCPU, but may also be used |
| * directly for other vCPU non-runnable states, e.g. x86's Wait-For-SIPI. |
| */ |
| bool kvm_vcpu_block(struct kvm_vcpu *vcpu) |
| { |
| struct rcuwait *wait = kvm_arch_vcpu_get_wait(vcpu); |
| bool waited = false; |
| |
| vcpu->stat.generic.blocking = 1; |
| |
| preempt_disable(); |
| kvm_arch_vcpu_blocking(vcpu); |
| prepare_to_rcuwait(wait); |
| preempt_enable(); |
| |
| for (;;) { |
| set_current_state(TASK_INTERRUPTIBLE); |
| |
| if (kvm_vcpu_check_block(vcpu) < 0) |
| break; |
| |
| waited = true; |
| schedule(); |
| } |
| |
| preempt_disable(); |
| finish_rcuwait(wait); |
| kvm_arch_vcpu_unblocking(vcpu); |
| preempt_enable(); |
| |
| vcpu->stat.generic.blocking = 0; |
| |
| return waited; |
| } |
| |
| static inline void update_halt_poll_stats(struct kvm_vcpu *vcpu, ktime_t start, |
| ktime_t end, bool success) |
| { |
| struct kvm_vcpu_stat_generic *stats = &vcpu->stat.generic; |
| u64 poll_ns = ktime_to_ns(ktime_sub(end, start)); |
| |
| ++vcpu->stat.generic.halt_attempted_poll; |
| |
| if (success) { |
| ++vcpu->stat.generic.halt_successful_poll; |
| |
| if (!vcpu_valid_wakeup(vcpu)) |
| ++vcpu->stat.generic.halt_poll_invalid; |
| |
| stats->halt_poll_success_ns += poll_ns; |
| KVM_STATS_LOG_HIST_UPDATE(stats->halt_poll_success_hist, poll_ns); |
| } else { |
| stats->halt_poll_fail_ns += poll_ns; |
| KVM_STATS_LOG_HIST_UPDATE(stats->halt_poll_fail_hist, poll_ns); |
| } |
| } |
| |
| static unsigned int kvm_vcpu_max_halt_poll_ns(struct kvm_vcpu *vcpu) |
| { |
| struct kvm *kvm = vcpu->kvm; |
| |
| if (kvm->override_halt_poll_ns) { |
| /* |
| * Ensure kvm->max_halt_poll_ns is not read before |
| * kvm->override_halt_poll_ns. |
| * |
| * Pairs with the smp_wmb() when enabling KVM_CAP_HALT_POLL. |
| */ |
| smp_rmb(); |
| return READ_ONCE(kvm->max_halt_poll_ns); |
| } |
| |
| return READ_ONCE(halt_poll_ns); |
| } |
| |
| /* |
| * Emulate a vCPU halt condition, e.g. HLT on x86, WFI on arm, etc... If halt |
| * polling is enabled, busy wait for a short time before blocking to avoid the |
| * expensive block+unblock sequence if a wake event arrives soon after the vCPU |
| * is halted. |
| */ |
| void kvm_vcpu_halt(struct kvm_vcpu *vcpu) |
| { |
| unsigned int max_halt_poll_ns = kvm_vcpu_max_halt_poll_ns(vcpu); |
| bool halt_poll_allowed = !kvm_arch_no_poll(vcpu); |
| ktime_t start, cur, poll_end; |
| bool waited = false; |
| bool do_halt_poll; |
| u64 halt_ns; |
| |
| if (vcpu->halt_poll_ns > max_halt_poll_ns) |
| vcpu->halt_poll_ns = max_halt_poll_ns; |
| |
| do_halt_poll = halt_poll_allowed && vcpu->halt_poll_ns; |
| |
| start = cur = poll_end = ktime_get(); |
| if (do_halt_poll) { |
| ktime_t stop = ktime_add_ns(start, vcpu->halt_poll_ns); |
| |
| do { |
| if (kvm_vcpu_check_block(vcpu) < 0) |
| goto out; |
| cpu_relax(); |
| poll_end = cur = ktime_get(); |
| } while (kvm_vcpu_can_poll(cur, stop)); |
| } |
| |
| waited = kvm_vcpu_block(vcpu); |
| |
| cur = ktime_get(); |
| if (waited) { |
| vcpu->stat.generic.halt_wait_ns += |
| ktime_to_ns(cur) - ktime_to_ns(poll_end); |
| KVM_STATS_LOG_HIST_UPDATE(vcpu->stat.generic.halt_wait_hist, |
| ktime_to_ns(cur) - ktime_to_ns(poll_end)); |
| } |
| out: |
| /* The total time the vCPU was "halted", including polling time. */ |
| halt_ns = ktime_to_ns(cur) - ktime_to_ns(start); |
| |
| /* |
| * Note, halt-polling is considered successful so long as the vCPU was |
| * never actually scheduled out, i.e. even if the wake event arrived |
| * after of the halt-polling loop itself, but before the full wait. |
| */ |
| if (do_halt_poll) |
| update_halt_poll_stats(vcpu, start, poll_end, !waited); |
| |
| if (halt_poll_allowed) { |
| /* Recompute the max halt poll time in case it changed. */ |
| max_halt_poll_ns = kvm_vcpu_max_halt_poll_ns(vcpu); |
| |
| if (!vcpu_valid_wakeup(vcpu)) { |
| shrink_halt_poll_ns(vcpu); |
| } else if (max_halt_poll_ns) { |
| if (halt_ns <= vcpu->halt_poll_ns) |
| ; |
| /* we had a long block, shrink polling */ |
| else if (vcpu->halt_poll_ns && |
| halt_ns > max_halt_poll_ns) |
| shrink_halt_poll_ns(vcpu); |
| /* we had a short halt and our poll time is too small */ |
| else if (vcpu->halt_poll_ns < max_halt_poll_ns && |
| halt_ns < max_halt_poll_ns) |
| grow_halt_poll_ns(vcpu); |
| } else { |
| vcpu->halt_poll_ns = 0; |
| } |
| } |
| |
| trace_kvm_vcpu_wakeup(halt_ns, waited, vcpu_valid_wakeup(vcpu)); |
| } |
| EXPORT_SYMBOL_GPL(kvm_vcpu_halt); |
| |
| bool kvm_vcpu_wake_up(struct kvm_vcpu *vcpu) |
| { |
| if (__kvm_vcpu_wake_up(vcpu)) { |
| WRITE_ONCE(vcpu->ready, true); |
| ++vcpu->stat.generic.halt_wakeup; |
| return true; |
| } |
| |
| return false; |
| } |
| EXPORT_SYMBOL_GPL(kvm_vcpu_wake_up); |
| |
| #ifndef CONFIG_S390 |
| /* |
| * Kick a sleeping VCPU, or a guest VCPU in guest mode, into host kernel mode. |
| */ |
| void kvm_vcpu_kick(struct kvm_vcpu *vcpu) |
| { |
| int me, cpu; |
| |
| if (kvm_vcpu_wake_up(vcpu)) |
| return; |
| |
| me = get_cpu(); |
| /* |
| * The only state change done outside the vcpu mutex is IN_GUEST_MODE |
| * to EXITING_GUEST_MODE. Therefore the moderately expensive "should |
| * kick" check does not need atomic operations if kvm_vcpu_kick is used |
| * within the vCPU thread itself. |
| */ |
| if (vcpu == __this_cpu_read(kvm_running_vcpu)) { |
| if (vcpu->mode == IN_GUEST_MODE) |
| WRITE_ONCE(vcpu->mode, EXITING_GUEST_MODE); |
| goto out; |
| } |
| |
| /* |
| * Note, the vCPU could get migrated to a different pCPU at any point |
| * after kvm_arch_vcpu_should_kick(), which could result in sending an |
| * IPI to the previous pCPU. But, that's ok because the purpose of the |
| * IPI is to force the vCPU to leave IN_GUEST_MODE, and migrating the |
| * vCPU also requires it to leave IN_GUEST_MODE. |
| */ |
| if (kvm_arch_vcpu_should_kick(vcpu)) { |
| cpu = READ_ONCE(vcpu->cpu); |
| if (cpu != me && (unsigned)cpu < nr_cpu_ids && cpu_online(cpu)) |
| smp_send_reschedule(cpu); |
| } |
| out: |
| put_cpu(); |
| } |
| EXPORT_SYMBOL_GPL(kvm_vcpu_kick); |
| #endif /* !CONFIG_S390 */ |
| |
| int kvm_vcpu_yield_to(struct kvm_vcpu *target) |
| { |
| struct pid *pid; |
| struct task_struct *task = NULL; |
| int ret = 0; |
| |
| rcu_read_lock(); |
| pid = rcu_dereference(target->pid); |
| if (pid) |
| task = get_pid_task(pid, PIDTYPE_PID); |
| rcu_read_unlock(); |
| if (!task) |
| return ret; |
| ret = yield_to(task, 1); |
| put_task_struct(task); |
| |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(kvm_vcpu_yield_to); |
| |
| /* |
| * Helper that checks whether a VCPU is eligible for directed yield. |
| * Most eligible candidate to yield is decided by following heuristics: |
| * |
| * (a) VCPU which has not done pl-exit or cpu relax intercepted recently |
| * (preempted lock holder), indicated by @in_spin_loop. |
| * Set at the beginning and cleared at the end of interception/PLE handler. |
| * |
| * (b) VCPU which has done pl-exit/ cpu relax intercepted but did not get |
| * chance last time (mostly it has become eligible now since we have probably |
| * yielded to lockholder in last iteration. This is done by toggling |
| * @dy_eligible each time a VCPU checked for eligibility.) |
| * |
| * Yielding to a recently pl-exited/cpu relax intercepted VCPU before yielding |
| * to preempted lock-holder could result in wrong VCPU selection and CPU |
| * burning. Giving priority for a potential lock-holder increases lock |
| * progress. |
| * |
| * Since algorithm is based on heuristics, accessing another VCPU data without |
| * locking does not harm. It may result in trying to yield to same VCPU, fail |
| * and continue with next VCPU and so on. |
| */ |
| static bool kvm_vcpu_eligible_for_directed_yield(struct kvm_vcpu *vcpu) |
| { |
| #ifdef CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT |
| bool eligible; |
| |
| eligible = !vcpu->spin_loop.in_spin_loop || |
| vcpu->spin_loop.dy_eligible; |
| |
| if (vcpu->spin_loop.in_spin_loop) |
| kvm_vcpu_set_dy_eligible(vcpu, !vcpu->spin_loop.dy_eligible); |
| |
| return eligible; |
| #else |
| return true; |
| #endif |
| } |
| |
| /* |
| * Unlike kvm_arch_vcpu_runnable, this function is called outside |
| * a vcpu_load/vcpu_put pair. However, for most architectures |
| * kvm_arch_vcpu_runnable does not require vcpu_load. |
| */ |
| bool __weak kvm_arch_dy_runnable(struct kvm_vcpu *vcpu) |
| { |
| return kvm_arch_vcpu_runnable(vcpu); |
| } |
| |
| static bool vcpu_dy_runnable(struct kvm_vcpu *vcpu) |
| { |
| if (kvm_arch_dy_runnable(vcpu)) |
| return true; |
| |
| #ifdef CONFIG_KVM_ASYNC_PF |
| if (!list_empty_careful(&vcpu->async_pf.done)) |
| return true; |
| #endif |
| |
| return false; |
| } |
| |
| /* |
| * By default, simply query the target vCPU's current mode when checking if a |
| * vCPU was preempted in kernel mode. All architectures except x86 (or more |
| * specifical, except VMX) allow querying whether or not a vCPU is in kernel |
| * mode even if the vCPU is NOT loaded, i.e. using kvm_arch_vcpu_in_kernel() |
| * directly for cross-vCPU checks is functionally correct and accurate. |
| */ |
| bool __weak kvm_arch_vcpu_preempted_in_kernel(struct kvm_vcpu *vcpu) |
| { |
| return kvm_arch_vcpu_in_kernel(vcpu); |
| } |
| |
| bool __weak kvm_arch_dy_has_pending_interrupt(struct kvm_vcpu *vcpu) |
| { |
| return false; |
| } |
| |
| void kvm_vcpu_on_spin(struct kvm_vcpu *me, bool yield_to_kernel_mode) |
| { |
| struct kvm *kvm = me->kvm; |
| struct kvm_vcpu *vcpu; |
| int last_boosted_vcpu; |
| unsigned long i; |
| int yielded = 0; |
| int try = 3; |
| int pass; |
| |
| last_boosted_vcpu = READ_ONCE(kvm->last_boosted_vcpu); |
| kvm_vcpu_set_in_spin_loop(me, true); |
| /* |
| * We boost the priority of a VCPU that is runnable but not |
| * currently running, because it got preempted by something |
| * else and called schedule in __vcpu_run. Hopefully that |
