| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * Copyright (C) 2012 - Virtual Open Systems and Columbia University |
| * Author: Christoffer Dall <c.dall@virtualopensystems.com> |
| */ |
| |
| #include <linux/mman.h> |
| #include <linux/kvm_host.h> |
| #include <linux/io.h> |
| #include <linux/hugetlb.h> |
| #include <linux/sched/signal.h> |
| #include <trace/events/kvm.h> |
| #include <asm/pgalloc.h> |
| #include <asm/cacheflush.h> |
| #include <asm/kvm_arm.h> |
| #include <asm/kvm_mmu.h> |
| #include <asm/kvm_pgtable.h> |
| #include <asm/kvm_ras.h> |
| #include <asm/kvm_asm.h> |
| #include <asm/kvm_emulate.h> |
| #include <asm/virt.h> |
| |
| #include "trace.h" |
| |
| static struct kvm_pgtable *hyp_pgtable; |
| static DEFINE_MUTEX(kvm_hyp_pgd_mutex); |
| |
| static unsigned long hyp_idmap_start; |
| static unsigned long hyp_idmap_end; |
| static phys_addr_t hyp_idmap_vector; |
| |
| static unsigned long io_map_base; |
| |
| |
| /* |
| * Release kvm_mmu_lock periodically if the memory region is large. Otherwise, |
| * we may see kernel panics with CONFIG_DETECT_HUNG_TASK, |
| * CONFIG_LOCKUP_DETECTOR, CONFIG_LOCKDEP. Additionally, holding the lock too |
| * long will also starve other vCPUs. We have to also make sure that the page |
| * tables are not freed while we released the lock. |
| */ |
| static int stage2_apply_range(struct kvm *kvm, phys_addr_t addr, |
| phys_addr_t end, |
| int (*fn)(struct kvm_pgtable *, u64, u64), |
| bool resched) |
| { |
| int ret; |
| u64 next; |
| |
| do { |
| struct kvm_pgtable *pgt = kvm->arch.mmu.pgt; |
| if (!pgt) |
| return -EINVAL; |
| |
| next = stage2_pgd_addr_end(kvm, addr, end); |
| ret = fn(pgt, addr, next - addr); |
| if (ret) |
| break; |
| |
| if (resched && next != end) |
| cond_resched_lock(&kvm->mmu_lock); |
| } while (addr = next, addr != end); |
| |
| return ret; |
| } |
| |
| #define stage2_apply_range_resched(kvm, addr, end, fn) \ |
| stage2_apply_range(kvm, addr, end, fn, true) |
| |
| static bool memslot_is_logging(struct kvm_memory_slot *memslot) |
| { |
| return memslot->dirty_bitmap && !(memslot->flags & KVM_MEM_READONLY); |
| } |
| |
| /** |
| * kvm_flush_remote_tlbs() - flush all VM TLB entries for v7/8 |
| * @kvm: pointer to kvm structure. |
| * |
| * Interface to HYP function to flush all VM TLB entries |
| */ |
| void kvm_flush_remote_tlbs(struct kvm *kvm) |
| { |
| kvm_call_hyp(__kvm_tlb_flush_vmid, &kvm->arch.mmu); |
| } |
| |
| static bool kvm_is_device_pfn(unsigned long pfn) |
| { |
| return !pfn_is_map_memory(pfn); |
| } |
| |
| static void *stage2_memcache_zalloc_page(void *arg) |
| { |
| struct kvm_mmu_memory_cache *mc = arg; |
| |
| /* Allocated with __GFP_ZERO, so no need to zero */ |
| return kvm_mmu_memory_cache_alloc(mc); |
| } |
| |
| static void *kvm_host_zalloc_pages_exact(size_t size) |
| { |
| return alloc_pages_exact(size, GFP_KERNEL_ACCOUNT | __GFP_ZERO); |
| } |
| |
| static void kvm_host_get_page(void *addr) |
| { |
| get_page(virt_to_page(addr)); |
| } |
| |
| static void kvm_host_put_page(void *addr) |
| { |
| put_page(virt_to_page(addr)); |
| } |
| |
| static int kvm_host_page_count(void *addr) |
| { |
| return page_count(virt_to_page(addr)); |
| } |
| |
| static phys_addr_t kvm_host_pa(void *addr) |
| { |
| return __pa(addr); |
| } |
| |
| static void *kvm_host_va(phys_addr_t phys) |
| { |
| return __va(phys); |
| } |
| |
| static void clean_dcache_guest_page(void *va, size_t size) |
| { |
| __clean_dcache_guest_page(va, size); |
| } |
| |
| static void invalidate_icache_guest_page(void *va, size_t size) |
| { |
| __invalidate_icache_guest_page(va, size); |
| } |
| |
| /* |
| * Unmapping vs dcache management: |
| * |
| * If a guest maps certain memory pages as uncached, all writes will |
| * bypass the data cache and go directly to RAM. However, the CPUs |
| * can still speculate reads (not writes) and fill cache lines with |
| * data. |
| * |
| * Those cache lines will be *clean* cache lines though, so a |
| * clean+invalidate operation is equivalent to an invalidate |
| * operation, because no cache lines are marked dirty. |
| * |
| * Those clean cache lines could be filled prior to an uncached write |
| * by the guest, and the cache coherent IO subsystem would therefore |
| * end up writing old data to disk. |
| * |
| * This is why right after unmapping a page/section and invalidating |
| * the corresponding TLBs, we flush to make sure the IO subsystem will |
| * never hit in the cache. |
| * |
| * This is all avoided on systems that have ARM64_HAS_STAGE2_FWB, as |
| * we then fully enforce cacheability of RAM, no matter what the guest |
| * does. |
| */ |
| /** |
| * unmap_stage2_range -- Clear stage2 page table entries to unmap a range |
| * @mmu: The KVM stage-2 MMU pointer |
| * @start: The intermediate physical base address of the range to unmap |
| * @size: The size of the area to unmap |
| * @may_block: Whether or not we are permitted to block |
| * |
| * Clear a range of stage-2 mappings, lowering the various ref-counts. Must |
| * be called while holding mmu_lock (unless for freeing the stage2 pgd before |
| * destroying the VM), otherwise another faulting VCPU may come in and mess |
| * with things behind our backs. |
| */ |
| static void __unmap_stage2_range(struct kvm_s2_mmu *mmu, phys_addr_t start, u64 size, |
| bool may_block) |
| { |
| struct kvm *kvm = kvm_s2_mmu_to_kvm(mmu); |
| phys_addr_t end = start + size; |
| |
| assert_spin_locked(&kvm->mmu_lock); |
| WARN_ON(size & ~PAGE_MASK); |
| WARN_ON(stage2_apply_range(kvm, start, end, kvm_pgtable_stage2_unmap, |
| may_block)); |
| } |
| |
| static void unmap_stage2_range(struct kvm_s2_mmu *mmu, phys_addr_t start, u64 size) |
| { |
| __unmap_stage2_range(mmu, start, size, true); |
| } |
| |
| static void stage2_flush_memslot(struct kvm *kvm, |
| struct kvm_memory_slot *memslot) |
| { |
| phys_addr_t addr = memslot->base_gfn << PAGE_SHIFT; |
| phys_addr_t end = addr + PAGE_SIZE * memslot->npages; |
| |
