Re: [PATCH 6.6] perf/x86/intel: Hide Topdown metrics events if the feature is not enumerated

[Sasha Levin <sashal@kernel.org>]

[ Sasha's backport helper bot ]

Hi,

The upstream commit SHA1 provided is correct: 556a7c039a52c21da33eaae9269984a1ef59189b

WARNING: Author mismatch between patch and upstream commit:
Backport author: Hagar Hemdan <hagarhem@amazon.com>
Commit author: Kan Liang <kan.liang@linux.intel.com>


Status in newer kernel trees:
6.12.y | Present (exact SHA1)
6.11.y | Present (exact SHA1)
6.6.y | Not found

Note: The patch differs from the upstream commit:
---
1:  556a7c039a52c ! 1:  46084b673b37e perf/x86/intel: Hide Topdown metrics events if the feature is not enumerated
    @@ Metadata
      ## Commit message ##
         perf/x86/intel: Hide Topdown metrics events if the feature is not enumerated
     
    +    [ Upstream commit 556a7c039a52c21da33eaae9269984a1ef59189b ]
    +
         The below error is observed on Ice Lake VM.
     
         $ perf stat
    @@ Commit message
         Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
         Tested-by: Dongli Zhang <dongli.zhang@oracle.com>
         Link: https://lkml.kernel.org/r/20240708193336.1192217-2-kan.liang@linux.intel.com
    +    [ Minor changes to make it work on 6.6 ]
    +    Signed-off-by: Hagar Hemdan <hagarhem@amazon.com>
     
      ## arch/x86/events/intel/core.c ##
    -@@ arch/x86/events/intel/core.c: exra_is_visible(struct kobject *kobj, struct attribute *attr, int i)
    - 	return x86_pmu.version >= 2 ? attr->mode : 0;
    +@@ arch/x86/events/intel/core.c: default_is_visible(struct kobject *kobj, struct attribute *attr, int i)
    + 	return attr->mode;
      }
      
     +static umode_t
    @@ arch/x86/events/intel/core.c: exra_is_visible(struct kobject *kobj, struct attri
      
      static struct attribute_group group_events_mem = {
     @@ arch/x86/events/intel/core.c: static umode_t hybrid_format_is_visible(struct kobject *kobj,
    - 	return (cpu >= 0) && (pmu->pmu_type & pmu_attr->pmu_type) ? attr->mode : 0;
    + 	return (cpu >= 0) && (pmu->cpu_type & pmu_attr->pmu_type) ? attr->mode : 0;
      }
      
     +static umode_t hybrid_td_is_visible(struct kobject *kobj,
    @@ arch/x86/events/intel/core.c: static umode_t hybrid_format_is_visible(struct kob
     +
     +
     +	/* Only the big core supports perf metrics */
    -+	if (pmu->pmu_type == hybrid_big)
    ++	if (pmu->cpu_type == hybrid_big)
     +		return pmu->intel_cap.perf_metrics ? attr->mode : 0;
     +
     +	return attr->mode;
---

Results of testing on various branches:

| Branch                    | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-6.6.y        |  Success    |  Success   |