> > > > > > IIUC, LAM_47 userspace canonical checking rule requests "bit 63 == > > > bit 47 == 0" > > > before sign-extened the address. > > > > > > if so looks it's guest's fault to not follow the LAM canonical > > > checking rule, > > > what's the behavior of such violation on bare metal, #GP ? > > > > Spec (ISE 10.2) doesn't mention a #GP for this case. IIUC, those > > overlap bits are zeroed. > > I mean the behavior of violation of "bit 63 == bit 47 == 0" rule, > yes no words in ISE 10.2/3 describe the behavior of such violation > case, but do you know more details of this or had some experiments > on hardware/SIMIC ? Yes, the ISE is vague. But I do believe a #GP will be generated for such violation, and KVM shall inject one if guest does no follow the requirement, because such check is called(by the spec) as a "modified canonicality check". Anyway, we'd better confirm with the spec owner, instead of making assumptions by ourselves. :) B.R. Yu