| stage2_apply_range_resched(kvm, addr, end, kvm_pgtable_stage2_flush); |
| } |
| |
| /** |
| * stage2_flush_vm - Invalidate cache for pages mapped in stage 2 |
| * @kvm: The struct kvm pointer |
| * |
| * Go through the stage 2 page tables and invalidate any cache lines |
| * backing memory already mapped to the VM. |
| */ |
| static void stage2_flush_vm(struct kvm *kvm) |
| { |
| struct kvm_memslots *slots; |
| struct kvm_memory_slot *memslot; |
| int idx; |
| |
| idx = srcu_read_lock(&kvm->srcu); |
| spin_lock(&kvm->mmu_lock); |
| |
| slots = kvm_memslots(kvm); |
| kvm_for_each_memslot(memslot, slots) |
| stage2_flush_memslot(kvm, memslot); |
| |
| spin_unlock(&kvm->mmu_lock); |
| srcu_read_unlock(&kvm->srcu, idx); |
| } |
| |
| /** |
| * free_hyp_pgds - free Hyp-mode page tables |
| */ |
| void free_hyp_pgds(void) |
| { |
| mutex_lock(&kvm_hyp_pgd_mutex); |
| if (hyp_pgtable) { |
| kvm_pgtable_hyp_destroy(hyp_pgtable); |
| kfree(hyp_pgtable); |
| hyp_pgtable = NULL; |
| } |
| mutex_unlock(&kvm_hyp_pgd_mutex); |
| } |
| |
| static bool kvm_host_owns_hyp_mappings(void) |
| { |
| if (static_branch_likely(&kvm_protected_mode_initialized)) |
| return false; |
| |
| /* |
| * This can happen at boot time when __create_hyp_mappings() is called |
| * after the hyp protection has been enabled, but the static key has |
| * not been flipped yet. |
| */ |
| if (!hyp_pgtable && is_protected_kvm_enabled()) |
| return false; |
| |
| WARN_ON(!hyp_pgtable); |
| |
| return true; |
| } |
| |
| static int __create_hyp_mappings(unsigned long start, unsigned long size, |
| unsigned long phys, enum kvm_pgtable_prot prot) |
| { |
| int err; |
| |
| if (!kvm_host_owns_hyp_mappings()) { |
| return kvm_call_hyp_nvhe(__pkvm_create_mappings, |
| start, size, phys, prot); |
| } |
| |
| mutex_lock(&kvm_hyp_pgd_mutex); |
| err = kvm_pgtable_hyp_map(hyp_pgtable, start, size, phys, prot); |
| mutex_unlock(&kvm_hyp_pgd_mutex); |
| |
| return err; |
| } |
| |
| static phys_addr_t kvm_kaddr_to_phys(void *kaddr) |
| { |
| if (!is_vmalloc_addr(kaddr)) { |
| BUG_ON(!virt_addr_valid(kaddr)); |
| return __pa(kaddr); |
| } else { |
| return page_to_phys(vmalloc_to_page(kaddr)) + |
| offset_in_page(kaddr); |
| } |
| } |
| |
| /** |
| * create_hyp_mappings - duplicate a kernel virtual address range in Hyp mode |
| * @from: The virtual kernel start address of the range |
| * @to: The virtual kernel end address of the range (exclusive) |
| * @prot: The protection to be applied to this range |
| * |
| * The same virtual address as the kernel virtual address is also used |
| * in Hyp-mode mapping (modulo HYP_PAGE_OFFSET) to the same underlying |
| * physical pages. |
| */ |
| int create_hyp_mappings(void *from, void *to, enum kvm_pgtable_prot prot) |
| { |
| phys_addr_t phys_addr; |
| unsigned long virt_addr; |
| unsigned long start = kern_hyp_va((unsigned long)from); |
| unsigned long end = kern_hyp_va((unsigned long)to); |
| |
| if (is_kernel_in_hyp_mode()) |
| return 0; |
| |
| start = start & PAGE_MASK; |
| end = PAGE_ALIGN(end); |
| |
| for (virt_addr = start; virt_addr < end; virt_addr += PAGE_SIZE) { |
| int err; |
| |
| phys_addr = kvm_kaddr_to_phys(from + virt_addr - start); |
| err = __create_hyp_mappings(virt_addr, PAGE_SIZE, phys_addr, |
| prot); |
| if (err) |
| return err; |
| } |
| |
| return 0; |
| } |
| |
| static int __create_hyp_private_mapping(phys_addr_t phys_addr, size_t size, |
| unsigned long *haddr, |
| enum kvm_pgtable_prot prot) |
| { |
| unsigned long base; |
| int ret = 0; |
| |
| if (!kvm_host_owns_hyp_mappings()) { |
| base = kvm_call_hyp_nvhe(__pkvm_create_private_mapping, |
| phys_addr, size, prot); |
| if (IS_ERR_OR_NULL((void *)base)) |
| return PTR_ERR((void *)base); |
| *haddr = base; |
| |
| return 0; |
| } |
| |
| mutex_lock(&kvm_hyp_pgd_mutex); |
| |
| /* |
| * This assumes that we have enough space below the idmap |
| * page to allocate our VAs. If not, the check below will |
| * kick. A potential alternative would be to detect that |
| * overflow and switch to an allocation above the idmap. |
| * |
| * The allocated size is always a multiple of PAGE_SIZE. |
| */ |
| size = PAGE_ALIGN(size + offset_in_page(phys_addr)); |
| base = io_map_base - size; |
| |
| /* |
| * Verify that BIT(VA_BITS - 1) hasn't been flipped by |
| * allocating the new area, as it would indicate we've |
| * overflowed the idmap/IO address range. |
| */ |
| if ((base ^ io_map_base) & BIT(VA_BITS - 1)) |
| ret = -ENOMEM; |
| else |
| io_map_base = base; |
| |
| mutex_unlock(&kvm_hyp_pgd_mutex); |
| |
| if (ret) |
| goto out; |
| |
| ret = __create_hyp_mappings(base, size, phys_addr, prot); |
| if (ret) |
| goto out; |
| |
| *haddr = base + offset_in_page(phys_addr); |
| out: |
| return ret; |
| } |
| |
| /** |
| * create_hyp_io_mappings - Map IO into both kernel and HYP |
| * @phys_addr: The physical start address which gets mapped |
| * @size: Size of the region being mapped |
| * @kaddr: Kernel VA for this mapping |
| * @haddr: HYP VA for this mapping |
| */ |
| int create_hyp_io_mappings(phys_addr_t phys_addr, size_t size, |
| void __iomem **kaddr, |
| void __iomem **haddr) |
| { |
| unsigned long addr; |
| int ret; |
| |
| *kaddr = ioremap(phys_addr, size); |
| if (!*kaddr) |
| return -ENOMEM; |
| |
| if (is_kernel_in_hyp_mode()) { |
| *haddr = *kaddr; |
| return 0; |
| } |
| |
| ret = __create_hyp_private_mapping(phys_addr, size, |
| &addr, PAGE_HYP_DEVICE); |
| if (ret) { |
| iounmap(*kaddr); |
| *kaddr = NULL; |
| *haddr = NULL; |
| return ret; |
| } |
| |
| *haddr = (void __iomem *)addr; |
| return 0; |
| } |
| |
| /** |
| * create_hyp_exec_mappings - Map an executable range into HYP |
| * @phys_addr: The physical start address which gets mapped |
| * @size: Size of the region being mapped |
| * @haddr: HYP VA for this mapping |
| */ |
| int create_hyp_exec_mappings(phys_addr_t phys_addr, size_t size, |
| void **haddr) |
| { |
| unsigned long addr; |
| int ret; |
| |
| BUG_ON(is_kernel_in_hyp_mode()); |
| |
| ret = __create_hyp_private_mapping(phys_addr, size, |
| &addr, PAGE_HYP_EXEC); |
| if (ret) { |
| *haddr = NULL; |
| return ret; |
| } |
| |
| *haddr = (void *)addr; |
| return 0; |
| } |
| |
| static struct kvm_pgtable_mm_ops kvm_s2_mm_ops = { |
| .zalloc_page = stage2_memcache_zalloc_page, |
| .zalloc_pages_exact = kvm_host_zalloc_pages_exact, |
| .free_pages_exact = free_pages_exact, |
| .get_page = kvm_host_get_page, |
| .put_page = kvm_host_put_page, |
| .page_count = kvm_host_page_count, |
| .phys_to_virt = kvm_host_va, |
| .virt_to_phys = kvm_host_pa, |
| .dcache_clean_inval_poc = clean_dcache_guest_page, |
| .icache_inval_pou = invalidate_icache_guest_page, |
| }; |
| |
| /** |
| * kvm_init_stage2_mmu - Initialise a S2 MMU strucrure |
| * @kvm: The pointer to the KVM structure |
| * @mmu: The pointer to the s2 MMU structure |
| * |
| * Allocates only the stage-2 HW PGD level table(s). |
| * Note we don't need locking here as this is only called when the VM is |
| * created, which can only be done once. |
| */ |
| int kvm_init_stage2_mmu(struct kvm *kvm, struct kvm_s2_mmu *mmu) |
| { |
| int cpu, err; |
| struct kvm_pgtable *pgt; |
| |
| if (mmu->pgt != NULL) { |
| kvm_err("kvm_arch already initialized?\n"); |
| return -EINVAL; |
| } |
| |
| pgt = kzalloc(sizeof(*pgt), GFP_KERNEL); |
| if (!pgt) |
| return -ENOMEM; |
| |
| err = kvm_pgtable_stage2_init(pgt, &kvm->arch, &kvm_s2_mm_ops); |
| if (err) |
| goto out_free_pgtable; |
| |
| mmu->last_vcpu_ran = alloc_percpu(typeof(*mmu->last_vcpu_ran)); |
| if (!mmu->last_vcpu_ran) { |
| err = -ENOMEM; |
| goto out_destroy_pgtable; |
| } |
| |
| for_each_possible_cpu(cpu) |
| *per_cpu_ptr(mmu->last_vcpu_ran, cpu) = -1; |
| |
| mmu->arch = &kvm->arch; |
| mmu->pgt = pgt; |
| mmu->pgd_phys = __pa(pgt->pgd); |
| mmu->vmid.vmid_gen = 0; |
| return 0; |
| |
| out_destroy_pgtable: |
| kvm_pgtable_stage2_destroy(pgt); |
| out_free_pgtable: |
| kfree(pgt); |
| return err; |
| } |
| |
| static void stage2_unmap_memslot(struct kvm *kvm, |
| struct kvm_memory_slot *memslot) |
| { |
| hva_t hva = memslot->userspace_addr; |
| phys_addr_t addr = memslot->base_gfn << PAGE_SHIFT; |
| phys_addr_t size = PAGE_SIZE * memslot->npages; |
| hva_t reg_end = hva + size; |
| |
| /* |
| * A memory region could potentially cover multiple VMAs, and any holes |
| * between them, so iterate over all of them to find out if we should |
| * unmap any of them. |
| * |
| * +--------------------------------------------+ |
| * +---------------+----------------+ +----------------+ |
| * | : VMA 1 | VMA 2 | | VMA 3 : | |
| * +---------------+----------------+ +----------------+ |
| * | memory region | |
| * +--------------------------------------------+ |
| */ |
| do { |
| struct vm_area_struct *vma; |
| hva_t vm_start, vm_end; |
| |
| vma = find_vma_intersection(current->mm, hva, reg_end); |
| if (!vma) |
| break; |
| |
| /* |
| * Take the intersection of this VMA with the memory region |
| */ |
| vm_start = max(hva, vma->vm_start); |
| vm_end = min(reg_end, vma->vm_end); |
| |
| if (!(vma->vm_flags & VM_PFNMAP)) { |
| gpa_t gpa = addr + (vm_start - memslot->userspace_addr); |
| unmap_stage2_range(&kvm->arch.mmu, gpa, vm_end - vm_start); |
| } |
| hva = vm_end; |
| } while (hva < reg_end); |
| } |
| |
| /** |
| * stage2_unmap_vm - Unmap Stage-2 RAM mappings |
| * @kvm: The struct kvm pointer |
| * |
| * Go through the memregions and unmap any regular RAM |
| * backing memory already mapped to the VM. |
| */ |
| void stage2_unmap_vm(struct kvm *kvm) |
| { |
| struct kvm_memslots *slots; |
| struct kvm_memory_slot *memslot; |
| int idx; |
| |
| idx = srcu_read_lock(&kvm->srcu); |
| mmap_read_lock(current->mm); |
| spin_lock(&kvm->mmu_lock); |
| |
| slots = kvm_memslots(kvm); |
| kvm_for_each_memslot(memslot, slots) |
| stage2_unmap_memslot(kvm, memslot); |
| |
| spin_unlock(&kvm->mmu_lock); |
| mmap_read_unlock(current->mm); |
| srcu_read_unlock(&kvm->srcu, idx); |
| } |
| |
| void kvm_free_stage2_pgd(struct kvm_s2_mmu *mmu) |
| { |
| struct kvm *kvm = kvm_s2_mmu_to_kvm(mmu); |
| struct kvm_pgtable *pgt = NULL; |
| |
| spin_lock(&kvm->mmu_lock); |
| pgt = mmu->pgt; |
| if (pgt) { |
| mmu->pgd_phys = 0; |
| mmu->pgt = NULL; |
| free_percpu(mmu->last_vcpu_ran); |
| } |
| spin_unlock(&kvm->mmu_lock); |
| |
| if (pgt) { |
| kvm_pgtable_stage2_destroy(pgt); |
| kfree(pgt); |
| } |
| } |
| |
| /** |
| * kvm_phys_addr_ioremap - map a device range to guest IPA |
| * |
| * @kvm: The KVM pointer |
| * @guest_ipa: The IPA at which to insert the mapping |
| * @pa: The physical address of the device |
| * @size: The size of the mapping |
| * @writable: Whether or not to create a writable mapping |
| */ |
| int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa, |
| phys_addr_t pa, unsigned long size, bool writable) |
| { |
| phys_addr_t addr; |
| int ret = 0; |
| struct kvm_mmu_memory_cache cache = { 0, __GFP_ZERO, NULL, }; |
| struct kvm_pgtable *pgt = kvm->arch.mmu.pgt; |
| enum kvm_pgtable_prot prot = KVM_PGTABLE_PROT_DEVICE | |
| KVM_PGTABLE_PROT_R | |
| (writable ? KVM_PGTABLE_PROT_W : 0); |
| |
| size += offset_in_page(guest_ipa); |
| guest_ipa &= PAGE_MASK; |
| |
| for (addr = guest_ipa; addr < guest_ipa + size; addr += PAGE_SIZE) { |
| ret = kvm_mmu_topup_memory_cache(&cache, |
| kvm_mmu_cache_min_pages(kvm)); |
| if (ret) |
| break; |
| |
| spin_lock(&kvm->mmu_lock); |
| ret = kvm_pgtable_stage2_map(pgt, addr, PAGE_SIZE, pa, prot, |
| &cache); |
| spin_unlock(&kvm->mmu_lock); |
| if (ret) |
| break; |
| |
| pa += PAGE_SIZE; |
| } |
| |
| kvm_mmu_free_memory_cache(&cache); |
| return ret; |
| } |
| |
| /** |
| * stage2_wp_range() - write protect stage2 memory region range |
| * @mmu: The KVM stage-2 MMU pointer |
| * @addr: Start address of range |
| * @end: End address of range |
| */ |
| static void stage2_wp_range(struct kvm_s2_mmu *mmu, phys_addr_t addr, phys_addr_t end) |
| { |
| struct kvm *kvm = kvm_s2_mmu_to_kvm(mmu); |
| stage2_apply_range_resched(kvm, addr, end, kvm_pgtable_stage2_wrprotect); |
