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authorAvi Kivity <avi@qumranet.com>2006-12-13 00:34:02 -0800
committerLinus Torvalds <torvalds@woody.osdl.org>2006-12-13 09:05:47 -0800
commit8c7bb723b4e36dbd4b144176116d126104dc65e0 (patch)
treed5f13bce4876887c8892297e2a31339efa5e6268
parent0770b19b94ed8fc97e1fcac91c320ec738919628 (diff)
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[PATCH] KVM: MMU: Ignore pcd, pwt, and pat bits on ptes
The pcd, pwt, and pat bits on page table entries affect the cpu cache. Since the cache is a host resource, the guest should not be able to control it. Moreover, the meaning of these bits changes depending on whether pat is enabled or not. So, force these bits to zero on shadow page table entries at all times. Signed-off-by: Avi Kivity <avi@qumranet.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r--drivers/kvm/mmu.c17
-rw-r--r--drivers/kvm/paging_tmpl.h20
2 files changed, 9 insertions, 28 deletions
diff --git a/drivers/kvm/mmu.c b/drivers/kvm/mmu.c
index 4e29d9b7211..3d367cbfe1f 100644
--- a/drivers/kvm/mmu.c
+++ b/drivers/kvm/mmu.c
@@ -61,22 +61,9 @@
#define PT32_PTE_COPY_MASK \
- (PT_PRESENT_MASK | PT_PWT_MASK | PT_PCD_MASK | \
- PT_ACCESSED_MASK | PT_DIRTY_MASK | PT_PAT_MASK | \
- PT_GLOBAL_MASK )
-
-#define PT32_NON_PTE_COPY_MASK \
- (PT_PRESENT_MASK | PT_PWT_MASK | PT_PCD_MASK | \
- PT_ACCESSED_MASK | PT_DIRTY_MASK)
-
-
-#define PT64_PTE_COPY_MASK \
- (PT64_NX_MASK | PT32_PTE_COPY_MASK)
-
-#define PT64_NON_PTE_COPY_MASK \
- (PT64_NX_MASK | PT32_NON_PTE_COPY_MASK)
-
+ (PT_PRESENT_MASK | PT_ACCESSED_MASK | PT_DIRTY_MASK | PT_GLOBAL_MASK)
+#define PT64_PTE_COPY_MASK (PT64_NX_MASK | PT32_PTE_COPY_MASK)
#define PT_FIRST_AVAIL_BITS_SHIFT 9
#define PT64_SECOND_AVAIL_BITS_SHIFT 52
diff --git a/drivers/kvm/paging_tmpl.h b/drivers/kvm/paging_tmpl.h
index 765c2e1a048..a9771b4c5bb 100644
--- a/drivers/kvm/paging_tmpl.h
+++ b/drivers/kvm/paging_tmpl.h
@@ -32,7 +32,6 @@
#define SHADOW_PT_INDEX(addr, level) PT64_INDEX(addr, level)
#define PT_LEVEL_MASK(level) PT64_LEVEL_MASK(level)
#define PT_PTE_COPY_MASK PT64_PTE_COPY_MASK
- #define PT_NON_PTE_COPY_MASK PT64_NON_PTE_COPY_MASK
#elif PTTYPE == 32
#define pt_element_t u32
#define guest_walker guest_walker32
@@ -43,7 +42,6 @@
#define SHADOW_PT_INDEX(addr, level) PT64_INDEX(addr, level)
#define PT_LEVEL_MASK(level) PT32_LEVEL_MASK(level)
#define PT_PTE_COPY_MASK PT32_PTE_COPY_MASK
- #define PT_NON_PTE_COPY_MASK PT32_NON_PTE_COPY_MASK
#else
#error Invalid PTTYPE value
#endif
@@ -105,9 +103,7 @@ static void FNAME(set_pde)(struct kvm_vcpu *vcpu, u64 guest_pde,
if (PTTYPE == 32 && is_cpuid_PSE36())
gaddr |= (guest_pde & PT32_DIR_PSE36_MASK) <<
(32 - PT32_DIR_PSE36_SHIFT);
- *shadow_pte = (guest_pde & (PT_NON_PTE_COPY_MASK | PT_GLOBAL_MASK)) |
- ((guest_pde & PT_DIR_PAT_MASK) >>
- (PT_DIR_PAT_SHIFT - PT_PAT_SHIFT));
+ *shadow_pte = guest_pde & PT_PTE_COPY_MASK;
set_pte_common(vcpu, shadow_pte, gaddr,
guest_pde & PT_DIRTY_MASK, access_bits);
}
@@ -162,6 +158,7 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
u32 index = SHADOW_PT_INDEX(addr, level);
u64 *shadow_ent = ((u64 *)__va(shadow_addr)) + index;
pt_element_t *guest_ent;
+ u64 shadow_pte;
if (is_present_pte(*shadow_ent) || is_io_pte(*shadow_ent)) {
if (level == PT_PAGE_TABLE_LEVEL)
@@ -204,14 +201,11 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
shadow_addr = kvm_mmu_alloc_page(vcpu, shadow_ent);
if (!VALID_PAGE(shadow_addr))
return ERR_PTR(-ENOMEM);
- if (!kvm_arch_ops->is_long_mode(vcpu) && level == 3)
- *shadow_ent = shadow_addr |
- (*guest_ent & (PT_PRESENT_MASK | PT_PWT_MASK | PT_PCD_MASK));
- else {
- *shadow_ent = shadow_addr |
- (*guest_ent & PT_NON_PTE_COPY_MASK);
- *shadow_ent |= (PT_WRITABLE_MASK | PT_USER_MASK);
- }
+ shadow_pte = shadow_addr | PT_PRESENT_MASK;
+ if (vcpu->mmu.root_level > 3 || level != 3)
+ shadow_pte |= PT_ACCESSED_MASK
+ | PT_WRITABLE_MASK | PT_USER_MASK;
+ *shadow_ent = shadow_pte;
prev_shadow_ent = shadow_ent;
}
}