| * VCPU is holding the lock that we need and will release it. |
| * We approximate round-robin by starting at the last boosted VCPU. |
| */ |
| for (pass = 0; pass < 2 && !yielded && try; pass++) { |
| kvm_for_each_vcpu(i, vcpu, kvm) { |
| if (!pass && i <= last_boosted_vcpu) { |
| i = last_boosted_vcpu; |
| continue; |
| } else if (pass && i > last_boosted_vcpu) |
| break; |
| if (!READ_ONCE(vcpu->ready)) |
| continue; |
| if (vcpu == me) |
| continue; |
| if (kvm_vcpu_is_blocking(vcpu) && !vcpu_dy_runnable(vcpu)) |
| continue; |
| |
| /* |
| * Treat the target vCPU as being in-kernel if it has a |
| * pending interrupt, as the vCPU trying to yield may |
| * be spinning waiting on IPI delivery, i.e. the target |
| * vCPU is in-kernel for the purposes of directed yield. |
| */ |
| if (READ_ONCE(vcpu->preempted) && yield_to_kernel_mode && |
| !kvm_arch_dy_has_pending_interrupt(vcpu) && |
| !kvm_arch_vcpu_preempted_in_kernel(vcpu)) |
| continue; |
| if (!kvm_vcpu_eligible_for_directed_yield(vcpu)) |
| continue; |
| |
| yielded = kvm_vcpu_yield_to(vcpu); |
| if (yielded > 0) { |
| WRITE_ONCE(kvm->last_boosted_vcpu, i); |
| break; |
| } else if (yielded < 0) { |
| try--; |
| if (!try) |
| break; |
| } |
| } |
| } |
| kvm_vcpu_set_in_spin_loop(me, false); |
| |
| /* Ensure vcpu is not eligible during next spinloop */ |
| kvm_vcpu_set_dy_eligible(me, false); |
| } |
| EXPORT_SYMBOL_GPL(kvm_vcpu_on_spin); |
| |
| static bool kvm_page_in_dirty_ring(struct kvm *kvm, unsigned long pgoff) |
| { |
| #ifdef CONFIG_HAVE_KVM_DIRTY_RING |
| return (pgoff >= KVM_DIRTY_LOG_PAGE_OFFSET) && |
| (pgoff < KVM_DIRTY_LOG_PAGE_OFFSET + |
| kvm->dirty_ring_size / PAGE_SIZE); |
| #else |
| return false; |
| #endif |
| } |
| |
| static vm_fault_t kvm_vcpu_fault(struct vm_fault *vmf) |
| { |
| struct kvm_vcpu *vcpu = vmf->vma->vm_file->private_data; |
| struct page *page; |
| |
| if (vmf->pgoff == 0) |
| page = virt_to_page(vcpu->run); |
| #ifdef CONFIG_X86 |
| else if (vmf->pgoff == KVM_PIO_PAGE_OFFSET) |
| page = virt_to_page(vcpu->arch.pio_data); |
| #endif |
| #ifdef CONFIG_KVM_MMIO |
| else if (vmf->pgoff == KVM_COALESCED_MMIO_PAGE_OFFSET) |
| page = virt_to_page(vcpu->kvm->coalesced_mmio_ring); |
| #endif |
| else if (kvm_page_in_dirty_ring(vcpu->kvm, vmf->pgoff)) |
| page = kvm_dirty_ring_get_page( |
| &vcpu->dirty_ring, |
| vmf->pgoff - KVM_DIRTY_LOG_PAGE_OFFSET); |
| else |
| return kvm_arch_vcpu_fault(vcpu, vmf); |
| get_page(page); |
| vmf->page = page; |
| return 0; |
| } |
| |
| static const struct vm_operations_struct kvm_vcpu_vm_ops = { |
| .fault = kvm_vcpu_fault, |
| }; |
| |
| static int kvm_vcpu_mmap(struct file *file, struct vm_area_struct *vma) |
| { |
| struct kvm_vcpu *vcpu = file->private_data; |
| unsigned long pages = vma_pages(vma); |
| |
| if ((kvm_page_in_dirty_ring(vcpu->kvm, vma->vm_pgoff) || |
| kvm_page_in_dirty_ring(vcpu->kvm, vma->vm_pgoff + pages - 1)) && |
| ((vma->vm_flags & VM_EXEC) || !(vma->vm_flags & VM_SHARED))) |
| return -EINVAL; |
| |
| vma->vm_ops = &kvm_vcpu_vm_ops; |
| return 0; |
| } |
| |
| static int kvm_vcpu_release(struct inode *inode, struct file *filp) |
| { |
| struct kvm_vcpu *vcpu = filp->private_data; |
| |
| kvm_put_kvm(vcpu->kvm); |
| return 0; |
| } |
| |
| static struct file_operations kvm_vcpu_fops = { |
| .release = kvm_vcpu_release, |
| .unlocked_ioctl = kvm_vcpu_ioctl, |
| .mmap = kvm_vcpu_mmap, |
| .llseek = noop_llseek, |
| KVM_COMPAT(kvm_vcpu_compat_ioctl), |
| }; |
| |
| /* |
| * Allocates an inode for the vcpu. |
| */ |
| static int create_vcpu_fd(struct kvm_vcpu *vcpu) |
| { |
| char name[8 + 1 + ITOA_MAX_LEN + 1]; |
| |
| snprintf(name, sizeof(name), "kvm-vcpu:%d", vcpu->vcpu_id); |
| return anon_inode_getfd(name, &kvm_vcpu_fops, vcpu, O_RDWR | O_CLOEXEC); |
| } |
| |
| #ifdef __KVM_HAVE_ARCH_VCPU_DEBUGFS |
| static int vcpu_get_pid(void *data, u64 *val) |
| { |
| struct kvm_vcpu *vcpu = data; |
| |
| rcu_read_lock(); |
| *val = pid_nr(rcu_dereference(vcpu->pid)); |
| rcu_read_unlock(); |
| return 0; |
| } |
| |
| DEFINE_SIMPLE_ATTRIBUTE(vcpu_get_pid_fops, vcpu_get_pid, NULL, "%llu\n"); |
| |
| static void kvm_create_vcpu_debugfs(struct kvm_vcpu *vcpu) |
| { |
| struct dentry *debugfs_dentry; |
| char dir_name[ITOA_MAX_LEN * 2]; |
| |
| if (!debugfs_initialized()) |
| return; |
| |
| snprintf(dir_name, sizeof(dir_name), "vcpu%d", vcpu->vcpu_id); |
| debugfs_dentry = debugfs_create_dir(dir_name, |
| vcpu->kvm->debugfs_dentry); |
| debugfs_create_file("pid", 0444, debugfs_dentry, vcpu, |
| &vcpu_get_pid_fops); |
| |
| kvm_arch_create_vcpu_debugfs(vcpu, debugfs_dentry); |
| } |
| #endif |
| |
| /* |
| * Creates some virtual cpus. Good luck creating more than one. |
| */ |
| static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, unsigned long id) |
| { |
| int r; |
| struct kvm_vcpu *vcpu; |
| struct page *page; |
| |
| /* |
| * KVM tracks vCPU IDs as 'int', be kind to userspace and reject |
| * too-large values instead of silently truncating. |
| * |
| * Ensure KVM_MAX_VCPU_IDS isn't pushed above INT_MAX without first |
| * changing the storage type (at the very least, IDs should be tracked |
| * as unsigned ints). |
| */ |
| BUILD_BUG_ON(KVM_MAX_VCPU_IDS > INT_MAX); |
| if (id >= KVM_MAX_VCPU_IDS) |
| return -EINVAL; |
| |
| mutex_lock(&kvm->lock); |
| if (kvm->created_vcpus >= kvm->max_vcpus) { |
| mutex_unlock(&kvm->lock); |
| return -EINVAL; |
| } |
| |
| r = kvm_arch_vcpu_precreate(kvm, id); |
| if (r) { |
| mutex_unlock(&kvm->lock); |
| return r; |
| } |
| |
| kvm->created_vcpus++; |
| mutex_unlock(&kvm->lock); |
| |
| vcpu = kmem_cache_zalloc(kvm_vcpu_cache, GFP_KERNEL_ACCOUNT); |
| if (!vcpu) { |
| r = -ENOMEM; |
| goto vcpu_decrement; |
| } |
| |
| BUILD_BUG_ON(sizeof(struct kvm_run) > PAGE_SIZE); |
| page = alloc_page(GFP_KERNEL_ACCOUNT | __GFP_ZERO); |
| if (!page) { |
| r = -ENOMEM; |
| goto vcpu_free; |
| } |
| vcpu->run = page_address(page); |
| |
| kvm_vcpu_init(vcpu, kvm, id); |
| |
| r = kvm_arch_vcpu_create(vcpu); |
| if (r) |
| goto vcpu_free_run_page; |
| |
| if (kvm->dirty_ring_size) { |
| r = kvm_dirty_ring_alloc(&vcpu->dirty_ring, |
| id, kvm->dirty_ring_size); |
| if (r) |
| goto arch_vcpu_destroy; |
| } |
| |
| mutex_lock(&kvm->lock); |
| |
| #ifdef CONFIG_LOCKDEP |
| /* Ensure that lockdep knows vcpu->mutex is taken *inside* kvm->lock */ |
| mutex_lock(&vcpu->mutex); |
| mutex_unlock(&vcpu->mutex); |
| #endif |
| |
| if (kvm_get_vcpu_by_id(kvm, id)) { |
| r = -EEXIST; |
| goto unlock_vcpu_destroy; |
| } |
| |
| vcpu->vcpu_idx = atomic_read(&kvm->online_vcpus); |
| r = xa_reserve(&kvm->vcpu_array, vcpu->vcpu_idx, GFP_KERNEL_ACCOUNT); |
| if (r) |
| goto unlock_vcpu_destroy; |
| |
| /* Now it's all set up, let userspace reach it */ |
| kvm_get_kvm(kvm); |
| r = create_vcpu_fd(vcpu); |
| if (r < 0) |
| goto kvm_put_xa_release; |
| |
| if (KVM_BUG_ON(xa_store(&kvm->vcpu_array, vcpu->vcpu_idx, vcpu, 0), kvm)) { |
| r = -EINVAL; |
| goto kvm_put_xa_release; |
| } |
| |
| /* |
| * Pairs with smp_rmb() in kvm_get_vcpu. Store the vcpu |
| * pointer before kvm->online_vcpu's incremented value. |
| */ |
| smp_wmb(); |
| atomic_inc(&kvm->online_vcpus); |
| |
| mutex_unlock(&kvm->lock); |
| kvm_arch_vcpu_postcreate(vcpu); |
| kvm_create_vcpu_debugfs(vcpu); |
| return r; |
| |
| kvm_put_xa_release: |
| kvm_put_kvm_no_destroy(kvm); |
| xa_release(&kvm->vcpu_array, vcpu->vcpu_idx); |
| unlock_vcpu_destroy: |
| mutex_unlock(&kvm->lock); |
| kvm_dirty_ring_free(&vcpu->dirty_ring); |
| arch_vcpu_destroy: |
| kvm_arch_vcpu_destroy(vcpu); |
| vcpu_free_run_page: |
| free_page((unsigned long)vcpu->run); |
| vcpu_free: |
| kmem_cache_free(kvm_vcpu_cache, vcpu); |
| vcpu_decrement: |
| mutex_lock(&kvm->lock); |
| kvm->created_vcpus--; |
| mutex_unlock(&kvm->lock); |
| return r; |
| } |
| |
| static int kvm_vcpu_ioctl_set_sigmask(struct kvm_vcpu *vcpu, sigset_t *sigset) |
| { |
| if (sigset) { |
| sigdelsetmask(sigset, sigmask(SIGKILL)|sigmask(SIGSTOP)); |
| vcpu->sigset_active = 1; |
| vcpu->sigset = *sigset; |
| } else |
| vcpu->sigset_active = 0; |
| return 0; |
| } |
| |
| static ssize_t kvm_vcpu_stats_read(struct file *file, char __user *user_buffer, |
| size_t size, loff_t *offset) |
| { |
| struct kvm_vcpu *vcpu = file->private_data; |
| |
| return kvm_stats_read(vcpu->stats_id, &kvm_vcpu_stats_header, |
| &kvm_vcpu_stats_desc[0], &vcpu->stat, |
| sizeof(vcpu->stat), user_buffer, size, offset); |
| } |
| |
| static int kvm_vcpu_stats_release(struct inode *inode, struct file *file) |
| { |
| struct kvm_vcpu *vcpu = file->private_data; |
| |
| kvm_put_kvm(vcpu->kvm); |
| return 0; |
| } |
| |
| static const struct file_operations kvm_vcpu_stats_fops = { |
| .owner = THIS_MODULE, |
| .read = kvm_vcpu_stats_read, |
| .release = kvm_vcpu_stats_release, |
| .llseek = noop_llseek, |
| }; |
| |
| static int kvm_vcpu_ioctl_get_stats_fd(struct kvm_vcpu *vcpu) |
| { |
| int fd; |
| struct file *file; |
| char name[15 + ITOA_MAX_LEN + 1]; |
| |
| snprintf(name, sizeof(name), "kvm-vcpu-stats:%d", vcpu->vcpu_id); |
| |
| fd = get_unused_fd_flags(O_CLOEXEC); |
| if (fd < 0) |
| return fd; |
| |
| file = anon_inode_getfile(name, &kvm_vcpu_stats_fops, vcpu, O_RDONLY); |
| if (IS_ERR(file)) { |
| put_unused_fd(fd); |
| return PTR_ERR(file); |
| } |
| |
| kvm_get_kvm(vcpu->kvm); |
| |
| file->f_mode |= FMODE_PREAD; |
| fd_install(fd, file); |
| |
| return fd; |
| } |
| |
| #ifdef CONFIG_KVM_GENERIC_PRE_FAULT_MEMORY |
| static int kvm_vcpu_pre_fault_memory(struct kvm_vcpu *vcpu, |
| struct kvm_pre_fault_memory *range) |
| { |
| int idx; |
| long r; |
| u64 full_size; |
| |
| if (range->flags) |
| return -EINVAL; |
| |
| if (!PAGE_ALIGNED(range->gpa) || |
| !PAGE_ALIGNED(range->size) || |
| range->gpa + range->size <= range->gpa) |
| return -EINVAL; |
| |
