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[PATCH] KVM: MU: Special treatment for shadow pae root pages

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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 <avi@qumranet.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Avi Kivity 2007-01-05 16:36:40 -08:00 committed by Linus Torvalds
parent ac79c978f1
commit 17ac10ad2b
2 changed files with 82 additions and 45 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

17
drivers/kvm/kvm.h
View file

@ -123,6 +123,8 @@ struct kvm_mmu {
hpa_t root_hpa; hpa_t root_hpa;
int root_level; int root_level;
int shadow_root_level; int shadow_root_level;
u64 *pae_root;
}; };
struct kvm_guest_debug { struct kvm_guest_debug {
@ -548,19 +550,4 @@ static inline u32 get_rdx_init_val(void)
#define TSS_REDIRECTION_SIZE (256 / 8) #define TSS_REDIRECTION_SIZE (256 / 8)
#define RMODE_TSS_SIZE (TSS_BASE_SIZE + TSS_REDIRECTION_SIZE + TSS_IOPB_SIZE + 1) #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 #endif

110
drivers/kvm/mmu.c
View file

@ -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) static void nonpaging_flush(struct kvm_vcpu *vcpu)
{ {
hpa_t root = vcpu->mmu.root_hpa; hpa_t root = vcpu->mmu.root_hpa;
++kvm_stat.tlb_flush; ++kvm_stat.tlb_flush;
pgprintk("nonpaging_flush\n"); pgprintk("nonpaging_flush\n");
ASSERT(VALID_PAGE(root)); mmu_free_roots(vcpu);
release_pt_page_64(vcpu, root, vcpu->mmu.shadow_root_level); mmu_alloc_roots(vcpu);
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));
kvm_arch_ops->set_cr3(vcpu, root); kvm_arch_ops->set_cr3(vcpu, root);
kvm_arch_ops->tlb_flush(vcpu); 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) static void nonpaging_free(struct kvm_vcpu *vcpu)
{ {
hpa_t root; mmu_free_roots(vcpu);
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;
} }
static int nonpaging_init_context(struct kvm_vcpu *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->free = nonpaging_free;
context->root_level = PT32E_ROOT_LEVEL; context->root_level = PT32E_ROOT_LEVEL;
context->shadow_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)); ASSERT(VALID_PAGE(context->root_hpa));
kvm_arch_ops->set_cr3(vcpu, context->root_hpa); kvm_arch_ops->set_cr3(vcpu, context->root_hpa);
return 0; return 0;
@ -647,7 +685,7 @@ static void paging_free(struct kvm_vcpu *vcpu)
#include "paging_tmpl.h" #include "paging_tmpl.h"
#undef PTTYPE #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; 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->inval_page = paging_inval_page;
context->gva_to_gpa = paging64_gva_to_gpa; context->gva_to_gpa = paging64_gva_to_gpa;
context->free = paging_free; context->free = paging_free;
context->root_level = PT64_ROOT_LEVEL; context->root_level = level;
context->shadow_root_level = PT64_ROOT_LEVEL; context->shadow_root_level = level;
context->root_hpa = kvm_mmu_alloc_page(vcpu, NULL); mmu_alloc_roots(vcpu);
ASSERT(VALID_PAGE(context->root_hpa)); ASSERT(VALID_PAGE(context->root_hpa));
kvm_arch_ops->set_cr3(vcpu, context->root_hpa | kvm_arch_ops->set_cr3(vcpu, context->root_hpa |
(vcpu->cr3 & (CR3_PCD_MASK | CR3_WPT_MASK))); (vcpu->cr3 & (CR3_PCD_MASK | CR3_WPT_MASK)));
return 0; 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) static int paging32_init_context(struct kvm_vcpu *vcpu)
{ {
struct kvm_mmu *context = &vcpu->mmu; struct kvm_mmu *context = &vcpu->mmu;
@ -677,7 +720,7 @@ static int paging32_init_context(struct kvm_vcpu *vcpu)
context->free = paging_free; context->free = paging_free;
context->root_level = PT32_ROOT_LEVEL; context->root_level = PT32_ROOT_LEVEL;
context->shadow_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)); ASSERT(VALID_PAGE(context->root_hpa));
kvm_arch_ops->set_cr3(vcpu, context->root_hpa | kvm_arch_ops->set_cr3(vcpu, context->root_hpa |
(vcpu->cr3 & (CR3_PCD_MASK | CR3_WPT_MASK))); (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) static int paging32E_init_context(struct kvm_vcpu *vcpu)
{ {
int ret; return paging64_init_context_common(vcpu, PT32E_ROOT_LEVEL);
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;
} }
static int init_kvm_mmu(struct kvm_vcpu *vcpu) 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)); __free_page(pfn_to_page(page->page_hpa >> PAGE_SHIFT));
page->page_hpa = INVALID_PAGE; page->page_hpa = INVALID_PAGE;
} }
free_page((unsigned long)vcpu->mmu.pae_root);
} }
static int alloc_mmu_pages(struct kvm_vcpu *vcpu) static int alloc_mmu_pages(struct kvm_vcpu *vcpu)
{ {
struct page *page;
int i; int i;
ASSERT(vcpu); ASSERT(vcpu);
for (i = 0; i < KVM_NUM_MMU_PAGES; i++) { for (i = 0; i < KVM_NUM_MMU_PAGES; i++) {
struct page *page;
struct kvm_mmu_page *page_header = &vcpu->page_header_buf[i]; struct kvm_mmu_page *page_header = &vcpu->page_header_buf[i];
INIT_LIST_HEAD(&page_header->link); INIT_LIST_HEAD(&page_header->link);
if ((page = alloc_page(GFP_KVM_MMU)) == NULL) if ((page = alloc_page(GFP_KERNEL)) == NULL)
goto error_1; goto error_1;
page->private = (unsigned long)page_header; page->private = (unsigned long)page_header;
page_header->page_hpa = (hpa_t)page_to_pfn(page) << PAGE_SHIFT; page_header->page_hpa = (hpa_t)page_to_pfn(page) << PAGE_SHIFT;
memset(__va(page_header->page_hpa), 0, PAGE_SIZE); memset(__va(page_header->page_hpa), 0, PAGE_SIZE);
list_add(&page_header->link, &vcpu->free_pages); 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; return 0;
error_1: error_1: