diff options
| -rw-r--r-- | arch/x86/kvm/mmu.c | 10 | ||||
| -rw-r--r-- | arch/x86/kvm/paging_tmpl.h | 54 | ||||
| -rw-r--r-- | include/asm-x86/kvm_host.h | 2 |
3 files changed, 66 insertions, 0 deletions
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 731e6fe9cb0..90f01169c8f 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -871,6 +871,12 @@ static void nonpaging_prefetch_page(struct kvm_vcpu *vcpu, sp->spt[i] = shadow_trap_nonpresent_pte; } +static int nonpaging_sync_page(struct kvm_vcpu *vcpu, + struct kvm_mmu_page *sp) +{ + return 1; +} + static struct kvm_mmu_page *kvm_mmu_lookup_page(struct kvm *kvm, gfn_t gfn) { unsigned index; @@ -1547,6 +1553,7 @@ static int nonpaging_init_context(struct kvm_vcpu *vcpu) context->gva_to_gpa = nonpaging_gva_to_gpa; context->free = nonpaging_free; context->prefetch_page = nonpaging_prefetch_page; + context->sync_page = nonpaging_sync_page; context->root_level = 0; context->shadow_root_level = PT32E_ROOT_LEVEL; context->root_hpa = INVALID_PAGE; @@ -1594,6 +1601,7 @@ static int paging64_init_context_common(struct kvm_vcpu *vcpu, int level) context->page_fault = paging64_page_fault; context->gva_to_gpa = paging64_gva_to_gpa; context->prefetch_page = paging64_prefetch_page; + context->sync_page = paging64_sync_page; context->free = paging_free; context->root_level = level; context->shadow_root_level = level; @@ -1615,6 +1623,7 @@ static int paging32_init_context(struct kvm_vcpu *vcpu) context->gva_to_gpa = paging32_gva_to_gpa; context->free = paging_free; context->prefetch_page = paging32_prefetch_page; + context->sync_page = paging32_sync_page; context->root_level = PT32_ROOT_LEVEL; context->shadow_root_level = PT32E_ROOT_LEVEL; context->root_hpa = INVALID_PAGE; @@ -1634,6 +1643,7 @@ static int init_kvm_tdp_mmu(struct kvm_vcpu *vcpu) context->page_fault = tdp_page_fault; context->free = nonpaging_free; context->prefetch_page = nonpaging_prefetch_page; + context->sync_page = nonpaging_sync_page; context->shadow_root_level = kvm_x86_ops->get_tdp_level(); context->root_hpa = INVALID_PAGE; diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h index e9fbaa44d44..776fb6d2fd8 100644 --- a/arch/x86/kvm/paging_tmpl.h +++ b/arch/x86/kvm/paging_tmpl.h @@ -507,6 +507,60 @@ static void FNAME(prefetch_page)(struct kvm_vcpu *vcpu, } } +/* + * Using the cached information from sp->gfns is safe because: + * - The spte has a reference to the struct page, so the pfn for a given gfn + * can't change unless all sptes pointing to it are nuked first. + * - Alias changes zap the entire shadow cache. + */ +static int FNAME(sync_page)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp) +{ + int i, offset, nr_present; + + offset = nr_present = 0; + + if (PTTYPE == 32) + offset = sp->role.quadrant << PT64_LEVEL_BITS; + + for (i = 0; i < PT64_ENT_PER_PAGE; i++) { + unsigned pte_access; + pt_element_t gpte; + gpa_t pte_gpa; + gfn_t gfn = sp->gfns[i]; + + if (!is_shadow_present_pte(sp->spt[i])) + continue; + + pte_gpa = gfn_to_gpa(sp->gfn); + pte_gpa += (i+offset) * sizeof(pt_element_t); + + if (kvm_read_guest_atomic(vcpu->kvm, pte_gpa, &gpte, + sizeof(pt_element_t))) + return -EINVAL; + + if (gpte_to_gfn(gpte) != gfn || !is_present_pte(gpte) || + !(gpte & PT_ACCESSED_MASK)) { + u64 nonpresent; + + rmap_remove(vcpu->kvm, &sp->spt[i]); + if (is_present_pte(gpte)) + nonpresent = shadow_trap_nonpresent_pte; + else + nonpresent = shadow_notrap_nonpresent_pte; + set_shadow_pte(&sp->spt[i], nonpresent); + continue; + } + + nr_present++; + pte_access = sp->role.access & FNAME(gpte_access)(vcpu, gpte); + set_spte(vcpu, &sp->spt[i], pte_access, 0, 0, + is_dirty_pte(gpte), 0, gfn, + spte_to_pfn(sp->spt[i]), true); + } + + return !nr_present; +} + #undef pt_element_t #undef guest_walker #undef shadow_walker diff --git a/include/asm-x86/kvm_host.h b/include/asm-x86/kvm_host.h index 805629c0f15..8bad9bd9b37 100644 --- a/include/asm-x86/kvm_host.h +++ b/include/asm-x86/kvm_host.h @@ -220,6 +220,8 @@ struct kvm_mmu { gpa_t (*gva_to_gpa)(struct kvm_vcpu *vcpu, gva_t gva); void (*prefetch_page)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *page); + int (*sync_page)(struct kvm_vcpu *vcpu, + struct kvm_mmu_page *sp); hpa_t root_hpa; int root_level; int shadow_root_level; |