Hi Peter, Dave, On 26/04/2017 10:48, Dr. David Alan Gilbert wrote: > * Peter Maydell (peter.maydell@xxxxxxxxxx) wrote: >> On 26 April 2017 at 09:26, Auger Eric <eric.auger@xxxxxxxxxx> 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. > > Yes, no abort()'s during migration due to guest behaviour. > They always end up coming back around to being filed as migration > bugs and people worry why they've got cores. > > Ideally log a message into stderr to say that the guest state > is inconsistent so that when someone comes to debug it then they > can see it's obvious. OK I agree. I will respin the QEMU part accordingly and in that situation I won't abort and will print a message. Thanks Eric > > Dave > >> thanks >> -- PMM > -- > Dr. David Alan Gilbert / dgilbert@xxxxxxxxxx / Manchester, UK > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@xxxxxxxxxxxxxxxxxxx > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel >
