In order to interoperate correctly with the rest of KVM and other Linux subsystems, the TDP MMU must correctly handle various MMU notifiers. Add a hook and handle the change_pte MMU notifier. Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell machine. This series introduced no new failures. This series can be viewed in Gerrit at: https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538 Signed-off-by: Ben Gardon <bgardon@xxxxxxxxxx> --- arch/x86/kvm/mmu/mmu.c | 46 +++++++++++++------------ arch/x86/kvm/mmu/mmu_internal.h | 13 +++++++ arch/x86/kvm/mmu/tdp_mmu.c | 61 +++++++++++++++++++++++++++++++++ arch/x86/kvm/mmu/tdp_mmu.h | 3 ++ 4 files changed, 102 insertions(+), 21 deletions(-) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 8c1e806b3d53f..0d80abe82ca93 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -122,9 +122,6 @@ module_param(dbg, bool, 0644); #define PTE_PREFETCH_NUM 8 -#define PT_FIRST_AVAIL_BITS_SHIFT 10 -#define PT64_SECOND_AVAIL_BITS_SHIFT 54 - /* * The mask used to denote special SPTEs, which can be either MMIO SPTEs or * Access Tracking SPTEs. @@ -147,13 +144,6 @@ module_param(dbg, bool, 0644); #define PT32_INDEX(address, level)\ (((address) >> PT32_LEVEL_SHIFT(level)) & ((1 << PT32_LEVEL_BITS) - 1)) - -#ifdef CONFIG_DYNAMIC_PHYSICAL_MASK -#define PT64_BASE_ADDR_MASK (physical_mask & ~(u64)(PAGE_SIZE-1)) -#else -#define PT64_BASE_ADDR_MASK (((1ULL << 52) - 1) & ~(u64)(PAGE_SIZE-1)) -#endif - #define PT32_BASE_ADDR_MASK PAGE_MASK #define PT32_DIR_BASE_ADDR_MASK \ (PAGE_MASK & ~((1ULL << (PAGE_SHIFT + PT32_LEVEL_BITS)) - 1)) @@ -170,9 +160,6 @@ module_param(dbg, bool, 0644); #include <trace/events/kvm.h> -#define SPTE_HOST_WRITEABLE (1ULL << PT_FIRST_AVAIL_BITS_SHIFT) -#define SPTE_MMU_WRITEABLE (1ULL << (PT_FIRST_AVAIL_BITS_SHIFT + 1)) - /* make pte_list_desc fit well in cache line */ #define PTE_LIST_EXT 3 @@ -1708,6 +1695,21 @@ static int kvm_unmap_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, return kvm_zap_rmapp(kvm, rmap_head); } +u64 kvm_mmu_changed_pte_notifier_make_spte(u64 old_spte, kvm_pfn_t new_pfn) +{ + u64 new_spte; + + new_spte = old_spte & ~PT64_BASE_ADDR_MASK; + new_spte |= (u64)new_pfn << PAGE_SHIFT; + + new_spte &= ~PT_WRITABLE_MASK; + new_spte &= ~SPTE_HOST_WRITEABLE; + + new_spte = mark_spte_for_access_track(new_spte); + + return new_spte; +} + 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) @@ -1733,13 +1735,8 @@ static int kvm_set_pte_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, pte_list_remove(rmap_head, sptep); goto restart; } else { - new_spte = *sptep & ~PT64_BASE_ADDR_MASK; - new_spte |= (u64)new_pfn << PAGE_SHIFT; - - new_spte &= ~PT_WRITABLE_MASK; - new_spte &= ~SPTE_HOST_WRITEABLE; - - new_spte = mark_spte_for_access_track(new_spte); + new_spte = kvm_mmu_changed_pte_notifier_make_spte( + *sptep, new_pfn); mmu_spte_clear_track_bits(sptep); mmu_spte_set(sptep, new_spte); @@ -1895,7 +1892,14 @@ int kvm_unmap_hva_range(struct kvm *kvm, unsigned long start, unsigned long end, int kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte) { - return kvm_handle_hva(kvm, hva, (unsigned long)&pte, kvm_set_pte_rmapp); + int r; + + r = kvm_handle_hva(kvm, hva, (unsigned long)&pte, kvm_set_pte_rmapp); + + if (kvm->arch.tdp_mmu_enabled) + r |= kvm_tdp_mmu_set_spte_hva(kvm, hva, &pte); + + return r; } static int kvm_age_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, diff --git a/arch/x86/kvm/mmu/mmu_internal.h b/arch/x86/kvm/mmu/mmu_internal.h index 228bda0885552..8eaa6e4764bce 100644 --- a/arch/x86/kvm/mmu/mmu_internal.h +++ b/arch/x86/kvm/mmu/mmu_internal.h @@ -80,6 +80,12 @@ bool kvm_mmu_slot_gfn_write_protect(struct kvm *kvm, (PT64_BASE_ADDR_MASK & ((1ULL << (PAGE_SHIFT + (((level) - 1) \ * PT64_LEVEL_BITS))) - 1)) +#ifdef CONFIG_DYNAMIC_PHYSICAL_MASK +#define PT64_BASE_ADDR_MASK (physical_mask & ~(u64)(PAGE_SIZE-1)) +#else +#define PT64_BASE_ADDR_MASK (((1ULL << 52) - 1) & ~(u64)(PAGE_SIZE-1)) +#endif + extern u64 shadow_user_mask; extern u64 shadow_accessed_mask; extern u64 shadow_present_mask; @@ -89,6 +95,12 @@ extern u64 shadow_present_mask; #define ACC_USER_MASK PT_USER_MASK #define ACC_ALL (ACC_EXEC_MASK | ACC_WRITE_MASK | ACC_USER_MASK) +#define PT_FIRST_AVAIL_BITS_SHIFT 10 +#define PT64_SECOND_AVAIL_BITS_SHIFT 54 + +#define SPTE_HOST_WRITEABLE (1ULL << PT_FIRST_AVAIL_BITS_SHIFT) +#define SPTE_MMU_WRITEABLE (1ULL << (PT_FIRST_AVAIL_BITS_SHIFT + 1)) + /* Functions for interpreting SPTEs */ kvm_pfn_t spte_to_pfn(u64 pte); bool is_mmio_spte(u64 spte); @@ -138,5 +150,6 @@ bool is_nx_huge_page_enabled(void); void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc); u64 mark_spte_for_access_track(u64 spte); +u64 kvm_mmu_changed_pte_notifier_make_spte(u64 old_spte, kvm_pfn_t new_pfn); #endif /* __KVM_X86_MMU_INTERNAL_H */ diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c index 0a4b98669b3ef..3119583409131 100644 --- a/arch/x86/kvm/mmu/tdp_mmu.c +++ b/arch/x86/kvm/mmu/tdp_mmu.c @@ -722,3 +722,64 @@ int kvm_tdp_mmu_test_age_hva(struct kvm *kvm, unsigned long hva) return kvm_tdp_mmu_handle_hva_range(kvm, hva, hva + 1, 0, test_age_gfn); } + +/* + * Handle the changed_pte MMU notifier for the TDP MMU. + * data is a pointer to the new pte_t mapping the HVA specified by the MMU + * notifier. + * Returns non-zero if a flush is needed before releasing the MMU lock. + */ +static int set_tdp_spte(struct kvm *kvm, struct kvm_memory_slot *slot, + struct kvm_mmu_page *root, gfn_t gfn, gfn_t unused, + unsigned long data) +{ + struct tdp_iter iter; + pte_t *ptep = (pte_t *)data; + kvm_pfn_t new_pfn; + u64 new_spte; + int need_flush = 0; + int as_id = kvm_mmu_page_as_id(root); + + WARN_ON(pte_huge(*ptep)); + + new_pfn = pte_pfn(*ptep); + + for_each_tdp_pte_root(iter, root, gfn, gfn + 1) { + if (iter.level != PG_LEVEL_4K) + continue; + + if (!is_shadow_present_pte(iter.old_spte)) + break; + + *iter.sptep = 0; + handle_changed_spte(kvm, as_id, iter.gfn, iter.old_spte, + new_spte, iter.level); + + kvm_flush_remote_tlbs_with_address(kvm, iter.gfn, 1); + + if (!pte_write(*ptep)) { + new_spte = kvm_mmu_changed_pte_notifier_make_spte( + iter.old_spte, new_pfn); + + *iter.sptep = new_spte; + handle_changed_spte(kvm, as_id, iter.gfn, iter.old_spte, + new_spte, iter.level); + } + + need_flush = 1; + } + + if (need_flush) + kvm_flush_remote_tlbs_with_address(kvm, gfn, 1); + + return 0; +} + +int kvm_tdp_mmu_set_spte_hva(struct kvm *kvm, unsigned long address, + pte_t *host_ptep) +{ + return kvm_tdp_mmu_handle_hva_range(kvm, address, address + 1, + (unsigned long)host_ptep, + set_tdp_spte); +} + diff --git a/arch/x86/kvm/mmu/tdp_mmu.h b/arch/x86/kvm/mmu/tdp_mmu.h index f316773b7b5a8..5a399aa60b8d8 100644 --- a/arch/x86/kvm/mmu/tdp_mmu.h +++ b/arch/x86/kvm/mmu/tdp_mmu.h @@ -25,4 +25,7 @@ int kvm_tdp_mmu_zap_hva_range(struct kvm *kvm, unsigned long start, int kvm_tdp_mmu_age_hva_range(struct kvm *kvm, unsigned long start, unsigned long end); int kvm_tdp_mmu_test_age_hva(struct kvm *kvm, unsigned long hva); + +int kvm_tdp_mmu_set_spte_hva(struct kvm *kvm, unsigned long address, + pte_t *host_ptep); #endif /* __KVM_X86_MMU_TDP_MMU_H */ -- 2.28.0.709.gb0816b6eb0-goog