| vcpu_load(vcpu); |
| idx = srcu_read_lock(&vcpu->kvm->srcu); |
| |
| full_size = range->size; |
| do { |
| if (signal_pending(current)) { |
| r = -EINTR; |
| break; |
| } |
| |
| r = kvm_arch_vcpu_pre_fault_memory(vcpu, range); |
| if (WARN_ON_ONCE(r == 0 || r == -EIO)) |
| break; |
| |
| if (r < 0) |
| break; |
| |
| range->size -= r; |
| range->gpa += r; |
| cond_resched(); |
| } while (range->size); |
| |
| srcu_read_unlock(&vcpu->kvm->srcu, idx); |
| vcpu_put(vcpu); |
| |
| /* Return success if at least one page was mapped successfully. */ |
| return full_size == range->size ? r : 0; |
| } |
| #endif |
| |
| static long kvm_vcpu_ioctl(struct file *filp, |
| unsigned int ioctl, unsigned long arg) |
| { |
| struct kvm_vcpu *vcpu = filp->private_data; |
| void __user *argp = (void __user *)arg; |
| int r; |
| struct kvm_fpu *fpu = NULL; |
| struct kvm_sregs *kvm_sregs = NULL; |
| |
| if (vcpu->kvm->mm != current->mm || vcpu->kvm->vm_dead) |
| return -EIO; |
| |
| if (unlikely(_IOC_TYPE(ioctl) != KVMIO)) |
| return -EINVAL; |
| |
| /* |
| * Some architectures have vcpu ioctls that are asynchronous to vcpu |
| * execution; mutex_lock() would break them. |
| */ |
| r = kvm_arch_vcpu_async_ioctl(filp, ioctl, arg); |
| if (r != -ENOIOCTLCMD) |
| return r; |
| |
| if (mutex_lock_killable(&vcpu->mutex)) |
| return -EINTR; |
| switch (ioctl) { |
| case KVM_RUN: { |
| struct pid *oldpid; |
| r = -EINVAL; |
| if (arg) |
| goto out; |
| oldpid = rcu_access_pointer(vcpu->pid); |
| if (unlikely(oldpid != task_pid(current))) { |
| /* The thread running this VCPU changed. */ |
| struct pid *newpid; |
| |
| r = kvm_arch_vcpu_run_pid_change(vcpu); |
| if (r) |
| break; |
| |
| newpid = get_task_pid(current, PIDTYPE_PID); |
| rcu_assign_pointer(vcpu->pid, newpid); |
| if (oldpid) |
| synchronize_rcu(); |
| put_pid(oldpid); |
| } |
| vcpu->wants_to_run = !READ_ONCE(vcpu->run->immediate_exit__unsafe); |
| r = kvm_arch_vcpu_ioctl_run(vcpu); |
| vcpu->wants_to_run = false; |
| |
| trace_kvm_userspace_exit(vcpu->run->exit_reason, r); |
| break; |
| } |
| case KVM_GET_REGS: { |
| struct kvm_regs *kvm_regs; |
| |
| r = -ENOMEM; |
| kvm_regs = kzalloc(sizeof(struct kvm_regs), GFP_KERNEL); |
| if (!kvm_regs) |
| goto out; |
| r = kvm_arch_vcpu_ioctl_get_regs(vcpu, kvm_regs); |
| if (r) |
| goto out_free1; |
| r = -EFAULT; |
| if (copy_to_user(argp, kvm_regs, sizeof(struct kvm_regs))) |
| goto out_free1; |
| r = 0; |
| out_free1: |
| kfree(kvm_regs); |
| break; |
| } |
| case KVM_SET_REGS: { |
| struct kvm_regs *kvm_regs; |
| |
| kvm_regs = memdup_user(argp, sizeof(*kvm_regs)); |
| if (IS_ERR(kvm_regs)) { |
| r = PTR_ERR(kvm_regs); |
| goto out; |
| } |
| r = kvm_arch_vcpu_ioctl_set_regs(vcpu, kvm_regs); |
| kfree(kvm_regs); |
| break; |
| } |
| case KVM_GET_SREGS: { |
| kvm_sregs = kzalloc(sizeof(struct kvm_sregs), GFP_KERNEL); |
| r = -ENOMEM; |
| if (!kvm_sregs) |
| goto out; |
| r = kvm_arch_vcpu_ioctl_get_sregs(vcpu, kvm_sregs); |
| if (r) |
| goto out; |
| r = -EFAULT; |
| if (copy_to_user(argp, kvm_sregs, sizeof(struct kvm_sregs))) |
| goto out; |
| r = 0; |
| break; |
| } |
| case KVM_SET_SREGS: { |
| kvm_sregs = memdup_user(argp, sizeof(*kvm_sregs)); |
| if (IS_ERR(kvm_sregs)) { |
| r = PTR_ERR(kvm_sregs); |
| kvm_sregs = NULL; |
| goto out; |
| } |
| r = kvm_arch_vcpu_ioctl_set_sregs(vcpu, kvm_sregs); |
| break; |
| } |
| case KVM_GET_MP_STATE: { |
| struct kvm_mp_state mp_state; |
| |
| r = kvm_arch_vcpu_ioctl_get_mpstate(vcpu, &mp_state); |
| if (r) |
| goto out; |
| r = -EFAULT; |
| if (copy_to_user(argp, &mp_state, sizeof(mp_state))) |
| goto out; |
| r = 0; |
| break; |
| } |
| case KVM_SET_MP_STATE: { |
| struct kvm_mp_state mp_state; |
| |
| r = -EFAULT; |
| if (copy_from_user(&mp_state, argp, sizeof(mp_state))) |
| goto out; |
| r = kvm_arch_vcpu_ioctl_set_mpstate(vcpu, &mp_state); |
| break; |
| } |
| case KVM_TRANSLATE: { |
| struct kvm_translation tr; |
| |
| r = -EFAULT; |
| if (copy_from_user(&tr, argp, sizeof(tr))) |
| goto out; |
| r = kvm_arch_vcpu_ioctl_translate(vcpu, &tr); |
| if (r) |
| goto out; |
| r = -EFAULT; |
| if (copy_to_user(argp, &tr, sizeof(tr))) |
| goto out; |
| r = 0; |
| break; |
| } |
| case KVM_SET_GUEST_DEBUG: { |
| struct kvm_guest_debug dbg; |
| |
| r = -EFAULT; |
| if (copy_from_user(&dbg, argp, sizeof(dbg))) |
| goto out; |
| r = kvm_arch_vcpu_ioctl_set_guest_debug(vcpu, &dbg); |
| break; |
| } |
| case KVM_SET_SIGNAL_MASK: { |
| struct kvm_signal_mask __user *sigmask_arg = argp; |
| struct kvm_signal_mask kvm_sigmask; |
| sigset_t sigset, *p; |
| |
| p = NULL; |
| if (argp) { |
| r = -EFAULT; |
| if (copy_from_user(&kvm_sigmask, argp, |
| sizeof(kvm_sigmask))) |
| goto out; |
| r = -EINVAL; |
| if (kvm_sigmask.len != sizeof(sigset)) |
| goto out; |
| r = -EFAULT; |
| if (copy_from_user(&sigset, sigmask_arg->sigset, |
| sizeof(sigset))) |
| goto out; |
| p = &sigset; |
| } |
| r = kvm_vcpu_ioctl_set_sigmask(vcpu, p); |
| break; |
| } |
| case KVM_GET_FPU: { |
| fpu = kzalloc(sizeof(struct kvm_fpu), GFP_KERNEL); |
| r = -ENOMEM; |
| if (!fpu) |
| goto out; |
| r = kvm_arch_vcpu_ioctl_get_fpu(vcpu, fpu); |
| if (r) |
| goto out; |
| r = -EFAULT; |
| if (copy_to_user(argp, fpu, sizeof(struct kvm_fpu))) |
| goto out; |
| r = 0; |
| break; |
| } |
| case KVM_SET_FPU: { |
| fpu = memdup_user(argp, sizeof(*fpu)); |
| if (IS_ERR(fpu)) { |
| r = PTR_ERR(fpu); |
| fpu = NULL; |
| goto out; |
| } |
| r = kvm_arch_vcpu_ioctl_set_fpu(vcpu, fpu); |
| break; |
| } |
| case KVM_GET_STATS_FD: { |
| r = kvm_vcpu_ioctl_get_stats_fd(vcpu); |
| break; |
| } |
| #ifdef CONFIG_KVM_GENERIC_PRE_FAULT_MEMORY |
| case KVM_PRE_FAULT_MEMORY: { |
| struct kvm_pre_fault_memory range; |
| |
| r = -EFAULT; |
| if (copy_from_user(&range, argp, sizeof(range))) |
| break; |
| r = kvm_vcpu_pre_fault_memory(vcpu, &range); |
| /* Pass back leftover range. */ |
| if (copy_to_user(argp, &range, sizeof(range))) |
| r = -EFAULT; |
| break; |
| } |
| #endif |
| default: |
| r = kvm_arch_vcpu_ioctl(filp, ioctl, arg); |
| } |
| out: |
| mutex_unlock(&vcpu->mutex); |
| kfree(fpu); |
| kfree(kvm_sregs); |
| return r; |
| } |
| |
| #ifdef CONFIG_KVM_COMPAT |
| static long kvm_vcpu_compat_ioctl(struct file *filp, |
| unsigned int ioctl, unsigned long arg) |
| { |
| struct kvm_vcpu *vcpu = filp->private_data; |
| void __user *argp = compat_ptr(arg); |
| int r; |
| |
| if (vcpu->kvm->mm != current->mm || vcpu->kvm->vm_dead) |
| return -EIO; |
| |
| switch (ioctl) { |
| case KVM_SET_SIGNAL_MASK: { |
| struct kvm_signal_mask __user *sigmask_arg = argp; |
| struct kvm_signal_mask kvm_sigmask; |
| sigset_t sigset; |
| |
| if (argp) { |
| r = -EFAULT; |
| if (copy_from_user(&kvm_sigmask, argp, |
| sizeof(kvm_sigmask))) |
| goto out; |
| r = -EINVAL; |
| if (kvm_sigmask.len != sizeof(compat_sigset_t)) |
| goto out; |
| r = -EFAULT; |
| if (get_compat_sigset(&sigset, |
| (compat_sigset_t __user *)sigmask_arg->sigset)) |
| goto out; |
| r = kvm_vcpu_ioctl_set_sigmask(vcpu, &sigset); |
| } else |
| r = kvm_vcpu_ioctl_set_sigmask(vcpu, NULL); |
| break; |
| } |
| default: |
| r = kvm_vcpu_ioctl(filp, ioctl, arg); |
| } |
| |
| out: |
| return r; |
| } |
| #endif |
| |
| static int kvm_device_mmap(struct file *filp, struct vm_area_struct *vma) |
| { |
| struct kvm_device *dev = filp->private_data; |
| |
| if (dev->ops->mmap) |
| return dev->ops->mmap(dev, vma); |
| |
| return -ENODEV; |
| } |
| |
| static int kvm_device_ioctl_attr(struct kvm_device *dev, |
| int (*accessor)(struct kvm_device *dev, |
| struct kvm_device_attr *attr), |
| unsigned long arg) |
| { |
| struct kvm_device_attr attr; |
| |
| if (!accessor) |
| return -EPERM; |
| |
| if (copy_from_user(&attr, (void __user *)arg, sizeof(attr))) |
| return -EFAULT; |
| |
| return accessor(dev, &attr); |
| } |
| |
| static long kvm_device_ioctl(struct file *filp, unsigned int ioctl, |
| unsigned long arg) |
| { |
| struct kvm_device *dev = filp->private_data; |
| |
| if (dev->kvm->mm != current->mm || dev->kvm->vm_dead) |
| return -EIO; |
| |
| switch (ioctl) { |
| case KVM_SET_DEVICE_ATTR: |
| return kvm_device_ioctl_attr(dev, dev->ops->set_attr, arg); |
| case KVM_GET_DEVICE_ATTR: |
| return kvm_device_ioctl_attr(dev, dev->ops->get_attr, arg); |
| case KVM_HAS_DEVICE_ATTR: |
| return kvm_device_ioctl_attr(dev, dev->ops->has_attr, arg); |
| default: |
| if (dev->ops->ioctl) |
| return dev->ops->ioctl(dev, ioctl, arg); |
| |
| return -ENOTTY; |
| } |
| } |
| |
| static int kvm_device_release(struct inode *inode, struct file *filp) |
| { |
| struct kvm_device *dev = filp->private_data; |
| struct kvm *kvm = dev->kvm; |
| |
| if (dev->ops->release) { |
| mutex_lock(&kvm->lock); |
| list_del_rcu(&dev->vm_node); |
| synchronize_rcu(); |
| dev->ops->release(dev); |
| mutex_unlock(&kvm->lock); |
| } |
| |
| kvm_put_kvm(kvm); |
| return 0; |
| } |
| |
| static struct file_operations kvm_device_fops = { |
| .unlocked_ioctl = kvm_device_ioctl, |
| .release = kvm_device_release, |
| KVM_COMPAT(kvm_device_ioctl), |
| .mmap = kvm_device_mmap, |
| }; |
| |
| struct kvm_device *kvm_device_from_filp(struct file *filp) |
| { |
| if (filp->f_op != &kvm_device_fops) |
| return NULL; |
| |
| return filp->private_data; |
| } |
| |
| static const struct kvm_device_ops *kvm_device_ops_table[KVM_DEV_TYPE_MAX] = { |
| #ifdef CONFIG_KVM_MPIC |
| [KVM_DEV_TYPE_FSL_MPIC_20] = &kvm_mpic_ops, |
| [KVM_DEV_TYPE_FSL_MPIC_42] = &kvm_mpic_ops, |
| #endif |
| }; |
| |
| int kvm_register_device_ops(const struct kvm_device_ops *ops, u32 type) |
| { |
| if (type >= ARRAY_SIZE(kvm_device_ops_table)) |
| return -ENOSPC; |
| |
| if (kvm_device_ops_table[type] != NULL) |
| return -EEXIST; |
| |
| kvm_device_ops_table[type] = ops; |
| return 0; |
| } |
| |
| void kvm_unregister_device_ops(u32 type) |
| { |
| if (kvm_device_ops_table[type] != NULL) |
