[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <CAM9d7ciksqA7KGgc07HJAdE0TMpe1YCoS+NhzNEvdygh8T=PPA@mail.gmail.com>
Date: Sat, 30 Sep 2023 17:31:39 -0700
From: Namhyung Kim <namhyung@...nel.org>
To: Jim Mattson <jmattson@...gle.com>
Cc: Sean Christopherson <seanjc@...gle.com>,
Peter Zijlstra <peterz@...radead.org>,
Dapeng Mi <dapeng1.mi@...ux.intel.com>,
Paolo Bonzini <pbonzini@...hat.com>,
Arnaldo Carvalho de Melo <acme@...nel.org>,
Kan Liang <kan.liang@...ux.intel.com>,
Like Xu <likexu@...cent.com>,
Mark Rutland <mark.rutland@....com>,
Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
Jiri Olsa <jolsa@...nel.org>, Ian Rogers <irogers@...gle.com>,
Adrian Hunter <adrian.hunter@...el.com>, kvm@...r.kernel.org,
linux-perf-users@...r.kernel.org, linux-kernel@...r.kernel.org,
Zhenyu Wang <zhenyuw@...ux.intel.com>,
Zhang Xiong <xiong.y.zhang@...el.com>,
Lv Zhiyuan <zhiyuan.lv@...el.com>,
Yang Weijiang <weijiang.yang@...el.com>,
Dapeng Mi <dapeng1.mi@...el.com>,
David Dunn <daviddunn@...gle.com>,
Mingwei Zhang <mizhang@...gle.com>,
Thomas Gleixner <tglx@...utronix.de>,
Ingo Molnar <mingo@...nel.org>
Subject: Re: [Patch v4 07/13] perf/x86: Add constraint for guest perf metrics event
Hello,
On Fri, Sep 29, 2023 at 8:29 PM Jim Mattson <jmattson@...gle.com> wrote:
> For things to work well in the "vPMU as a client of host perf" world,
> we need to have the following at a minimum:
> 1) Guaranteed identity mapping of guest PMCs to host PMCs, so that we
> don't have to intercept accesses to IA32_PERF_GLOBAL_CTRL.
> 2) Exclusive ownership of the PMU MSRs while in the KVM_RUN loop, so
> that we don't have to switch any PMU MSRs on VM-entry/VM-exit (with
> the exception of IA32_PERF_GLOBAL_CTRL, which has guest and host
> fields in the VMCS).
IIUC that means multiplexing should be handled in the guest.
Not sure it can support mixing host and guest events at the
same time.
Thanks,
Namhyung
Powered by blists - more mailing lists