From e833240f3c1b0b415efb14eaa102718769d5f063 Mon Sep 17 00:00:00 2001 From: Avi Kivity Date: Sun, 9 Dec 2007 18:43:00 +0200 Subject: [PATCH] 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: Avi Kivity --- drivers/kvm/mmu.c | 41 ++++++++++------------------------------- 1 file changed, 10 insertions(+), 31 deletions(-) diff --git a/drivers/kvm/mmu.c b/drivers/kvm/mmu.c index b4dd726..ba71e8d 100644 --- a/drivers/kvm/mmu.c +++ b/drivers/kvm/mmu.c @@ -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) -- 2.7.4