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| author | Avi Kivity <avi@qumranet.com> | 2007-04-30 14:47:02 +0300 |
|---|---|---|
| committer | Avi Kivity <avi@qumranet.com> | 2007-07-16 12:05:38 +0300 |
| commit | e925c5ba9380dad5fdf1d0a9d9199ac43be74c6a (patch) | |
| tree | 9de2c9a4530170d77609af5236d8eaf546fd1ec9 /drivers/kvm/mmu.c | |
| parent | c86813393f8b8f9f738ab57d9837858ed850df4b (diff) | |
| download | blackbird-op-linux-e925c5ba9380dad5fdf1d0a9d9199ac43be74c6a.tar.gz blackbird-op-linux-e925c5ba9380dad5fdf1d0a9d9199ac43be74c6a.zip | |
KVM: Assume that writes smaller than 4 bytes are to non-pagetable pages
This allows us to remove write protection earlier than otherwise. Should
some mad OS choose to use byte writes to update pagetables, it will suffer
a performance hit, but still work correctly.
Signed-off-by: Avi Kivity <avi@qumranet.com>
Diffstat (limited to 'drivers/kvm/mmu.c')
| -rw-r--r-- | drivers/kvm/mmu.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/kvm/mmu.c b/drivers/kvm/mmu.c index e8e228118de9..2277b7cd118c 100644 --- a/drivers/kvm/mmu.c +++ b/drivers/kvm/mmu.c @@ -1169,6 +1169,7 @@ void kvm_mmu_pre_write(struct kvm_vcpu *vcpu, gpa_t gpa, int bytes) continue; pte_size = page->role.glevels == PT32_ROOT_LEVEL ? 4 : 8; misaligned = (offset ^ (offset + bytes - 1)) & ~(pte_size - 1); + misaligned |= bytes < 4; if (misaligned || flooded) { /* * Misaligned accesses are too much trouble to fix |