| kvm_device_ops_table[type] = NULL; |
| } |
| |
| static int kvm_ioctl_create_device(struct kvm *kvm, |
| struct kvm_create_device *cd) |
| { |
| const struct kvm_device_ops *ops; |
| struct kvm_device *dev; |
| bool test = cd->flags & KVM_CREATE_DEVICE_TEST; |
| int type; |
| int ret; |
| |
| if (cd->type >= ARRAY_SIZE(kvm_device_ops_table)) |
| return -ENODEV; |
| |
| type = array_index_nospec(cd->type, ARRAY_SIZE(kvm_device_ops_table)); |
| ops = kvm_device_ops_table[type]; |
| if (ops == NULL) |
| return -ENODEV; |
| |
| if (test) |
| return 0; |
| |
| dev = kzalloc(sizeof(*dev), GFP_KERNEL_ACCOUNT); |
| if (!dev) |
| return -ENOMEM; |
| |
| dev->ops = ops; |
| dev->kvm = kvm; |
| |
| mutex_lock(&kvm->lock); |
| ret = ops->create(dev, type); |
| if (ret < 0) { |
| mutex_unlock(&kvm->lock); |
| kfree(dev); |
| return ret; |
| } |
| list_add_rcu(&dev->vm_node, &kvm->devices); |
| mutex_unlock(&kvm->lock); |
| |
| if (ops->init) |
| ops->init(dev); |
| |
| kvm_get_kvm(kvm); |
| ret = anon_inode_getfd(ops->name, &kvm_device_fops, dev, O_RDWR | O_CLOEXEC); |
| if (ret < 0) { |
| kvm_put_kvm_no_destroy(kvm); |
| mutex_lock(&kvm->lock); |
| list_del_rcu(&dev->vm_node); |
| synchronize_rcu(); |
| if (ops->release) |
| ops->release(dev); |
| mutex_unlock(&kvm->lock); |
| if (ops->destroy) |
| ops->destroy(dev); |
| return ret; |
| } |
| |
| cd->fd = ret; |
| return 0; |
| } |
| |
| static int kvm_vm_ioctl_check_extension_generic(struct kvm *kvm, long arg) |
| { |
| switch (arg) { |
| case KVM_CAP_USER_MEMORY: |
| case KVM_CAP_USER_MEMORY2: |
| case KVM_CAP_DESTROY_MEMORY_REGION_WORKS: |
| case KVM_CAP_JOIN_MEMORY_REGIONS_WORKS: |
| case KVM_CAP_INTERNAL_ERROR_DATA: |
| #ifdef CONFIG_HAVE_KVM_MSI |
| case KVM_CAP_SIGNAL_MSI: |
| #endif |
| #ifdef CONFIG_HAVE_KVM_IRQCHIP |
| case KVM_CAP_IRQFD: |
| #endif |
| case KVM_CAP_IOEVENTFD_ANY_LENGTH: |
| case KVM_CAP_CHECK_EXTENSION_VM: |
| case KVM_CAP_ENABLE_CAP_VM: |
| case KVM_CAP_HALT_POLL: |
| return 1; |
| #ifdef CONFIG_KVM_MMIO |
| case KVM_CAP_COALESCED_MMIO: |
| return KVM_COALESCED_MMIO_PAGE_OFFSET; |
| case KVM_CAP_COALESCED_PIO: |
| return 1; |
| #endif |
| #ifdef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT |
| case KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2: |
| return KVM_DIRTY_LOG_MANUAL_CAPS; |
| #endif |
| #ifdef CONFIG_HAVE_KVM_IRQ_ROUTING |
| case KVM_CAP_IRQ_ROUTING: |
| return KVM_MAX_IRQ_ROUTES; |
| #endif |
| #if KVM_MAX_NR_ADDRESS_SPACES > 1 |
| case KVM_CAP_MULTI_ADDRESS_SPACE: |
| if (kvm) |
| return kvm_arch_nr_memslot_as_ids(kvm); |
| return KVM_MAX_NR_ADDRESS_SPACES; |
| #endif |
| case KVM_CAP_NR_MEMSLOTS: |
| return KVM_USER_MEM_SLOTS; |
| case KVM_CAP_DIRTY_LOG_RING: |
| #ifdef CONFIG_HAVE_KVM_DIRTY_RING_TSO |
| return KVM_DIRTY_RING_MAX_ENTRIES * sizeof(struct kvm_dirty_gfn); |
| #else |
| return 0; |
| #endif |
| case KVM_CAP_DIRTY_LOG_RING_ACQ_REL: |
| #ifdef CONFIG_HAVE_KVM_DIRTY_RING_ACQ_REL |
| return KVM_DIRTY_RING_MAX_ENTRIES * sizeof(struct kvm_dirty_gfn); |
| #else |
| return 0; |
| #endif |
| #ifdef CONFIG_NEED_KVM_DIRTY_RING_WITH_BITMAP |
| case KVM_CAP_DIRTY_LOG_RING_WITH_BITMAP: |
| #endif |
| case KVM_CAP_BINARY_STATS_FD: |
| case KVM_CAP_SYSTEM_EVENT_DATA: |
| case KVM_CAP_DEVICE_CTRL: |
| return 1; |
| #ifdef CONFIG_KVM_GENERIC_MEMORY_ATTRIBUTES |
| case KVM_CAP_MEMORY_ATTRIBUTES: |
| return kvm_supported_mem_attributes(kvm); |
| #endif |
| #ifdef CONFIG_KVM_PRIVATE_MEM |
| case KVM_CAP_GUEST_MEMFD: |
| return !kvm || kvm_arch_has_private_mem(kvm); |
| #endif |
| default: |
| break; |
| } |
| return kvm_vm_ioctl_check_extension(kvm, arg); |
| } |
| |
| static int kvm_vm_ioctl_enable_dirty_log_ring(struct kvm *kvm, u32 size) |
| { |
| int r; |
| |
| if (!KVM_DIRTY_LOG_PAGE_OFFSET) |
| return -EINVAL; |
| |
| /* the size should be power of 2 */ |
| if (!size || (size & (size - 1))) |
| return -EINVAL; |
| |
| /* Should be bigger to keep the reserved entries, or a page */ |
| if (size < kvm_dirty_ring_get_rsvd_entries() * |
| sizeof(struct kvm_dirty_gfn) || size < PAGE_SIZE) |
| return -EINVAL; |
| |
| if (size > KVM_DIRTY_RING_MAX_ENTRIES * |
| sizeof(struct kvm_dirty_gfn)) |
| return -E2BIG; |
| |
| /* We only allow it to set once */ |
| if (kvm->dirty_ring_size) |
| return -EINVAL; |
| |
| mutex_lock(&kvm->lock); |
| |
| if (kvm->created_vcpus) { |
| /* We don't allow to change this value after vcpu created */ |
| r = -EINVAL; |
| } else { |
| kvm->dirty_ring_size = size; |
| r = 0; |
| } |
| |
| mutex_unlock(&kvm->lock); |
| return r; |
| } |
| |
| static int kvm_vm_ioctl_reset_dirty_pages(struct kvm *kvm) |
| { |
| unsigned long i; |
| struct kvm_vcpu *vcpu; |
| int cleared = 0; |
| |
| if (!kvm->dirty_ring_size) |
| return -EINVAL; |
| |
| mutex_lock(&kvm->slots_lock); |
| |
| kvm_for_each_vcpu(i, vcpu, kvm) |
| cleared += kvm_dirty_ring_reset(vcpu->kvm, &vcpu->dirty_ring); |
| |
| mutex_unlock(&kvm->slots_lock); |
| |
| if (cleared) |
| kvm_flush_remote_tlbs(kvm); |
| |
| return cleared; |
| } |
| |
| int __attribute__((weak)) kvm_vm_ioctl_enable_cap(struct kvm *kvm, |
| struct kvm_enable_cap *cap) |
| { |
| return -EINVAL; |
| } |
| |
| bool kvm_are_all_memslots_empty(struct kvm *kvm) |
| { |
| int i; |
| |
| lockdep_assert_held(&kvm->slots_lock); |
| |
| for (i = 0; i < kvm_arch_nr_memslot_as_ids(kvm); i++) { |
| if (!kvm_memslots_empty(__kvm_memslots(kvm, i))) |
| return false; |
| } |
| |
| return true; |
| } |
| EXPORT_SYMBOL_GPL(kvm_are_all_memslots_empty); |
| |
| static int kvm_vm_ioctl_enable_cap_generic(struct kvm *kvm, |
| struct kvm_enable_cap *cap) |
| { |
| switch (cap->cap) { |
| #ifdef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT |
| case KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2: { |
| u64 allowed_options = KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE; |
| |
| if (cap->args[0] & KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE) |
| allowed_options = KVM_DIRTY_LOG_MANUAL_CAPS; |
| |
| if (cap->flags || (cap->args[0] & ~allowed_options)) |
| return -EINVAL; |
| kvm->manual_dirty_log_protect = cap->args[0]; |
| return 0; |
| } |
| #endif |
| case KVM_CAP_HALT_POLL: { |
| if (cap->flags || cap->args[0] != (unsigned int)cap->args[0]) |
| return -EINVAL; |
| |
| kvm->max_halt_poll_ns = cap->args[0]; |
| |
| /* |
| * Ensure kvm->override_halt_poll_ns does not become visible |
| * before kvm->max_halt_poll_ns. |
| * |
| * Pairs with the smp_rmb() in kvm_vcpu_max_halt_poll_ns(). |
| */ |
| smp_wmb(); |
| kvm->override_halt_poll_ns = true; |
| |
| return 0; |
| } |
| case KVM_CAP_DIRTY_LOG_RING: |
| case KVM_CAP_DIRTY_LOG_RING_ACQ_REL: |
| if (!kvm_vm_ioctl_check_extension_generic(kvm, cap->cap)) |
| return -EINVAL; |
| |
| return kvm_vm_ioctl_enable_dirty_log_ring(kvm, cap->args[0]); |
| case KVM_CAP_DIRTY_LOG_RING_WITH_BITMAP: { |
| int r = -EINVAL; |
| |
| if (!IS_ENABLED(CONFIG_NEED_KVM_DIRTY_RING_WITH_BITMAP) || |
| !kvm->dirty_ring_size || cap->flags) |
| return r; |
| |
| mutex_lock(&kvm->slots_lock); |
| |
| /* |
| * For simplicity, allow enabling ring+bitmap if and only if |
| * there are no memslots, e.g. to ensure all memslots allocate |
| * a bitmap after the capability is enabled. |
| */ |
| if (kvm_are_all_memslots_empty(kvm)) { |
| kvm->dirty_ring_with_bitmap = true; |
| r = 0; |
| } |
| |
| mutex_unlock(&kvm->slots_lock); |
| |
| return r; |
| } |
| default: |
| return kvm_vm_ioctl_enable_cap(kvm, cap); |
| } |
| } |
| |
| static ssize_t kvm_vm_stats_read(struct file *file, char __user *user_buffer, |
| size_t size, loff_t *offset) |
| { |
| struct kvm *kvm = file->private_data; |
| |
| return kvm_stats_read(kvm->stats_id, &kvm_vm_stats_header, |
| &kvm_vm_stats_desc[0], &kvm->stat, |
| sizeof(kvm->stat), user_buffer, size, offset); |
| } |
| |
| static int kvm_vm_stats_release(struct inode *inode, struct file *file) |
| { |
| struct kvm *kvm = file->private_data; |
| |
| kvm_put_kvm(kvm); |
| return 0; |
| } |
| |
| static const struct file_operations kvm_vm_stats_fops = { |
| .owner = THIS_MODULE, |
| .read = kvm_vm_stats_read, |
| .release = kvm_vm_stats_release, |
| .llseek = noop_llseek, |
| }; |
| |
| static int kvm_vm_ioctl_get_stats_fd(struct kvm *kvm) |
| { |
| int fd; |
| struct file *file; |
| |
| fd = get_unused_fd_flags(O_CLOEXEC); |
| if (fd < 0) |
| return fd; |
| |
| file = anon_inode_getfile("kvm-vm-stats", |
| &kvm_vm_stats_fops, kvm, O_RDONLY); |
| if (IS_ERR(file)) { |
| put_unused_fd(fd); |
| return PTR_ERR(file); |
| } |
| |
| kvm_get_kvm(kvm); |
| |
| file->f_mode |= FMODE_PREAD; |
| fd_install(fd, file); |
| |
| return fd; |
| } |
| |
| #define SANITY_CHECK_MEM_REGION_FIELD(field) \ |
| do { \ |
| BUILD_BUG_ON(offsetof(struct kvm_userspace_memory_region, field) != \ |
| offsetof(struct kvm_userspace_memory_region2, field)); \ |
| BUILD_BUG_ON(sizeof_field(struct kvm_userspace_memory_region, field) != \ |
| sizeof_field(struct kvm_userspace_memory_region2, field)); \ |
| } while (0) |
| |
| static long kvm_vm_ioctl(struct file *filp, |
| unsigned int ioctl, unsigned long arg) |
| { |
| struct kvm *kvm = filp->private_data; |
| void __user *argp = (void __user *)arg; |
| int r; |
| |
| if (kvm->mm != current->mm || kvm->vm_dead) |
| return -EIO; |
| switch (ioctl) { |
| case KVM_CREATE_VCPU: |
| r = kvm_vm_ioctl_create_vcpu(kvm, arg); |
| break; |
| case KVM_ENABLE_CAP: { |
| struct kvm_enable_cap cap; |
| |
| r = -EFAULT; |
| if (copy_from_user(&cap, argp, sizeof(cap))) |
| goto out; |
| r = kvm_vm_ioctl_enable_cap_generic(kvm, &cap); |
| break; |
| } |
| case KVM_SET_USER_MEMORY_REGION2: |
| case KVM_SET_USER_MEMORY_REGION: { |
| struct kvm_userspace_memory_region2 mem; |
| unsigned long size; |
| |
| if (ioctl == KVM_SET_USER_MEMORY_REGION) { |
| /* |
| * Fields beyond struct kvm_userspace_memory_region shouldn't be |
