[kvm-devel] [PATCH 04/31] KVM: SVM: align shadow CR4.MCE with host

[Avi K. <av...@qu...>]

From: Joerg Roedel <joe...@am...>

This patch aligns the host version of the CR4.MCE bit with the CR4 active in
the guest. This is necessary to get MCE exceptions when the guest is running.

Signed-off-by: Joerg Roedel <joe...@am...>
Signed-off-by: Avi Kivity <av...@qu...>
---
 arch/x86/kvm/svm.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index d7439ce..8af463b 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -878,9 +878,12 @@ set:
 
 static void svm_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
 {
+	unsigned long host_cr4_mce = read_cr4() & X86_CR4_MCE;
+
 	vcpu->arch.cr4 = cr4;
 	if (!npt_enabled)
 		cr4 |= X86_CR4_PAE;
+	cr4 |= host_cr4_mce;
 	to_svm(vcpu)->vmcb->save.cr4 = cr4;
 }
 
-- 
1.5.5