On Tue, Jul 3, 2012 at 3:51 PM, Peter Maydell <peter.maydell at linaro.org> wrote: > On 3 July 2012 14:29, Avi Kivity <avi at redhat.com> wrote: >> On 07/03/2012 11:59 AM, Christoffer Dall wrote: >>> Additionally a few major milestones are coming up shortly: >>> - Support Thumb MMIO emulation and test MMIO emulation code (under way) >>> - Merge Marc Zyngier's patch series for VGIC and timers (review in >>> progress) >> >> Does it make sense to keep the pre-VGIC interrupt stuff in then? It >> would be better to support just one setup, but kernel-VGIC is of course >> less flexible than user space. > > We've gone back and forth on this one, I think. For an A15 guest > we want to say that userspace GIC isn't permitted (ie you must use > the in-kernel-irqchip). For an A9 guest you would have to use the > userspace GIC, but on the other hand we don't currently actually > support an A9 guest... It seems a little unfortunate to remove > code that is actually working but I could certainly see the > cleanliness argument for dropping it and letting anybody who > wanted an A9 guest put it back later. > I prefer keeping the user space code as the virtualization extensions do not mandate VGIC support, so one could imagine hypothetical future cores without VGIC support. Also, we don't really have any profiling information about the VGIC implementation yet, so the user space support version may be useful for some performance poking, maybe. -Christoffer
