[5/5] KVM: VMX: Atomically switch efer if EPT && !EFER.NX

Commit Message

Avi Kivity April 28, 2010, 1:47 p.m. UTC

None

Patch

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index ae22dcf..cc78fee 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -678,6 +678,17 @@  static bool update_transition_efer(struct vcpu_vmx *vmx, int efer_offset)
 	guest_efer |= host_efer & ignore_bits;
 	vmx->guest_msrs[efer_offset].data = guest_efer;
 	vmx->guest_msrs[efer_offset].mask = ~ignore_bits;
+
+	clear_atomic_switch_msr(vmx, MSR_EFER);
+	/* On ept, can't emulate nx, and must switch nx atomically */
+	if (enable_ept && ((vmx->vcpu.arch.efer ^ host_efer) & EFER_NX)) {
+		guest_efer = vmx->vcpu.arch.efer;
+		if (!(guest_efer & EFER_LMA))
+			guest_efer &= ~EFER_LME;
+		add_atomic_switch_msr(vmx, MSR_EFER, guest_efer, host_efer);
+		return false;
+	}
+
 	return true;
 }