On Thu, Apr 23, 2015 at 9:51 AM, Peter Maydell <peter.mayd...@linaro.org> wrote:
> 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. > ​Right, that is exactly what it says. So if QEMU never goes into a low power state than neither wfi or wfe should trap as they have the same explanation. In which case the best solution is to pull the patches out. That work? > > -- PMM >
