Intel hosts, without long mode, and with nx support disabled in the bios
have an efer that is readable but not writable. This causes a lockup on
switch to guest mode (even though it should exit with reason 34 according to
the documentation).
Signed-off-by: Avi Kivity <avi@xxxxxxxxxxxx>
Index: linux-2.6/drivers/kvm/vmx.c
===================================================================
--- linux-2.6.orig/drivers/kvm/vmx.c
+++ linux-2.6/drivers/kvm/vmx.c
@@ -1128,6 +1128,8 @@ static int vmx_vcpu_setup(struct kvm_vcp
if (rdmsr_safe(index, &data_low, &data_high) < 0)
continue;
+ if (wrmsr_safe(index, data_low, data_high) < 0)
+ continue;
data = data_low | ((u64)data_high << 32);
vcpu->host_msrs[j].index = index;
vcpu->host_msrs[j].reserved = 0;