Unconditionally allow the guest to read and zero-write MSR TEST_CTRL.
This matches the fact that most Intel CPUs support MSR TEST_CTRL, and
it also alleviates the effort to handle wrmsr/rdmsr when split lock
detection is exposed to the guest in a future patch.
Signed-off-by: Xiaoyao Li <xiaoyao.li@xxxxxxxxx>
---
arch/x86/kvm/vmx/vmx.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 46ba2e03a892..e113c9171bcc 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -1832,6 +1832,9 @@ static int vmx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
u32 index;
switch (msr_info->index) {
+ case MSR_TEST_CTRL:
+ msr_info->data = 0;
+ break;
#ifdef CONFIG_X86_64
case MSR_FS_BASE:
msr_info->data = vmcs_readl(GUEST_FS_BASE);
@@ -1995,6 +1998,11 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
u32 index;
switch (msr_index) {
+ case MSR_TEST_CTRL:
+ if (data)
+ return 1;
+
+ break;
case MSR_EFER:
ret = kvm_set_msr_common(vcpu, msr_info);
break;
--
2.18.4
