| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * Copyright (C) 2020 Google LLC |
| * Author: Quentin Perret <qperret@google.com> |
| */ |
| |
| #include <linux/kvm_host.h> |
| #include <asm/kvm_hyp.h> |
| #include <asm/kvm_mmu.h> |
| #include <asm/kvm_pgtable.h> |
| #include <asm/kvm_pkvm.h> |
| |
| #include <nvhe/early_alloc.h> |
| #include <nvhe/fixed_config.h> |
| #include <nvhe/gfp.h> |
| #include <nvhe/memory.h> |
| #include <nvhe/mem_protect.h> |
| #include <nvhe/mm.h> |
| #include <nvhe/pkvm.h> |
| #include <nvhe/trap_handler.h> |
| |
| unsigned long hyp_nr_cpus; |
| |
| #define hyp_percpu_size ((unsigned long)__per_cpu_end - \ |
| (unsigned long)__per_cpu_start) |
| |
| static void *vmemmap_base; |
| static void *vm_table_base; |
| static void *hyp_pgt_base; |
| static void *host_s2_pgt_base; |
| static struct kvm_pgtable_mm_ops pkvm_pgtable_mm_ops; |
| static struct hyp_pool hpool; |
| |
| static int divide_memory_pool(void *virt, unsigned long size) |
| { |
| unsigned long nr_pages; |
| |
| hyp_early_alloc_init(virt, size); |
| |
| nr_pages = hyp_vmemmap_pages(sizeof(struct hyp_page)); |
| vmemmap_base = hyp_early_alloc_contig(nr_pages); |
| if (!vmemmap_base) |
| return -ENOMEM; |
| |
| nr_pages = hyp_vm_table_pages(); |
| vm_table_base = hyp_early_alloc_contig(nr_pages); |
| if (!vm_table_base) |
| return -ENOMEM; |
| |
| nr_pages = hyp_s1_pgtable_pages(); |
| hyp_pgt_base = hyp_early_alloc_contig(nr_pages); |
| if (!hyp_pgt_base) |
| return -ENOMEM; |
| |
| nr_pages = host_s2_pgtable_pages(); |
| host_s2_pgt_base = hyp_early_alloc_contig(nr_pages); |
| if (!host_s2_pgt_base) |
| return -ENOMEM; |
| |
| return 0; |
| } |
| |
| static int recreate_hyp_mappings(phys_addr_t phys, unsigned long size, |
| unsigned long *per_cpu_base, |
| u32 hyp_va_bits) |
| { |
| void *start, *end, *virt = hyp_phys_to_virt(phys); |
| unsigned long pgt_size = hyp_s1_pgtable_pages() << PAGE_SHIFT; |
| enum kvm_pgtable_prot prot; |
| int ret, i; |
| |
| /* Recreate the hyp page-table using the early page allocator */ |
| hyp_early_alloc_init(hyp_pgt_base, pgt_size); |
| ret = kvm_pgtable_hyp_init(&pkvm_pgtable, hyp_va_bits, |
| &hyp_early_alloc_mm_ops); |
| if (ret) |
| return ret; |
| |
| ret = hyp_create_idmap(hyp_va_bits); |
| if (ret) |
| return ret; |
| |
| ret = hyp_map_vectors(); |
| if (ret) |
| return ret; |
| |
| ret = hyp_back_vmemmap(hyp_virt_to_phys(vmemmap_base)); |
| if (ret) |
| return ret; |
| |
| ret = pkvm_create_mappings(__hyp_text_start, __hyp_text_end, PAGE_HYP_EXEC); |
| if (ret) |
| return ret; |
| |
| ret = pkvm_create_mappings(__hyp_rodata_start, __hyp_rodata_end, PAGE_HYP_RO); |
| if (ret) |
| return ret; |
| |
| ret = pkvm_create_mappings(__hyp_bss_start, __hyp_bss_end, PAGE_HYP); |
| if (ret) |
| return ret; |
| |
| ret = pkvm_create_mappings(virt, virt + size, PAGE_HYP); |
| if (ret) |
| return ret; |
| |
| for (i = 0; i < hyp_nr_cpus; i++) { |
| struct kvm_nvhe_init_params *params = per_cpu_ptr(&kvm_init_params, i); |
| unsigned long hyp_addr; |
| |
| start = (void *)kern_hyp_va(per_cpu_base[i]); |
| end = start + PAGE_ALIGN(hyp_percpu_size); |
| ret = pkvm_create_mappings(start, end, PAGE_HYP); |
| if (ret) |
| return ret; |
| |
| /* |
| * Allocate a contiguous HYP private VA range for the stack |
| * and guard page. The allocation is also aligned based on |
| * the order of its size. |
| */ |
| ret = pkvm_alloc_private_va_range(PAGE_SIZE * 2, &hyp_addr); |
