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