| * accessed, but avoid leaking kernel memory in case of a bug. |
| */ |
| memset(&mem, 0, sizeof(mem)); |
| size = sizeof(struct kvm_userspace_memory_region); |
| } else { |
| size = sizeof(struct kvm_userspace_memory_region2); |
| } |
| |
| /* Ensure the common parts of the two structs are identical. */ |
| SANITY_CHECK_MEM_REGION_FIELD(slot); |
| SANITY_CHECK_MEM_REGION_FIELD(flags); |
| SANITY_CHECK_MEM_REGION_FIELD(guest_phys_addr); |
| SANITY_CHECK_MEM_REGION_FIELD(memory_size); |
| SANITY_CHECK_MEM_REGION_FIELD(userspace_addr); |
| |
| r = -EFAULT; |
| if (copy_from_user(&mem, argp, size)) |
| goto out; |
| |
| r = -EINVAL; |
| if (ioctl == KVM_SET_USER_MEMORY_REGION && |
| (mem.flags & ~KVM_SET_USER_MEMORY_REGION_V1_FLAGS)) |
| goto out; |
| |
| r = kvm_vm_ioctl_set_memory_region(kvm, &mem); |
| break; |
| } |
| case KVM_GET_DIRTY_LOG: { |
| struct kvm_dirty_log log; |
| |
| r = -EFAULT; |
| if (copy_from_user(&log, argp, sizeof(log))) |
| goto out; |
| r = kvm_vm_ioctl_get_dirty_log(kvm, &log); |
| break; |
| } |
| #ifdef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT |
| case KVM_CLEAR_DIRTY_LOG: { |
| struct kvm_clear_dirty_log log; |
| |
| r = -EFAULT; |
| if (copy_from_user(&log, argp, sizeof(log))) |
| goto out; |
| r = kvm_vm_ioctl_clear_dirty_log(kvm, &log); |
| break; |
| } |
| #endif |
| #ifdef CONFIG_KVM_MMIO |
| case KVM_REGISTER_COALESCED_MMIO: { |
| struct kvm_coalesced_mmio_zone zone; |
| |
| r = -EFAULT; |
| if (copy_from_user(&zone, argp, sizeof(zone))) |
| goto out; |
| r = kvm_vm_ioctl_register_coalesced_mmio(kvm, &zone); |
| break; |
| } |
| case KVM_UNREGISTER_COALESCED_MMIO: { |
| struct kvm_coalesced_mmio_zone zone; |
| |
| r = -EFAULT; |
| if (copy_from_user(&zone, argp, sizeof(zone))) |
| goto out; |
| r = kvm_vm_ioctl_unregister_coalesced_mmio(kvm, &zone); |
| break; |
| } |
| #endif |
| case KVM_IRQFD: { |
| struct kvm_irqfd data; |
| |
| r = -EFAULT; |
| if (copy_from_user(&data, argp, sizeof(data))) |
| goto out; |
| r = kvm_irqfd(kvm, &data); |
| break; |
| } |
| case KVM_IOEVENTFD: { |
| struct kvm_ioeventfd data; |
| |
| r = -EFAULT; |
| if (copy_from_user(&data, argp, sizeof(data))) |
| goto out; |
| r = kvm_ioeventfd(kvm, &data); |
| break; |
| } |
| #ifdef CONFIG_HAVE_KVM_MSI |
| case KVM_SIGNAL_MSI: { |
| struct kvm_msi msi; |
| |
| r = -EFAULT; |
| if (copy_from_user(&msi, argp, sizeof(msi))) |
| goto out; |
| r = kvm_send_userspace_msi(kvm, &msi); |
| break; |
| } |
| #endif |
| #ifdef __KVM_HAVE_IRQ_LINE |
| case KVM_IRQ_LINE_STATUS: |
| case KVM_IRQ_LINE: { |
| struct kvm_irq_level irq_event; |
| |
| r = -EFAULT; |
| if (copy_from_user(&irq_event, argp, sizeof(irq_event))) |
| goto out; |
| |
| r = kvm_vm_ioctl_irq_line(kvm, &irq_event, |
| ioctl == KVM_IRQ_LINE_STATUS); |
| if (r) |
| goto out; |
| |
| r = -EFAULT; |
| if (ioctl == KVM_IRQ_LINE_STATUS) { |
| if (copy_to_user(argp, &irq_event, sizeof(irq_event))) |
| goto out; |
| } |
| |
| r = 0; |
| break; |
| } |
| #endif |
| #ifdef CONFIG_HAVE_KVM_IRQ_ROUTING |
| case KVM_SET_GSI_ROUTING: { |
| struct kvm_irq_routing routing; |
| struct kvm_irq_routing __user *urouting; |
| struct kvm_irq_routing_entry *entries = NULL; |
| |
| r = -EFAULT; |
| if (copy_from_user(&routing, argp, sizeof(routing))) |
| goto out; |
| r = -EINVAL; |
| if (!kvm_arch_can_set_irq_routing(kvm)) |
| goto out; |
| if (routing.nr > KVM_MAX_IRQ_ROUTES) |
| goto out; |
| if (routing.flags) |
| goto out; |
| if (routing.nr) { |
| urouting = argp; |
| entries = vmemdup_array_user(urouting->entries, |
| routing.nr, sizeof(*entries)); |
| if (IS_ERR(entries)) { |
| r = PTR_ERR(entries); |
| goto out; |
| } |
| } |
| r = kvm_set_irq_routing(kvm, entries, routing.nr, |
| routing.flags); |
| kvfree(entries); |
| break; |
| } |
| #endif /* CONFIG_HAVE_KVM_IRQ_ROUTING */ |
| #ifdef CONFIG_KVM_GENERIC_MEMORY_ATTRIBUTES |
| case KVM_SET_MEMORY_ATTRIBUTES: { |
| struct kvm_memory_attributes attrs; |
| |
| r = -EFAULT; |
| if (copy_from_user(&attrs, argp, sizeof(attrs))) |
| goto out; |
| |
| r = kvm_vm_ioctl_set_mem_attributes(kvm, &attrs); |
| break; |
| } |
| #endif /* CONFIG_KVM_GENERIC_MEMORY_ATTRIBUTES */ |
| case KVM_CREATE_DEVICE: { |
| struct kvm_create_device cd; |
| |
| r = -EFAULT; |
| if (copy_from_user(&cd, argp, sizeof(cd))) |
| goto out; |
| |
| r = kvm_ioctl_create_device(kvm, &cd); |
| if (r) |
| goto out; |
| |
| r = -EFAULT; |
| if (copy_to_user(argp, &cd, sizeof(cd))) |
| goto out; |
| |
| r = 0; |
| break; |
| } |
| case KVM_CHECK_EXTENSION: |
| r = kvm_vm_ioctl_check_extension_generic(kvm, arg); |
| break; |
| case KVM_RESET_DIRTY_RINGS: |
| r = kvm_vm_ioctl_reset_dirty_pages(kvm); |
| break; |
| case KVM_GET_STATS_FD: |
| r = kvm_vm_ioctl_get_stats_fd(kvm); |
| break; |
| #ifdef CONFIG_KVM_PRIVATE_MEM |
| case KVM_CREATE_GUEST_MEMFD: { |
| struct kvm_create_guest_memfd guest_memfd; |
| |
| r = -EFAULT; |
| if (copy_from_user(&guest_memfd, argp, sizeof(guest_memfd))) |
| goto out; |
| |
| r = kvm_gmem_create(kvm, &guest_memfd); |
| break; |
| } |
| #endif |
| default: |
| r = kvm_arch_vm_ioctl(filp, ioctl, arg); |
| } |
| out: |
| return r; |
| } |
| |
| #ifdef CONFIG_KVM_COMPAT |
| struct compat_kvm_dirty_log { |
| __u32 slot; |
| __u32 padding1; |
| union { |
| compat_uptr_t dirty_bitmap; /* one bit per page */ |
| __u64 padding2; |
| }; |
| }; |
| |
| struct compat_kvm_clear_dirty_log { |
| __u32 slot; |
| __u32 num_pages; |
| __u64 first_page; |
| union { |
| compat_uptr_t dirty_bitmap; /* one bit per page */ |
| __u64 padding2; |
| }; |
| }; |
| |
| long __weak kvm_arch_vm_compat_ioctl(struct file *filp, unsigned int ioctl, |
| unsigned long arg) |
| { |
| return -ENOTTY; |
| } |
| |
| static long kvm_vm_compat_ioctl(struct file *filp, |
| unsigned int ioctl, unsigned long arg) |
| { |
| struct kvm *kvm = filp->private_data; |
| int r; |
| |
| if (kvm->mm != current->mm || kvm->vm_dead) |
| return -EIO; |
| |
| r = kvm_arch_vm_compat_ioctl(filp, ioctl, arg); |
| if (r != -ENOTTY) |
| return r; |
| |
| switch (ioctl) { |
| #ifdef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT |
| case KVM_CLEAR_DIRTY_LOG: { |
| struct compat_kvm_clear_dirty_log compat_log; |
| struct kvm_clear_dirty_log log; |
| |
| if (copy_from_user(&compat_log, (void __user *)arg, |
| sizeof(compat_log))) |
| return -EFAULT; |
| log.slot = compat_log.slot; |
| log.num_pages = compat_log.num_pages; |
| log.first_page = compat_log.first_page; |
| log.padding2 = compat_log.padding2; |
| log.dirty_bitmap = compat_ptr(compat_log.dirty_bitmap); |
| |
| r = kvm_vm_ioctl_clear_dirty_log(kvm, &log); |
| break; |
| } |
| #endif |
| case KVM_GET_DIRTY_LOG: { |
| struct compat_kvm_dirty_log compat_log; |
| struct kvm_dirty_log log; |
| |
| if (copy_from_user(&compat_log, (void __user *)arg, |
| sizeof(compat_log))) |
| return -EFAULT; |
| log.slot = compat_log.slot; |
| log.padding1 = compat_log.padding1; |
| log.padding2 = compat_log.padding2; |
| log.dirty_bitmap = compat_ptr(compat_log.dirty_bitmap); |
| |
| r = kvm_vm_ioctl_get_dirty_log(kvm, &log); |
| break; |
| } |
| default: |
| r = kvm_vm_ioctl(filp, ioctl, arg); |
| } |
| return r; |
| } |
| #endif |
| |
| static struct file_operations kvm_vm_fops = { |
| .release = kvm_vm_release, |
| .unlocked_ioctl = kvm_vm_ioctl, |
| .llseek = noop_llseek, |
| KVM_COMPAT(kvm_vm_compat_ioctl), |
| }; |
| |
| bool file_is_kvm(struct file *file) |
| { |
| return file && file->f_op == &kvm_vm_fops; |
| } |
| EXPORT_SYMBOL_GPL(file_is_kvm); |
| |
| static int kvm_dev_ioctl_create_vm(unsigned long type) |
| { |
| char fdname[ITOA_MAX_LEN + 1]; |
| int r, fd; |
| struct kvm *kvm; |
| struct file *file; |
| |
| fd = get_unused_fd_flags(O_CLOEXEC); |
| if (fd < 0) |
| return fd; |
| |
| snprintf(fdname, sizeof(fdname), "%d", fd); |
| |
| kvm = kvm_create_vm(type, fdname); |
| if (IS_ERR(kvm)) { |
| r = PTR_ERR(kvm); |
| goto put_fd; |
| } |
| |
| file = anon_inode_getfile("kvm-vm", &kvm_vm_fops, kvm, O_RDWR); |
| if (IS_ERR(file)) { |
| r = PTR_ERR(file); |
| goto put_kvm; |
| } |
| |
| /* |
| * Don't call kvm_put_kvm anymore at this point; file->f_op is |
| * already set, with ->release() being kvm_vm_release(). In error |
| * cases it will be called by the final fput(file) and will take |
| * care of doing kvm_put_kvm(kvm). |
| */ |
| kvm_uevent_notify_change(KVM_EVENT_CREATE_VM, kvm); |
| |
| fd_install(fd, file); |
| return fd; |
| |
| put_kvm: |
| kvm_put_kvm(kvm); |
| put_fd: |
| put_unused_fd(fd); |
| return r; |
| } |
| |
| static long kvm_dev_ioctl(struct file *filp, |
| unsigned int ioctl, unsigned long arg) |
| { |
| int r = -EINVAL; |
| |
| switch (ioctl) { |
| case KVM_GET_API_VERSION: |
| if (arg) |
| goto out; |
| r = KVM_API_VERSION; |
| break; |
| case KVM_CREATE_VM: |
| r = kvm_dev_ioctl_create_vm(arg); |
| break; |
| case KVM_CHECK_EXTENSION: |
| r = kvm_vm_ioctl_check_extension_generic(NULL, arg); |
| break; |
| case KVM_GET_VCPU_MMAP_SIZE: |
| if (arg) |
| goto out; |
| r = PAGE_SIZE; /* struct kvm_run */ |
| #ifdef CONFIG_X86 |
| r += PAGE_SIZE; /* pio data page */ |
| #endif |
| #ifdef CONFIG_KVM_MMIO |
| r += PAGE_SIZE; /* coalesced mmio ring page */ |
| #endif |
| break; |
| default: |
| return kvm_arch_dev_ioctl(filp, ioctl, arg); |
| } |
| out: |
| return r; |
| } |
| |
| static struct file_operations kvm_chardev_ops = { |
| .unlocked_ioctl = kvm_dev_ioctl, |
| .llseek = noop_llseek, |
| KVM_COMPAT(kvm_dev_ioctl), |
| }; |
| |
| static struct miscdevice kvm_dev = { |
| KVM_MINOR, |
| "kvm", |
| &kvm_chardev_ops, |
| }; |
| |
| #ifdef CONFIG_KVM_GENERIC_HARDWARE_ENABLING |
| __visible bool kvm_rebooting; |
| EXPORT_SYMBOL_GPL(kvm_rebooting); |
| |
| static DEFINE_PER_CPU(bool, hardware_enabled); |
| static int kvm_usage_count; |
| |
| static int __hardware_enable_nolock(void) |
