On 26 April 2017 at 14:14, Christoffer Dall <christoffer.dall@xxxxxxxxxx> wrote: > On Wed, Apr 26, 2017 at 02:01:55PM +0100, Peter Maydell wrote: >> On 26 April 2017 at 14:00, Christoffer Dall <cdall@xxxxxxxxxx> wrote: >> > Alternatively we should mark a pending error notification to the guest >> > in KVM, so that when the guest boots it gets something like an SError >> > instead, given that presumably the guest wrote the weird value. Except >> > of course if the problem is caused by QEMU fudging with the register >> > value for the PENDBASER. >> >> If we have scope for complaining at the guest we should do it at >> the point where the guest sets PENDBASER in the first place... >> > > Is that what the hardware would have done? I think it's UNPREDICTABLE to enable the GIC with a bogus PENDBASER, but I can't find the bit in the spec that actually says that. I don't know what hardware actually does, but I imagine it will only notice that it's been handed bogus memory at the point where it tries to use it. > Also, userspace could restore a bogus value in the PENDBASER (even > though the guest wrote something sane), so maybe we should just keep > this as is and handle it nicely in QEMU? Yeah, I don't have a strong objection to doing it that way round. thanks -- PMM