| if (ret) |
| return ret; |
| |
| /* |
| * Since the stack grows downwards, map the stack to the page |
| * at the higher address and leave the lower guard page |
| * unbacked. |
| * |
| * Any valid stack address now has the PAGE_SHIFT bit as 1 |
| * and addresses corresponding to the guard page have the |
| * PAGE_SHIFT bit as 0 - this is used for overflow detection. |
| */ |
| hyp_spin_lock(&pkvm_pgd_lock); |
| ret = kvm_pgtable_hyp_map(&pkvm_pgtable, hyp_addr + PAGE_SIZE, |
| PAGE_SIZE, params->stack_pa, PAGE_HYP); |
| hyp_spin_unlock(&pkvm_pgd_lock); |
| if (ret) |
| return ret; |
| |
| /* Update stack_hyp_va to end of the stack's private VA range */ |
| params->stack_hyp_va = hyp_addr + (2 * PAGE_SIZE); |
| } |
| |
| /* |
| * Map the host sections RO in the hypervisor, but transfer the |
| * ownership from the host to the hypervisor itself to make sure they |
| * can't be donated or shared with another entity. |
| * |
| * The ownership transition requires matching changes in the host |
| * stage-2. This will be done later (see finalize_host_mappings()) once |
| * the hyp_vmemmap is addressable. |
| */ |
| prot = pkvm_mkstate(PAGE_HYP_RO, PKVM_PAGE_SHARED_OWNED); |
| ret = pkvm_create_mappings(&kvm_vgic_global_state, |
| &kvm_vgic_global_state + 1, prot); |
| if (ret) |
| return ret; |
| |
| return 0; |
| } |
| |
| static void update_nvhe_init_params(void) |
| { |
| struct kvm_nvhe_init_params *params; |
| unsigned long i; |
| |
| for (i = 0; i < hyp_nr_cpus; i++) { |
| params = per_cpu_ptr(&kvm_init_params, i); |
| params->pgd_pa = __hyp_pa(pkvm_pgtable.pgd); |
| dcache_clean_inval_poc((unsigned long)params, |
| (unsigned long)params + sizeof(*params)); |
| } |
| } |
| |
| static void *hyp_zalloc_hyp_page(void *arg) |
| { |
| return hyp_alloc_pages(&hpool, 0); |
| } |
| |
| static void hpool_get_page(void *addr) |
| { |
| hyp_get_page(&hpool, addr); |
| } |
| |
| static void hpool_put_page(void *addr) |
| { |
| hyp_put_page(&hpool, addr); |
| } |
| |
| static int fix_host_ownership_walker(u64 addr, u64 end, u32 level, |
| kvm_pte_t *ptep, |
| enum kvm_pgtable_walk_flags flag, |
| void * const arg) |
| { |
| enum kvm_pgtable_prot prot; |
| enum pkvm_page_state state; |
| kvm_pte_t pte = *ptep; |
| phys_addr_t phys; |
| |
| if (!kvm_pte_valid(pte)) |
| return 0; |
| |
| if (level != (KVM_PGTABLE_MAX_LEVELS - 1)) |
| return -EINVAL; |
| |
| phys = kvm_pte_to_phys(pte); |
| if (!addr_is_memory(phys)) |
| return -EINVAL; |
| |
| /* |
| * Adjust the host stage-2 mappings to match the ownership attributes |
| * configured in the hypervisor stage-1. |
| */ |
| state = pkvm_getstate(kvm_pgtable_hyp_pte_prot(pte)); |
| switch (state) { |
| case PKVM_PAGE_OWNED: |
| return host_stage2_set_owner_locked(phys, PAGE_SIZE, PKVM_ID_HYP); |
| case PKVM_PAGE_SHARED_OWNED: |
| prot = pkvm_mkstate(PKVM_HOST_MEM_PROT, PKVM_PAGE_SHARED_BORROWED); |
| break; |
| case PKVM_PAGE_SHARED_BORROWED: |
| prot = pkvm_mkstate(PKVM_HOST_MEM_PROT, PKVM_PAGE_SHARED_OWNED); |
| break; |
| default: |
| return -EINVAL; |
| } |
| |
| return host_stage2_idmap_locked(phys, PAGE_SIZE, prot); |
| } |
| |
| static int fix_hyp_pgtable_refcnt_walker(u64 addr, u64 end, u32 level, |
| kvm_pte_t *ptep, |
| enum kvm_pgtable_walk_flags flag, |
| void * const arg) |
| { |
| struct kvm_pgtable_mm_ops *mm_ops = arg; |
| kvm_pte_t pte = *ptep; |
| |
| /* |
| * Fix-up the refcount for the page-table pages as the early allocator |
