On Thu, Feb 25, 2010 at 04:04:28PM +0100, Jes Sorensen wrote: > 1) Add support to perf to allow it to monitor a KVM guest from the > host. This shouldn't be a big problem. The PMU of AMD Fam10 processors can be configured to count only when in guest mode. Perf needs to be aware of that and fetch the rip from a different place when monitoring a guest. > 2) Allow guests access to the PMU (or an emulated PMU), making it > possible to run perf on applications running within the guest. The biggest problem I see here is teaching the guest about the available events. The available event sets are dependent on the processor family (at least on AMD). A simple approach would be shadowing the perf msrs which is a simple thing to do. More problematic is the reinjection of performance interrupts and performance nmis. I personally don't like a self-defined event-set as the only solution because that would probably only work with linux and perf. I think we should have a way (additionally to a soft-event interface) which allows to expose the host pmu events to the guest. Joerg -- 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
