Messages in this thread | | | Date | Fri, 17 Nov 2017 12:44:45 +0100 | From | Borislav Petkov <> | Subject | Re: [PATCH v2 3/4] Add support for AMD Core Perf Extension in guest |
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On Thu, Nov 16, 2017 at 12:00:11PM -0600, Natarajan, Janakarajan wrote: > Ah my apologies. So when the pmu is initialized the cpuid entries > aren't available then.
So let's see:
... kvm_arch_vcpu_create() -> svm_create_vcpu() -> kvm_vcpu_init() -> kvm_arch_vcpu_init() ->
<--- HERE
kvm_pmu_init()
But at HERE in kvm_arch_vcpu_init() right before kvm_pmu_init() we do already query cpuid:
vcpu->arch.maxphyaddr = cpuid_query_maxphyaddr(vcpu);
so it's not like we don't know about cpuid leafs at that point. Which would mean that the code can be made to set the CPU family earlier, before kvm_pmu_init() runs so that you have the proper CPU family and thus have this thing properly designed.
Maybe Paolo and Radim have a better suggestion here...
-- Regards/Gruss, Boris.
SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg) --
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