Messages in this thread Patch in this message | | | From | Avi Kivity <> | Subject | [PATCH 03/58] KVM: Assume that writes smaller than 4 bytes are to non-pagetable pages | Date | Sun, 17 Jun 2007 12:43:44 +0300 |
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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> --- 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 e8e2281..2277b7c 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 -- 1.5.0.6 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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