On Tue, Apr 28, 2020 at 10:39 AM Krish Sadhukhan <krish.sadhukhan@xxxxxxxxxx> wrote: > > > On 4/28/20 1:14 AM, Paolo Bonzini wrote: > > On 28/04/20 09:25, Krish Sadhukhan wrote: > >>> Absolutely. Unrestricted guest requires EPT, but EPT is invisible to > >>> the guest. (Currently EPT requires guest MAXPHYADDR = host MAXPHYADDR, > >>> in the sense that the guest can detect that the host is lying about > >>> MAXPHYADDR; but that is really a bug that I hope will be fixed in 5.8, > >>> relaxing the requirement to guest MAXPHYADDR <= host PHYADDR). > >> Should EPT for the nested guest be set up in the normal way (PML4E -> > >> PDPTE-> PDE -> PTE) when GUEST_CR0.PE is zero ? Or does it have to be a > >> special set up like only the PTEs are needed because no protection and > >> no paging are used ? > > I don't understand. When EPT is in use, the vmcs02 CR3 is simply set to > > the vmcs12 CR3. > > > Sorry, I should have framed my question in a better way. > > My question is how should L1 in the test code set up EPTP for L2 when > L2 is an unrestricted guest with no protection (GUEST_CR0.PE = 0) and no > paging (GUEST_CR0.PG = 0) ? Should EPTP in test code be set up in the > same way as when L2 is an unrestricted guest with protection and paging > enabled ? The EPT maps guest physical addresses to host physical addresses. That mapping is the same regardless of whether the guest is using paging or not.
