diff --git a/arch/x86/events/amd/brs.c b/arch/x86/events/amd/brs.c index 3c13c484c637..40461c3ce714 100644 --- a/arch/x86/events/amd/brs.c +++ b/arch/x86/events/amd/brs.c @@ -92,10 +92,6 @@ int amd_brs_setup_filter(struct perf_event *event) if ((type & ~PERF_SAMPLE_BRANCH_PLM_ALL) != PERF_SAMPLE_BRANCH_ANY) return -EINVAL; - /* can only capture at all priv levels due to the way BRS works */ - if ((type & PERF_SAMPLE_BRANCH_PLM_ALL) != PERF_SAMPLE_BRANCH_PLM_ALL) - return -EINVAL; - return 0; } @@ -195,6 +191,21 @@ void amd_brs_disable_all(void) amd_brs_disable(); } +static bool amd_brs_match_plm(struct perf_event *event, u64 to) +{ + int type = event->attr.branch_sample_type; + int plm_k = PERF_SAMPLE_BRANCH_KERNEL | PERF_SAMPLE_BRANCH_HV; + int plm_u = PERF_SAMPLE_BRANCH_USER; + + if (!(type & plm_k) && kernel_ip(to)) + return 0; + + if (!(type & plm_u) && !kernel_ip(to)) + return 0; + + return 1; +} + /* * Caller must ensure amd_brs_inuse() is true before calling * return: @@ -252,8 +263,6 @@ void amd_brs_drain(void) if (to == BRS_POISON) break; - rdmsrl(brs_from(brs_idx), from); - /* * Sign-extend SAMP_BR_TO to 64 bits, bits 61-63 are reserved. * Necessary to generate proper virtual addresses suitable for @@ -261,6 +270,11 @@ void amd_brs_drain(void) */ to = (u64)(((s64)to << shift) >> shift); + if (!amd_brs_match_plm(event, to)) + continue; + + rdmsrl(brs_from(brs_idx), from); + perf_clear_branch_entry_bitfields(br+nr); br[nr].from = from;