Commit e833240f authored by Avi Kivity's avatar Avi Kivity
Browse files

KVM: MMU: Use mmu_set_spte() for real-mode shadows 



In addition to removing some duplicated code, this also handles the unlikely
case of real-mode code updating a guest page table.  This can happen when
one vcpu (in real mode) touches a second vcpu's (in protected mode) page
tables, or if a vcpu switches to real mode, touches page tables, and switches
back.

Signed-off-by: default avatarAvi Kivity <avi@qumranet.com>
parent bc750ba8

drivers/kvm/mmu.c

+10 −31
Original line number Diff line number Diff line
@@ -966,40 +966,23 @@ static void nonpaging_new_cr3(struct kvm_vcpu *vcpu) 
{

}



static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, struct page *page)

static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, int write, gfn_t gfn)

{

	int level = PT32E_ROOT_LEVEL;

	hpa_t table_addr = vcpu->mmu.root_hpa;

	int pt_write = 0;



	for (; ; level--) {

		u32 index = PT64_INDEX(v, level);

		u64 *table;

		u64 pte;



		ASSERT(VALID_PAGE(table_addr));

		table = __va(table_addr);



		if (level == 1) {

			int was_rmapped;



			pte = table[index];

			was_rmapped = is_rmap_pte(pte);

			if (is_shadow_present_pte(pte) && is_writeble_pte(pte)) {

				kvm_release_page_clean(page);

				return 0;

			}

			mark_page_dirty(vcpu->kvm, v >> PAGE_SHIFT);

			page_header_update_slot(vcpu->kvm, table,

						v >> PAGE_SHIFT);

			table[index] = page_to_phys(page)

				| PT_PRESENT_MASK | PT_WRITABLE_MASK

				| PT_USER_MASK;

			if (!was_rmapped)

				rmap_add(vcpu, &table[index], v >> PAGE_SHIFT);

			else

				kvm_release_page_clean(page);



			return 0;

			mmu_set_spte(vcpu, &table[index], ACC_ALL, ACC_ALL,

				     0, write, 1, &pt_write, gfn);

			return pt_write || is_io_pte(table[index]);

		}



		if (table[index] == shadow_trap_nonpresent_pte) {
@@ -1013,7 +996,6 @@ static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, struct page *page) 
						     1, ACC_ALL, &table[index]);

			if (!new_table) {

				pgprintk("nonpaging_map: ENOMEM\n");

				kvm_release_page_clean(page);

				return -ENOMEM;

			}
@@ -1114,9 +1096,10 @@ static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, gva_t vaddr) 
static int nonpaging_page_fault(struct kvm_vcpu *vcpu, gva_t gva,

				u32 error_code)

{

	struct page *page;

	gfn_t gfn;

	int r;



	pgprintk("%s: gva %lx error %x\n", __FUNCTION__, gva, error_code);

	r = mmu_topup_memory_caches(vcpu);

	if (r)

		return r;
@@ -1124,14 +1107,10 @@ static int nonpaging_page_fault(struct kvm_vcpu *vcpu, gva_t gva, 
	ASSERT(vcpu);

	ASSERT(VALID_PAGE(vcpu->mmu.root_hpa));



	page = gfn_to_page(vcpu->kvm, gva >> PAGE_SHIFT);



	if (is_error_page(page)) {

		kvm_release_page_clean(page);

		return 1;

	}

	gfn = gva >> PAGE_SHIFT;



	return nonpaging_map(vcpu, gva & PAGE_MASK, page);

	return nonpaging_map(vcpu, gva & PAGE_MASK,

			     error_code & PFERR_WRITE_MASK, gfn);

}



static void nonpaging_free(struct kvm_vcpu *vcpu)

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