Re: [PATCH v4 3/3] KVM: nVMX: Emulate EPTP switching for the L1 hypervisor

[Radim KrÄmÃÅ]

2017-07-11 14:35-0400, Bandan Das:
> Jim Mattson <jmattson@xxxxxxxxxx> writes:
> ...
> >>> I can find the definition for an vmexit in case of index >=
> >>> VMFUNC_EPTP_ENTRIES, but not for !vmcs12->eptp_list_address in the SDM.
> >>>
> >>> Can you give me a hint?
> >>
> >> I don't think there is. Since, we are basically emulating eptp switching
> >> for L2, this is a good check to have.
> >
> > There is nothing wrong with a hypervisor using physical page 0 for
> > whatever purpose it likes, including an EPTP list.
> 
> Right, but of all the things, a l1 hypervisor wanting page 0 for a eptp list
> address most likely means it forgot to initialize it. Whatever damage it does will
> still end up with vmfunc vmexit anyway.

Most likely, but not certainly.  I also don't see a to diverge from the
spec here.