Re: [RESEND v13 00/10] KVM: x86/pmu: Guest Last Branch Recording Enabling

From: Xu, Like
Date: Fri Jan 15 2021 - 03:51:59 EST


Hi Alex,

Thank you for trying this guest feature on multiple Intel platforms!
If you have more specific comments or any concerns, just let me know.

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thx, likexu

On 2021/1/15 16:19, Alex Shi wrote:

在 2021/1/8 上午9:36, Like Xu 写道:
Because saving/restoring tens of LBR MSRs (e.g. 32 LBR stack entries) in
VMX transition brings too excessive overhead to frequent vmx transition
itself, the guest LBR event would help save/restore the LBR stack msrs
during the context switching with the help of native LBR event callstack
mechanism, including LBR_SELECT msr.

Sounds the feature is much helpful for VMM guest performance tunning.
Good job!

Thanks
Alex