| } |
| |
| /** |
| * kvm_mmu_wp_memory_region() - write protect stage 2 entries for memory slot |
| * @kvm: The KVM pointer |
| * @slot: The memory slot to write protect |
| * |
| * Called to start logging dirty pages after memory region |
| * KVM_MEM_LOG_DIRTY_PAGES operation is called. After this function returns |
| * all present PUD, PMD and PTEs are write protected in the memory region. |
| * Afterwards read of dirty page log can be called. |
| * |
| * Acquires kvm_mmu_lock. Called with kvm->slots_lock mutex acquired, |
| * serializing operations for VM memory regions. |
| */ |
| static void kvm_mmu_wp_memory_region(struct kvm *kvm, int slot) |
| { |
| struct kvm_memslots *slots = kvm_memslots(kvm); |
| struct kvm_memory_slot *memslot = id_to_memslot(slots, slot); |
| phys_addr_t start, end; |
| |
| if (WARN_ON_ONCE(!memslot)) |
| return; |
| |
| start = memslot->base_gfn << PAGE_SHIFT; |
| end = (memslot->base_gfn + memslot->npages) << PAGE_SHIFT; |
| |
| spin_lock(&kvm->mmu_lock); |
| stage2_wp_range(&kvm->arch.mmu, start, end); |
| spin_unlock(&kvm->mmu_lock); |
| kvm_flush_remote_tlbs(kvm); |
| } |
| |
| /** |
| * kvm_mmu_write_protect_pt_masked() - write protect dirty pages |
| * @kvm: The KVM pointer |
| * @slot: The memory slot associated with mask |
| * @gfn_offset: The gfn offset in memory slot |
| * @mask: The mask of dirty pages at offset 'gfn_offset' in this memory |
| * slot to be write protected |
| * |
| * Walks bits set in mask write protects the associated pte's. Caller must |
| * acquire kvm_mmu_lock. |
| */ |
| static void kvm_mmu_write_protect_pt_masked(struct kvm *kvm, |
| struct kvm_memory_slot *slot, |
| gfn_t gfn_offset, unsigned long mask) |
| { |
| phys_addr_t base_gfn = slot->base_gfn + gfn_offset; |
| phys_addr_t start = (base_gfn + __ffs(mask)) << PAGE_SHIFT; |
| phys_addr_t end = (base_gfn + __fls(mask) + 1) << PAGE_SHIFT; |
| |
| stage2_wp_range(&kvm->arch.mmu, start, end); |
| } |
| |
| /* |
| * kvm_arch_mmu_enable_log_dirty_pt_masked - enable dirty logging for selected |
| * dirty pages. |
| * |
| * It calls kvm_mmu_write_protect_pt_masked to write protect selected pages to |
| * enable dirty logging for them. |
| */ |
| void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm, |
| struct kvm_memory_slot *slot, |
| gfn_t gfn_offset, unsigned long mask) |
| { |
| kvm_mmu_write_protect_pt_masked(kvm, slot, gfn_offset, mask); |
| } |
| |
| static void kvm_send_hwpoison_signal(unsigned long address, short lsb) |
| { |
| send_sig_mceerr(BUS_MCEERR_AR, (void __user *)address, lsb, current); |
| } |
| |
| static bool fault_supports_stage2_huge_mapping(struct kvm_memory_slot *memslot, |
| unsigned long hva, |
| unsigned long map_size) |
| { |
| gpa_t gpa_start; |
| hva_t uaddr_start, uaddr_end; |
| size_t size; |
| |
| /* The memslot and the VMA are guaranteed to be aligned to PAGE_SIZE */ |
| if (map_size == PAGE_SIZE) |
| return true; |
| |
| size = memslot->npages * PAGE_SIZE; |
| |
| gpa_start = memslot->base_gfn << PAGE_SHIFT; |
| |
| uaddr_start = memslot->userspace_addr; |
| uaddr_end = uaddr_start + size; |
| |
| /* |
| * Pages belonging to memslots that don't have the same alignment |
| * within a PMD/PUD for userspace and IPA cannot be mapped with stage-2 |
| * PMD/PUD entries, because we'll end up mapping the wrong pages. |
| * |
| * Consider a layout like the following: |
| * |
| * memslot->userspace_addr: |
| * +-----+--------------------+--------------------+---+ |
| * |abcde|fgh Stage-1 block | Stage-1 block tv|xyz| |
| * +-----+--------------------+--------------------+---+ |
| * |
| * memslot->base_gfn << PAGE_SHIFT: |
| * +---+--------------------+--------------------+-----+ |
| * |abc|def Stage-2 block | Stage-2 block |tvxyz| |
| * +---+--------------------+--------------------+-----+ |
| * |
| * If we create those stage-2 blocks, we'll end up with this incorrect |
| * mapping: |
| * d -> f |
| * e -> g |
| * f -> h |
| */ |
| if ((gpa_start & (map_size - 1)) != (uaddr_start & (map_size - 1))) |
| return false; |
| |
| /* |
| * Next, let's make sure we're not trying to map anything not covered |
| * by the memslot. This means we have to prohibit block size mappings |
| * for the beginning and end of a non-block aligned and non-block sized |
| * memory slot (illustrated by the head and tail parts of the |
| * userspace view above containing pages 'abcde' and 'xyz', |
| * respectively). |
| * |
| * Note that it doesn't matter if we do the check using the |
| * userspace_addr or the base_gfn, as both are equally aligned (per |
| * the check above) and equally sized. |
| */ |
| return (hva & ~(map_size - 1)) >= uaddr_start && |
| (hva & ~(map_size - 1)) + map_size <= uaddr_end; |
| } |
| |
| /* |
| * Check if the given hva is backed by a transparent huge page (THP) and |
| * whether it can be mapped using block mapping in stage2. If so, adjust |
| * the stage2 PFN and IPA accordingly. Only PMD_SIZE THPs are currently |
| * supported. This will need to be updated to support other THP sizes. |
| * |
| * Returns the size of the mapping. |
| */ |
| static unsigned long |
| transparent_hugepage_adjust(struct kvm_memory_slot *memslot, |
| unsigned long hva, kvm_pfn_t *pfnp, |
| phys_addr_t *ipap) |
| { |
| kvm_pfn_t pfn = *pfnp; |
| |
| /* |
| * Make sure the adjustment is done only for THP pages. Also make |
| * sure that the HVA and IPA are sufficiently aligned and that the |
| * block map is contained within the memslot. |
| */ |
| if (kvm_is_transparent_hugepage(pfn) && |
| fault_supports_stage2_huge_mapping(memslot, hva, PMD_SIZE)) { |
| /* |
| * The address we faulted on is backed by a transparent huge |
| * page. However, because we map the compound huge page and |
| * not the individual tail page, we need to transfer the |
| * refcount to the head page. We have to be careful that the |
| * THP doesn't start to split while we are adjusting the |
| * refcounts. |
| * |
| * We are sure this doesn't happen, because mmu_notifier_retry |
