All of lore.kernel.org
 help / color / mirror / Atom feed
From: Sean Christopherson <seanjc@google.com>
To: Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@redhat.com>,
	 Arnaldo Carvalho de Melo <acme@kernel.org>,
	Namhyung Kim <namhyung@kernel.org>,
	 Sean Christopherson <seanjc@google.com>,
	Paolo Bonzini <pbonzini@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>,
	 Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	Jiri Olsa <jolsa@kernel.org>,  Ian Rogers <irogers@google.com>,
	Adrian Hunter <adrian.hunter@intel.com>,
	 James Clark <james.clark@linaro.org>,
	linux-perf-users@vger.kernel.org,  linux-kernel@vger.kernel.org,
	kvm@vger.kernel.org,  Jim Mattson <jmattson@google.com>,
	Mingwei Zhang <mizhang@google.com>,
	 Stephane Eranian <eranian@google.com>,
	Dapeng Mi <dapeng1.mi@linux.intel.com>
Subject: [PATCH v3 7/9] perf/x86/intel: KVM: Handle cross-mapped PEBS PMCs entirely within KVM
Date: Fri,  8 May 2026 16:13:51 -0700	[thread overview]
Message-ID: <20260508231353.406465-8-seanjc@google.com> (raw)
In-Reply-To: <20260508231353.406465-1-seanjc@google.com>

Now that perf operates on a KVM-provided snapshot of PMU state, handled
cross-mapped PEBS counters entirely in KVM by clearing unusable counters
from the to-be-enabled mask instead of foisting the work on perf.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 arch/x86/events/intel/core.c      |  8 --------
 arch/x86/include/asm/perf_event.h |  1 -
 arch/x86/kvm/vmx/vmx.c            | 10 ++++++++--
 3 files changed, 8 insertions(+), 11 deletions(-)

diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
index e9acfc3f3a82..8f6be0cc4c4b 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -5053,14 +5053,6 @@ static struct perf_guest_switch_msr *intel_guest_get_msrs(int *nr,
 			  ~cpuc->intel_ctrl_exclude_guest_mask &
 			  cpuc->intel_ctrl_exclude_host_mask;
 
-	/*
-	 * Disable counters where the guest PMC is different than the host PMC
-	 * being used on behalf of the guest, as the PEBS record includes
-	 * PERF_GLOBAL_STATUS, i.e. the guest will see overflow status for the
-	 * wrong counter(s).
-	 */
-	guest_pebs_mask &= ~guest_pebs->cross_mapped_mask;
-
 	/*
 	 * FIXME: Allow guest and host usage of PEBS events to co-exist instead
 	 *        of disabling guest PEBS entirely if the host is using PEBS.
diff --git a/arch/x86/include/asm/perf_event.h b/arch/x86/include/asm/perf_event.h
index bc7e48f6f4a8..19f874a79ab0 100644
--- a/arch/x86/include/asm/perf_event.h
+++ b/arch/x86/include/asm/perf_event.h
@@ -790,7 +790,6 @@ struct x86_guest_pebs {
 	u64	enable;
 	u64	ds_area;
 	u64	data_cfg;
-	u64	cross_mapped_mask;
 };
 #if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_CPU_SUP_INTEL)
 extern struct perf_guest_switch_msr *perf_guest_get_msrs(int *nr,
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 9f0a028cf10b..fbe3ce5f5a51 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7319,8 +7319,14 @@ static void atomic_switch_perf_msrs(struct vcpu_vmx *vmx)
 		.data_cfg = pmu->pebs_data_cfg,
 	};
 
-	if (pmu->pebs_enable & pmu->global_ctrl)
-		guest_pebs.cross_mapped_mask = intel_pmu_get_cross_mapped_mask(pmu);
+	/*
+	 * Disable counters where the guest PMC is different than the host PMC
+	 * being used on behalf of the guest, as the PEBS record includes
+	 * PERF_GLOBAL_STATUS, i.e. the guest will see overflow status for the
+	 * wrong counter(s).
+	 */
+	if (guest_pebs.enable & pmu->global_ctrl)
+		guest_pebs.enable &= ~intel_pmu_get_cross_mapped_mask(pmu);
 
 	/* Note, nr_msrs may be garbage if perf_guest_get_msrs() returns NULL. */
 	msrs = perf_guest_get_msrs(&nr_msrs, &guest_pebs);
-- 
2.54.0.563.g4f69b47b94-goog


  parent reply	other threads:[~2026-05-08 23:14 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-05-08 23:13 [PATCH v3 0/9] perf/x86: Don't write PEBS_ENABLED on KVM transitions Sean Christopherson
2026-05-08 23:13 ` [PATCH v3 1/9] perf/x86/intel: Ensure guest PEBS path doesn't set unwanted PERF_GLOBAL_CTRL bits Sean Christopherson
2026-05-08 23:40   ` sashiko-bot
2026-05-12 11:30     ` Mi, Dapeng
2026-05-15  0:01       ` Sean Christopherson
2026-05-15  1:49         ` Mi, Dapeng
2026-05-12  4:53   ` Mi, Dapeng
2026-05-08 23:13 ` [PATCH v3 2/9] perf/x86/intel: Don't write PEBS_ENABLED on host<=>guest xfers if CPU has isolation Sean Christopherson
2026-05-12  4:53   ` Mi, Dapeng
2026-05-08 23:13 ` [PATCH v3 3/9] perf/x86/intel: Don't context switch DS_AREA (and PEBS config) if PEBS is unused Sean Christopherson
2026-05-08 23:13 ` [PATCH v3 4/9] perf/x86/intel: Make @data a mandatory param for intel_guest_get_msrs() Sean Christopherson
2026-05-12 12:39   ` Jim Mattson
2026-05-08 23:13 ` [PATCH v3 5/9] perf/x86/intel: Invert names of intel_ctrl_{guest,host}_mask Sean Christopherson
2026-05-12  4:58   ` Mi, Dapeng
2026-05-08 23:13 ` [PATCH v3 6/9] perf/x86: KVM: Have perf define a dedicated struct for getting guest PEBS data Sean Christopherson
2026-05-08 23:13 ` Sean Christopherson [this message]
2026-05-12  4:59   ` [PATCH v3 7/9] perf/x86/intel: KVM: Handle cross-mapped PEBS PMCs entirely within KVM Mi, Dapeng
2026-05-08 23:13 ` [PATCH v3 8/9] KVM: VMX: Drop a redundant pmu->global_ctrl check when processing pebs_enable Sean Christopherson
2026-05-12  5:00   ` Mi, Dapeng
2026-05-08 23:13 ` [PATCH v3 9/9] KVM: VMX: Only tell perf to enable PEBS counters for fully enabled PMCs Sean Christopherson
2026-05-12  5:01   ` Mi, Dapeng

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=20260508231353.406465-8-seanjc@google.com \
    --to=seanjc@google.com \
    --cc=acme@kernel.org \
    --cc=adrian.hunter@intel.com \
    --cc=alexander.shishkin@linux.intel.com \
    --cc=dapeng1.mi@linux.intel.com \
    --cc=eranian@google.com \
    --cc=irogers@google.com \
    --cc=james.clark@linaro.org \
    --cc=jmattson@google.com \
    --cc=jolsa@kernel.org \
    --cc=kvm@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-perf-users@vger.kernel.org \
    --cc=mark.rutland@arm.com \
    --cc=mingo@redhat.com \
    --cc=mizhang@google.com \
    --cc=namhyung@kernel.org \
    --cc=pbonzini@redhat.com \
    --cc=peterz@infradead.org \
    /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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.