Messages in this thread | | | Date | Fri, 4 Aug 2023 23:45:13 +0200 | Subject | Re: [PATCH v5 11/19] KVM:VMX: Emulate read and write to CET MSRs | From | Paolo Bonzini <> |
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On 8/4/23 23:27, Sean Christopherson wrote: >>> + >>> + if (!kvm_cpu_cap_has(X86_FEATURE_SHSTK) && >>> + !kvm_cpu_cap_has(X86_FEATURE_IBT)) >>> + return false; >>> + >>> + return msr->host_initiated || >>> + guest_cpuid_has(vcpu, X86_FEATURE_IBT) || >>> + guest_cpuid_has(vcpu, X86_FEATURE_SHSTK); > > Similar to my suggestsion for XSS, I think we drop the waiver for host_initiated > accesses, i.e. require the feature to be enabled and exposed to the guest, even > for the host.
No, please don't. Allowing host-initiated accesses is what makes it possible to take the list of MSR indices and pass it blindly to KVM_GET_MSR and KVM_SET_MSR. This should be documented, will send a patch.
Paolo
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