| * was unable to access the hyp_vmemmap and so the buddy allocator has |
| * initialised the refcount to '1'. |
| */ |
| if (kvm_pte_valid(pte)) |
| mm_ops->get_page(ptep); |
| |
| return 0; |
| } |
| |
| static int fix_host_ownership(void) |
| { |
| struct kvm_pgtable_walker walker = { |
| .cb = fix_host_ownership_walker, |
| .flags = KVM_PGTABLE_WALK_LEAF, |
| }; |
| int i, ret; |
| |
| for (i = 0; i < hyp_memblock_nr; i++) { |
| struct memblock_region *reg = &hyp_memory[i]; |
| u64 start = (u64)hyp_phys_to_virt(reg->base); |
| |
| ret = kvm_pgtable_walk(&pkvm_pgtable, start, reg->size, &walker); |
| if (ret) |
| return ret; |
| } |
| |
| return 0; |
| } |
| |
| static int fix_hyp_pgtable_refcnt(void) |
| { |
| struct kvm_pgtable_walker walker = { |
| .cb = fix_hyp_pgtable_refcnt_walker, |
| .flags = KVM_PGTABLE_WALK_LEAF | KVM_PGTABLE_WALK_TABLE_POST, |
| .arg = pkvm_pgtable.mm_ops, |
| }; |
| |
| return kvm_pgtable_walk(&pkvm_pgtable, 0, BIT(pkvm_pgtable.ia_bits), |
| &walker); |
| } |
| |
| void __noreturn __pkvm_init_finalise(void) |
| { |
| struct kvm_host_data *host_data = this_cpu_ptr(&kvm_host_data); |
| struct kvm_cpu_context *host_ctxt = &host_data->host_ctxt; |
| unsigned long nr_pages, reserved_pages, pfn; |
| int ret; |
| |
| /* Now that the vmemmap is backed, install the full-fledged allocator */ |
| pfn = hyp_virt_to_pfn(hyp_pgt_base); |
| nr_pages = hyp_s1_pgtable_pages(); |
| reserved_pages = hyp_early_alloc_nr_used_pages(); |
| ret = hyp_pool_init(&hpool, pfn, nr_pages, reserved_pages); |
| if (ret) |
| goto out; |
| |
| ret = kvm_host_prepare_stage2(host_s2_pgt_base); |
| if (ret) |
| goto out; |
| |
| pkvm_pgtable_mm_ops = (struct kvm_pgtable_mm_ops) { |
| .zalloc_page = hyp_zalloc_hyp_page, |
| .phys_to_virt = hyp_phys_to_virt, |
| .virt_to_phys = hyp_virt_to_phys, |
| .get_page = hpool_get_page, |
| .put_page = hpool_put_page, |
| .page_count = hyp_page_count, |
| }; |
| pkvm_pgtable.mm_ops = &pkvm_pgtable_mm_ops; |
| |
| ret = fix_host_ownership(); |
| if (ret) |
| goto out; |
| |
| ret = fix_hyp_pgtable_refcnt(); |
| if (ret) |
| goto out; |
| |
| ret = hyp_create_pcpu_fixmap(); |
| if (ret) |
| goto out; |
| |
| pkvm_hyp_vm_table_init(vm_table_base); |
| out: |
| /* |
| * We tail-called to here from handle___pkvm_init() and will not return, |
| * so make sure to propagate the return value to the host. |
| */ |
| cpu_reg(host_ctxt, 1) = ret; |
| |
| __host_enter(host_ctxt); |
| } |
| |
| int __pkvm_init(phys_addr_t phys, unsigned long size, unsigned long nr_cpus, |
| unsigned long *per_cpu_base, u32 hyp_va_bits) |
| { |
| struct kvm_nvhe_init_params *params; |
| void *virt = hyp_phys_to_virt(phys); |
| void (*fn)(phys_addr_t params_pa, void *finalize_fn_va); |
| int ret; |
| |
| BUG_ON(kvm_check_pvm_sysreg_table()); |
| |
| if (!PAGE_ALIGNED(phys) || !PAGE_ALIGNED(size)) |
| return -EINVAL; |
| |
| hyp_spin_lock_init(&pkvm_pgd_lock); |
| hyp_nr_cpus = nr_cpus; |
| |
| ret = divide_memory_pool(virt, size); |
| if (ret) |
| return ret; |
| |
| ret = recreate_hyp_mappings(phys, size, per_cpu_base, hyp_va_bits); |
| if (ret) |
| return ret; |
| |
| update_nvhe_init_params(); |
| |
| /* Jump in the idmap page to switch to the new page-tables */ |
| params = this_cpu_ptr(&kvm_init_params); |
| fn = (typeof(fn))__hyp_pa(__pkvm_init_switch_pgd); |
| fn(__hyp_pa(params), __pkvm_init_finalise); |
| |
| unreachable(); |
| } |