diff options
Diffstat (limited to 'arch/x86/kvm/mmu/mmu.c')
| -rw-r--r-- | arch/x86/kvm/mmu/mmu.c | 639 |
1 files changed, 358 insertions, 281 deletions
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 62b1729277ef..0144c40d09c7 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -48,6 +48,7 @@ #include <asm/memtype.h> #include <asm/cmpxchg.h> #include <asm/io.h> +#include <asm/set_memory.h> #include <asm/vmx.h> #include <asm/kvm_page_track.h> #include "trace.h" @@ -215,10 +216,10 @@ bool is_nx_huge_page_enabled(void) static void mark_mmio_spte(struct kvm_vcpu *vcpu, u64 *sptep, u64 gfn, unsigned int access) { - u64 mask = make_mmio_spte(vcpu, gfn, access); + u64 spte = make_mmio_spte(vcpu, gfn, access); - trace_mark_mmio_spte(sptep, gfn, mask); - mmu_spte_set(sptep, mask); + trace_mark_mmio_spte(sptep, gfn, spte); + mmu_spte_set(sptep, spte); } static gfn_t get_mmio_spte_gfn(u64 spte) @@ -236,17 +237,6 @@ static unsigned get_mmio_spte_access(u64 spte) return spte & shadow_mmio_access_mask; } -static bool set_mmio_spte(struct kvm_vcpu *vcpu, u64 *sptep, gfn_t gfn, - kvm_pfn_t pfn, unsigned int access) -{ - if (unlikely(is_noslot_pfn(pfn))) { - mark_mmio_spte(vcpu, sptep, gfn, access); - return true; - } - - return false; -} - static bool check_mmio_spte(struct kvm_vcpu *vcpu, u64 spte) { u64 kvm_gen, spte_gen, gen; @@ -725,8 +715,7 @@ static void kvm_mmu_page_set_gfn(struct kvm_mmu_page *sp, int index, gfn_t gfn) * handling slots that are not large page aligned. */ static struct kvm_lpage_info *lpage_info_slot(gfn_t gfn, - struct kvm_memory_slot *slot, - int level) + const struct kvm_memory_slot *slot, int level) { unsigned long idx; @@ -1118,7 +1107,7 @@ static bool spte_write_protect(u64 *sptep, bool pt_protect) rmap_printk("spte %p %llx\n", sptep, *sptep); if (pt_protect) - spte &= ~SPTE_MMU_WRITEABLE; + spte &= ~shadow_mmu_writable_mask; spte = spte & ~PT_WRITABLE_MASK; return mmu_spte_update(sptep, spte); @@ -1308,26 +1297,25 @@ static bool kvm_zap_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, return flush; } -static int kvm_unmap_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, - struct kvm_memory_slot *slot, gfn_t gfn, int level, - unsigned long data) +static bool kvm_unmap_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, + struct kvm_memory_slot *slot, gfn_t gfn, int level, + pte_t unused) { return kvm_zap_rmapp(kvm, rmap_head, slot); } -static int kvm_set_pte_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, - struct kvm_memory_slot *slot, gfn_t gfn, int level, - unsigned long data) +static bool kvm_set_pte_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, + struct kvm_memory_slot *slot, gfn_t gfn, int level, + pte_t pte) { u64 *sptep; struct rmap_iterator iter; int need_flush = 0; u64 new_spte; - pte_t *ptep = (pte_t *)data; kvm_pfn_t new_pfn; - WARN_ON(pte_huge(*ptep)); - new_pfn = pte_pfn(*ptep); + WARN_ON(pte_huge(pte)); + new_pfn = pte_pfn(pte); restart: for_each_rmap_spte(rmap_head, &iter, sptep) { @@ -1336,7 +1324,7 @@ restart: need_flush = 1; - if (pte_write(*ptep)) { + if (pte_write(pte)) { pte_list_remove(rmap_head, sptep); goto restart; } else { @@ -1424,93 +1412,52 @@ static void slot_rmap_walk_next(struct slot_rmap_walk_iterator *iterator) slot_rmap_walk_okay(_iter_); \ slot_rmap_walk_next(_iter_)) -static __always_inline int -kvm_handle_hva_range(struct kvm *kvm, - unsigned long start, - unsigned long end, - unsigned long data, - int (*handler)(struct kvm *kvm, - struct kvm_rmap_head *rmap_head, - struct kvm_memory_slot *slot, - gfn_t gfn, - int level, - unsigned long data)) +typedef bool (*rmap_handler_t)(struct kvm *kvm, struct kvm_rmap_head *rmap_head, + struct kvm_memory_slot *slot, gfn_t gfn, + int level, pte_t pte); + +static __always_inline bool kvm_handle_gfn_range(struct kvm *kvm, + struct kvm_gfn_range *range, + rmap_handler_t handler) { - struct kvm_memslots *slots; - struct kvm_memory_slot *memslot; struct slot_rmap_walk_iterator iterator; - int ret = 0; - int i; - - for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) { - slots = __kvm_memslots(kvm, i); - kvm_for_each_memslot(memslot, slots) { - unsigned long hva_start, hva_end; - gfn_t gfn_start, gfn_end; + bool ret = false; - hva_start = max(start, memslot->userspace_addr); - hva_end = min(end, memslot->userspace_addr + - (memslot->npages << PAGE_SHIFT)); - if (hva_start >= hva_end) - continue; - /* - * {gfn(page) | page intersects with [hva_start, hva_end)} = - * {gfn_start, gfn_start+1, ..., gfn_end-1}. - */ - gfn_start = hva_to_gfn_memslot(hva_start, memslot); - gfn_end = hva_to_gfn_memslot(hva_end + PAGE_SIZE - 1, memslot); - - for_each_slot_rmap_range(memslot, PG_LEVEL_4K, - KVM_MAX_HUGEPAGE_LEVEL, - gfn_start, gfn_end - 1, - &iterator) - ret |= handler(kvm, iterator.rmap, memslot, - iterator.gfn, iterator.level, data); - } - } + for_each_slot_rmap_range(range->slot, PG_LEVEL_4K, KVM_MAX_HUGEPAGE_LEVEL, + range->start, range->end - 1, &iterator) + ret |= handler(kvm, iterator.rmap, range->slot, iterator.gfn, + iterator.level, range->pte); return ret; } -static int kvm_handle_hva(struct kvm *kvm, unsigned long hva, - unsigned long data, - int (*handler)(struct kvm *kvm, - struct kvm_rmap_head *rmap_head, - struct kvm_memory_slot *slot, - gfn_t gfn, int level, - unsigned long data)) +bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range) { - return kvm_handle_hva_range(kvm, hva, hva + 1, data, handler); -} - -int kvm_unmap_hva_range(struct kvm *kvm, unsigned long start, unsigned long end, - unsigned flags) -{ - int r; + bool flush; - r = kvm_handle_hva_range(kvm, start, end, 0, kvm_unmap_rmapp); + flush = kvm_handle_gfn_range(kvm, range, kvm_unmap_rmapp); if (is_tdp_mmu_enabled(kvm)) - r |= kvm_tdp_mmu_zap_hva_range(kvm, start, end); + flush |= kvm_tdp_mmu_unmap_gfn_range(kvm, range, flush); - return r; + return flush; } -int kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte) +bool kvm_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range) { - int r; + bool flush; - r = kvm_handle_hva(kvm, hva, (unsigned long)&pte, kvm_set_pte_rmapp); + flush = kvm_handle_gfn_range(kvm, range, kvm_set_pte_rmapp); if (is_tdp_mmu_enabled(kvm)) - r |= kvm_tdp_mmu_set_spte_hva(kvm, hva, &pte); + flush |= kvm_tdp_mmu_set_spte_gfn(kvm, range); - return r; + return flush; } -static int kvm_age_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, - struct kvm_memory_slot *slot, gfn_t gfn, int level, - unsigned long data) +static bool kvm_age_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, + struct kvm_memory_slot *slot, gfn_t gfn, int level, + pte_t unused) { u64 *sptep; struct rmap_iterator iter; @@ -1519,13 +1466,12 @@ static int kvm_age_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, for_each_rmap_spte(rmap_head, &iter, sptep) young |= mmu_spte_age(sptep); - trace_kvm_age_page(gfn, level, slot, young); return young; } -static int kvm_test_age_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, - struct kvm_memory_slot *slot, gfn_t gfn, - int level, unsigned long data) +static bool kvm_test_age_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, + struct kvm_memory_slot *slot, gfn_t gfn, + int level, pte_t unused) { u64 *sptep; struct rmap_iterator iter; @@ -1547,29 +1493,31 @@ static void rmap_recycle(struct kvm_vcpu *vcpu, u64 *spte, gfn_t gfn) rmap_head = gfn_to_rmap(vcpu->kvm, gfn, sp); - kvm_unmap_rmapp(vcpu->kvm, rmap_head, NULL, gfn, sp->role.level, 0); + kvm_unmap_rmapp(vcpu->kvm, rmap_head, NULL, gfn, sp->role.level, __pte(0)); kvm_flush_remote_tlbs_with_address(vcpu->kvm, sp->gfn, KVM_PAGES_PER_HPAGE(sp->role.level)); } -int kvm_age_hva(struct kvm *kvm, unsigned long start, unsigned long end) +bool kvm_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) { - int young = false; + bool young; + + young = kvm_handle_gfn_range(kvm, range, kvm_age_rmapp); - young = kvm_handle_hva_range(kvm, start, end, 0, kvm_age_rmapp); if (is_tdp_mmu_enabled(kvm)) - young |= kvm_tdp_mmu_age_hva_range(kvm, start, end); + young |= kvm_tdp_mmu_age_gfn_range(kvm, range); return young; } -int kvm_test_age_hva(struct kvm *kvm, unsigned long hva) +bool kvm_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) { - int young = false; + bool young; + + young = kvm_handle_gfn_range(kvm, range, kvm_test_age_rmapp); - young = kvm_handle_hva(kvm, hva, 0, kvm_test_age_rmapp); if (is_tdp_mmu_enabled(kvm)) - young |= kvm_tdp_mmu_test_age_hva(kvm, hva); + young |= kvm_tdp_mmu_test_age_gfn(kvm, range); return young; } @@ -2421,6 +2369,15 @@ static int make_mmu_pages_available(struct kvm_vcpu *vcpu) kvm_mmu_zap_oldest_mmu_pages(vcpu->kvm, KVM_REFILL_PAGES - avail); + /* + * Note, this check is intentionally soft, it only guarantees that one + * page is available, while the caller may end up allocating as many as + * four pages, e.g. for PAE roots or for 5-level paging. Temporarily + * exceeding the (arbitrary by default) limit will not harm the host, + * being too agressive may unnecessarily kill the guest, and getting an + * exact count is far more trouble than it's worth, especially in the + * page fault paths. + */ if (!kvm_mmu_available_pages(vcpu->kvm)) return -ENOSPC; return 0; @@ -2561,9 +2518,6 @@ static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep, struct kvm_mmu_page *sp; int ret; - if (set_mmio_spte(vcpu, sptep, gfn, pfn, pte_access)) - return 0; - sp = sptep_to_sp(sptep); ret = make_spte(vcpu, pte_access, level, gfn, pfn, *sptep, speculative, @@ -2593,6 +2547,11 @@ static int mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep, pgprintk("%s: spte %llx write_fault %d gfn %llx\n", __func__, *sptep, write_fault, gfn); + if (unlikely(is_noslot_pfn(pfn))) { + mark_mmio_spte(vcpu, sptep, gfn, pte_access); + return RET_PF_EMULATE; + } + if (is_shadow_present_pte(*sptep)) { /* * If we overwrite a PTE page pointer with a 2MB PMD, unlink @@ -2626,9 +2585,6 @@ static int mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep, kvm_flush_remote_tlbs_with_address(vcpu->kvm, gfn, KVM_PAGES_PER_HPAGE(level)); - if (unlikely(is_mmio_spte(*sptep))) - ret = RET_PF_EMULATE; - /* * The fault is fully spurious if and only if the new SPTE and old SPTE * are identical, and emulation is not required. @@ -2745,7 +2701,7 @@ static void direct_pte_prefetch(struct kvm_vcpu *vcpu, u64 *sptep) } static int host_pfn_mapping_level(struct kvm *kvm, gfn_t gfn, kvm_pfn_t pfn, - struct kvm_memory_slot *slot) + const struct kvm_memory_slot *slot) { unsigned long hva; pte_t *pte; @@ -2771,8 +2727,9 @@ static int host_pfn_mapping_level(struct kvm *kvm, gfn_t gfn, kvm_pfn_t pfn, return level; } -int kvm_mmu_max_mapping_level(struct kvm *kvm, struct kvm_memory_slot *slot, - gfn_t gfn, kvm_pfn_t pfn, int max_level) +int kvm_mmu_max_mapping_level(struct kvm *kvm, + const struct kvm_memory_slot *slot, gfn_t gfn, + kvm_pfn_t pfn, int max_level) { struct kvm_lpage_info *linfo; @@ -2946,9 +2903,19 @@ static bool handle_abnormal_pfn(struct kvm_vcpu *vcpu, gva_t gva, gfn_t gfn, return true; } - if (unlikely(is_noslot_pfn(pfn))) + if (unlikely(is_noslot_pfn(pfn))) { vcpu_cache_mmio_info(vcpu, gva, gfn, access & shadow_mmio_access_mask); + /* + * If MMIO caching is disabled, emulate immediately without + * touching the shadow page tables as attempting to install an + * MMIO SPTE will just be an expensive nop. + */ + if (unlikely(!shadow_mmio_value)) { + *ret_val = RET_PF_EMULATE; + return true; + } + } return false; } @@ -3061,6 +3028,9 @@ static int fast_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, if (!is_shadow_present_pte(spte)) break; + if (!is_shadow_present_pte(spte)) + break; + sp = sptep_to_sp(iterator.sptep); if (!is_last_spte(spte, sp->role.level)) break; @@ -3150,12 +3120,10 @@ static void mmu_free_root_page(struct kvm *kvm, hpa_t *root_hpa, sp = to_shadow_page(*root_hpa & PT64_BASE_ADDR_MASK); - if (kvm_mmu_put_root(kvm, sp)) { - if (is_tdp_mmu_page(sp)) - kvm_tdp_mmu_free_root(kvm, sp); - else if (sp->role.invalid) - kvm_mmu_prepare_zap_page(kvm, sp, invalid_list); - } + if (is_tdp_mmu_page(sp)) + kvm_tdp_mmu_put_root(kvm, sp, false); + else if (!