| * was successful and we are holding the mmu_lock, so if this |
| * THP is trying to split, it will be blocked in the mmu |
| * notifier before touching any of the pages, specifically |
| * before being able to call __split_huge_page_refcount(). |
| * |
| * We can therefore safely transfer the refcount from PG_tail |
| * to PG_head and switch the pfn from a tail page to the head |
| * page accordingly. |
| */ |
| *ipap &= PMD_MASK; |
| kvm_release_pfn_clean(pfn); |
| pfn &= ~(PTRS_PER_PMD - 1); |
| kvm_get_pfn(pfn); |
| *pfnp = pfn; |
| |
| return PMD_SIZE; |
| } |
| |
| /* Use page mapping if we cannot use block mapping. */ |
| return PAGE_SIZE; |
| } |
| |
| static int get_vma_page_shift(struct vm_area_struct *vma, unsigned long hva) |
| { |
| unsigned long pa; |
| |
| if (is_vm_hugetlb_page(vma) && !(vma->vm_flags & VM_PFNMAP)) |
| return huge_page_shift(hstate_vma(vma)); |
| |
| if (!(vma->vm_flags & VM_PFNMAP)) |
| return PAGE_SHIFT; |
| |
| VM_BUG_ON(is_vm_hugetlb_page(vma)); |
| |
| pa = (vma->vm_pgoff << PAGE_SHIFT) + (hva - vma->vm_start); |
| |
| #ifndef __PAGETABLE_PMD_FOLDED |
| if ((hva & (PUD_SIZE - 1)) == (pa & (PUD_SIZE - 1)) && |
| ALIGN_DOWN(hva, PUD_SIZE) >= vma->vm_start && |
| ALIGN(hva, PUD_SIZE) <= vma->vm_end) |
| return PUD_SHIFT; |
| #endif |
| |
| if ((hva & (PMD_SIZE - 1)) == (pa & (PMD_SIZE - 1)) && |
| ALIGN_DOWN(hva, PMD_SIZE) >= vma->vm_start && |
| ALIGN(hva, PMD_SIZE) <= vma->vm_end) |
| return PMD_SHIFT; |
| |
| return PAGE_SHIFT; |
| } |
| |
| /* |
| * The page will be mapped in stage 2 as Normal Cacheable, so the VM will be |
| * able to see the page's tags and therefore they must be initialised first. If |
| * PG_mte_tagged is set, tags have already been initialised. |
| * |
| * The race in the test/set of the PG_mte_tagged flag is handled by: |
| * - preventing VM_SHARED mappings in a memslot with MTE preventing two VMs |
| * racing to santise the same page |
| * - mmap_lock protects between a VM faulting a page in and the VMM performing |
| * an mprotect() to add VM_MTE |
| */ |
| static int sanitise_mte_tags(struct kvm *kvm, kvm_pfn_t pfn, |
| unsigned long size) |
| { |
| unsigned long i, nr_pages = size >> PAGE_SHIFT; |
| struct page *page; |
| |
| if (!kvm_has_mte(kvm)) |
| return 0; |
| |
| /* |
| * pfn_to_online_page() is used to reject ZONE_DEVICE pages |
| * that may not support tags. |
| */ |
| page = pfn_to_online_page(pfn); |
| |
| if (!page) |
| return -EFAULT; |
| |
| for (i = 0; i < nr_pages; i++, page++) { |
| if (!test_bit(PG_mte_tagged, &page->flags)) { |
| mte_clear_page_tags(page_address(page)); |
| set_bit(PG_mte_tagged, &page->flags); |
| } |
| } |
| |
| return 0; |
| } |
| |
| static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, |
| struct kvm_memory_slot *memslot, unsigned long hva, |
| unsigned long fault_status) |
| { |
| int ret = 0; |
| bool write_fault, writable, force_pte = false; |
| bool exec_fault; |
| bool device = false; |
| bool shared; |
| unsigned long mmu_seq; |
| struct kvm *kvm = vcpu->kvm; |
| struct kvm_mmu_memory_cache *memcache = &vcpu->arch.mmu_page_cache; |
| struct vm_area_struct *vma; |
| short vma_shift; |
| gfn_t gfn; |
| kvm_pfn_t pfn; |
| bool logging_active = memslot_is_logging(memslot); |
| unsigned long fault_level = kvm_vcpu_trap_get_fault_level(vcpu); |
| unsigned long vma_pagesize, fault_granule; |
| enum kvm_pgtable_prot prot = KVM_PGTABLE_PROT_R; |
| struct kvm_pgtable *pgt; |
| |
| fault_granule = 1UL << ARM64_HW_PGTABLE_LEVEL_SHIFT(fault_level); |
| write_fault = kvm_is_write_fault(vcpu); |
| exec_fault = kvm_vcpu_trap_is_exec_fault(vcpu); |
| VM_BUG_ON(write_fault && exec_fault); |
| |
| if (fault_status == FSC_PERM && !write_fault && !exec_fault) { |
| kvm_err("Unexpected L2 read permission error\n"); |
| return -EFAULT; |
| } |
| |
| /* |
| * Let's check if we will get back a huge page backed by hugetlbfs, or |
| * get block mapping for device MMIO region. |
| */ |
| mmap_read_lock(current->mm); |
| vma = vma_lookup(current->mm, hva); |
| if (unlikely(!vma)) { |
| kvm_err("Failed to find VMA for hva 0x%lx\n", hva); |
| mmap_read_unlock(current->mm); |
| return -EFAULT; |
| } |
| |
| /* |
| * logging_active is guaranteed to never be true for VM_PFNMAP |
| * memslots. |
| */ |
| if (logging_active) { |
| force_pte = true; |
| vma_shift = PAGE_SHIFT; |
| } else { |
| vma_shift = get_vma_page_shift(vma, hva); |
| } |
| |
| shared = (vma->vm_flags & VM_PFNMAP); |
| |
| switch (vma_shift) { |
| #ifndef __PAGETABLE_PMD_FOLDED |
| case PUD_SHIFT: |
| if (fault_supports_stage2_huge_mapping(memslot, hva, PUD_SIZE)) |
| break; |
| fallthrough; |
| #endif |
| case CONT_PMD_SHIFT: |
| vma_shift = PMD_SHIFT; |
| fallthrough; |
| case PMD_SHIFT: |
| if (fault_supports_stage2_huge_mapping(memslot, hva, PMD_SIZE)) |
| break; |
| fallthrough; |
| case CONT_PTE_SHIFT: |
| vma_shift = PAGE_SHIFT; |
| force_pte = true; |
| fallthrough; |
| case PAGE_SHIFT: |
| break; |
| default: |
| WARN_ONCE(1, "Unknown vma_shift %d", vma_shift); |
| } |
| |
| vma_pagesize = 1UL << vma_shift; |
| if (vma_pagesize == PMD_SIZE || vma_pagesize == PUD_SIZE) |
| fault_ipa &= ~(vma_pagesize - 1); |
| |
| gfn = fault_ipa >> PAGE_SHIFT; |
| mmap_read_unlock(current->mm); |
| |
| /* |
| * Permission faults just need to update the existing leaf entry, |
| * and so normally don't require allocations from the memcache. The |
| * only exception to this is when dirty logging is enabled at runtime |
| * and a write fault needs to collapse a block entry into a table. |
| */ |
| if (fault_status != FSC_PERM || (logging_active && write_fault)) { |
| ret = kvm_mmu_topup_memory_cache(memcache, |
| kvm_mmu_cache_min_pages(kvm)); |
| if (ret) |
| return ret; |
| } |
| |
| mmu_seq = vcpu->kvm->mmu_notifier_seq; |
| /* |
| * Ensure the read of mmu_notifier_seq happens before we call |
| * gfn_to_pfn_prot (which calls get_user_pages), so that we don't risk |
| * the page we just got a reference to gets unmapped before we have a |
