Messages in this thread Patch in this message | | | Date | Tue, 17 May 2022 22:14:33 -0000 | From | "tip-bot2 for Borislav Petkov" <> | Subject | [tip: perf/core] perf/x86/amd: Run AMD BRS code only on supported hw |
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The following commit has been merged into the perf/core branch of tip:
Commit-ID: 841b51e4a3590866d17fa2663c64688c25b891b1 Gitweb: https://git.kernel.org/tip/841b51e4a3590866d17fa2663c64688c25b891b1 Author: Borislav Petkov <bp@suse.de> AuthorDate: Mon, 16 May 2022 17:48:38 +02:00 Committer: Peter Zijlstra <peterz@infradead.org> CommitterDate: Wed, 18 May 2022 00:08:26 +02:00
perf/x86/amd: Run AMD BRS code only on supported hw
This fires on a Fam16h machine here:
unchecked MSR access error: WRMSR to 0xc000010f (tried to write 0x0000000000000018) \ at rIP: 0xffffffff81007db1 (amd_brs_reset+0x11/0x50) Call Trace: <TASK> amd_pmu_cpu_starting ? x86_pmu_dead_cpu x86_pmu_starting_cpu cpuhp_invoke_callback ? x86_pmu_starting_cpu ? x86_pmu_dead_cpu cpuhp_issue_call ? x86_pmu_starting_cpu __cpuhp_setup_state_cpuslocked ? x86_pmu_dead_cpu ? x86_pmu_starting_cpu __cpuhp_setup_state ? map_vsyscall init_hw_perf_events ? map_vsyscall do_one_initcall ? _raw_spin_unlock_irqrestore ? try_to_wake_up kernel_init_freeable ? rest_init kernel_init ret_from_fork
because that CPU hotplug callback gets executed on any AMD CPU - not only on the BRS-enabled ones. Check the BRS feature bit properly.
Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-By: Stephane Eranian <eranian@google.com> Link: https://lkml.kernel.org/r/20220516154838.7044-1-bp@alien8.de --- arch/x86/events/amd/brs.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/arch/x86/events/amd/brs.c b/arch/x86/events/amd/brs.c index 895c821..bee8765 100644 --- a/arch/x86/events/amd/brs.c +++ b/arch/x86/events/amd/brs.c @@ -57,7 +57,7 @@ static inline u64 get_debug_extn_cfg(void) static bool __init amd_brs_detect(void) { - if (!boot_cpu_has(X86_FEATURE_BRS)) + if (!cpu_feature_enabled(X86_FEATURE_BRS)) return false; switch (boot_cpu_data.x86) { @@ -112,6 +112,9 @@ static inline int amd_brs_get_tos(union amd_debug_extn_cfg *cfg) */ void amd_brs_reset(void) { + if (!cpu_feature_enabled(X86_FEATURE_BRS)) + return; + /* * Reset config */
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