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

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <3deac361-05fa-60a5-0d88-4f6b968f10bf@linux.alibaba.com>
Date:   Fri, 15 Jan 2021 16:19:06 +0800
From:   Alex Shi <alex.shi@...ux.alibaba.com>
To:     Like Xu <like.xu@...ux.intel.com>,
        Paolo Bonzini <pbonzini@...hat.com>,
        Sean Christopherson <seanjc@...gle.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Jim Mattson <jmattson@...gle.com>,
        Joerg Roedel <joro@...tes.org>
Cc:     Ingo Molnar <mingo@...hat.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Borislav Petkov <bp@...en8.de>,
        "H . Peter Anvin" <hpa@...or.com>, ak@...ux.intel.com,
        wei.w.wang@...el.com, kan.liang@...el.com, x86@...nel.org,
        kvm@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [RESEND v13 00/10] KVM: x86/pmu: Guest Last Branch Recording
 Enabling



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