From 815af8d42ee3f844c0ceaf2104bd9c6a0bb1e26c Mon Sep 17 00:00:00 2001 From: Avi Kivity Date: Fri, 5 Jan 2007 16:36:44 -0800 Subject: [PATCH] [PATCH] KVM: MMU: Let the walker extract the target page gfn from the pte This fixes a problem where set_pte_common() looked for shadowed pages based on the page directory gfn (a huge page) instead of the actual gfn being mapped. Signed-off-by: Avi Kivity Acked-by: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/kvm/mmu.c | 7 ++++--- drivers/kvm/paging_tmpl.h | 41 ++++++++++++++++++++++++++------------- 2 files changed, 31 insertions(+), 17 deletions(-) diff --git a/drivers/kvm/mmu.c b/drivers/kvm/mmu.c index ba813f49f8..ceae25bfd4 100644 --- a/drivers/kvm/mmu.c +++ b/drivers/kvm/mmu.c @@ -752,7 +752,8 @@ static inline void set_pte_common(struct kvm_vcpu *vcpu, u64 *shadow_pte, gpa_t gaddr, int dirty, - u64 access_bits) + u64 access_bits, + gfn_t gfn) { hpa_t paddr; @@ -779,10 +780,10 @@ static inline void set_pte_common(struct kvm_vcpu *vcpu, if (access_bits & PT_WRITABLE_MASK) { struct kvm_mmu_page *shadow; - shadow = kvm_mmu_lookup_page(vcpu, gaddr >> PAGE_SHIFT); + shadow = kvm_mmu_lookup_page(vcpu, gfn); if (shadow) { pgprintk("%s: found shadow page for %lx, marking ro\n", - __FUNCTION__, (gfn_t)(gaddr >> PAGE_SHIFT)); + __FUNCTION__, gfn); access_bits &= ~PT_WRITABLE_MASK; *shadow_pte &= ~PT_WRITABLE_MASK; } diff --git a/drivers/kvm/paging_tmpl.h b/drivers/kvm/paging_tmpl.h index cd71973c78..cf4b74cc75 100644 --- a/drivers/kvm/paging_tmpl.h +++ b/drivers/kvm/paging_tmpl.h @@ -62,6 +62,7 @@ struct guest_walker { pt_element_t *table; pt_element_t *ptep; pt_element_t inherited_ar; + gfn_t gfn; }; /* @@ -113,12 +114,23 @@ static void FNAME(walk_addr)(struct guest_walker *walker, if (is_present_pte(*ptep) && !(*ptep & PT_ACCESSED_MASK)) *ptep |= PT_ACCESSED_MASK; - if (!is_present_pte(*ptep) || - walker->level == PT_PAGE_TABLE_LEVEL || - (walker->level == PT_DIRECTORY_LEVEL && - (*ptep & PT_PAGE_SIZE_MASK) && - (PTTYPE == 64 || is_pse(vcpu)))) + if (!is_present_pte(*ptep)) + break; + + if (walker->level == PT_PAGE_TABLE_LEVEL) { + walker->gfn = (*ptep & PT_BASE_ADDR_MASK) + >> PAGE_SHIFT; + break; + } + + if (walker->level == PT_DIRECTORY_LEVEL + && (*ptep & PT_PAGE_SIZE_MASK) + && (PTTYPE == 64 || is_pse(vcpu))) { + walker->gfn = (*ptep & PT_DIR_BASE_ADDR_MASK) + >> PAGE_SHIFT; + walker->gfn += PT_INDEX(addr, PT_PAGE_TABLE_LEVEL); break; + } if (walker->level != 3 || is_long_mode(vcpu)) walker->inherited_ar &= walker->table[index]; @@ -143,30 +155,29 @@ static void FNAME(release_walker)(struct guest_walker *walker) } static void FNAME(set_pte)(struct kvm_vcpu *vcpu, u64 guest_pte, - u64 *shadow_pte, u64 access_bits) + u64 *shadow_pte, u64 access_bits, gfn_t gfn) { ASSERT(*shadow_pte == 0); access_bits &= guest_pte; *shadow_pte = (guest_pte & PT_PTE_COPY_MASK); set_pte_common(vcpu, shadow_pte, guest_pte & PT_BASE_ADDR_MASK, - guest_pte & PT_DIRTY_MASK, access_bits); + guest_pte & PT_DIRTY_MASK, access_bits, gfn); } static void FNAME(set_pde)(struct kvm_vcpu *vcpu, u64 guest_pde, - u64 *shadow_pte, u64 access_bits, - int index) + u64 *shadow_pte, u64 access_bits, gfn_t gfn) { gpa_t gaddr; ASSERT(*shadow_pte == 0); access_bits &= guest_pde; - gaddr = (guest_pde & PT_DIR_BASE_ADDR_MASK) + PAGE_SIZE * index; + gaddr = (gpa_t)gfn << PAGE_SHIFT; if (PTTYPE == 32 && is_cpuid_PSE36()) gaddr |= (guest_pde & PT32_DIR_PSE36_MASK) << (32 - PT32_DIR_PSE36_SHIFT); *shadow_pte = guest_pde & PT_PTE_COPY_MASK; set_pte_common(vcpu, shadow_pte, gaddr, - guest_pde & PT_DIRTY_MASK, access_bits); + guest_pde & PT_DIRTY_MASK, access_bits, gfn); } /* @@ -214,10 +225,12 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr, *prev_shadow_ent |= PT_SHADOW_PS_MARK; FNAME(set_pde)(vcpu, *guest_ent, shadow_ent, walker->inherited_ar, - PT_INDEX(addr, PT_PAGE_TABLE_LEVEL)); + walker->gfn); } else { ASSERT(walker->level == PT_PAGE_TABLE_LEVEL); - FNAME(set_pte)(vcpu, *guest_ent, shadow_ent, walker->inherited_ar); + FNAME(set_pte)(vcpu, *guest_ent, shadow_ent, + walker->inherited_ar, + walker->gfn); } return shadow_ent; } @@ -291,7 +304,7 @@ static int FNAME(fix_write_pf)(struct kvm_vcpu *vcpu, return 0; } - gfn = (*guest_ent & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT; + gfn = walker->gfn; if (kvm_mmu_lookup_page(vcpu, gfn)) { pgprintk("%s: found shadow page for %lx, marking ro\n", __FUNCTION__, gfn); -- 2.39.5