Re: [PATCH 0/6] Enable SMM page level protection.

[Paolo Bonzini <pbonzini@redhat.com>]

On 04/11/2016 16:22, Laszlo Ersek wrote:
>> > What does this *KVM internal error. Suberror: 1* mean?
> The key message is "emulation failure" -- it means that the processor
> exits to the hypervisor (KVM) because it finds some code that it cannot
> execute in guest mode natively, so the hypervisor needs to emulate it.
> And, this emulation fails. The reasons can be:
> - the code is valid, but KVM lacks the emulation code for it,
> - the code is actually garbage (not code) -- there was some corruption
> in the guest (the location used to contain code but it was corrupted, or
> the guest jumped to non-code data).
> 
> Usually the register dump contains a short hexadecimal snippet from the
> instruction stream (near Code=...), pinpointing the byte that caused the
> problem. However, in this case, all we have is question marks, and this
> is the very first time I see those. That's why I CC'd Paolo and Radim :)

The question marks usually mean that the page tables do not map a page
at that address, but I don't know offhand why KVM would fail emulation
instead of triple-faulting.

Try "info tlb" to dump the page tables (huge output of course, you may
want to use the GTK+ backend which has scrollable consoles).

Paolo