diff options
| author | Marc Zyngier <maz@kernel.org> | 2019-10-08 17:09:55 +0300 |
|---|---|---|
| committer | Marc Zyngier <maz@kernel.org> | 2019-10-20 12:47:07 +0300 |
| commit | 725ce66979fb6da5c1aec5b064d0871bedc23bf7 (patch) | |
| tree | 160b07ae49fd048279fc3a8684fafc17de14bbd4 /virt | |
| parent | 6f16371453476fd094760ea3d6f00144e9ae3057 (diff) | |
| download | linux-725ce66979fb6da5c1aec5b064d0871bedc23bf7.tar.xz | |
KVM: arm64: pmu: Set the CHAINED attribute before creating the in-kernel event
The current convention for KVM to request a chained event from the
host PMU is to set bit[0] in attr.config1 (PERF_ATTR_CFG1_KVM_PMU_CHAINED).
But as it turns out, this bit gets set *after* we create the kernel
event that backs our virtual counter, meaning that we never get
a 64bit counter.
Moving the setting to an earlier point solves the problem.
Fixes: 80f393a23be6 ("KVM: arm/arm64: Support chained PMU counters")
Reviewed-by: Andrew Murray <andrew.murray@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Diffstat (limited to 'virt')
| -rw-r--r-- | virt/kvm/arm/pmu.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/virt/kvm/arm/pmu.c b/virt/kvm/arm/pmu.c index c30c3a74fc7f..f291d4ac3519 100644 --- a/virt/kvm/arm/pmu.c +++ b/virt/kvm/arm/pmu.c @@ -569,12 +569,12 @@ static void kvm_pmu_create_perf_event(struct kvm_vcpu *vcpu, u64 select_idx) * high counter. */ attr.sample_period = (-counter) & GENMASK(63, 0); + if (kvm_pmu_counter_is_enabled(vcpu, pmc->idx + 1)) + attr.config1 |= PERF_ATTR_CFG1_KVM_PMU_CHAINED; + event = perf_event_create_kernel_counter(&attr, -1, current, kvm_pmu_perf_overflow, pmc + 1); - - if (kvm_pmu_counter_is_enabled(vcpu, pmc->idx + 1)) - attr.config1 |= PERF_ATTR_CFG1_KVM_PMU_CHAINED; } else { /* The initial sample period (overflow count) of an event. */ if (kvm_pmu_idx_is_64bit(vcpu, pmc->idx)) |