On Sunday 17 February 2008 03:34:43 am Anthony Liguori wrote: > Balaji Rao wrote: > > Hi all! > > > > Earlier it was suggested that we go ahead with emulating Perf Mon Events > > in exposing it to the guest. The serious limitation in this approach is > > that we end up exposing only a small number of events to the guest, even > > though the host hardware is capable of much more. The only benefit this > > approach offers is that, it doesn't break live migration. > > I think performance monitors are no different than anything else in > KVM. We should virtualize as much as possible and by default provide > only the common subset to the guest supported by the majority of hardware. > > Then we can use mechanisms like QEMU's CPU support to enable additional > features that may be available and unique to the underlying hardware. > It's then up to the management tools to deal with migratability since > they've explicitly enabled the feature.
Sorry, I don't understand how it can done through QEMU, but according to what I understand, it makes migration very difficult/impossible. So, why should we go for this approach at all ? Its the very reason direct access to PMU was thought of as a bad idea. Do you see any other problem in directly exposing the PMU ? -- regards, balaji rao NITK ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ kvm-devel mailing list kvm-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kvm-devel
