Messages in this thread | | | Subject | Re: [PATCH v7 05/13] perf/x86/intel/pt: Introduce a new function to get capability of Intel PT | From | Paolo Bonzini <> | Date | Thu, 3 May 2018 14:30:15 +0200 |
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On 03/05/2018 14:13, Alexander Shishkin wrote: >>>> New function __pt_cap_get() will be invoked in KVM to check if a >>>> specific capability is availiable in KVM guest. >>>> Another function pt_cap_get() can only check the hardware capabilities >>>> but this may different with KVM guest because some features may not be >>>> exposed to guest. >>> Do we really need both in KVM? >> Yes, KVM need get host capability to estimate if can expose this feature >> to guest > Can you elaborate on this, what information do we need besides > MSR_IA32_VMX_MISC[14]?
It needs all the CPUID data, and it's nice to query it in a more manageable form than with bit shifts.
Paolo
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