kvm.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Peter Zijlstra <peterz@infradead.org>
To: Like Xu <like.xu@linux.intel.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>,
	linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
	Sean Christopherson <sean.j.christopherson@intel.com>,
	Vitaly Kuznetsov <vkuznets@redhat.com>,
	Wanpeng Li <wanpengli@tencent.com>,
	Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	ak@linux.intel.com, wei.w.wang@intel.com
Subject: Re: [PATCH v11 05/11] perf/x86: Keep LBR stack unchanged in host context for guest LBR event
Date: Mon, 18 May 2020 14:02:05 +0200	[thread overview]
Message-ID: <20200518120205.GF277222@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20200514083054.62538-6-like.xu@linux.intel.com>

On Thu, May 14, 2020 at 04:30:48PM +0800, Like Xu wrote:
> @@ -544,7 +562,12 @@ void intel_pmu_lbr_enable_all(bool pmi)
>  {
>  	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
>  
> -	if (cpuc->lbr_users)
> +	/*
> +	 * When the LBR hardware is scheduled for a guest LBR event,
> +	 * the guest will dis/enables LBR itself at the appropriate time,
> +	 * including configuring MSR_LBR_SELECT.
> +	 */
> +	if (cpuc->lbr_users && !cpuc->guest_lbr_enabled)
>  		__intel_pmu_lbr_enable(pmi);
>  }

No!, that should be done through perf_event_attr::exclude_host, as I
believe all the other KVM event do it.

  parent reply	other threads:[~2020-05-18 12:09 UTC|newest]

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-14  8:30 [PATCH v11 00/11] Guest Last Branch Recording Enabling Like Xu
2020-05-14  8:30 ` [PATCH v11 01/11] perf/x86: Fix variable types for LBR registers Like Xu
2020-05-14  8:30 ` [PATCH v11 02/11] perf/x86/core: Refactor hw->idx checks and cleanup Like Xu
2020-05-14  8:30 ` [PATCH v11 03/11] perf/x86/lbr: Add interface to get basic information about LBR stack Like Xu
2020-05-14  8:30 ` [PATCH v11 04/11] perf/x86: Add constraint to create guest LBR event without hw counter Like Xu
2020-05-18 11:43   ` Peter Zijlstra
2020-05-14  8:30 ` [PATCH v11 05/11] perf/x86: Keep LBR stack unchanged in host context for guest LBR event Like Xu
2020-05-18 11:59   ` Peter Zijlstra
2020-05-18 12:02   ` Peter Zijlstra [this message]
2020-05-19  3:08     ` Like Xu
2020-05-19 10:45       ` Peter Zijlstra
2020-05-19 13:25         ` Xu, Like
2020-05-14  8:30 ` [PATCH v11 06/11] KVM: x86/pmu: Tweak kvm_pmu_get_msr to pass 'struct msr_data' in Like Xu
2020-05-14  8:30 ` [PATCH v11 07/11] KVM: x86: Expose MSR_IA32_PERF_CAPABILITIES for LBR record format Like Xu
2020-05-19 10:53   ` Peter Zijlstra
2020-05-19 12:19     ` Xu, Like
2020-05-19 15:12     ` Sean Christopherson
2020-05-14  8:30 ` [PATCH v11 08/11] KVM: x86/pmu: Emulate LBR feature via guest LBR event Like Xu
2020-05-19 11:00   ` Peter Zijlstra
2020-05-19 12:24     ` Xu, Like
2020-05-19 11:01   ` Peter Zijlstra
2020-05-19 12:28     ` Xu, Like
2020-05-19 11:03   ` Peter Zijlstra
2020-05-19 12:40     ` Xu, Like
2020-05-14  8:30 ` [PATCH v11 09/11] KVM: x86/pmu: Release guest LBR event via vPMU lazy release mechanism Like Xu
2020-05-14  8:30 ` [PATCH v11 10/11] KVM: x86/pmu: Check guest LBR availability in case host reclaims them Like Xu
2020-05-19 11:15   ` Peter Zijlstra
2020-05-19 13:10     ` Xu, Like
2020-05-19 14:57       ` Peter Zijlstra
2020-05-20  2:01         ` Xu, Like
2020-05-27  8:17           ` Like Xu
2020-05-14  8:30 ` [PATCH v11 11/11] KVM: x86/pmu: Reduce the overhead of LBR passthrough or cancellation Like Xu
2020-05-27  8:28 ` [PATCH v11 00/11] Guest Last Branch Recording Enabling Xu, Like

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200518120205.GF277222@hirez.programming.kicks-ass.net \
    --to=peterz@infradead.org \
    --cc=ak@linux.intel.com \
    --cc=jmattson@google.com \
    --cc=joro@8bytes.org \
    --cc=kvm@vger.kernel.org \
    --cc=like.xu@linux.intel.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=pbonzini@redhat.com \
    --cc=sean.j.christopherson@intel.com \
    --cc=tglx@linutronix.de \
    --cc=vkuznets@redhat.com \
    --cc=wanpengli@tencent.com \
    --cc=wei.w.wang@intel.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).