| { |
| if (__this_cpu_read(hardware_enabled)) |
| return 0; |
| |
| if (kvm_arch_hardware_enable()) { |
| pr_info("kvm: enabling virtualization on CPU%d failed\n", |
| raw_smp_processor_id()); |
| return -EIO; |
| } |
| |
| __this_cpu_write(hardware_enabled, true); |
| return 0; |
| } |
| |
| static void hardware_enable_nolock(void *failed) |
| { |
| if (__hardware_enable_nolock()) |
| atomic_inc(failed); |
| } |
| |
| static int kvm_online_cpu(unsigned int cpu) |
| { |
| int ret = 0; |
| |
| /* |
| * Abort the CPU online process if hardware virtualization cannot |
| * be enabled. Otherwise running VMs would encounter unrecoverable |
| * errors when scheduled to this CPU. |
| */ |
| mutex_lock(&kvm_lock); |
| if (kvm_usage_count) |
| ret = __hardware_enable_nolock(); |
| mutex_unlock(&kvm_lock); |
| return ret; |
| } |
| |
| static void hardware_disable_nolock(void *junk) |
| { |
| /* |
| * Note, hardware_disable_all_nolock() tells all online CPUs to disable |
| * hardware, not just CPUs that successfully enabled hardware! |
| */ |
| if (!__this_cpu_read(hardware_enabled)) |
| return; |
| |
| kvm_arch_hardware_disable(); |
| |
| __this_cpu_write(hardware_enabled, false); |
| } |
| |
| static int kvm_offline_cpu(unsigned int cpu) |
| { |
| mutex_lock(&kvm_lock); |
| if (kvm_usage_count) |
| hardware_disable_nolock(NULL); |
| mutex_unlock(&kvm_lock); |
| return 0; |
| } |
| |
| static void hardware_disable_all_nolock(void) |
| { |
| BUG_ON(!kvm_usage_count); |
| |
| kvm_usage_count--; |
| if (!kvm_usage_count) |
| on_each_cpu(hardware_disable_nolock, NULL, 1); |
| } |
| |
| static void hardware_disable_all(void) |
| { |
| cpus_read_lock(); |
| mutex_lock(&kvm_lock); |
| hardware_disable_all_nolock(); |
| mutex_unlock(&kvm_lock); |
| cpus_read_unlock(); |
| } |
| |
| static int hardware_enable_all(void) |
| { |
| atomic_t failed = ATOMIC_INIT(0); |
| int r; |
| |
| /* |
| * Do not enable hardware virtualization if the system is going down. |
| * If userspace initiated a forced reboot, e.g. reboot -f, then it's |
| * possible for an in-flight KVM_CREATE_VM to trigger hardware enabling |
| * after kvm_reboot() is called. Note, this relies on system_state |
| * being set _before_ kvm_reboot(), which is why KVM uses a syscore ops |
| * hook instead of registering a dedicated reboot notifier (the latter |
| * runs before system_state is updated). |
| */ |
| if (system_state == SYSTEM_HALT || system_state == SYSTEM_POWER_OFF || |
| system_state == SYSTEM_RESTART) |
| return -EBUSY; |
| |
| /* |
| * When onlining a CPU, cpu_online_mask is set before kvm_online_cpu() |
| * is called, and so on_each_cpu() between them includes the CPU that |
| * is being onlined. As a result, hardware_enable_nolock() may get |
| * invoked before kvm_online_cpu(), which also enables hardware if the |
| * usage count is non-zero. Disable CPU hotplug to avoid attempting to |
| * enable hardware multiple times. |
| */ |
| cpus_read_lock(); |
| mutex_lock(&kvm_lock); |
| |
| r = 0; |
| |
| kvm_usage_count++; |
| if (kvm_usage_count == 1) { |
| on_each_cpu(hardware_enable_nolock, &failed, 1); |
| |
| if (atomic_read(&failed)) { |
| hardware_disable_all_nolock(); |
| r = -EBUSY; |
| } |
| } |
| |
| mutex_unlock(&kvm_lock); |
| cpus_read_unlock(); |
| |
| return r; |
| } |
| |
| static void kvm_shutdown(void) |
| { |
| /* |
| * Disable hardware virtualization and set kvm_rebooting to indicate |
| * that KVM has asynchronously disabled hardware virtualization, i.e. |
| * that relevant errors and exceptions aren't entirely unexpected. |
| * Some flavors of hardware virtualization need to be disabled before |
| * transferring control to firmware (to perform shutdown/reboot), e.g. |
| * on x86, virtualization can block INIT interrupts, which are used by |
| * firmware to pull APs back under firmware control. Note, this path |
| * is used for both shutdown and reboot scenarios, i.e. neither name is |
| * 100% comprehensive. |
| */ |
| pr_info("kvm: exiting hardware virtualization\n"); |
| kvm_rebooting = true; |
| on_each_cpu(hardware_disable_nolock, NULL, 1); |
| } |
| |
| static int kvm_suspend(void) |
| { |
| /* |
| * Secondary CPUs and CPU hotplug are disabled across the suspend/resume |
| * callbacks, i.e. no need to acquire kvm_lock to ensure the usage count |
| * is stable. Assert that kvm_lock is not held to ensure the system |
| * isn't suspended while KVM is enabling hardware. Hardware enabling |
| * can be preempted, but the task cannot be frozen until it has dropped |
| * all locks (userspace tasks are frozen via a fake signal). |
| */ |
| lockdep_assert_not_held(&kvm_lock); |
| lockdep_assert_irqs_disabled(); |
| |
| if (kvm_usage_count) |
| hardware_disable_nolock(NULL); |
| return 0; |
| } |
| |
| static void kvm_resume(void) |
| { |
| lockdep_assert_not_held(&kvm_lock); |
| lockdep_assert_irqs_disabled(); |
| |
| if (kvm_usage_count) |
| WARN_ON_ONCE(__hardware_enable_nolock()); |
| } |
| |
| static struct syscore_ops kvm_syscore_ops = { |
| .suspend = kvm_suspend, |
| .resume = kvm_resume, |
| .shutdown = kvm_shutdown, |
| }; |
| #else /* CONFIG_KVM_GENERIC_HARDWARE_ENABLING */ |
| static int hardware_enable_all(void) |
| { |
| return 0; |
| } |
| |
| static void hardware_disable_all(void) |
| { |
| |
| } |
| #endif /* CONFIG_KVM_GENERIC_HARDWARE_ENABLING */ |
| |
| static void kvm_iodevice_destructor(struct kvm_io_device *dev) |
| { |
| if (dev->ops->destructor) |
| dev->ops->destructor(dev); |
| } |
| |
| static void kvm_io_bus_destroy(struct kvm_io_bus *bus) |
| { |
| int i; |
| |
| for (i = 0; i < bus->dev_count; i++) { |
| struct kvm_io_device *pos = bus->range[i].dev; |
| |
| kvm_iodevice_destructor(pos); |
| } |
| kfree(bus); |
| } |
| |
| static inline int kvm_io_bus_cmp(const struct kvm_io_range *r1, |
| const struct kvm_io_range *r2) |
| { |
| gpa_t addr1 = r1->addr; |
| gpa_t addr2 = r2->addr; |
| |
| if (addr1 < addr2) |
| return -1; |
| |
| /* If r2->len == 0, match the exact address. If r2->len != 0, |
| * accept any overlapping write. Any order is acceptable for |
| * overlapping ranges, because kvm_io_bus_get_first_dev ensures |
| * we process all of them. |
| */ |
| if (r2->len) { |
| addr1 += r1->len; |
| addr2 += r2->len; |
| } |
| |
| if (addr1 > addr2) |
| return 1; |
| |
| return 0; |
| } |
| |
| static int kvm_io_bus_sort_cmp(const void *p1, const void *p2) |
| { |
| return kvm_io_bus_cmp(p1, p2); |
| } |
| |
| static int kvm_io_bus_get_first_dev(struct kvm_io_bus *bus, |
| gpa_t addr, int len) |
| { |
| struct kvm_io_range *range, key; |
| int off; |
| |
| key = (struct kvm_io_range) { |
| .addr = addr, |
| .len = len, |
| }; |
| |
| range = bsearch(&key, bus->range, bus->dev_count, |
| sizeof(struct kvm_io_range), kvm_io_bus_sort_cmp); |
| if (range == NULL) |
| return -ENOENT; |
| |
| off = range - bus->range; |
| |
| while (off > 0 && kvm_io_bus_cmp(&key, &bus->range[off-1]) == 0) |
| off--; |
| |
| return off; |
| } |
| |
| static int __kvm_io_bus_write(struct kvm_vcpu *vcpu, struct kvm_io_bus *bus, |
| struct kvm_io_range *range, const void *val) |
| { |
| int idx; |
| |
| idx = kvm_io_bus_get_first_dev(bus, range->addr, range->len); |
| if (idx < 0) |
| return -EOPNOTSUPP; |
| |
| while (idx < bus->dev_count && |
| kvm_io_bus_cmp(range, &bus->range[idx]) == 0) { |
| if (!kvm_iodevice_write(vcpu, bus->range[idx].dev, range->addr, |
| range->len, val)) |
| return idx; |
| idx++; |
| } |
| |
| return -EOPNOTSUPP; |
| } |
| |
| /* kvm_io_bus_write - called under kvm->slots_lock */ |
| int kvm_io_bus_write(struct kvm_vcpu *vcpu, enum kvm_bus bus_idx, gpa_t addr, |
| int len, const void *val) |
| { |
| struct kvm_io_bus *bus; |
| struct kvm_io_range range; |
| int r; |
| |
| range = (struct kvm_io_range) { |
| .addr = addr, |
| .len = len, |
| }; |
| |
| bus = srcu_dereference(vcpu->kvm->buses[bus_idx], &vcpu->kvm->srcu); |
| if (!bus) |
| return -ENOMEM; |
| r = __kvm_io_bus_write(vcpu, bus, &range, val); |
| return r < 0 ? r : 0; |
| } |
| EXPORT_SYMBOL_GPL(kvm_io_bus_write); |
| |
| /* kvm_io_bus_write_cookie - called under kvm->slots_lock */ |
| int kvm_io_bus_write_cookie(struct kvm_vcpu *vcpu, enum kvm_bus bus_idx, |
| gpa_t addr, int len, const void *val, long cookie) |
| { |
| struct kvm_io_bus *bus; |
| struct kvm_io_range range; |
| |
| range = (struct kvm_io_range) { |
| .addr = addr, |
| .len = len, |
| }; |
| |
| bus = srcu_dereference(vcpu->kvm->buses[bus_idx], &vcpu->kvm->srcu); |
| if (!bus) |
| return -ENOMEM; |
| |
| /* First try the device referenced by cookie. */ |
| if ((cookie >= 0) && (cookie < bus->dev_count) && |
| (kvm_io_bus_cmp(&range, &bus->range[cookie]) == 0)) |
| if (!kvm_iodevice_write(vcpu, bus->range[cookie].dev, addr, len, |
| val)) |
| return cookie; |
| |
| /* |
| * cookie contained garbage; fall back to search and return the |
| * correct cookie value. |
| */ |
| return __kvm_io_bus_write(vcpu, bus, &range, val); |
| } |
| |
| static int __kvm_io_bus_read(struct kvm_vcpu *vcpu, struct kvm_io_bus *bus, |
| struct kvm_io_range *range, void *val) |
| { |
| int idx; |
| |
| idx = kvm_io_bus_get_first_dev(bus, range->addr, range->len); |
| if (idx < 0) |
| return -EOPNOTSUPP; |
| |
| while (idx < bus->dev_count && |
| kvm_io_bus_cmp(range, &bus->range[idx]) == 0) { |
| if (!kvm_iodevice_read(vcpu, bus->range[idx].dev, range->addr, |
| range->len, val)) |
| return idx; |
| idx++; |
| } |
| |
| return -EOPNOTSUPP; |
| } |
| |
| /* kvm_io_bus_read - called under kvm->slots_lock */ |
| int kvm_io_bus_read(struct kvm_vcpu *vcpu, enum kvm_bus bus_idx, gpa_t addr, |
| int len, void *val) |
| { |
| struct kvm_io_bus *bus; |
| struct kvm_io_range range; |
| int r; |
| |
| range = (struct kvm_io_range) { |
| .addr = addr, |
| .len = len, |
| }; |
| |
