[PATCH 13/18] KVM: arm64: Remove redundant call to kvm_pmu_vcpu_reset()

Marc Zyngier
2021-01-07T11:50:46Z

From: Alexandru Elisei <alexandru.elisei@arm.com>

KVM_ARM_VCPU_INIT ioctl calls kvm_reset_vcpu(), which in turn resets the
PMU with a call to kvm_pmu_vcpu_reset(). The function zeroes the PMU
chained counters bitmap and stops all the counters with a perf event
attached. Because it is called before the VCPU has had the chance to run,
no perf events are in use and none are released.

kvm_arm_pmu_v3_enable(), called by kvm_vcpu_first_run_init() only if the
VCPU has been initialized, also resets the PMU. kvm_pmu_vcpu_reset() in
this case does the exact same thing as the previous call, so remove it.

Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201201150157.223625-6-alexandru.elisei@arm.com
---
arch/arm64/kvm/pmu-emul.c | 2 --
1 file changed, 2 deletions(-)

diff --git a/arch/arm64/kvm/pmu-emul.c b/arch/arm64/kvm/pmu-emul.c
index 398f6df1bbe4..4ad66a532e38 100644
--- a/arch/arm64/kvm/pmu-emul.c
+++ b/arch/arm64/kvm/pmu-emul.c
@@ -850,8 +850,6 @@ int kvm_arm_pmu_v3_enable(struct kvm_vcpu *vcpu)
return -EINVAL;
}

- kvm_pmu_vcpu_reset(vcpu);
-
return 0;
}

--
2.29.2