--sp->root_count && sp->role.invalid) + kvm_mmu_prepare_zap_page(kvm, sp, invalid_list); *root_hpa = INVALID_PAGE; } @@ -3193,14 +3161,17 @@ void kvm_mmu_free_roots(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, if (mmu->shadow_root_level >= PT64_ROOT_4LEVEL && (mmu->root_level >= PT64_ROOT_4LEVEL || mmu->direct_map)) { mmu_free_root_page(kvm, &mmu->root_hpa, &invalid_list); - } else { - for (i = 0; i < 4; ++i) - if (mmu->pae_root[i] != 0) - mmu_free_root_page(kvm, - &mmu->pae_root[i], - &invalid_list); - mmu->root_hpa = INVALID_PAGE; + } else if (mmu->pae_root) { + for (i = 0; i < 4; ++i) { + if (!IS_VALID_PAE_ROOT(mmu->pae_root[i])) + continue; + + mmu_free_root_page(kvm, &mmu->pae_root[i], + &invalid_list); + mmu->pae_root[i] = INVALID_PAE_ROOT; + } } + mmu->root_hpa = INVALID_PAGE; mmu->root_pgd = 0; } @@ -3226,155 +3197,208 @@ static hpa_t mmu_alloc_root(struct kvm_vcpu *vcpu, gfn_t gfn, gva_t gva, { struct kvm_mmu_page *sp; - write_lock(&vcpu->kvm->mmu_lock); - - if (make_mmu_pages_available(vcpu)) { - write_unlock(&vcpu->kvm->mmu_lock); - return INVALID_PAGE; - } sp = kvm_mmu_get_page(vcpu, gfn, gva, level, direct, ACC_ALL); ++sp->root_count; - write_unlock(&vcpu->kvm->mmu_lock); return __pa(sp->spt); } static int mmu_alloc_direct_roots(struct kvm_vcpu *vcpu) { - u8 shadow_root_level = vcpu->arch.mmu->shadow_root_level; + struct kvm_mmu *mmu = vcpu->arch.mmu; + u8 shadow_root_level = mmu->shadow_root_level; hpa_t root; unsigned i; + int r; + + write_lock(&vcpu->kvm->mmu_lock); + r = make_mmu_pages_available(vcpu); + if (r < 0) + goto out_unlock; if (is_tdp_mmu_enabled(vcpu->kvm)) { root = kvm_tdp_mmu_get_vcpu_root_hpa(vcpu); - - if (!VALID_PAGE(root)) - return -ENOSPC; - vcpu->arch.mmu->root_hpa = root; + mmu->root_hpa = root; } else if (shadow_root_level >= PT64_ROOT_4LEVEL) { - root = mmu_alloc_root(vcpu, 0, 0, shadow_root_level, - true); - - if (!VALID_PAGE(root)) - return -ENOSPC; - vcpu->arch.mmu->root_hpa = root; + root = mmu_alloc_root(vcpu, 0, 0, shadow_root_level, true); + mmu->root_hpa = root; } else if (shadow_root_level == PT32E_ROOT_LEVEL) { + if (WARN_ON_ONCE(!mmu->pae_root)) { + r = -EIO; + goto out_unlock; + } + for (i = 0; i < 4; ++i) { - MMU_WARN_ON(VALID_PAGE(vcpu->arch.mmu->pae_root[i])); + WARN_ON_ONCE(IS_VALID_PAE_ROOT(mmu->pae_root[i])); root = mmu_alloc_root(vcpu, i << (30 - PAGE_SHIFT), i << 30, PT32_ROOT_LEVEL, true); - if (!VALID_PAGE(root)) - return -ENOSPC; - vcpu->arch.mmu->pae_root[i] = root | PT_PRESENT_MASK; + mmu->pae_root[i] = root | PT_PRESENT_MASK | + shadow_me_mask; } - vcpu->arch.mmu->root_hpa = __pa(vcpu->arch.mmu->pae_root); - } else - BUG(); + mmu->root_hpa = __pa(mmu->pae_root); + } else { + WARN_ONCE(1, "Bad TDP root level = %d\n", shadow_root_level); + r = -EIO; + goto out_unlock; + } /* root_pgd is ignored for direct MMUs. */ - vcpu->arch.mmu->root_pgd = 0; - - return 0; + mmu->root_pgd = 0; +out_unlock: + write_unlock(&vcpu->kvm->mmu_lock); + return r; } static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu) { - u64 pdptr, pm_mask; + struct kvm_mmu *mmu = vcpu->arch.mmu; + u64 pdptrs[4], pm_mask; gfn_t root_gfn, root_pgd; hpa_t root; - int i; + unsigned i; + int r; - root_pgd = vcpu->arch.mmu->get_guest_pgd(vcpu); + root_pgd = mmu->get_guest_pgd(vcpu); root_gfn = root_pgd >> PAGE_SHIFT; if (mmu_check_root(vcpu, root_gfn)) return 1; /* + * On SVM, reading PDPTRs might access guest memory, which might fault + * and thus might sleep. Grab the PDPTRs before acquiring mmu_lock. + */ + if (mmu->root_level == PT32E_ROOT_LEVEL) { + for (i = 0; i < 4; ++i) { + pdptrs[i] = mmu->get_pdptr(vcpu, i); + if (!(pdptrs[i] & PT_PRESENT_MASK)) + continue; + + if (mmu_check_root(vcpu, pdptrs[i] >> PAGE_SHIFT)) + return 1; + } + } + + write_lock(&vcpu->kvm->mmu_lock); + r = make_mmu_pages_available(vcpu); + if (r < 0) + goto out_unlock; + + /* * Do we shadow a long mode page table? If so we need to * write-protect the guests page table root. */ - if (vcpu->arch.mmu->root_level >= PT64_ROOT_4LEVEL) { - MMU_WARN_ON(VALID_PAGE(vcpu->arch.mmu->root_hpa)); - + if (mmu->root_level >= PT64_ROOT_4LEVEL) { root = mmu_alloc_root(vcpu, root_gfn, 0, - vcpu->arch.mmu->shadow_root_level, false); - if (!VALID_PAGE(root)) - return -ENOSPC; - vcpu->arch.mmu->root_hpa = root; + mmu->shadow_root_level, false); + mmu->root_hpa = root; goto set_root_pgd; } + if (WARN_ON_ONCE(!mmu->pae_root)) { + r = -EIO; + goto out_unlock; + } + /* * We shadow a 32 bit page table. This may be a legacy 2-level * or a PAE 3-level page table. In either case we need to be aware that * the shadow page table may be a PAE or a long mode page table. */ - pm_mask = PT_PRESENT_MASK; - if (vcpu->arch.mmu->shadow_root_level == PT64_ROOT_4LEVEL) + pm_mask = PT_PRESENT_MASK | shadow_me_mask; + if (mmu->shadow_root_level == PT64_ROOT_4LEVEL) { pm_mask |= PT_ACCESSED_MASK | PT_WRITABLE_MASK | PT_USER_MASK; + if (WARN_ON_ONCE(!mmu->pml4_root)) { + r = -EIO; + goto out_unlock; + } + + mmu->pml4_root[0] = __pa(mmu->pae_root) | pm_mask; + } + for (i = 0; i < 4; ++i) { - MMU_WARN_ON(VALID_PAGE(vcpu->arch.mmu->pae_root[i])); - if (vcpu->arch.mmu->root_level == PT32E_ROOT_LEVEL) { - pdptr = vcpu->arch.mmu->get_pdptr(vcpu, i); - if (!