| bus = srcu_dereference(vcpu->kvm->buses[bus_idx], &vcpu->kvm->srcu); |
| if (!bus) |
| return -ENOMEM; |
| r = __kvm_io_bus_read(vcpu, bus, &range, val); |
| return r < 0 ? r : 0; |
| } |
| |
| int kvm_io_bus_register_dev(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr, |
| int len, struct kvm_io_device *dev) |
| { |
| int i; |
| struct kvm_io_bus *new_bus, *bus; |
| struct kvm_io_range range; |
| |
| lockdep_assert_held(&kvm->slots_lock); |
| |
| bus = kvm_get_bus(kvm, bus_idx); |
| if (!bus) |
| return -ENOMEM; |
| |
| /* exclude ioeventfd which is limited by maximum fd */ |
| if (bus->dev_count - bus->ioeventfd_count > NR_IOBUS_DEVS - 1) |
| return -ENOSPC; |
| |
| new_bus = kmalloc(struct_size(bus, range, bus->dev_count + 1), |
| GFP_KERNEL_ACCOUNT); |
| if (!new_bus) |
| return -ENOMEM; |
| |
| range = (struct kvm_io_range) { |
| .addr = addr, |
| .len = len, |
| .dev = dev, |
| }; |
| |
| for (i = 0; i < bus->dev_count; i++) |
| if (kvm_io_bus_cmp(&bus->range[i], &range) > 0) |
| break; |
| |
| memcpy(new_bus, bus, sizeof(*bus) + i * sizeof(struct kvm_io_range)); |
| new_bus->dev_count++; |
| new_bus->range[i] = range; |
| memcpy(new_bus->range + i + 1, bus->range + i, |
| (bus->dev_count - i) * sizeof(struct kvm_io_range)); |
| rcu_assign_pointer(kvm->buses[bus_idx], new_bus); |
| synchronize_srcu_expedited(&kvm->srcu); |
| kfree(bus); |
| |
| return 0; |
| } |
| |
| int kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx, |
| struct kvm_io_device *dev) |
| { |
| int i; |
| struct kvm_io_bus *new_bus, *bus; |
| |
| lockdep_assert_held(&kvm->slots_lock); |
| |
| bus = kvm_get_bus(kvm, bus_idx); |
| if (!bus) |
| return 0; |
| |
| for (i = 0; i < bus->dev_count; i++) { |
| if (bus->range[i].dev == dev) { |
| break; |
| } |
| } |
| |
| if (i == bus->dev_count) |
| return 0; |
| |
| new_bus = kmalloc(struct_size(bus, range, bus->dev_count - 1), |
| GFP_KERNEL_ACCOUNT); |
| if (new_bus) { |
| memcpy(new_bus, bus, struct_size(bus, range, i)); |
| new_bus->dev_count--; |
| memcpy(new_bus->range + i, bus->range + i + 1, |
| flex_array_size(new_bus, range, new_bus->dev_count - i)); |
| } |
| |
| rcu_assign_pointer(kvm->buses[bus_idx], new_bus); |
| synchronize_srcu_expedited(&kvm->srcu); |
| |
| /* |
| * If NULL bus is installed, destroy the old bus, including all the |
| * attached devices. Otherwise, destroy the caller's device only. |
| */ |
| if (!new_bus) { |
| pr_err("kvm: failed to shrink bus, removing it completely\n"); |
| kvm_io_bus_destroy(bus); |
| return -ENOMEM; |
| } |
| |
| kvm_iodevice_destructor(dev); |
| kfree(bus); |
| return 0; |
| } |
| |
| struct kvm_io_device *kvm_io_bus_get_dev(struct kvm *kvm, enum kvm_bus bus_idx, |
| gpa_t addr) |
| { |
| struct kvm_io_bus *bus; |
| int dev_idx, srcu_idx; |
| struct kvm_io_device *iodev = NULL; |
| |
| srcu_idx = srcu_read_lock(&kvm->srcu); |
| |
| bus = srcu_dereference(kvm->buses[bus_idx], &kvm->srcu); |
| if (!bus) |
| goto out_unlock; |
| |
| dev_idx = kvm_io_bus_get_first_dev(bus, addr, 1); |
| if (dev_idx < 0) |
| goto out_unlock; |
| |
| iodev = bus->range[dev_idx].dev; |
| |
| out_unlock: |
| srcu_read_unlock(&kvm->srcu, srcu_idx); |
| |
| return iodev; |
| } |
| EXPORT_SYMBOL_GPL(kvm_io_bus_get_dev); |
| |
| static int kvm_debugfs_open(struct inode *inode, struct file *file, |
| int (*get)(void *, u64 *), int (*set)(void *, u64), |
| const char *fmt) |
| { |
| int ret; |
| struct kvm_stat_data *stat_data = inode->i_private; |
| |
| /* |
| * The debugfs files are a reference to the kvm struct which |
| * is still valid when kvm_destroy_vm is called. kvm_get_kvm_safe |
| * avoids the race between open and the removal of the debugfs directory. |
| */ |
| if (!kvm_get_kvm_safe(stat_data->kvm)) |
| return -ENOENT; |
| |
| ret = simple_attr_open(inode, file, get, |
| kvm_stats_debugfs_mode(stat_data->desc) & 0222 |
| ? set : NULL, fmt); |
| if (ret) |
| kvm_put_kvm(stat_data->kvm); |
| |
| return ret; |
| } |
| |
| static int kvm_debugfs_release(struct inode *inode, struct file *file) |
| { |
| struct kvm_stat_data *stat_data = inode->i_private; |
| |
| simple_attr_release(inode, file); |
| kvm_put_kvm(stat_data->kvm); |
| |
| return 0; |
| } |
| |
| static int kvm_get_stat_per_vm(struct kvm *kvm, size_t offset, u64 *val) |
| { |
| *val = *(u64 *)((void *)(&kvm->stat) + offset); |
| |
| return 0; |
| } |
| |
| static int kvm_clear_stat_per_vm(struct kvm *kvm, size_t offset) |
| { |
| *(u64 *)((void *)(&kvm->stat) + offset) = 0; |
| |
| return 0; |
| } |
| |
| static int kvm_get_stat_per_vcpu(struct kvm *kvm, size_t offset, u64 *val) |
| { |
| unsigned long i; |
| struct kvm_vcpu *vcpu; |
| |
| *val = 0; |
| |
| kvm_for_each_vcpu(i, vcpu, kvm) |
| *val += *(u64 *)((void *)(&vcpu->stat) + offset); |
| |
| return 0; |
| } |
| |
| static int kvm_clear_stat_per_vcpu(struct kvm *kvm, size_t offset) |
| { |
| unsigned long i; |
| struct kvm_vcpu *vcpu; |
| |
| kvm_for_each_vcpu(i, vcpu, kvm) |
| *(u64 *)((void *)(&vcpu->stat) + offset) = 0; |
| |
| return 0; |
| } |
| |
| static int kvm_stat_data_get(void *data, u64 *val) |
| { |
| int r = -EFAULT; |
| struct kvm_stat_data *stat_data = data; |
| |
| switch (stat_data->kind) { |
| case KVM_STAT_VM: |
| r = kvm_get_stat_per_vm(stat_data->kvm, |
| stat_data->desc->desc.offset, val); |
| break; |
| case KVM_STAT_VCPU: |
| r = kvm_get_stat_per_vcpu(stat_data->kvm, |
| stat_data->desc->desc.offset, val); |
| break; |
| } |
| |
| return r; |
| } |
| |
| static int kvm_stat_data_clear(void *data, u64 val) |
| { |
| int r = -EFAULT; |
| struct kvm_stat_data *stat_data = data; |
| |
| if (val) |
| return -EINVAL; |
| |
| switch (stat_data->kind) { |
| case KVM_STAT_VM: |
| r = kvm_clear_stat_per_vm(stat_data->kvm, |
| stat_data->desc->desc.offset); |
| break; |
| case KVM_STAT_VCPU: |
| r = kvm_clear_stat_per_vcpu(stat_data->kvm, |
| stat_data->desc->desc.offset); |
| break; |
| } |
| |
| return r; |
| } |
| |
| static int kvm_stat_data_open(struct inode *inode, struct file *file) |
| { |
| __simple_attr_check_format("%llu\n", 0ull); |
| return kvm_debugfs_open(inode, file, kvm_stat_data_get, |
| kvm_stat_data_clear, "%llu\n"); |
| } |
| |
| static const struct file_operations stat_fops_per_vm = { |
| .owner = THIS_MODULE, |
| .open = kvm_stat_data_open, |
| .release = kvm_debugfs_release, |
| .read = simple_attr_read, |
| .write = simple_attr_write, |
| .llseek = no_llseek, |
| }; |
| |
| static int vm_stat_get(void *_offset, u64 *val) |
| { |
| unsigned offset = (long)_offset; |
| struct kvm *kvm; |
| u64 tmp_val; |
| |
| *val = 0; |
| mutex_lock(&kvm_lock); |
| list_for_each_entry(kvm, &vm_list, vm_list) { |
| kvm_get_stat_per_vm(kvm, offset, &tmp_val); |
| *val += tmp_val; |
| } |
| mutex_unlock(&kvm_lock); |
| return 0; |
| } |
| |
| static int vm_stat_clear(void *_offset, u64 val) |
| { |
| unsigned offset = (long)_offset; |
| struct kvm *kvm; |
| |
| if (val) |
| return -EINVAL; |
| |
| mutex_lock(&kvm_lock); |
| list_for_each_entry(kvm, &vm_list, vm_list) { |
| kvm_clear_stat_per_vm(kvm, offset); |
| } |
| mutex_unlock(&kvm_lock); |
| |
| return 0; |
| } |
| |
| DEFINE_SIMPLE_ATTRIBUTE(vm_stat_fops, vm_stat_get, vm_stat_clear, "%llu\n"); |
| DEFINE_SIMPLE_ATTRIBUTE(vm_stat_readonly_fops, vm_stat_get, NULL, "%llu\n"); |
| |
| static int vcpu_stat_get(void *_offset, u64 *val) |
| { |
| unsigned offset = (long)_offset; |
| struct kvm *kvm; |
| u64 tmp_val; |
| |
| *val = 0; |
| mutex_lock(&kvm_lock); |
| list_for_each_entry(kvm, &vm_list, vm_list) { |
| kvm_get_stat_per_vcpu(kvm, offset, &tmp_val); |
| *val += tmp_val; |
| } |
| mutex_unlock(&kvm_lock); |
| return 0; |
| } |
| |
| static int vcpu_stat_clear(void *_offset, u64 val) |
| { |
| unsigned offset = (long)_offset; |
| struct kvm *kvm; |
| |
| if (val) |
| return -EINVAL; |
| |
| mutex_lock(&kvm_lock); |
| list_for_each_entry(kvm, &vm_list, vm_list) { |
| kvm_clear_stat_per_vcpu(kvm, offset); |
| } |
| mutex_unlock(&kvm_lock); |
| |
| return 0; |
| } |
| |
| DEFINE_SIMPLE_ATTRIBUTE(vcpu_stat_fops, vcpu_stat_get, vcpu_stat_clear, |
| "%llu\n"); |
| DEFINE_SIMPLE_ATTRIBUTE(vcpu_stat_readonly_fops, vcpu_stat_get, NULL, "%llu\n"); |
| |
| static void kvm_uevent_notify_change(unsigned int type, struct kvm *kvm) |
| { |
| struct kobj_uevent_env *env; |
| unsigned long long created, active; |
| |
| if (!kvm_dev.this_device || !kvm) |
| return; |
| |
| mutex_lock(&kvm_lock); |
| if (type == KVM_EVENT_CREATE_VM) { |
| kvm_createvm_count++; |
| kvm_active_vms++; |
| } else if (type == KVM_EVENT_DESTROY_VM) { |
| kvm_active_vms--; |
| } |
| created = kvm_createvm_count; |
| active = kvm_active_vms; |
| mutex_unlock(&kvm_lock); |
| |
| env = kzalloc(sizeof(*env), GFP_KERNEL); |
| if (!env) |
| return; |
| |
| add_uevent_var(env, "CREATED=%llu", created); |
| add_uevent_var(env, "COUNT=%llu", active); |
| |
| if (type == KVM_EVENT_CREATE_VM) { |
| add_uevent_var(env, "EVENT=create"); |
| kvm->userspace_pid = task_pid_nr(current); |
| } else if (type == KVM_EVENT_DESTROY_VM) { |
| add_uevent_var(env, "EVENT=destroy"); |
| } |
| add_uevent_var(env, "PID=%d", kvm->userspace_pid); |
| |
| if (!IS_ERR(kvm->debugfs_dentry)) { |
| char *tmp, *p = kmalloc(PATH_MAX, GFP_KERNEL); |
| |
| if (p) { |
| tmp = dentry_path_raw(kvm->debugfs_dentry, p, PATH_MAX); |
| if (!IS_ERR(tmp)) |
| add_uevent_var(env, "STATS_PATH=%s", tmp); |
| kfree(p); |
| } |
| } |
| /* no need for checks, since we are adding at most only 5 keys */ |
| env->envp[env->envp_idx++] = NULL; |
| kobject_uevent_env(&kvm_dev.this_device->kobj, KOBJ_CHANGE, env->envp); |
| kfree(env); |
| } |
| |
| static void kvm_init_debug(void) |
| { |
| const struct file_operations *fops; |
| const struct _kvm_stats_desc *pdesc; |
| int i; |
| |
| kvm_debugfs_dir = debugfs_create_dir("kvm", NULL); |
| |
