4.20-stable review patch. If anyone has any objections, please let me know.
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[ 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 vkuznets@redhat.com Signed-off-by: Radim Krčmář rkrcmar@redhat.com Signed-off-by: Sasha Levin sashal@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; }