| * chance to grab the mmu_lock, which ensure that if the page gets |
| * unmapped afterwards, the call to kvm_unmap_gfn will take it away |
| * from us again properly. This smp_rmb() interacts with the smp_wmb() |
| * in kvm_mmu_notifier_invalidate_<page|range_end>. |
| * |
| * Besides, __gfn_to_pfn_memslot() instead of gfn_to_pfn_prot() is |
| * used to avoid unnecessary overhead introduced to locate the memory |
| * slot because it's always fixed even @gfn is adjusted for huge pages. |
| */ |
| smp_rmb(); |
| |
| pfn = __gfn_to_pfn_memslot(memslot, gfn, false, NULL, |
| write_fault, &writable, NULL); |
| if (pfn == KVM_PFN_ERR_HWPOISON) { |
| kvm_send_hwpoison_signal(hva, vma_shift); |
| return 0; |
| } |
| if (is_error_noslot_pfn(pfn)) |
| return -EFAULT; |
| |
| if (kvm_is_device_pfn(pfn)) { |
| /* |
| * If the page was identified as device early by looking at |
| * the VMA flags, vma_pagesize is already representing the |
| * largest quantity we can map. If instead it was mapped |
| * via gfn_to_pfn_prot(), vma_pagesize is set to PAGE_SIZE |
| * and must not be upgraded. |
| * |
| * In both cases, we don't let transparent_hugepage_adjust() |
| * change things at the last minute. |
| */ |
| device = true; |
| } else if (logging_active && !write_fault) { |
| /* |
| * Only actually map the page as writable if this was a write |
| * fault. |
| */ |
| writable = false; |
| } |
| |
| if (exec_fault && device) |
| return -ENOEXEC; |
| |
| spin_lock(&kvm->mmu_lock); |
| pgt = vcpu->arch.hw_mmu->pgt; |
| if (mmu_notifier_retry(kvm, mmu_seq)) |
| goto out_unlock; |
| |
| /* |
| * If we are not forced to use page mapping, check if we are |
| * backed by a THP and thus use block mapping if possible. |
| */ |
| if (vma_pagesize == PAGE_SIZE && !(force_pte || device)) |
| vma_pagesize = transparent_hugepage_adjust(memslot, hva, |
| &pfn, &fault_ipa); |
| |
| if (fault_status != FSC_PERM && !device && kvm_has_mte(kvm)) { |
| /* Check the VMM hasn't introduced a new VM_SHARED VMA */ |
| if (!shared) |
| ret = sanitise_mte_tags(kvm, pfn, vma_pagesize); |
| else |
| ret = -EFAULT; |
| if (ret) |
| goto out_unlock; |
| } |
| |
| if (writable) |
| prot |= KVM_PGTABLE_PROT_W; |
| |
| if (exec_fault) |
| prot |= KVM_PGTABLE_PROT_X; |
| |
| if (device) |
| prot |= KVM_PGTABLE_PROT_DEVICE; |
| else if (cpus_have_const_cap(ARM64_HAS_CACHE_DIC)) |
| prot |= KVM_PGTABLE_PROT_X; |
| |
| /* |
| * Under the premise of getting a FSC_PERM fault, we just need to relax |
| * permissions only if vma_pagesize equals fault_granule. Otherwise, |
| * kvm_pgtable_stage2_map() should be called to change block size. |
| */ |
| if (fault_status == FSC_PERM && vma_pagesize == fault_granule) { |
| ret = kvm_pgtable_stage2_relax_perms(pgt, fault_ipa, prot); |
| } else { |
| ret = kvm_pgtable_stage2_map(pgt, fault_ipa, vma_pagesize, |
| __pfn_to_phys(pfn), prot, |
| memcache); |
| } |
| |
| /* Mark the page dirty only if the fault is handled successfully */ |
| if (writable && !ret) { |
| kvm_set_pfn_dirty(pfn); |
| mark_page_dirty_in_slot(kvm, memslot, gfn); |
| } |
| |
| out_unlock: |
| spin_unlock(&kvm->mmu_lock); |
| kvm_set_pfn_accessed(pfn); |
| kvm_release_pfn_clean(pfn); |
| return ret != -EAGAIN ? ret : 0; |
| } |
| |
| /* Resolve the access fault by making the page young again. */ |
| static void handle_access_fault(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa) |
| { |
| pte_t pte; |
| kvm_pte_t kpte; |
| struct kvm_s2_mmu *mmu; |
| |
| trace_kvm_access_fault(fault_ipa); |
| |
| spin_lock(&vcpu->kvm->mmu_lock); |
| mmu = vcpu->arch.hw_mmu; |
| kpte = kvm_pgtable_stage2_mkyoung(mmu->pgt, fault_ipa); |
| spin_unlock(&vcpu->kvm->mmu_lock); |
| |
| pte = __pte(kpte); |
| if (pte_valid(pte)) |
| kvm_set_pfn_accessed(pte_pfn(pte)); |
| } |
| |
| /** |
| * kvm_handle_guest_abort - handles all 2nd stage aborts |
| * @vcpu: the VCPU pointer |
| * |
| * Any abort that gets to the host is almost guaranteed to be caused by a |
| * missing second stage translation table entry, which can mean that either the |
| * guest simply needs more memory and we must allocate an appropriate page or it |
| * can mean that the guest tried to access I/O memory, which is emulated by user |
| * space. The distinction is based on the IPA causing the fault and whether this |
| * memory region has been registered as standard RAM by user space. |
| */ |
| int kvm_handle_guest_abort(struct kvm_vcpu *vcpu) |
| { |
| unsigned long fault_status; |
| phys_addr_t fault_ipa; |
| struct kvm_memory_slot *memslot; |
| unsigned long hva; |
| bool is_iabt, write_fault, writable; |
| gfn_t gfn; |
| int ret, idx; |
| |
| fault_status = kvm_vcpu_trap_get_fault_type(vcpu); |
| |
| fault_ipa = kvm_vcpu_get_fault_ipa(vcpu); |
| is_iabt = kvm_vcpu_trap_is_iabt(vcpu); |
| |
| /* Synchronous External Abort? */ |
| if (kvm_vcpu_abt_issea(vcpu)) { |
| /* |
| * For RAS the host kernel may handle this abort. |
| * There is no need to pass the error into the guest. |
| */ |
| if (kvm_handle_guest_sea(fault_ipa, kvm_vcpu_get_esr(vcpu))) |
| kvm_inject_vabt(vcpu); |
| |
| return 1; |
| } |
| |
| trace_kvm_guest_fault(*vcpu_pc(vcpu), kvm_vcpu_get_esr(vcpu), |
| kvm_vcpu_get_hfar(vcpu), fault_ipa); |
| |
| /* Check the stage-2 fault is trans. fault or write fault */ |
| if (fault_status != FSC_FAULT && fault_status != FSC_PERM && |
| fault_status != FSC_ACCESS) { |
| kvm_err("Unsupported FSC: EC=%#x xFSC=%#lx ESR_EL2=%#lx\n", |
| kvm_vcpu_trap_get_class(vcpu), |
| (unsigned long)kvm_vcpu_trap_get_fault(vcpu), |
| (unsigned long)kvm_vcpu_get_esr(vcpu)); |
| return -EFAULT; |
| } |
| |
| idx = srcu_read_lock(&vcpu->kvm->srcu); |
| |
| gfn = fault_ipa >> PAGE_SHIFT; |
| memslot = gfn_to_memslot(vcpu->kvm, gfn); |
| hva = gfn_to_hva_memslot_prot(memslot, gfn, &writable); |
| write_fault = kvm_is_write_fault(vcpu); |
| if (kvm_is_error_hva(hva) || (write_fault && !writable)) { |
| /* |
| * The guest has put either its instructions or its page-tables |
| * somewhere it shouldn't have. Userspace won't be able to do |
