On Wed, Apr 19, 2017 at 11:14:06PM +0530, Ganapatrao Kulkarni wrote: > commit d98ecda (arm64: perf: Count EL2 events if the kernel is running in HYP) > is returning error for perf syscall with mixed attribute set for > exclude_kernel > and exclude_hv. This change is breaking some applications (observed with hhvm) > when ran on VHE enabled platforms. > > Adding fix to consider only exclude_kernel attribute when kernel is > running in HYP. Also adding sysfs file to notify the bhehaviour > of attribute exclude_hv. > > Signed-off-by: Ganapatrao Kulkarni <ganapatrao.kulka...@cavium.com> > --- > > Changelog: > > V2: > - Changes as per Will Deacon's suggestion. > > V1: Initial patch > > arch/arm64/kernel/perf_event.c | 28 ++++++++++++++++++++++++---- > include/linux/perf/arm_pmu.h | 1 + > 2 files changed, 25 insertions(+), 4 deletions(-) > > @@ -871,14 +890,13 @@ static int armv8pmu_set_event_filter(struct > hw_perf_event *event, > > if (attr->exclude_idle) > return -EPERM; > - if (is_kernel_in_hyp_mode() && > - attr->exclude_kernel != attr->exclude_hv) > - return -EINVAL; > + if (is_kernel_in_hyp_mode() && !attr->exclude_kernel) > + config_base |= ARMV8_PMU_INCLUDE_EL2; > if (attr->exclude_user) > config_base |= ARMV8_PMU_EXCLUDE_EL0; > if (!is_kernel_in_hyp_mode() && attr->exclude_kernel) > config_base |= ARMV8_PMU_EXCLUDE_EL1; > - if (!attr->exclude_hv) > + if (!is_kernel_in_hyp_mode() && !attr->exclude_hv) > config_base |= ARMV8_PMU_INCLUDE_EL2;
This isn't quite what Will suggested. The idea was that userspace would read sysfs, then use that to determine the correct exclusion parameters [1,2]. This logic was not expected to change; it correctly validates whether we can provide what the user requests. Thanks, Mark. [1] http://lists.infradead.org/pipermail/linux-arm-kernel/2017-April/499224.html [2] http://lists.infradead.org/pipermail/linux-arm-kernel/2017-April/499493.html > > /* > @@ -1008,6 +1026,8 @@ static int armv8_pmuv3_init(struct arm_pmu *cpu_pmu) > &armv8_pmuv3_events_attr_group; > cpu_pmu->attr_groups[ARMPMU_ATTR_GROUP_FORMATS] = > &armv8_pmuv3_format_attr_group; > + cpu_pmu->attr_groups[ARMPMU_ATTR_GROUP_ATTR] = > + &armv8_pmuv3_attr_group; > return armv8pmu_probe_pmu(cpu_pmu); > } > > diff --git a/include/linux/perf/arm_pmu.h b/include/linux/perf/arm_pmu.h > index 8462da2..a26ffc7 100644 > --- a/include/linux/perf/arm_pmu.h > +++ b/include/linux/perf/arm_pmu.h > @@ -81,6 +81,7 @@ enum armpmu_attr_groups { > ARMPMU_ATTR_GROUP_COMMON, > ARMPMU_ATTR_GROUP_EVENTS, > ARMPMU_ATTR_GROUP_FORMATS, > + ARMPMU_ATTR_GROUP_ATTR, > ARMPMU_NR_ATTR_GROUPS > }; > > -- > 1.8.1.4 >
