From 17ac10ad2bb7d8c4f401668484b2e661a15726c6 Mon Sep 17 00:00:00 2001 From: Avi Kivity Date: Fri, 5 Jan 2007 16:36:40 -0800 Subject: [PATCH] [PATCH] KVM: MU: Special treatment for shadow pae root pages Since we're not going to cache the pae-mode shadow root pages, allocate a single pae shadow that will hold the four lower-level pages, which will act as roots. Signed-off-by: Avi Kivity Acked-by: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/kvm/kvm.h | 17 +------ drivers/kvm/mmu.c | 110 +++++++++++++++++++++++++++++++++------------- 2 files changed, 82 insertions(+), 45 deletions(-) diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h index 8323f4009362..abe40dd34eea 100644 --- a/drivers/kvm/kvm.h +++ b/drivers/kvm/kvm.h @@ -123,6 +123,8 @@ struct kvm_mmu { hpa_t root_hpa; int root_level; int shadow_root_level; + + u64 *pae_root; }; struct kvm_guest_debug { @@ -548,19 +550,4 @@ static inline u32 get_rdx_init_val(void) #define TSS_REDIRECTION_SIZE (256 / 8) #define RMODE_TSS_SIZE (TSS_BASE_SIZE + TSS_REDIRECTION_SIZE + TSS_IOPB_SIZE + 1) -#ifdef CONFIG_X86_64 - -/* - * When emulating 32-bit mode, cr3 is only 32 bits even on x86_64. Therefore - * we need to allocate shadow page tables in the first 4GB of memory, which - * happens to fit the DMA32 zone. - */ -#define GFP_KVM_MMU (GFP_KERNEL | __GFP_DMA32) - -#else - -#define GFP_KVM_MMU GFP_KERNEL - -#endif - #endif diff --git a/drivers/kvm/mmu.c b/drivers/kvm/mmu.c index 0f27beb6c5df..1dcbbd511660 100644 --- a/drivers/kvm/mmu.c +++ b/drivers/kvm/mmu.c @@ -420,19 +420,63 @@ static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, hpa_t p) } } +static void mmu_free_roots(struct kvm_vcpu *vcpu) +{ + int i; + +#ifdef CONFIG_X86_64 + if (vcpu->mmu.shadow_root_level == PT64_ROOT_LEVEL) { + hpa_t root = vcpu->mmu.root_hpa; + + ASSERT(VALID_PAGE(root)); + release_pt_page_64(vcpu, root, PT64_ROOT_LEVEL); + vcpu->mmu.root_hpa = INVALID_PAGE; + return; + } +#endif + for (i = 0; i < 4; ++i) { + hpa_t root = vcpu->mmu.pae_root[i]; + + ASSERT(VALID_PAGE(root)); + root &= PT64_BASE_ADDR_MASK; + release_pt_page_64(vcpu, root, PT32E_ROOT_LEVEL - 1); + vcpu->mmu.pae_root[i] = INVALID_PAGE; + } + vcpu->mmu.root_hpa = INVALID_PAGE; +} + +static void mmu_alloc_roots(struct kvm_vcpu *vcpu) +{ + int i; + +#ifdef CONFIG_X86_64 + if (vcpu->mmu.shadow_root_level == PT64_ROOT_LEVEL) { + hpa_t root = vcpu->mmu.root_hpa; + + ASSERT(!VALID_PAGE(root)); + root = kvm_mmu_alloc_page(vcpu, NULL); + vcpu->mmu.root_hpa = root; + return; + } +#endif + for (i = 0; i < 4; ++i) { + hpa_t root = vcpu->mmu.pae_root[i]; + + ASSERT(!VALID_PAGE(root)); + root = kvm_mmu_alloc_page(vcpu, NULL); + vcpu->mmu.pae_root[i] = root | PT_PRESENT_MASK; + } + vcpu->mmu.root_hpa = __pa(vcpu->mmu.pae_root); +} + static void nonpaging_flush(struct kvm_vcpu *vcpu) { hpa_t root = vcpu->mmu.root_hpa; ++kvm_stat.tlb_flush; pgprintk("nonpaging_flush\n"); - ASSERT(VALID_PAGE(root)); - release_pt_page_64(vcpu, root, vcpu->mmu.shadow_root_level); - root = kvm_mmu_alloc_page(vcpu, NULL); - ASSERT(VALID_PAGE(root)); - vcpu->mmu.root_hpa = root; - if (is_paging(vcpu)) - root |= (vcpu->cr3 & (CR3_PCD_MASK | CR3_WPT_MASK)); + mmu_free_roots(vcpu); + mmu_alloc_roots(vcpu); kvm_arch_ops->set_cr3(vcpu, root); kvm_arch_ops->tlb_flush(vcpu); } @@ -475,13 +519,7 @@ static void nonpaging_inval_page(struct kvm_vcpu *vcpu, gva_t addr) static void nonpaging_free(struct kvm_vcpu *vcpu) { - hpa_t root; - - ASSERT(vcpu); - root = vcpu->mmu.root_hpa; - if (VALID_PAGE(root)) - release_pt_page_64(vcpu, root, vcpu->mmu.shadow_root_level); - vcpu->mmu.root_hpa = INVALID_PAGE; + mmu_free_roots(vcpu); } static int nonpaging_init_context(struct kvm_vcpu *vcpu) @@ -495,7 +533,7 @@ static int nonpaging_init_context(struct kvm_vcpu *vcpu) context->free = nonpaging_free; context->root_level = PT32E_ROOT_LEVEL; context->shadow_root_level = PT32E_ROOT_LEVEL; - context->root_hpa = kvm_mmu_alloc_page(vcpu, NULL); + mmu_alloc_roots(vcpu); ASSERT(VALID_PAGE(context->root_hpa)); kvm_arch_ops->set_cr3(vcpu, context->root_hpa); return 0; @@ -647,7 +685,7 @@ static void paging_free(struct kvm_vcpu *vcpu) #include "paging_tmpl.h" #undef PTTYPE -static int paging64_init_context(struct kvm_vcpu *vcpu) +static int paging64_init_context_common(struct kvm_vcpu *vcpu, int level) { struct kvm_mmu *context = &vcpu->mmu; @@ -657,15 +695,20 @@ static int paging64_init_context(struct kvm_vcpu *vcpu) context->inval_page = paging_inval_page; context->gva_to_gpa = paging64_gva_to_gpa; context->free = paging_free; - context->root_level = PT64_ROOT_LEVEL; - context->shadow_root_level = PT64_ROOT_LEVEL; - context->root_hpa = kvm_mmu_alloc_page(vcpu, NULL); + context->root_level = level; + context->shadow_root_level = level; + mmu_alloc_roots(vcpu); ASSERT(VALID_PAGE(context->root_hpa)); kvm_arch_ops->set_cr3(vcpu, context->root_hpa | (vcpu->cr3 & (CR3_PCD_MASK | CR3_WPT_MASK))); return 0; } +static int paging64_init_context(struct kvm_vcpu *vcpu) +{ + return paging64_init_context_common(vcpu, PT64_ROOT_LEVEL); +} + static int paging32_init_context(struct kvm_vcpu *vcpu) { struct kvm_mmu *context = &vcpu->mmu; @@ -677,7 +720,7 @@ static int paging32_init_context(struct kvm_vcpu *vcpu) context->free = paging_free; context->root_level = PT32_ROOT_LEVEL; context->shadow_root_level = PT32E_ROOT_LEVEL; - context->root_hpa = kvm_mmu_alloc_page(vcpu, NULL); + mmu_alloc_roots(vcpu); ASSERT(VALID_PAGE(context->root_hpa)); kvm_arch_ops->set_cr3(vcpu, context->root_hpa | (vcpu->cr3 & (CR3_PCD_MASK | CR3_WPT_MASK))); @@ -686,14 +729,7 @@ static int paging32_init_context(struct kvm_vcpu *vcpu) static int paging32E_init_context(struct kvm_vcpu *vcpu) { - int ret; - - if ((ret = paging64_init_context(vcpu))) - return ret; - - vcpu->mmu.root_level = PT32E_ROOT_LEVEL; - vcpu->mmu.shadow_root_level = PT32E_ROOT_LEVEL; - return 0; + return paging64_init_context_common(vcpu, PT32E_ROOT_LEVEL); } static int init_kvm_mmu(struct kvm_vcpu *vcpu) @@ -737,26 +773,40 @@ static void free_mmu_pages(struct kvm_vcpu *vcpu) __free_page(pfn_to_page(page->page_hpa >> PAGE_SHIFT)); page->page_hpa = INVALID_PAGE; } + free_page((unsigned long)vcpu->mmu.pae_root); } static int alloc_mmu_pages(struct kvm_vcpu *vcpu) { + struct page *page; int i; ASSERT(vcpu); for (i = 0; i < KVM_NUM_MMU_PAGES; i++) { - struct page *page; struct kvm_mmu_page *page_header = &vcpu->page_header_buf[i]; INIT_LIST_HEAD(&page_header->link); - if ((page = alloc_page(GFP_KVM_MMU)) == NULL) + if ((page = alloc_page(GFP_KERNEL)) == NULL) goto error_1; page->private = (unsigned long)page_header; page_header->page_hpa = (hpa_t)page_to_pfn(page) << PAGE_SHIFT; memset(__va(page_header->page_hpa), 0, PAGE_SIZE); list_add(&page_header->link, &vcpu->free_pages); } + + /* + * When emulating 32-bit mode, cr3 is only 32 bits even on x86_64. + * Therefore we need to allocate shadow page tables in the first + * 4GB of memory, which happens to fit the DMA32 zone. + */ + page = alloc_page(GFP_KERNEL | __GFP_DMA32); + if (!page) + goto error_1; + vcpu->mmu.pae_root = page_address(page); + for (i = 0; i < 4; ++i) + vcpu->mmu.pae_root[i] = INVALID_PAGE; + return 0; error_1: -- 2.30.2