| for (i = 0; i < kvm_vm_stats_header.num_desc; ++i) { |
| pdesc = &kvm_vm_stats_desc[i]; |
| if (kvm_stats_debugfs_mode(pdesc) & 0222) |
| fops = &vm_stat_fops; |
| else |
| fops = &vm_stat_readonly_fops; |
| debugfs_create_file(pdesc->name, kvm_stats_debugfs_mode(pdesc), |
| kvm_debugfs_dir, |
| (void *)(long)pdesc->desc.offset, fops); |
| } |
| |
| for (i = 0; i < kvm_vcpu_stats_header.num_desc; ++i) { |
| pdesc = &kvm_vcpu_stats_desc[i]; |
| if (kvm_stats_debugfs_mode(pdesc) & 0222) |
| fops = &vcpu_stat_fops; |
| else |
| fops = &vcpu_stat_readonly_fops; |
| debugfs_create_file(pdesc->name, kvm_stats_debugfs_mode(pdesc), |
| kvm_debugfs_dir, |
| (void *)(long)pdesc->desc.offset, fops); |
| } |
| } |
| |
| static inline |
| struct kvm_vcpu *preempt_notifier_to_vcpu(struct preempt_notifier *pn) |
| { |
| return container_of(pn, struct kvm_vcpu, preempt_notifier); |
| } |
| |
| static void kvm_sched_in(struct preempt_notifier *pn, int cpu) |
| { |
| struct kvm_vcpu *vcpu = preempt_notifier_to_vcpu(pn); |
| |
| WRITE_ONCE(vcpu->preempted, false); |
| WRITE_ONCE(vcpu->ready, false); |
| |
| __this_cpu_write(kvm_running_vcpu, vcpu); |
| kvm_arch_vcpu_load(vcpu, cpu); |
| |
| WRITE_ONCE(vcpu->scheduled_out, false); |
| } |
| |
| static void kvm_sched_out(struct preempt_notifier *pn, |
| struct task_struct *next) |
| { |
| struct kvm_vcpu *vcpu = preempt_notifier_to_vcpu(pn); |
| |
| WRITE_ONCE(vcpu->scheduled_out, true); |
| |
| if (current->on_rq && vcpu->wants_to_run) { |
| WRITE_ONCE(vcpu->preempted, true); |
| WRITE_ONCE(vcpu->ready, true); |
| } |
| kvm_arch_vcpu_put(vcpu); |
| __this_cpu_write(kvm_running_vcpu, NULL); |
| } |
| |
| /** |
| * kvm_get_running_vcpu - get the vcpu running on the current CPU. |
| * |
| * We can disable preemption locally around accessing the per-CPU variable, |
| * and use the resolved vcpu pointer after enabling preemption again, |
| * because even if the current thread is migrated to another CPU, reading |
| * the per-CPU value later will give us the same value as we update the |
| * per-CPU variable in the preempt notifier handlers. |
| */ |
| struct kvm_vcpu *kvm_get_running_vcpu(void) |
| { |
| struct kvm_vcpu *vcpu; |
| |
| preempt_disable(); |
| vcpu = __this_cpu_read(kvm_running_vcpu); |
| preempt_enable(); |
| |
| return vcpu; |
| } |
| EXPORT_SYMBOL_GPL(kvm_get_running_vcpu); |
| |
| /** |
| * kvm_get_running_vcpus - get the per-CPU array of currently running vcpus. |
| */ |
| struct kvm_vcpu * __percpu *kvm_get_running_vcpus(void) |
| { |
| return &kvm_running_vcpu; |
| } |
| |
| #ifdef CONFIG_GUEST_PERF_EVENTS |
| static unsigned int kvm_guest_state(void) |
| { |
| struct kvm_vcpu *vcpu = kvm_get_running_vcpu(); |
| unsigned int state; |
| |
| if (!kvm_arch_pmi_in_guest(vcpu)) |
| return 0; |
| |
| state = PERF_GUEST_ACTIVE; |
| if (!kvm_arch_vcpu_in_kernel(vcpu)) |
| state |= PERF_GUEST_USER; |
| |
| return state; |
| } |
| |
| static unsigned long kvm_guest_get_ip(void) |
| { |
| struct kvm_vcpu *vcpu = kvm_get_running_vcpu(); |
| |
| /* Retrieving the IP must be guarded by a call to kvm_guest_state(). */ |
| if (WARN_ON_ONCE(!kvm_arch_pmi_in_guest(vcpu))) |
| return 0; |
| |
| return kvm_arch_vcpu_get_ip(vcpu); |
| } |
| |
| static struct perf_guest_info_callbacks kvm_guest_cbs = { |
| .state = kvm_guest_state, |
| .get_ip = kvm_guest_get_ip, |
| .handle_intel_pt_intr = NULL, |
| }; |
| |
| void kvm_register_perf_callbacks(unsigned int (*pt_intr_handler)(void)) |
| { |
| kvm_guest_cbs.handle_intel_pt_intr = pt_intr_handler; |
| perf_register_guest_info_callbacks(&kvm_guest_cbs); |
| } |
| void kvm_unregister_perf_callbacks(void) |
| { |
| perf_unregister_guest_info_callbacks(&kvm_guest_cbs); |
| } |
| #endif |
| |
| int kvm_init(unsigned vcpu_size, unsigned vcpu_align, struct module *module) |
| { |
| int r; |
| int cpu; |
| |
| #ifdef CONFIG_KVM_GENERIC_HARDWARE_ENABLING |
| r = cpuhp_setup_state_nocalls(CPUHP_AP_KVM_ONLINE, "kvm/cpu:online", |
| kvm_online_cpu, kvm_offline_cpu); |
| if (r) |
| return r; |
| |
| register_syscore_ops(&kvm_syscore_ops); |
| #endif |
| |
| /* A kmem cache lets us meet the alignment requirements of fx_save. */ |
| if (!vcpu_align) |
| vcpu_align = __alignof__(struct kvm_vcpu); |
| kvm_vcpu_cache = |
| kmem_cache_create_usercopy("kvm_vcpu", vcpu_size, vcpu_align, |
| SLAB_ACCOUNT, |
| offsetof(struct kvm_vcpu, arch), |
| offsetofend(struct kvm_vcpu, stats_id) |
| - offsetof(struct kvm_vcpu, arch), |
| NULL); |
| if (!kvm_vcpu_cache) { |
| r = -ENOMEM; |
| goto err_vcpu_cache; |
| } |
| |
| for_each_possible_cpu(cpu) { |
| if (!alloc_cpumask_var_node(&per_cpu(cpu_kick_mask, cpu), |
| GFP_KERNEL, cpu_to_node(cpu))) { |
| r = -ENOMEM; |
| goto err_cpu_kick_mask; |
| } |
| } |
| |
| r = kvm_irqfd_init(); |
| if (r) |
| goto err_irqfd; |
| |
| r = kvm_async_pf_init(); |
| if (r) |
| goto err_async_pf; |
| |
| kvm_chardev_ops.owner = module; |
| kvm_vm_fops.owner = module; |
| kvm_vcpu_fops.owner = module; |
| kvm_device_fops.owner = module; |
| |
| kvm_preempt_ops.sched_in = kvm_sched_in; |
| kvm_preempt_ops.sched_out = kvm_sched_out; |
| |
| kvm_init_debug(); |
| |
| r = kvm_vfio_ops_init(); |
| if (WARN_ON_ONCE(r)) |
| goto err_vfio; |
| |
| kvm_gmem_init(module); |
| |
| /* |
| * Registration _must_ be the very last thing done, as this exposes |
| * /dev/kvm to userspace, i.e. all infrastructure must be setup! |
| */ |
| r = misc_register(&kvm_dev); |
| if (r) { |
| pr_err("kvm: misc device register failed\n"); |
| goto err_register; |
| } |
| |
| return 0; |
| |
| err_register: |
| kvm_vfio_ops_exit(); |
| err_vfio: |
| kvm_async_pf_deinit(); |
| err_async_pf: |
| kvm_irqfd_exit(); |
| err_irqfd: |
| err_cpu_kick_mask: |
| for_each_possible_cpu(cpu) |
| free_cpumask_var(per_cpu(cpu_kick_mask, cpu)); |
| kmem_cache_destroy(kvm_vcpu_cache); |
| err_vcpu_cache: |
| #ifdef CONFIG_KVM_GENERIC_HARDWARE_ENABLING |
| unregister_syscore_ops(&kvm_syscore_ops); |
| cpuhp_remove_state_nocalls(CPUHP_AP_KVM_ONLINE); |
| #endif |
| return r; |
| } |
| EXPORT_SYMBOL_GPL(kvm_init); |
| |
| void kvm_exit(void) |
| { |
| int cpu; |
| |
| /* |
| * Note, unregistering /dev/kvm doesn't strictly need to come first, |
| * fops_get(), a.k.a. try_module_get(), prevents acquiring references |
| * to KVM while the module is being stopped. |
| */ |
| misc_deregister(&kvm_dev); |
| |
| debugfs_remove_recursive(kvm_debugfs_dir); |
| for_each_possible_cpu(cpu) |
| free_cpumask_var(per_cpu(cpu_kick_mask, cpu)); |
| kmem_cache_destroy(kvm_vcpu_cache); |
| kvm_vfio_ops_exit(); |
| kvm_async_pf_deinit(); |
| #ifdef CONFIG_KVM_GENERIC_HARDWARE_ENABLING |
| unregister_syscore_ops(&kvm_syscore_ops); |
| cpuhp_remove_state_nocalls(CPUHP_AP_KVM_ONLINE); |
| #endif |
| kvm_irqfd_exit(); |
| } |
| EXPORT_SYMBOL_GPL(kvm_exit); |
| |
| struct kvm_vm_worker_thread_context { |
| struct kvm *kvm; |
| struct task_struct *parent; |
| struct completion init_done; |
| kvm_vm_thread_fn_t thread_fn; |
| uintptr_t data; |
| int err; |
| }; |
| |
| static int kvm_vm_worker_thread(void *context) |
| { |
| /* |
| * The init_context is allocated on the stack of the parent thread, so |
| * we have to locally copy anything that is needed beyond initialization |
| */ |
| struct kvm_vm_worker_thread_context *init_context = context; |
| struct task_struct *parent; |
| struct kvm *kvm = init_context->kvm; |
| kvm_vm_thread_fn_t thread_fn = init_context->thread_fn; |
| uintptr_t data = init_context->data; |
| int err; |
| |
| err = kthread_park(current); |
| /* kthread_park(current) is never supposed to return an error */ |
| WARN_ON(err != 0); |
| if (err) |
| goto init_complete; |
| |
| err = cgroup_attach_task_all(init_context->parent, current); |
| if (err) { |
| kvm_err("%s: cgroup_attach_task_all failed with err %d\n", |
| __func__, err); |
| goto init_complete; |
| } |
| |
| set_user_nice(current, task_nice(init_context->parent)); |
| |
| init_complete: |
| init_context->err = err; |
| complete(&init_context->init_done); |
| init_context = NULL; |
| |
| if (err) |
| goto out; |
| |
| /* Wait to be woken up by the spawner before proceeding. */ |
| kthread_parkme(); |
| |
| if (!kthread_should_stop()) |
| err = thread_fn(kvm, data); |
| |
| out: |
| /* |
| * Move kthread back to its original cgroup to prevent it lingering in |
| * the cgroup of the VM process, after the latter finishes its |
| * execution. |
| * |
| * kthread_stop() waits on the 'exited' completion condition which is |
| * set in exit_mm(), via mm_release(), in do_exit(). However, the |
| * kthread is removed from the cgroup in the cgroup_exit() which is |
| * called after the exit_mm(). This causes the kthread_stop() to return |
| * before the kthread actually quits the cgroup. |
| */ |
| rcu_read_lock(); |
| parent = rcu_dereference(current->real_parent); |
| get_task_struct(parent); |
| rcu_read_unlock(); |
| cgroup_attach_task_all(parent, current); |
| put_task_struct(parent); |
| |
| return err; |
| } |
| |
| int kvm_vm_create_worker_thread(struct kvm *kvm, kvm_vm_thread_fn_t thread_fn, |
| uintptr_t data, const char *name, |
| struct task_struct **thread_ptr) |
| { |
| struct kvm_vm_worker_thread_context init_context = {}; |
| struct task_struct *thread; |
| |
| *thread_ptr = NULL; |
| init_context.kvm = kvm; |
| init_context.parent = current; |
| init_context.thread_fn = thread_fn; |
| init_context.data = data; |
| init_completion(&init_context.init_done); |
| |
| thread = kthread_run(kvm_vm_worker_thread, &init_context, |
| "%s-%d", name, task_pid_nr(current)); |
| if (IS_ERR(thread)) |
| return PTR_ERR(thread); |
| |
| /* kthread_run is never supposed to return NULL */ |
| WARN_ON(thread == NULL); |
| |
| wait_for_completion(&init_context.init_done); |
| |
| if (!init_context.err) |
| *thread_ptr = thread; |
| |
| return init_context.err; |
| } |