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[PATCH] KVM: MMU: Let the walker extract the target page gfn from the pte

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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 <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 16:36:44 -08:00
committed by Linus Torvalds
parent 374cbac033
commit 815af8d42e
2 changed files with 31 additions and 17 deletions
Download Patch File Download Diff File Expand all files Collapse all files

7
drivers/kvm/mmu.c
View File

@@ -752,7 +752,8 @@ static inline void set_pte_common(struct kvm_vcpu *vcpu,
u64 *shadow_pte, u64 *shadow_pte,
gpa_t gaddr, gpa_t gaddr,
int dirty, int dirty,
u64 access_bits) u64 access_bits,
gfn_t gfn)
{ {
hpa_t paddr; hpa_t paddr;
@@ -779,10 +780,10 @@ static inline void set_pte_common(struct kvm_vcpu *vcpu,
if (access_bits & PT_WRITABLE_MASK) { if (access_bits & PT_WRITABLE_MASK) {
struct kvm_mmu_page *shadow; struct kvm_mmu_page *shadow;
shadow = kvm_mmu_lookup_page(vcpu, gaddr >> PAGE_SHIFT); shadow = kvm_mmu_lookup_page(vcpu, gfn);
if (shadow) { if (shadow) {
pgprintk("%s: found shadow page for %lx, marking ro\n", pgprintk("%s: found shadow page for %lx, marking ro\n",
__FUNCTION__, (gfn_t)(gaddr >> PAGE_SHIFT)); __FUNCTION__, gfn);
access_bits &= ~PT_WRITABLE_MASK; access_bits &= ~PT_WRITABLE_MASK;
*shadow_pte &= ~PT_WRITABLE_MASK; *shadow_pte &= ~PT_WRITABLE_MASK;
} }

41
drivers/kvm/paging_tmpl.h
View File

@@ -62,6 +62,7 @@ struct guest_walker {
pt_element_t *table; pt_element_t *table;
pt_element_t *ptep; pt_element_t *ptep;
pt_element_t inherited_ar; pt_element_t inherited_ar;
gfn_t gfn;
}; };
/* /*
@@ -113,13 +114,24 @@ static void FNAME(walk_addr)(struct guest_walker *walker,
if (is_present_pte(*ptep) && !(*ptep & PT_ACCESSED_MASK)) if (is_present_pte(*ptep) && !(*ptep & PT_ACCESSED_MASK))
*ptep |= PT_ACCESSED_MASK; *ptep |= PT_ACCESSED_MASK;
if (!is_present_pte(*ptep) || 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))))
break; 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)) if (walker->level != 3 || is_long_mode(vcpu))
walker->inherited_ar &= walker->table[index]; walker->inherited_ar &= walker->table[index];
table_gfn = (*ptep & PT_BASE_ADDR_MASK) >> PAGE_SHIFT; table_gfn = (*ptep & PT_BASE_ADDR_MASK) >> PAGE_SHIFT;
@@ -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, 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); ASSERT(*shadow_pte == 0);
access_bits &= guest_pte; access_bits &= guest_pte;
*shadow_pte = (guest_pte & PT_PTE_COPY_MASK); *shadow_pte = (guest_pte & PT_PTE_COPY_MASK);
set_pte_common(vcpu, shadow_pte, guest_pte & PT_BASE_ADDR_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, static void FNAME(set_pde)(struct kvm_vcpu *vcpu, u64 guest_pde,
u64 *shadow_pte, u64 access_bits, u64 *shadow_pte, u64 access_bits, gfn_t gfn)
int index)
{ {
gpa_t gaddr; gpa_t gaddr;
ASSERT(*shadow_pte == 0); ASSERT(*shadow_pte == 0);
access_bits &= guest_pde; 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()) if (PTTYPE == 32 && is_cpuid_PSE36())
gaddr |= (guest_pde & PT32_DIR_PSE36_MASK) << gaddr |= (guest_pde & PT32_DIR_PSE36_MASK) <<
(32 - PT32_DIR_PSE36_SHIFT); (32 - PT32_DIR_PSE36_SHIFT);
*shadow_pte = guest_pde & PT_PTE_COPY_MASK; *shadow_pte = guest_pde & PT_PTE_COPY_MASK;
set_pte_common(vcpu, shadow_pte, gaddr, 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; *prev_shadow_ent |= PT_SHADOW_PS_MARK;
FNAME(set_pde)(vcpu, *guest_ent, shadow_ent, FNAME(set_pde)(vcpu, *guest_ent, shadow_ent,
walker->inherited_ar, walker->inherited_ar,
PT_INDEX(addr, PT_PAGE_TABLE_LEVEL)); walker->gfn);
} else { } else {
ASSERT(walker->level == PT_PAGE_TABLE_LEVEL); 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; return shadow_ent;
} }
@@ -291,7 +304,7 @@ static int FNAME(fix_write_pf)(struct kvm_vcpu *vcpu,
return 0; return 0;
} }
gfn = (*guest_ent & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT; gfn = walker->gfn;
if (kvm_mmu_lookup_page(vcpu, gfn)) { if (kvm_mmu_lookup_page(vcpu, gfn)) {
pgprintk("%s: found shadow page for %lx, marking ro\n", pgprintk("%s: found shadow page for %lx, marking ro\n",
__FUNCTION__, gfn); __FUNCTION__, gfn);