Paolo Bonzini <pbonzini@xxxxxxxxxx> writes: > On 17/10/2018 19:08, Jim Mattson wrote: >> I believe that ESXi reads GUEST_CS_AR_BYTES on every VM-exit to >> determine code size. > > Which makes me wonder, maybe we should add GUEST_SS_AR_BYTES which is > where the CPL lives. But then your tests from last year didn't find it. > Hyper-V does read GUEST_SS_AR_BYTES. Way less frequent than GUEST_CS_AR_BYTES but still. Based on that my suggestion would be to shadow GUEST_SS_AR_BYTES, keep GUEST_SS_AR_BYTES and unshadow the rest (GUEST_ES_BASE, GUEST_CS_SELECTOR, GUEST_CS_LIMIT, GUEST_CS_BASE). I can do this as a separate patch as I see this series is already in kvm/queue. -- Vitaly
