diff options
| author | Avi Kivity <avi@redhat.com> | 2012-09-12 13:44:53 +0300 |
|---|---|---|
| committer | Avi Kivity <avi@redhat.com> | 2012-09-20 13:00:07 +0300 |
| commit | 8ea667f259e3767fd3ee85a885c14e417835695e (patch) | |
| tree | d9fd33bd07ac8c497ba5fc94528da5b28626edef /arch/x86/kvm/mmu.h | |
| parent | 879238fecc051d95037ae76332916209a7770709 (diff) | |
| download | lwn-8ea667f259e3767fd3ee85a885c14e417835695e.tar.gz lwn-8ea667f259e3767fd3ee85a885c14e417835695e.zip | |
KVM: MMU: Push clean gpte write protection out of gpte_access()
gpte_access() computes the access permissions of a guest pte and also
write-protects clean gptes. This is wrong when we are servicing a
write fault (since we'll be setting the dirty bit momentarily) but
correct when instantiating a speculative spte, or when servicing a
read fault (since we'll want to trap a following write in order to
set the dirty bit).
It doesn't seem to hurt in practice, but in order to make the code
readable, push the write protection out of gpte_access() and into
a new protect_clean_gpte() which is called explicitly when needed.
Reviewed-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'arch/x86/kvm/mmu.h')
| -rw-r--r-- | arch/x86/kvm/mmu.h | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h index e374db9af021..2832081e9b2e 100644 --- a/arch/x86/kvm/mmu.h +++ b/arch/x86/kvm/mmu.h @@ -18,7 +18,8 @@ #define PT_PCD_MASK (1ULL << 4) #define PT_ACCESSED_SHIFT 5 #define PT_ACCESSED_MASK (1ULL << PT_ACCESSED_SHIFT) -#define PT_DIRTY_MASK (1ULL << 6) +#define PT_DIRTY_SHIFT 6 +#define PT_DIRTY_MASK (1ULL << PT_DIRTY_SHIFT) #define PT_PAGE_SIZE_MASK (1ULL << 7) #define PT_PAT_MASK (1ULL << 7) #define PT_GLOBAL_MASK (1ULL << 8) |