4.20-stable review patch.  If anyone has any objections, please let me know.

------------------

[ Upstream commit e87555e550cef4941579cd879759a7c0dee24e68 ]

AMD doesn't seem to implement MSR_IA32_MCG_EXT_CTL and svm code in kvm
knows nothing about it, however, this MSR is among emulated_msrs and
thus returned with KVM_GET_MSR_INDEX_LIST. The consequent KVM_GET_MSRS,
of course, fails.

Report the MSR as unsupported to not confuse userspace.

Signed-off-by: Vitaly Kuznetsov <vkuzn...@redhat.com>
Signed-off-by: Radim Krčmář <rkrc...@redhat.com>
Signed-off-by: Sasha Levin <sas...@kernel.org>
---
 arch/x86/kvm/svm.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 101f53ccf571..11641d9e7f6f 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -5836,6 +5836,13 @@ static bool svm_cpu_has_accelerated_tpr(void)
 
 static bool svm_has_emulated_msr(int index)
 {
+       switch (index) {
+       case MSR_IA32_MCG_EXT_CTL:
+               return false;
+       default:
+               break;
+       }
+
        return true;
 }
 
-- 
2.19.1



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