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 -- 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
