Re: [PATCH v2 0/4] perf/x86: Don't write PEBS_ENABLED on KVM transitions

Jim Mattson
2026-04-23T15:33:39Z

On Thu, Apr 23, 2026 at 8:03 AM Sean Christopherson <seanjc@google.com> wrote:
> ...
> - Dropping PEBS_ENABLED from the lists save three MSR writes, not two, as
> KVM performs an explicit WRMSR prior to VM-Entry to guarantee PEBS is
> quiesced.

Is the wrmsrq(MSR_IA32_PEBS_ENABLED, 0) in add_atomic_switch_msr()
necessary when the CPU has PEBS isolation?