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From: Marc Zyngier <maz@kernel.org>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: Alexandru Elisei <alexandru.elisei@arm.com>,
	Catalin Marinas <catalin.marinas@arm.com>,
	David Brazdil <dbrazdil@google.com>,
	Eric Auger <eric.auger@redhat.com>,
	Mark Rutland <mark.rutland@arm.com>,
	Nathan Chancellor <natechancellor@gmail.com>,
	Qian Cai <qcai@redhat.com>,
	Shannon Zhao <shannon.zhao@linux.alibaba.com>,
	James Morse <james.morse@arm.com>,
	Julien Thierry <julien.thierry.kdev@gmail.com>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	kernel-team@android.com, kvmarm@lists.cs.columbia.edu,
	kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org
Subject: [PATCH 13/18] KVM: arm64: Remove redundant call to kvm_pmu_vcpu_reset()
Date: Thu,  7 Jan 2021 11:20:56 +0000	[thread overview]
Message-ID: <20210107112101.2297944-14-maz@kernel.org> (raw)
In-Reply-To: <20210107112101.2297944-1-maz@kernel.org>

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


WARNING: multiple messages have this Message-ID
From: Marc Zyngier <maz@kernel.org>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: kernel-team@android.com, kvm@vger.kernel.org,
	Qian Cai <qcai@redhat.com>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Shannon Zhao <shannon.zhao@linux.alibaba.com>,
	linux-arm-kernel@lists.infradead.org,
	Nathan Chancellor <natechancellor@gmail.com>,
	kvmarm@lists.cs.columbia.edu
Subject: [PATCH 13/18] KVM: arm64: Remove redundant call to kvm_pmu_vcpu_reset()
Date: Thu,  7 Jan 2021 11:20:56 +0000	[thread overview]
Message-ID: <20210107112101.2297944-14-maz@kernel.org> (raw)
In-Reply-To: <20210107112101.2297944-1-maz@kernel.org>

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

_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

WARNING: multiple messages have this Message-ID
From: Marc Zyngier <maz@kernel.org>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>,
	kernel-team@android.com, kvm@vger.kernel.org,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	Qian Cai <qcai@redhat.com>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Shannon Zhao <shannon.zhao@linux.alibaba.com>,
	Eric Auger <eric.auger@redhat.com>,
	James Morse <james.morse@arm.com>,
	linux-arm-kernel@lists.infradead.org,
	Nathan Chancellor <natechancellor@gmail.com>,
	David Brazdil <dbrazdil@google.com>,
	Alexandru Elisei <alexandru.elisei@arm.com>,
	kvmarm@lists.cs.columbia.edu,
	Julien Thierry <julien.thierry.kdev@gmail.com>
Subject: [PATCH 13/18] KVM: arm64: Remove redundant call to kvm_pmu_vcpu_reset()
Date: Thu,  7 Jan 2021 11:20:56 +0000	[thread overview]
Message-ID: <20210107112101.2297944-14-maz@kernel.org> (raw)
In-Reply-To: <20210107112101.2297944-1-maz@kernel.org>

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


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

  parent reply	other threads:[~2021-01-07 11:50 UTC|newest]

