Messages in this thread | | | Date | Mon, 7 Jan 2019 10:20:12 -0800 | From | Andi Kleen <> | Subject | Re: [PATCH v4 05/10] KVM/x86: expose MSR_IA32_PERF_CAPABILITIES to the guest |
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> The issue is compatibility. Prior to your change, reading this MSR > from a VM would raise #GP. After your change, it won't. That means > that if you have a VM migrating between hosts with kernel versions > before and after this change, the results will be inconsistent. In the
No it will not be. All Linux kernel uses of this MSR are guarded by a CPUID check.
-Andi
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