(pdptr & PT_PRESENT_MASK)) { - vcpu->arch.mmu->pae_root[i] = 0; + WARN_ON_ONCE(IS_VALID_PAE_ROOT(mmu->pae_root[i])); + + if (mmu->root_level == PT32E_ROOT_LEVEL) { + if (!(pdptrs[i] & PT_PRESENT_MASK)) { + mmu->pae_root[i] = INVALID_PAE_ROOT; continue; } - root_gfn = pdptr >> PAGE_SHIFT; - if (mmu_check_root(vcpu, root_gfn)) - return 1; + root_gfn = pdptrs[i] >> PAGE_SHIFT; } root = mmu_alloc_root(vcpu, root_gfn, i << 30, PT32_ROOT_LEVEL, false); - if (!VALID_PAGE(root)) - return -ENOSPC; - vcpu->arch.mmu->pae_root[i] = root | pm_mask; + mmu->pae_root[i] = root | pm_mask; } - vcpu->arch.mmu->root_hpa = __pa(vcpu->arch.mmu->pae_root); + + if (mmu->shadow_root_level == PT64_ROOT_4LEVEL) + mmu->root_hpa = __pa(mmu->pml4_root); + else + mmu->root_hpa = __pa(mmu->pae_root); + +set_root_pgd: + mmu->root_pgd = root_pgd; +out_unlock: + write_unlock(&vcpu->kvm->mmu_lock); + + return 0; +} + +static int mmu_alloc_special_roots(struct kvm_vcpu *vcpu) +{ + struct kvm_mmu *mmu = vcpu->arch.mmu; + u64 *pml4_root, *pae_root; /* - * If we shadow a 32 bit page table with a long mode page - * table we enter this path. + * When shadowing 32-bit or PAE NPT with 64-bit NPT, the PML4 and PDP + * tables are allocated and initialized at root creation as there is no + * equivalent level in the guest's NPT to shadow. Allocate the tables + * on demand, as running a 32-bit L1 VMM on 64-bit KVM is very rare. */ - if (vcpu->arch.mmu->shadow_root_level == PT64_ROOT_4LEVEL) { - if (vcpu->arch.mmu->lm_root == NULL) { - /* - * The additional page necessary for this is only - * allocated on demand. - */ + if (mmu->direct_map || mmu->root_level >= PT64_ROOT_4LEVEL || + mmu->shadow_root_level < PT64_ROOT_4LEVEL) + return 0; - u64 *lm_root; + /* + * This mess only works with 4-level paging and needs to be updated to + * work with 5-level paging. + */ + if (WARN_ON_ONCE(mmu->shadow_root_level != PT64_ROOT_4LEVEL)) + return -EIO; - lm_root = (void*)get_zeroed_page(GFP_KERNEL_ACCOUNT); - if (lm_root == NULL) - return 1; + if (mmu->pae_root && mmu->pml4_root) + return 0; - lm_root[0] = __pa(vcpu->arch.mmu->pae_root) | pm_mask; + /* + * The special roots should always be allocated in concert. Yell and + * bail if KVM ends up in a state where only one of the roots is valid. + */ + if (WARN_ON_ONCE(!tdp_enabled || mmu->pae_root || mmu->pml4_root)) + return -EIO; - vcpu->arch.mmu->lm_root = lm_root; - } + /* + * Unlike 32-bit NPT, the PDP table doesn't need to be in low mem, and + * doesn't need to be decrypted. + */ + pae_root = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT); + if (!pae_root) + return -ENOMEM; - vcpu->arch.mmu->root_hpa = __pa(vcpu->arch.mmu->lm_root); + pml4_root = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT); + if (!pml4_root) { + free_page((unsigned long)pae_root); + return -ENOMEM; } -set_root_pgd: - vcpu->arch.mmu->root_pgd = root_pgd; + mmu->pae_root = pae_root; + mmu->pml4_root = pml4_root; return 0; } -static int mmu_alloc_roots(struct kvm_vcpu *vcpu) -{ - if (vcpu->arch.mmu->direct_map) - return mmu_alloc_direct_roots(vcpu); - else - return mmu_alloc_shadow_roots(vcpu); -} - void kvm_mmu_sync_roots(struct kvm_vcpu *vcpu) { int i; @@ -3422,7 +3446,7 @@ void kvm_mmu_sync_roots(struct kvm_vcpu *vcpu) for (i = 0; i < 4; ++i) { hpa_t root = vcpu->arch.mmu->pae_root[i]; - if (root && VALID_PAGE(root)) { + if (IS_VALID_PAE_ROOT(root)) { root &= PT64_BASE_ADDR_MASK; sp = to_shadow_page(root); mmu_sync_children(vcpu, sp); @@ -3554,11 +3578,12 @@ static bool get_mmio_spte(struct kvm_vcpu *vcpu, u64 addr, u64 *sptep) __is_rsvd_bits_set(rsvd_check, sptes[level], level); if (reserved) { - pr_err("%s: detect reserved bits on spte, addr 0x%llx, dump hierarchy:\n", + pr_err("%s: reserved bits set on MMU-present spte, addr 0x%llx, hierarchy:\n", __func__, addr); for (level = root; level >= leaf; level--) - pr_err("------ spte 0x%llx level %d.