Thread overview: 69+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-07 11:20 [GIT PULL] KVM/arm64 fixes for 5.11, take #1 Marc Zyngier
2021-01-07 11:20 ` Marc Zyngier
2021-01-07 11:20 ` Marc Zyngier
2021-01-07 11:20 ` [PATCH 01/18] KVM: arm64: Don't access PMCR_EL0 when no PMU is available Marc Zyngier
2021-01-07 11:20   ` Marc Zyngier
2021-01-07 11:20   ` Marc Zyngier
2021-01-07 11:20 ` [PATCH 02/18] KVM: arm64: Prevent use of invalid PSCI v0.1 function IDs Marc Zyngier
2021-01-07 11:20   ` Marc Zyngier
2021-01-07 11:20   ` Marc Zyngier
2021-01-07 11:20 ` [PATCH 03/18] KVM: arm64: Use lm_alias in nVHE-only VA conversion Marc Zyngier
2021-01-07 11:20   ` Marc Zyngier
2021-01-07 11:20   ` Marc Zyngier
2021-01-07 11:20 ` [PATCH 04/18] KVM: arm64: Skip computing hyp VA layout for VHE Marc Zyngier
2021-01-07 11:20   ` Marc Zyngier
2021-01-07 11:20   ` Marc Zyngier
2021-01-07 11:20 ` [PATCH 05/18] KVM: arm64: Minor cleanup of hyp variables used in host Marc Zyngier
2021-01-07 11:20   ` Marc Zyngier
2021-01-07 11:20   ` Marc Zyngier
2021-01-07 11:20 ` [PATCH 06/18] KVM: arm64: Remove unused includes in psci-relay.c Marc Zyngier
2021-01-07 11:20   ` Marc Zyngier
2021-01-07 11:20   ` Marc Zyngier
2021-01-07 11:20 ` [PATCH 07/18] KVM: arm64: Move skip_host_instruction to adjust_pc.h Marc Zyngier
2021-01-07 11:20   ` Marc Zyngier
2021-01-07 11:20   ` Marc Zyngier
2021-01-07 11:20 ` [PATCH 08/18] KVM: arm64: Declutter host PSCI 0.1 handling Marc Zyngier
2021-01-07 11:20   ` Marc Zyngier
2021-01-07 11:20   ` Marc Zyngier
2021-01-07 11:20 ` [PATCH 09/18] KVM: Documentation: Add arm64 KVM_RUN error codes Marc Zyngier
2021-01-07 11:20   ` Marc Zyngier
2021-01-07 11:20   ` Marc Zyngier
2021-01-07 11:20 ` [PATCH 10/18] KVM: arm64: arch_timer: Remove VGIC initialization check Marc Zyngier
2021-01-07 11:20   ` Marc Zyngier
2021-01-07 11:20   ` Marc Zyngier
2021-01-07 11:20 ` [PATCH 11/18] KVM: arm64: Move double-checked lock to kvm_vgic_map_resources() Marc Zyngier
2021-01-07 11:20   ` Marc Zyngier
2021-01-07 11:20   ` Marc Zyngier
2021-01-07 11:20 ` [PATCH 12/18] KVM: arm64: Update comment in kvm_vgic_map_resources() Marc Zyngier
2021-01-07 11:20   ` Marc Zyngier
2021-01-07 11:20   ` Marc Zyngier
2021-01-07 11:20 ` Marc Zyngier [this message]
2021-01-07 11:20   ` [PATCH 13/18] KVM: arm64: Remove redundant call to kvm_pmu_vcpu_reset() Marc Zyngier
2021-01-07 11:20   ` Marc Zyngier
2021-01-07 11:20 ` [PATCH 14/18] KVM: arm64: Consolidate dist->ready setting into kvm_vgic_map_resources() Marc Zyngier
2021-01-07 11:20   ` Marc Zyngier
2021-01-07 11:20   ` Marc Zyngier
2021-01-07 11:20 ` [PATCH 15/18] KVM: arm64: Fix hyp_cpu_pm_{init,exit} __init annotation Marc Zyngier
2021-01-07 11:20   ` [PATCH 15/18] KVM: arm64: Fix hyp_cpu_pm_{init, exit} " Marc Zyngier
2021-01-07 11:20   ` Marc Zyngier
2021-01-07 11:20 ` [PATCH 16/18] KVM: arm64: Remove spurious semicolon in reg_to_encoding() Marc Zyngier
2021-01-07 11:20   ` Marc Zyngier
2021-01-07 11:20   ` Marc Zyngier
2021-01-07 11:21 ` [PATCH 17/18] KVM: arm64: Replace KVM_ARM_PMU with HW_PERF_EVENTS Marc Zyngier
2021-01-07 11:21   ` Marc Zyngier
2021-01-07 11:21   ` Marc Zyngier
2021-01-07 11:21 ` [PATCH 18/18] arm64: cpufeature: remove non-exist CONFIG_KVM_ARM_HOST Marc Zyngier
2021-01-07 11:21   ` Marc Zyngier
2021-01-07 11:21   ` Marc Zyngier
2021-01-07 18:19 ` [GIT PULL] KVM/arm64 fixes for 5.11, take #1 Paolo Bonzini
2021-01-07 18:19   ` Paolo Bonzini
2021-01-07 18:19   ` Paolo Bonzini
2021-01-07 23:09 ` Paolo Bonzini
2021-01-07 23:09   ` Paolo Bonzini
2021-01-07 23:09   ` Paolo Bonzini
2021-01-08  8:22   ` Marc Zyngier
2021-01-08  8:22     ` Marc Zyngier
2021-01-08  8:22     ` Marc Zyngier
2021-01-08 10:03     ` Paolo Bonzini
2021-01-08 10:03       ` Paolo Bonzini
2021-01-08 10:03       ` Paolo Bonzini

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