Messages in this thread | | | Date | Thu, 3 Nov 2022 19:46:22 +0100 | Subject | Re: [PATCH 33/44] KVM: x86: Do VMX/SVM support checks directly in vendor code | From | Paolo Bonzini <> |
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On 11/3/22 19:35, Sean Christopherson wrote: > It's technically required. IA32_FEAT_CTL and thus KVM_INTEL depends on any of > CPU_SUP_{INTEL,CENATUR,ZHAOXIN}, but init_ia32_feat_ctl() is invoked if and only > if the actual CPU type matches one of the aforementioned CPU_SUP_*. > > E.g. running a kernel built with > > CONFIG_CPU_SUP_INTEL=y > CONFIG_CPU_SUP_AMD=y > # CONFIG_CPU_SUP_HYGON is not set > # CONFIG_CPU_SUP_CENTAUR is not set > # CONFIG_CPU_SUP_ZHAOXIN is not set > > on a Cenatur or Zhaoxin CPU will leave X86_FEATURE_VMX set but not set > X86_FEATURE_MSR_IA32_FEAT_CTL. If VMX isn't enabled in MSR_IA32_FEAT_CTL, KVM > will get unexpected #UDs when trying to enable VMX.
Oh, I see. Perhaps X86_FEATURE_VMX and X86_FEATURE_SGX should be moved to one of the software words instead of using cpuid. Nothing that you should care about for this series though.
Paolo
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