On 23 April 2015 at 15:41, Greg Bellows <greg.bell...@linaro.org> wrote: > Ok it sounds like the primary concern is the performance impact of > constantly trapping wfe to EL2 (in which case HCR must be set to cause > this). Should we still honor EL3 and EL1 trapping ofr wfe? In other words > check if they are the target and allow it if !has_work?
We should check what the architecture manual says, but I think that in all the trap-WFE cases it says "traps if the CPU would go into a low power state". QEMU *never* goes into a low power state on WFE, so we never trap. -- PMM
