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From: Zide Chen <zide.chen@intel.com>
To: qemu-devel@nongnu.org, kvm@vger.kernel.org,
	Paolo Bonzini <pbonzini@redhat.com>,
	Zhao Liu <zhao1.liu@intel.com>, Peter Xu <peterx@redhat.com>,
	Fabiano Rosas <farosas@suse.de>,
	Sandipan Das <sandipan.das@amd.com>
Cc: Xiaoyao Li <xiaoyao.li@intel.com>,
	Dongli Zhang <dongli.zhang@oracle.com>,
	Dapeng Mi <dapeng1.mi@linux.intel.com>,
	Zide Chen <zide.chen@intel.com>
Subject: [PATCH V3 08/13] target/i386: Make some PEBS features user-visible
Date: Wed,  4 Mar 2026 10:07:07 -0800	[thread overview]
Message-ID: <20260304180713.360471-9-zide.chen@intel.com> (raw)
In-Reply-To: <20260304180713.360471-1-zide.chen@intel.com>

Populate selected PEBS feature names in FEAT_PERF_CAPABILITIES to make
the corresponding bits user-visible CPU feature knobs, allowing them to
be explicitly enabled or disabled via -cpu +/-<feature>.

Once named, these bits become part of the guest CPU configuration
contract.  If a VM is configured with such a feature enabled, migration
to a destination that does not support the feature may fail, as the
destination cannot honor the guest-visible CPU model.

The PEBS_FMT bits are not exposed, as target/i386 currently does not
support multi-bit CPU properties.

Co-developed-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
Signed-off-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
Signed-off-by: Zide Chen <zide.chen@intel.com>
---
V2:
- Add the missing comma after "pebs-arch-reg".
- Simplify the PEBS_FMT description in the commit message.
---
 target/i386/cpu.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index a69c3108f64b..89691fba45e1 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -1618,10 +1618,10 @@ FeatureWordInfo feature_word_info[FEATURE_WORDS] = {
         .type = MSR_FEATURE_WORD,
         .feat_names = {
             NULL, NULL, NULL, NULL,
+            NULL, NULL, "pebs-trap", "pebs-arch-reg",
             NULL, NULL, NULL, NULL,
-            NULL, NULL, NULL, NULL,
-            NULL, "full-width-write", NULL, NULL,
-            NULL, NULL, NULL, NULL,
+            NULL, "full-width-write", "pebs-baseline", NULL,
+            NULL, "pebs-timing-info", NULL, NULL,
             NULL, NULL, NULL, NULL,
             NULL, NULL, NULL, NULL,
             NULL, NULL, NULL, NULL,
-- 
2.53.0


  parent reply	other threads:[~2026-03-04 18:15 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-03-04 18:06 [PATCH V3 00/13] target/i386: Misc PMU fixes and enabling Zide Chen
2026-03-04 18:07 ` [PATCH V3 01/13] target/i386: Disable unsupported BTS for guest Zide Chen
2026-03-04 18:07 ` [PATCH V3 02/13] target/i386: Don't save/restore PERF_GLOBAL_OVF_CTRL MSRs Zide Chen
2026-03-04 18:07 ` [PATCH V3 03/13] target/i386: Gate enable_pmu on kvm_enabled() Zide Chen
2026-03-04 18:07 ` [PATCH V3 04/13] target/i386: Adjust maximum number of PMU counters Zide Chen
2026-03-06  3:02   ` Mi, Dapeng
2026-03-04 18:07 ` [PATCH V3 05/13] target/i386: Support full-width writes for perf counters Zide Chen
2026-03-04 18:07 ` [PATCH V3 06/13] target/i386: Increase MSR_BUF_SIZE and split KVM_[GET/SET]_MSRS calls Zide Chen
2026-03-06  3:09   ` Mi, Dapeng
2026-03-04 18:07 ` [PATCH V3 07/13] target/i386: Add get/set/migrate support for legacy PEBS MSRs Zide Chen
2026-03-06  3:17   ` Mi, Dapeng
2026-03-04 18:07 ` Zide Chen [this message]
2026-03-06  3:25   ` [PATCH V3 08/13] target/i386: Make some PEBS features user-visible Mi, Dapeng
2026-03-04 18:07 ` [PATCH V3 09/13] target/i386: Clean up LBR format handling Zide Chen
2026-03-04 18:07 ` [PATCH V3 10/13] target/i386: Refactor " Zide Chen
2026-03-04 18:07 ` [PATCH V3 11/13] target/i386: Add pebs-fmt CPU option Zide Chen
2026-03-06  5:23   ` Mi, Dapeng
2026-03-04 18:07 ` [PATCH V3 12/13] target/i386: Clean up Intel Debug Store feature dependencies Zide Chen
2026-03-06  5:34   ` Mi, Dapeng
2026-03-16  3:21   ` Chenyi Qiang
2026-03-16  6:57     ` Xiaoyao Li
2026-03-16 18:17       ` Chen, Zide
2026-03-16 18:17     ` Chen, Zide
2026-03-04 18:07 ` [PATCH V3 13/13] target/i386: Add Topdown metrics feature support Zide Chen
2026-03-06  5:37   ` Mi, Dapeng

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