| * anything about this (there's no syndrome for a start), so |
| * re-inject the abort back into the guest. |
| */ |
| if (is_iabt) { |
| ret = -ENOEXEC; |
| goto out; |
| } |
| |
| if (kvm_vcpu_abt_iss1tw(vcpu)) { |
| kvm_inject_dabt(vcpu, kvm_vcpu_get_hfar(vcpu)); |
| ret = 1; |
| goto out_unlock; |
| } |
| |
| /* |
| * Check for a cache maintenance operation. Since we |
| * ended-up here, we know it is outside of any memory |
| * slot. But we can't find out if that is for a device, |
| * or if the guest is just being stupid. The only thing |
| * we know for sure is that this range cannot be cached. |
| * |
| * So let's assume that the guest is just being |
| * cautious, and skip the instruction. |
| */ |
| if (kvm_is_error_hva(hva) && kvm_vcpu_dabt_is_cm(vcpu)) { |
| kvm_incr_pc(vcpu); |
| ret = 1; |
| goto out_unlock; |
| } |
| |
| /* |
| * The IPA is reported as [MAX:12], so we need to |
| * complement it with the bottom 12 bits from the |
| * faulting VA. This is always 12 bits, irrespective |
| * of the page size. |
| */ |
| fault_ipa |= kvm_vcpu_get_hfar(vcpu) & ((1 << 12) - 1); |
| ret = io_mem_abort(vcpu, fault_ipa); |
| goto out_unlock; |
| } |
| |
| /* Userspace should not be able to register out-of-bounds IPAs */ |
| VM_BUG_ON(fault_ipa >= kvm_phys_size(vcpu->kvm)); |
| |
| if (fault_status == FSC_ACCESS) { |
| handle_access_fault(vcpu, fault_ipa); |
| ret = 1; |
| goto out_unlock; |
| } |
| |
| ret = user_mem_abort(vcpu, fault_ipa, memslot, hva, fault_status); |
| if (ret == 0) |
| ret = 1; |
| out: |
| if (ret == -ENOEXEC) { |
| kvm_inject_pabt(vcpu, kvm_vcpu_get_hfar(vcpu)); |
| ret = 1; |
| } |
| out_unlock: |
| srcu_read_unlock(&vcpu->kvm->srcu, idx); |
| return ret; |
| } |
| |
| bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range) |
| { |
| if (!kvm->arch.mmu.pgt) |
| return false; |
| |
| __unmap_stage2_range(&kvm->arch.mmu, range->start << PAGE_SHIFT, |
| (range->end - range->start) << PAGE_SHIFT, |
| range->may_block); |
| |
| return false; |
| } |
| |
| bool kvm_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range) |
| { |
| kvm_pfn_t pfn = pte_pfn(range->pte); |
| int ret; |
| |
| if (!kvm->arch.mmu.pgt) |
| return false; |
| |
| WARN_ON(range->end - range->start != 1); |
| |
| ret = sanitise_mte_tags(kvm, pfn, PAGE_SIZE); |
| if (ret) |
| return false; |
| |
| /* |
| * We've moved a page around, probably through CoW, so let's treat |
| * it just like a translation fault and the map handler will clean |
| * the cache to the PoC. |
| * |
| * The MMU notifiers will have unmapped a huge PMD before calling |
| * ->change_pte() (which in turn calls kvm_set_spte_gfn()) and |
| * therefore we never need to clear out a huge PMD through this |
| * calling path and a memcache is not required. |
| */ |
| kvm_pgtable_stage2_map(kvm->arch.mmu.pgt, range->start << PAGE_SHIFT, |
| PAGE_SIZE, __pfn_to_phys(pfn), |
| KVM_PGTABLE_PROT_R, NULL); |
| |
| return false; |
| } |
| |
| bool kvm_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) |
| { |
| u64 size = (range->end - range->start) << PAGE_SHIFT; |
| kvm_pte_t kpte; |
| pte_t pte; |
| |
| if (!kvm->arch.mmu.pgt) |
| return false; |
| |
| WARN_ON(size != PAGE_SIZE && size != PMD_SIZE && size != PUD_SIZE); |
| |
| kpte = kvm_pgtable_stage2_mkold(kvm->arch.mmu.pgt, |
| range->start << PAGE_SHIFT); |
| pte = __pte(kpte); |
| return pte_valid(pte) && pte_young(pte); |
| } |
| |
| bool kvm_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) |
| { |
| if (!kvm->arch.mmu.pgt) |
| return false; |
| |
| return kvm_pgtable_stage2_is_young(kvm->arch.mmu.pgt, |
| range->start << PAGE_SHIFT); |
| } |
| |
| phys_addr_t kvm_mmu_get_httbr(void) |
| { |
| return __pa(hyp_pgtable->pgd); |
| } |
| |
| phys_addr_t kvm_get_idmap_vector(void) |
| { |
| return hyp_idmap_vector; |
| } |
| |
| static int kvm_map_idmap_text(void) |
| { |
| unsigned long size = hyp_idmap_end - hyp_idmap_start; |
| int err = __create_hyp_mappings(hyp_idmap_start, size, hyp_idmap_start, |
| PAGE_HYP_EXEC); |
| if (err) |
| kvm_err("Failed to idmap %lx-%lx\n", |
| hyp_idmap_start, hyp_idmap_end); |
| |
| return err; |
| } |
| |
| static void *kvm_hyp_zalloc_page(void *arg) |
| { |
| return (void *)get_zeroed_page(GFP_KERNEL); |
| } |
| |
| static struct kvm_pgtable_mm_ops kvm_hyp_mm_ops = { |
| .zalloc_page = kvm_hyp_zalloc_page, |
| .get_page = kvm_host_get_page, |
| .put_page = kvm_host_put_page, |
| .phys_to_virt = kvm_host_va, |
| .virt_to_phys = kvm_host_pa, |
| }; |
| |
| int kvm_mmu_init(u32 *hyp_va_bits) |
| { |
| int err; |
| |
| hyp_idmap_start = __pa_symbol(__hyp_idmap_text_start); |
| hyp_idmap_start = ALIGN_DOWN(hyp_idmap_start, PAGE_SIZE); |
| hyp_idmap_end = __pa_symbol(__hyp_idmap_text_end); |
| hyp_idmap_end = ALIGN(hyp_idmap_end, PAGE_SIZE); |
| hyp_idmap_vector = __pa_symbol(__kvm_hyp_init); |
| |
| /* |
| * We rely on the linker script to ensure at build time that the HYP |
| * init code does not cross a page boundary. |
| */ |
| BUG_ON((hyp_idmap_start ^ (hyp_idmap_end - 1)) & PAGE_MASK); |
| |
| *hyp_va_bits = 64 - ((idmap_t0sz & TCR_T0SZ_MASK) >> TCR_T0SZ_OFFSET); |
| kvm_debug("Using %u-bit virtual addresses at EL2\n", *hyp_va_bits); |
| kvm_debug("IDMAP page: %lx\n", hyp_idmap_start); |
| kvm_debug("HYP VA range: %lx:%lx\n", |
| kern_hyp_va(PAGE_OFFSET), |
| kern_hyp_va((unsigned long)high_memory - 1)); |
| |
| if (hyp_idmap_start >= kern_hyp_va(PAGE_OFFSET) && |
| hyp_idmap_start < kern_hyp_va((unsigned long)high_memory - 1) && |
| hyp_idmap_start != (unsigned long)__hyp_idmap_text_start) { |
| /* |
| * The idmap page is intersecting with the VA space, |
| * it is not safe to continue further. |
| */ |
| kvm_err("IDMAP intersecting with HYP VA, unable to continue\n"); |
| err = -EINVAL; |
| goto out; |
| } |
| |
| hyp_pgtable = kzalloc(sizeof(*hyp_pgtable), GFP_KERNEL); |
| if (!hyp_pgtable) { |
| kvm_err("Hyp mode page-table not allocated\n"); |
| err = -ENOMEM; |
| goto out; |
| } |
| |
