KVM: Fetch guest cr3 from hardware on demand
Instead of syncing the guest cr3 every exit, which is expensince on vmx
with ept enabled, sync it only on demand.
[sheng: fix incorrect cr3 seen by Windows XP]
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/x86/kvm/kvm_cache_regs.h b/arch/x86/kvm/kvm_cache_regs.h
index a6bf8db..3377d53 100644
--- a/arch/x86/kvm/kvm_cache_regs.h
+++ b/arch/x86/kvm/kvm_cache_regs.h
@@ -75,6 +75,8 @@
static inline ulong kvm_read_cr3(struct kvm_vcpu *vcpu)
{
+ if (!test_bit(VCPU_EXREG_CR3, (ulong *)&vcpu->arch.regs_avail))
+ kvm_x86_ops->decache_cr3(vcpu);
return vcpu->arch.cr3;
}