>> Can't we rewrite that a little bit, avoiding that "best" handling
>> (introducing guest_cpuid_disable_invpcid() and guest_cpuid_has_invpcid())
>>
>> bool invpcid_enabled = guest_cpuid_has_pcid(vcpu) &&
>> guest_cpuid_has_invpcid();
>>
>> if (!invpcid_enabled) {
>> secondary_exec_ctl &= ~SECONDARY_EXEC_ENABLE_INVPCID;
>> /* make sure there is no no INVPCID without PCID */
>> guest_cpuid_disable_invpcid(vcpu);
>> }
>
> I don't know... if you need a comment, it means the different structure
> of the code doesn't spare many doubts from the reader. And the code
> doesn't become much simpler since you have to handle "nested" anyway.
> What I tried to do was to mimic as much as possible the rdtscp case, but
> it cannot be exactly the same due to the interaction between PCID and
> INVPCID.
It's more about the handling of best here, which can be avoided quite
easily as I showed (by encapsulating how cpuids are looked up/modified).
But you are the maintainer, so feel free to stick to what you have. :)
>
> Paolo
>
--
Thanks,
David
