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 <vkuzn...@redhat.com>
---
 arch/x86/kvm/hyperv.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
index b5bc16ea2595..13011803ebbd 100644
--- a/arch/x86/kvm/hyperv.c
+++ b/arch/x86/kvm/hyperv.c
@@ -1196,6 +1196,18 @@ void kvm_hv_invalidate_tsc_page(struct kvm *kvm)
 
 static bool hv_check_msr_access(struct kvm_vcpu_hv *hv_vcpu, u32 msr)
 {
+       if (!hv_vcpu->enforce_cpuid)
+               return true;
+
+       switch (msr) {
+       case HV_X64_MSR_GUEST_OS_ID:
+       case HV_X64_MSR_HYPERCALL:
+               return hv_vcpu->cpuid_cache.features_eax &
+                       HV_MSR_HYPERCALL_AVAILABLE;
+       default:
+               break;
+       }
+
        return true;
 }
 
-- 
2.30.2

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