diff options
| author | Song Liu <songliubraving@fb.com> | 2021-11-11 21:45:10 -0800 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2021-11-17 14:48:43 +0100 |
| commit | f3fd84a3b7754b60df67ebfe64e1d90623895111 (patch) | |
| tree | 80bfb788ff8a764e405ce3dc4f553a314d99f95d /arch/x86/events | |
| parent | bdc0feee05174418dec1fa68de2af19e1750b99f (diff) | |
| download | linux-f3fd84a3b7754b60df67ebfe64e1d90623895111.tar.bz2 | |
x86/perf: Fix snapshot_branch_stack warning in VM
When running in VM intel_pmu_snapshot_branch_stack triggers WRMSR warning
like:
[ ] unchecked MSR access error: WRMSR to 0x3f1 (tried to write 0x0000000000000000) at rIP: 0xffffffff81011a5b (intel_pmu_snapshot_branch_stack+0x3b/0xd0)
This can be triggered with BPF selftests:
tools/testing/selftests/bpf/test_progs -t get_branch_snapshot
This warning is caused by __intel_pmu_pebs_disable_all() in the VM.
Since it is not necessary to disable PEBS for LBR, remove it from
intel_pmu_snapshot_branch_stack and intel_pmu_snapshot_arch_branch_stack.
Fixes: c22ac2a3d4bd ("perf: Enable branch record for software events")
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Like Xu <likexu@tencent.com>
Link: https://lore.kernel.org/r/20211112054510.2667030-1-songliubraving@fb.com
Diffstat (limited to 'arch/x86/events')
| -rw-r--r-- | arch/x86/events/intel/core.c | 2 |
1 files changed, 0 insertions, 2 deletions
diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c index 42cf01ecdd13..ec6444f2c9dc 100644 --- a/arch/x86/events/intel/core.c +++ b/arch/x86/events/intel/core.c @@ -2211,7 +2211,6 @@ intel_pmu_snapshot_branch_stack(struct perf_branch_entry *entries, unsigned int /* must not have branches... */ local_irq_save(flags); __intel_pmu_disable_all(false); /* we don't care about BTS */ - __intel_pmu_pebs_disable_all(); __intel_pmu_lbr_disable(); /* ... until here */ return __intel_pmu_snapshot_branch_stack(entries, cnt, flags); @@ -2225,7 +2224,6 @@ intel_pmu_snapshot_arch_branch_stack(struct perf_branch_entry *entries, unsigned /* must not have branches... */ local_irq_save(flags); __intel_pmu_disable_all(false); /* we don't care about BTS */ - __intel_pmu_pebs_disable_all(); __intel_pmu_arch_lbr_disable(); /* ... until here */ return __intel_pmu_snapshot_branch_stack(entries, cnt, flags); |