On Thu, Apr 23, 2015 at 5:10 AM, Peter Maydell <peter.mayd...@linaro.org> wrote:
> On 23 April 2015 at 04:37, Edgar E. Iglesias <edgar.igles...@gmail.com> > wrote: > > I had a comment on the trapping of WFX, I recall not checking for > > has_work was causing a lot of exception round-trips when running > > XEN. To the point were things almost stopped working. > > For traps on WFE, or traps on WFI? If the former, we should > probably implement that as "never trap" since we don't actually > go into a 'low power state' for WFE (execution will always > continue even if there's no pending WFE event). > > -- PMM > I did notice that issuing a wfi without trapping causes QEMU to hang. I had to make sure to not test the non-trapping case in EL1. I didn't investigate too deeply, but I figured that there was nothing to wake it up. The WFx stuff was a good test case for the trap to ELn, but if it is troublesome I can pull the patch until we arrive at a reasonable solution. The FP stuff now also tests this.
