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Commit 17ac10ad authored by Avi Kivity's avatar Avi Kivity Committed by Linus Torvalds
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[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: default avatarAvi Kivity <avi@qumranet.com>
Acked-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent ac79c978

drivers/kvm/kvm.h

+2 −15
Original line number Diff line number Diff line
@@ -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

drivers/kvm/mmu.c

+80 −30
Original line number Diff line number Diff line
@@ -420,19 +420,63 @@ static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, hpa_t p) 
	}

}



static void nonpaging_flush(struct kvm_vcpu *vcpu)

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;



	++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);

		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;

	if (is_paging(vcpu))

		root |= (vcpu->cr3 & (CR3_PCD_MASK | CR3_WPT_MASK));

		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");

	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: