On 2011-05-03 16:37, Avi Kivity wrote: > On 05/03/2011 05:29 PM, Jan Kiszka wrote: >> On 2011-05-03 15:31, Avi Kivity wrote: >>> On 05/03/2011 01:37 PM, Jan Kiszka wrote: >>>>> >>>>> Yes. Unfortunately that is very vendor and model specific. The >>>>> architectural PMU is supported, but that is only available on Intel. >>>> >>>> Is it supposed to have any practical value already? I did not yet find a >>>> magic -cpu switch to let Linux detect anything, not to speak of perf or >>>> watchdog support. >>> >>> On the guest side it is supported for the watchdog >>> (arch/x86/kernel/cpu/perfctr-watchdog.c, look for >>> X86_FEATURE_ARCH_PERFMON). It's also mentioned in perf_event_intel.c, >>> but I don't know if it will work without the other PMU features being >>> present. >> >> I've tested with some SUSE 2.6.38 guest kernel, and it complained like >> this: >> >> (-cpu kvm64) >> Performance Events: unsupported Netburst CPU model 6 no PMU driver, software events only. >> NMI watchdog disabled (cpu0): hardware events not enabled >> > > Sorry, I meant to write, but forgot, that on the host side it is > completely unsupported. It shouldn't be too hard to use perf_events to > emulate the architectural PMU. Once we do that we can expose the > architectural pmu bit and the guest will use it. Oh, and I already thought I would have missed some thrilling KVM patches... Jan -- Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
