Re: [PATCH v3 7/9] KVM: VMX: Add guest physical address check in EPT violation and misconfig

From: Jim Mattson
Date: Wed Jan 20 2021 - 16:44:42 EST


On Fri, Jan 15, 2021 at 11:35 AM Jim Mattson <jmattson@xxxxxxxxxx> wrote:
>
> On Fri, Oct 23, 2020 at 10:43 AM Paolo Bonzini <pbonzini@xxxxxxxxxx> wrote:
> >
> > On 23/10/20 19:23, Jim Mattson wrote:
> > >> The information that we need is _not_ that provided by the advanced
> > >> VM-exit information (or by a page walk). If a page is neither writable
> > >> nor executable, the advanced information doesn't say if the injected #PF
> > >> should be a W=1 or a F=1 fault. We need the information in bits 0..2 of
> > >> the exit qualification for the final access, which however is not
> > >> available for the paging-structure access.
> > >>
> > > Are you planning to extend the emulator, then, to support all
> > > instructions? I'm not sure where you are going with this.
> >
> > I'm going to fix the bit 8=1 case, but for bit 8=0 there's not much that
> > you can do. In all likelihood the guest is buggy anyway.
>
> Did this drop off your radar? Are you still planning to fix the bit8=1
> case to use advanced EPT exit qualification information? Or did I just
> miss it?

Paolo,
If you're not working on this, do you mind if I ask Aaron to take a look at it?