\n", - sptes[level], level); + pr_err("------ spte = 0x%llx level = %d, rsvd bits = 0x%llx", + sptes[level], level, + rsvd_check->rsvd_bits_mask[(sptes[level] >> 7) & 1][level-1]); } return reserved; @@ -3653,6 +3678,14 @@ static bool try_async_pf(struct kvm_vcpu *vcpu, bool prefault, gfn_t gfn, struct kvm_memory_slot *slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); bool async; + /* + * Retry the page fault if the gfn hit a memslot that is being deleted + * or moved. This ensures any existing SPTEs for the old memslot will + * be zapped before KVM inserts a new MMIO SPTE for the gfn. + */ + if (slot && (slot->flags & KVM_MEMSLOT_INVALID)) + return true; + /* Don't expose private memslots to L2. */ if (is_guest_mode(vcpu) && !kvm_is_visible_memslot(slot)) { *pfn = KVM_PFN_NOSLOT; @@ -4615,12 +4648,17 @@ void kvm_init_shadow_npt_mmu(struct kvm_vcpu *vcpu, u32 cr0, u32 cr4, u32 efer, struct kvm_mmu *context = &vcpu->arch.guest_mmu; union kvm_mmu_role new_role = kvm_calc_shadow_npt_root_page_role(vcpu); - context->shadow_root_level = new_role.base.level; - __kvm_mmu_new_pgd(vcpu, nested_cr3, new_role.base, false, false); - if (new_role.as_u64 != context->mmu_role.as_u64) + if (new_role.as_u64 != context->mmu_role.as_u64) { shadow_mmu_init_context(vcpu, context, cr0, cr4, efer, new_role); + + /* + * Override the level set by the common init helper, nested TDP + * always uses the host's TDP configuration. + */ + context->shadow_root_level = new_role.base.level; + } } EXPORT_SYMBOL_GPL(kvm_init_shadow_npt_mmu); @@ -4802,16 +4840,23 @@ int kvm_mmu_load(struct kvm_vcpu *vcpu) r = mmu_topup_memory_caches(vcpu, !vcpu->arch.mmu->direct_map); if (r) goto out; - r = mmu_alloc_roots(vcpu); - kvm_mmu_sync_roots(vcpu); + r = mmu_alloc_special_roots(vcpu); + if (r) + goto out; + if (vcpu->arch.mmu->direct_map) + r = mmu_alloc_direct_roots(vcpu); + else + r = mmu_alloc_shadow_roots(vcpu); if (r) goto out; + + kvm_mmu_sync_roots(vcpu); + kvm_mmu_load_pgd(vcpu); static_call(kvm_x86_tlb_flush_current)(vcpu); out: return r; } -EXPORT_SYMBOL_GPL(kvm_mmu_load); void kvm_mmu_unload(struct kvm_vcpu *vcpu) { @@ -4820,7 +4865,6 @@ void kvm_mmu_unload(struct kvm_vcpu *vcpu) kvm_mmu_free_roots(vcpu, &vcpu->arch.guest_mmu, KVM_MMU_ROOTS_ALL); WARN_ON(VALID_PAGE(vcpu->arch.guest_mmu.root_hpa)); } -EXPORT_SYMBOL_GPL(kvm_mmu_unload); static bool need_remote_flush(u64 old, u64 new) { @@ -5169,10 +5213,10 @@ typedef bool (*slot_level_handler) (struct kvm *kvm, struct kvm_rmap_head *rmap_ static __always_inline bool slot_handle_level_range(struct kvm *kvm, struct kvm_memory_slot *memslot, slot_level_handler fn, int start_level, int end_level, - gfn_t start_gfn, gfn_t end_gfn, bool lock_flush_tlb) + gfn_t start_gfn, gfn_t end_gfn, bool flush_on_yield, + bool flush) { struct slot_rmap_walk_iterator iterator; - bool flush = false; for_each_slot_rmap_range(memslot, start_level, end_level, start_gfn, end_gfn, &iterator) { @@ -5180,7 +5224,7 @@ slot_handle_level_range(struct kvm *kvm, struct kvm_memory_slot *memslot, flush |= fn(kvm, iterator.rmap, memslot); if (need_resched() || rwlock_needbreak(&kvm->mmu_lock)) { - if (flush && lock_flush_tlb) { + if (flush && flush_on_yield) { kvm_flush_remote_tlbs_with_address(kvm, start_gfn, iterator.gfn - start_gfn + 1); @@ -5190,38 +5234,34 @@ slot_handle_level_range(struct kvm *kvm, struct kvm_memory_slot *memslot, } } - if (flush && lock_flush_tlb) { - kvm_flush_remote_tlbs_with_address(kvm, start_gfn, - end_gfn - start_gfn + 1); - flush = false; - } - return flush; } static __always_inline bool slot_handle_level(struct kvm *kvm, struct kvm_memory_slot *memslot, slot_level_handler fn, int start_level, int end_level, - bool lock_flush_tlb) + bool flush_on_yield) { return slot_handle_level_range(kvm, memslot, fn, start_level, end_level, memslot->base_gfn, memslot->base_gfn + memslot->npages - 1, - lock_flush_tlb); + flush_on_yield, false); } static __always_inline bool slot_handle_leaf(struct kvm *kvm, struct kvm_memory_slot *memslot, - slot_level_handler fn, bool lock_flush_tlb) + slot_level_handler fn, bool flush_on_yield) { return