HV_X64_MSR_GUEST_OS_ID/HV_X64_MSR_HYPERCALL are only available to guest
when HV_MSR_HYPERCALL_AVAILABLE bit is exposed.
Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
---
arch/x86/kvm/hyperv.c | 17 +++++++++++++++++
1 file changed, 17 insertions(+)
diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
index efb3d69c98fd..7fdd9b9c50d6 100644
--- a/arch/x86/kvm/hyperv.c
+++ b/arch/x86/kvm/hyperv.c
@@ -1198,9 +1198,14 @@ static int kvm_hv_set_msr_pw(struct kvm_vcpu *vcpu, u32 msr, u64 data,
{
struct kvm *kvm = vcpu->kvm;
struct kvm_hv *hv = to_kvm_hv(kvm);
+ struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
switch (msr) {
case HV_X64_MSR_GUEST_OS_ID:
+ if (unlikely(!host && !(hv_vcpu->cpuid_cache.features_eax &
+ HV_MSR_HYPERCALL_AVAILABLE)))
+ return 1;
+
hv->hv_guest_os_id = data;
/* setting guest os id to zero disables hypercall page */
if (!hv->hv_guest_os_id)
@@ -1211,6 +1216,10 @@ static int kvm_hv_set_msr_pw(struct kvm_vcpu *vcpu, u32 msr, u64 data,
int i = 0;
u64 addr;
+ if (unlikely(!host && !(hv_vcpu->cpuid_cache.features_eax &
+ HV_MSR_HYPERCALL_AVAILABLE)))
+ return 1;
+
/* if guest os id is not set hypercall should remain disabled */
if (!hv->hv_guest_os_id)
break;
@@ -1444,9 +1453,17 @@ static int kvm_hv_get_msr_pw(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata,
switch (msr) {
case HV_X64_MSR_GUEST_OS_ID:
+ if (unlikely(!host && !(hv_vcpu->cpuid_cache.features_eax &
+ HV_MSR_HYPERCALL_AVAILABLE)))
+ return 1;
+
data = hv->hv_guest_os_id;
break;
case HV_X64_MSR_HYPERCALL:
+ if (unlikely(!host && !(hv_vcpu->cpuid_cache.features_eax &
+ HV_MSR_HYPERCALL_AVAILABLE)))
+ return 1;
+
data = hv->hv_hypercall;
break;
case HV_X64_MSR_TIME_REF_COUNT:
--
2.30.2