| err = kvm_pgtable_hyp_init(hyp_pgtable, *hyp_va_bits, &kvm_hyp_mm_ops); |
| if (err) |
| goto out_free_pgtable; |
| |
| err = kvm_map_idmap_text(); |
| if (err) |
| goto out_destroy_pgtable; |
| |
| io_map_base = hyp_idmap_start; |
| return 0; |
| |
| out_destroy_pgtable: |
| kvm_pgtable_hyp_destroy(hyp_pgtable); |
| out_free_pgtable: |
| kfree(hyp_pgtable); |
| hyp_pgtable = NULL; |
| out: |
| return err; |
| } |
| |
| void kvm_arch_commit_memory_region(struct kvm *kvm, |
| const struct kvm_userspace_memory_region *mem, |
| struct kvm_memory_slot *old, |
| const struct kvm_memory_slot *new, |
| enum kvm_mr_change change) |
| { |
| /* |
| * At this point memslot has been committed and there is an |
| * allocated dirty_bitmap[], dirty pages will be tracked while the |
| * memory slot is write protected. |
| */ |
| if (change != KVM_MR_DELETE && mem->flags & KVM_MEM_LOG_DIRTY_PAGES) { |
| /* |
| * If we're with initial-all-set, we don't need to write |
| * protect any pages because they're all reported as dirty. |
| * Huge pages and normal pages will be write protect gradually. |
| */ |
| if (!kvm_dirty_log_manual_protect_and_init_set(kvm)) { |
| kvm_mmu_wp_memory_region(kvm, mem->slot); |
| } |
| } |
| } |
| |
| int kvm_arch_prepare_memory_region(struct kvm *kvm, |
| struct kvm_memory_slot *memslot, |
| const struct kvm_userspace_memory_region *mem, |
| enum kvm_mr_change change) |
| { |
| hva_t hva = mem->userspace_addr; |
| hva_t reg_end = hva + mem->memory_size; |
| int ret = 0; |
| |
| if (change != KVM_MR_CREATE && change != KVM_MR_MOVE && |
| change != KVM_MR_FLAGS_ONLY) |
| return 0; |
| |
| /* |
| * Prevent userspace from creating a memory region outside of the IPA |
| * space addressable by the KVM guest IPA space. |
| */ |
| if ((memslot->base_gfn + memslot->npages) > (kvm_phys_size(kvm) >> PAGE_SHIFT)) |
| return -EFAULT; |
| |
| mmap_read_lock(current->mm); |
| /* |
| * A memory region could potentially cover multiple VMAs, and any holes |
| * between them, so iterate over all of them. |
| * |
| * +--------------------------------------------+ |
| * +---------------+----------------+ +----------------+ |
| * | : VMA 1 | VMA 2 | | VMA 3 : | |
| * +---------------+----------------+ +----------------+ |
| * | memory region | |
| * +--------------------------------------------+ |
| */ |
| do { |
| struct vm_area_struct *vma; |
| |
| vma = find_vma_intersection(current->mm, hva, reg_end); |
| if (!vma) |
| break; |
| |
| /* |
| * VM_SHARED mappings are not allowed with MTE to avoid races |
| * when updating the PG_mte_tagged page flag, see |
| * sanitise_mte_tags for more details. |
| */ |
| if (kvm_has_mte(kvm) && vma->vm_flags & VM_SHARED) |
| return -EINVAL; |
| |
| if (vma->vm_flags & VM_PFNMAP) { |
| /* IO region dirty page logging not allowed */ |
| if (memslot->flags & KVM_MEM_LOG_DIRTY_PAGES) { |
| ret = -EINVAL; |
| break; |
| } |
| } |
| hva = min(reg_end, vma->vm_end); |
| } while (hva < reg_end); |
| |
| mmap_read_unlock(current->mm); |
| return ret; |
| } |
| |
| void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *slot) |
| { |
| } |
| |
| void kvm_arch_memslots_updated(struct kvm *kvm, u64 gen) |
| { |
| } |
| |
| void kvm_arch_flush_shadow_all(struct kvm *kvm) |
| { |
| kvm_free_stage2_pgd(&kvm->arch.mmu); |
| } |
| |
| void kvm_arch_flush_shadow_memslot(struct kvm *kvm, |
| struct kvm_memory_slot *slot) |
| { |
| gpa_t gpa = slot->base_gfn << PAGE_SHIFT; |
| phys_addr_t size = slot->npages << PAGE_SHIFT; |
| |
| spin_lock(&kvm->mmu_lock); |
| unmap_stage2_range(&kvm->arch.mmu, gpa, size); |
| spin_unlock(&kvm->mmu_lock); |
| } |
| |
| /* |
| * See note at ARMv7 ARM B1.14.4 (TL;DR: S/W ops are not easily virtualized). |
| * |
| * Main problems: |
| * - S/W ops are local to a CPU (not broadcast) |
| * - We have line migration behind our back (speculation) |
| * - System caches don't support S/W at all (damn!) |
| * |
| * In the face of the above, the best we can do is to try and convert |
| * S/W ops to VA ops. Because the guest is not allowed to infer the |
| * S/W to PA mapping, it can only use S/W to nuke the whole cache, |
| * which is a rather good thing for us. |
| * |
| * Also, it is only used when turning caches on/off ("The expected |
| * usage of the cache maintenance instructions that operate by set/way |
| * is associated with the cache maintenance instructions associated |
| * with the powerdown and powerup of caches, if this is required by |
| * the implementation."). |
| * |
| * We use the following policy: |
| * |
| * - If we trap a S/W operation, we enable VM trapping to detect |
| * caches being turned on/off, and do a full clean. |
| * |
| * - We flush the caches on both caches being turned on and off. |
| * |
| * - Once the caches are enabled, we stop trapping VM ops. |
| */ |
| void kvm_set_way_flush(struct kvm_vcpu *vcpu) |
| { |
| unsigned long hcr = *vcpu_hcr(vcpu); |
| |
| /* |
| * If this is the first time we do a S/W operation |
| * (i.e. HCR_TVM not set) flush the whole memory, and set the |
| * VM trapping. |
| * |
| * Otherwise, rely on the VM trapping to wait for the MMU + |
| * Caches to be turned off. At that point, we'll be able to |
| * clean the caches again. |
| */ |
| if (!(hcr & HCR_TVM)) { |
| trace_kvm_set_way_flush(*vcpu_pc(vcpu), |
| vcpu_has_cache_enabled(vcpu)); |
| stage2_flush_vm(vcpu->kvm); |
| *vcpu_hcr(vcpu) = hcr | HCR_TVM; |
| } |
| } |
| |
| void kvm_toggle_cache(struct kvm_vcpu *vcpu, bool was_enabled) |
| { |
| bool now_enabled = vcpu_has_cache_enabled(vcpu); |
| |
| /* |
| * If switching the MMU+caches on, need to invalidate the caches. |
| * If switching it off, need to clean the caches. |
| * Clean + invalidate does the trick always. |
| */ |
| if (now_enabled != was_enabled) |
| stage2_flush_vm(vcpu->kvm); |
| |
| /* Caches are now on, stop trapping VM ops (until a S/W op) */ |
| if (now_enabled) |
| *vcpu_hcr(vcpu) &= ~HCR_TVM; |
| |
| trace_kvm_toggle_cache(*vcpu_pc(vcpu), was_enabled, now_enabled); |
| } |