On Tue, Jun 24, 2014 at 4:38 PM, Paolo Bonzini <pbonzini@xxxxxxxxxx> wrote: > Il 24/06/2014 10:33, Jidong Xiao ha scritto: > >> I think I have figured out this. According to this patch (as well as >> the Intel SDM manual), it looks like pmu is exposed via the cpuid leaf >> 0xah. >> >> >> https://github.com/torvalds/linux/commit/a6c06ed1a60aff77b27ba558c315c3fed4e35565 >> >> Therefore, in the guest os, one can run the cpuid instruction with >> leaf 0xa, and if vpmu is supported/enabled, the return value in >> eax/ebx/ecx/edx should be something non-zero, and in the cloud machine >> which I am using I see these registers are all zero, therefore I think >> vpmu is not supported in my virtual machine. Probably it is masked by >> Qemu. > > > This is correct. QEMU only enables vPMU if you use "-cpu host". > > Paolo Thanks Paolo. -Jidong -- 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
