Messages in this thread | | | Date | Mon, 7 Aug 2023 08:55:05 +0200 | Subject | Re: [PATCH v5 04/19] KVM:x86: Refresh CPUID on write to guest MSR_IA32_XSS | From | Paolo Bonzini <> |
| |
On 8/4/23 20:27, Sean Christopherson wrote: > I think my preference is to enforce guest CPUID for host accesses to > XSS, XFD, XFD_ERR, etc I'm pretty sure I've advocated for the exact > opposite in the past, i.e. argued that KVM's ABI is to not enforce > ordering between KVM_SET_CPUID2 and KVM_SET_MSR. But this is becoming > untenable, juggling the dependencies in KVM is complex and is going > to result in a nasty bug at some point.
Fortunately, you are right now. Well, almost :) but the important part is that indeed the dependencies are too complex.
While host-side accesses must be allowed, they should only allow the default value if the CPUID bit is not set.
Paolo
| |