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 relying on the OSPM in dom0 kernel to parse out Cx/Px info which Xen itself *can* use. -- Keir -- 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
