On Sun, Nov 13, 2011 at 04:59:10PM +0000, Keir Fraser wrote: > On 13/11/2011 03:46, "Len Brown" <lenb@xxxxxxxxxx> wrote: > > >> The problem I see is that select_idle_routine() is called from > >> arch/x86/kernel/cpu/common.c and since Xen setup does not set pm_idle > >> anymore, it can cause mwait_idle or amd_e400_idle functions to be selected. > >> In testing it seem amd_e400_idle in PVM domU at least does not immediately > >> cause > >> problems, but mwait_idle just causes crashes. From the reports I have > >> this may be related to older hypervisors (3.1 and older) not clearing the > >> mwait > >> capability. But overall there seems something wrong in the interaction. > > > > Why is Xen advertising X86_FEATURE_MWAIT and then crashing > > when the dom0 (or other guests) use what it advertises? > > > > What versions of Xen have this bug? > > Xen doesn't advertise MWAIT. Possibly Xen-pv_ops is lying to the rest of the > kernel via the cpuid pv_ops hook. This would probably be because Xen is I can't seem to find anything in there advertising the MWAIT feature. > relying on the OSPM in dom0 kernel to parse out Cx/Px info which Xen itself > *can* use. The Cx/Px patches that would parse the Cx/Px and then percolate those up to the hypervisor are in mainline. So that is not it. -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
