Messages in this thread Patch in this message | | | From | Ganapatrao Kulkarni <> | Subject | [PATCH v2] arm64: perf: Use only exclude_kernel attribute when kernel is running in HYP | Date | Wed, 19 Apr 2017 23:14:06 +0530 |
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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.kulkarni@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(-)
diff --git a/arch/arm64/kernel/perf_event.c b/arch/arm64/kernel/perf_event.c index 57ae9d9..b35b94c 100644 --- a/arch/arm64/kernel/perf_event.c +++ b/arch/arm64/kernel/perf_event.c @@ -535,6 +535,25 @@ .attrs = armv8_pmuv3_format_attrs, }; +static ssize_t armv8_pmuv3_exclude_hv_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + return sprintf(buf, "%d\n", is_kernel_in_hyp_mode() ? 1 : 0); +} + +static struct device_attribute armv8_pmuv3_exclude_hv_attr = + __ATTR(exclude_hv, 0444, armv8_pmuv3_exclude_hv_show, NULL); + +static struct attribute *armv8_pmuv3_attrs[] = { + &armv8_pmuv3_exclude_hv_attr.attr, + NULL, +}; + +static struct attribute_group armv8_pmuv3_attr_group = { + .name = "attr", + .attrs = armv8_pmuv3_attrs, +}; + /* * Perf Events' indices */ @@ -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; /* @@ -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
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