[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>

1 files changed, 2 insertions, 15 deletions

diff --git a/drivers/kvm/mmu.c b/drivers/kvm/mmu.c
index 4e29d9b7211c..3d367cbfe1f9 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