Re: [PATCH v5 02/22] KVM: arm/arm64: Add GICV3 pending table save API documentation

Peter Maydell
2017-04-26T08:44:34Z

On 26 April 2017 at 09:26, Auger Eric <eric.auger@redhat.com> wrote:
> On 25/04/2017 12:43, Peter Maydell wrote:
>> When does the -EFAULT return happen? (if the guest points GITS_BASER<n>
>> etc at invalid memory, presumably?)
>
> Yes that's correct, when GICR_PENDBASER contains a bad GPA.
>
>> How does the QEMU migration code
>> handle this case? Failing migration because the guest has done something
>> silly doesn't seem too palatable, but trying to avoid that could be
>> more effort than an obscure corner case really merits.
>
> The kvm_device_access will cause an abort() as for other errors returned
> by kvm_device_ioctl().

That's pretty nasty. Guests shouldn't be able to provoke QEMU
into abort()ing, ideally. We don't necessarily have to produce
a successful migration, but we should at least fail it cleanly.

thanks
-- PMM