slot_handle_level(kvm, memslot, fn, PG_LEVEL_4K, - PG_LEVEL_4K, lock_flush_tlb); + PG_LEVEL_4K, flush_on_yield); } static void free_mmu_pages(struct kvm_mmu *mmu) { + if (!tdp_enabled && mmu->pae_root) + set_memory_encrypted((unsigned long)mmu->pae_root, 1); free_page((unsigned long)mmu->pae_root); - free_page((unsigned long)mmu->lm_root); + free_page((unsigned long)mmu->pml4_root); } static int __kvm_mmu_create(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu) @@ -5240,9 +5280,11 @@ static int __kvm_mmu_create(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu) * while the PDP table is a per-vCPU construct that's allocated at MMU * creation. When emulating 32-bit mode, cr3 is only 32 bits even on * x86_64. Therefore we need to allocate the PDP table in the first - * 4GB of memory, which happens to fit the DMA32 zone. Except for - * SVM's 32-bit NPT support, TDP paging doesn't use PAE paging and can - * skip allocating the PDP table. + * 4GB of memory, which happens to fit the DMA32 zone. TDP paging + * generally doesn't use PAE paging and can skip allocating the PDP + * table. The main exception, handled here, is SVM's 32-bit NPT. The + * other exception is for shadowing L1's 32-bit or PAE NPT on 64-bit + * KVM; that horror is handled on-demand by mmu_alloc_shadow_roots(). */ if (tdp_enabled && kvm_mmu_get_tdp_level(vcpu) > PT32E_ROOT_LEVEL) return 0; @@ -5252,8 +5294,22 @@ static int __kvm_mmu_create(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu) return -ENOMEM; mmu->pae_root = page_address(page); + + /* + * CR3 is only 32 bits when PAE paging is used, thus it's impossible to + * get the CPU to treat the PDPTEs as encrypted. Decrypt the page so + * that KVM's writes and the CPU's reads get along. Note, this is + * only necessary when using shadow paging, as 64-bit NPT can get at + * the C-bit even when shadowing 32-bit NPT, and SME isn't supported + * by 32-bit kernels (when KVM itself uses 32-bit NPT). + */ + if (!tdp_enabled) + set_memory_decrypted((unsigned long)mmu->pae_root, 1); + else + WARN_ON_ONCE(shadow_me_mask); + for (i = 0; i < 4; ++i) - mmu->pae_root[i] = INVALID_PAGE; + mmu->pae_root[i] = INVALID_PAE_ROOT; return 0; } @@ -5365,6 +5421,15 @@ static void kvm_mmu_zap_all_fast(struct kvm *kvm) */ kvm->arch.mmu_valid_gen = kvm->arch.mmu_valid_gen ? 0 : 1; + /* In order to ensure all threads see this change when + * handling the MMU reload signal, this must happen in the + * same critical section as kvm_reload_remote_mmus, and + * before kvm_zap_obsolete_pages as kvm_zap_obsolete_pages + * could drop the MMU lock and yield. + */ + if (is_tdp_mmu_enabled(kvm)) + kvm_tdp_mmu_invalidate_all_roots(kvm); + /* * Notify all vcpus to reload its shadow page table and flush TLB. * Then all vcpus will switch to new shadow page table with the new @@ -5377,10 +5442,13 @@ static void kvm_mmu_zap_all_fast(struct kvm *kvm) kvm_zap_obsolete_pages(kvm); - if (is_tdp_mmu_enabled(kvm)) - kvm_tdp_mmu_zap_all(kvm); - write_unlock(&kvm->mmu_lock); + + if (is_tdp_mmu_enabled(kvm)) { + read_lock(&kvm->mmu_lock); + kvm_tdp_mmu_zap_invalidated_roots(kvm); + read_unlock(&kvm->mmu_lock); + } } static bool kvm_has_zapped_obsolete_pages(struct kvm *kvm) @@ -5420,7 +5488,7 @@ void kvm_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end) struct kvm_memslots *slots; struct kvm_memory_slot *memslot; int i; - bool flush; + bool flush = false; write_lock(&kvm->mmu_lock); for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) { @@ -5433,20 +5501,31 @@ void kvm_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end) if (start >= end) continue; - slot_handle_level_range(kvm, memslot, kvm_zap_rmapp, - PG_LEVEL_4K, - KVM_MAX_HUGEPAGE_LEVEL, - start, end - 1, true); + flush = slot_handle_level_range(kvm, memslot, kvm_zap_rmapp, + PG_LEVEL_4K, + KVM_MAX_HUGEPAGE_LEVEL, + start, end - 1, true, flush); } } + if (flush) + kvm_flush_remote_tlbs_with_address(kvm, gfn_start, gfn_end); + + write_unlock(&kvm->mmu_lock); + if (is_tdp_mmu_enabled(kvm)) { - flush = kvm_tdp_mmu_zap_gfn_range(kvm, gfn_start, gfn_end); + flush = false; + + read_lock(&kvm->mmu_lock); + for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) + flush = kvm_tdp_mmu_zap_gfn_range(kvm, i, gfn_start, + gfn_end, flush, true); if (flush) - kvm_flush_remote_tlbs(kvm); - } + kvm_flush_remote_tlbs_with_address(kvm, gfn_start, + gfn_end); - write_unlock(&kvm->mmu_lock); + read_unlock(&kvm->mmu_lock); + } } static bool slot_rmap_write_protect(struct kvm *kvm, @@ -5465,10 +5544,14 @@ void kvm_mmu_slot_remove_write_access(struct kvm *kvm, write_lock(&kvm->mmu_lock); flush = slot_handle_level(kvm, memslot, slot_rmap_write_protect, start_level, KVM_MAX_HUGEPAGE_LEVEL, false); - if (is_tdp_mmu_enabled(kvm)) - flush |= kvm_tdp_mmu_wrprot_slot(kvm, memslot, PG_LEVEL_4K); write_unlock(&kvm->mmu_lock); + if (is_tdp_mmu_enabled(kvm)) { + read_lock(&kvm->mmu_lock); + flush |= kvm_tdp_mmu_wrprot_slot(kvm, memslot, start_level); + read_unlock(&kvm->mmu_lock); + } + /* * We can flush all the TLBs out of the mmu lock without TLB * corruption since we just change the spte from writable to @@ -5476,9 +5559,9 @@ void kvm_mmu_slot_remove_write_access(struct kvm *kvm, * spte from present to present (changing the spte from present * to nonpresent will flush all the TLBs immediately), in other * words, the only case we care is mmu_spte_update() where we - * have checked SPTE_HOST_WRITEABLE | SPTE_MMU_WRITEABLE - * instead of PT_WRITABLE_MASK, that means it does not depend - * on PT_WRITABLE_MASK anymore. + * have checked Host-writable | MMU-writable instead of + * PT_WRITABLE_MASK, that means it does not depend on PT_WRITABLE_MASK + * anymore. */ if (flush) kvm_arch_flush_remote_tlbs_memslot(kvm, memslot); @@ -5529,21 +5612,32 @@ void kvm_mmu_zap_collapsible_sptes(struct kvm *kvm, { /* FIXME: const-ify all uses of struct kvm_memory_slot. */ struct kvm_memory_slot *slot = (struct kvm_memory_slot *)memslot; + bool flush; write_lock(&kvm->mmu_lock); - slot_handle_leaf(kvm, slot, kvm_mmu_zap_collapsible_spte, true); + flush = slot_handle_leaf(kvm, slot, kvm_mmu_zap_collapsible_spte, true); - if (is_tdp_mmu_enabled(kvm)) - kvm_tdp_mmu_zap_collapsible_sptes(kvm, slot); + if (flush) + kvm_arch_flush_remote_tlbs_memslot(kvm, slot); write_unlock(&kvm->mmu_lock); + + if (is_tdp_mmu_enabled(kvm)) { + flush = false; + + read_lock(&kvm->mmu_lock); + flush = kvm_tdp_mmu_zap_collapsible_sptes(kvm, slot, flush); + if (flush) + kvm_arch_flush_remote_tlbs_memslot(kvm, slot); + read_unlock(&kvm->mmu_lock); + } } void kvm_arch_flush_remote_tlbs_memslot(struct kvm *kvm, - struct kvm_memory_slot *memslot) + const struct kvm_memory_slot *memslot) { /* * All current use cases for flushing the TLBs for a specific memslot - * are related to dirty logging, and do the TLB flush out of mmu_lock. + * 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. @@ -5560,10 +5654,14 @@ void kvm_mmu_slot_leaf_clear_dirty(struct kvm *kvm, write_lock(&kvm->mmu_lock); flush = slot_handle_leaf(kvm, memslot, __rmap_clear_dirty, false); - if (is_tdp_mmu_enabled(kvm)) - flush |= kvm_tdp_mmu_clear_dirty_slot(kvm, memslot); write_unlock(&kvm->mmu_lock); + if (is_tdp_mmu_enabled(kvm)) { + read_lock(&kvm->mmu_lock); + flush |= kvm_tdp_mmu_clear_dirty_slot(kvm, memslot); + read_unlock(&kvm->mmu_lock); + } + /* * It's also safe to flush TLBs out of mmu lock here as currently this * function is only used for dirty logging, in which case flushing TLB @@ -5701,25 +5799,6 @@ static void mmu_destroy_caches(void) kmem_cache_destroy(mmu_page_header_cache); } -static void kvm_set_mmio_spte_mask(void) -{ - u64 mask; - - /* - * Set a reserved PA bit in MMIO SPTEs to generate page faults with - * PFEC.RSVD=1 on MMIO accesses. 64-bit PTEs (PAE, x86-64, and EPT - * paging) support a maximum of 52 bits of PA, i.e. if the CPU supports - * 52-bit physical addresses then there are no reserved PA bits in the - * PTEs and so the reserved PA approach must be disabled. - */ - if (shadow_phys_bits < 52) - mask = BIT_ULL(51) | PT_PRESENT_MASK; - else - mask = 0; - - kvm_mmu_set_mmio_spte_mask(mask, ACC_WRITE_MASK | ACC_USER_MASK); -} - static bool get_nx_auto_mode(void) { /* Return true when CPU has the bug, and mitigations are ON */ @@ -5785,8 +5864,6 @@ int kvm_mmu_module_init(void) kvm_mmu_reset_all_pte_masks(); - kvm_set_mmio_spte_mask(); - pte_list_desc_cache = kmem_cache_create("pte_list_desc", sizeof(struct pte_list_desc), 0, SLAB_ACCOUNT, NULL); |