Paolo Bonzini <pbonz...@redhat.com> 于2019年9月26日周四 下午5:18写道：
> On 26/09/19 10:59, Maxim Levitsky wrote: > > If you mean to ask if there is a way to let guest access use no > > paging at all, that is access host physical addresses directly, then > > indeed there is no way, since regular non 'unrestricted guest' mode > > required both protected mode and paging, and 'unrestricted guest' > > requires EPT. Academically speaking it is of course possible to > > create paging tables that are 1:1... > > Not so academically, it's exactly what KVM does. However, indeed it > would also be possible to switch out of EPT mode when CR0.PG=0. I'm not > sure why it was done this way, maybe when the code was written it was > simpler to use the identity map. > Hi Paolo, what's the meaning of 'switch out of EPT mode'. Do you mean when the guest in real mode emulation(vm86) can do something to disable EPT? I don't find the code. Seems my understanding is wrong. Thanks, Li Qiang > > Let's see if Avi is listening... :) > > Paolo >
