From: Marc Zyngier <maz@kernel.org>
To: kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org,
linux-sh@vger.kernel.org
Cc: Mark Rutland <mark.rutland@arm.com>,
Will Deacon <will@kernel.org>, Rich Felker <dalias@libc.org>,
Yoshinori Sato <ysato@users.sourceforge.jp>,
Peter Zijlstra <peterz@infradead.org>,
Arnaldo Carvalho de Melo <acme@kernel.org>,
Christian Borntraeger <borntraeger@de.ibm.com>,
Heiko Carstens <hca@linux.ibm.com>,
nathan@kernel.org, Viresh Kumar <viresh.kumar@linaro.org>,
James Morse <james.morse@arm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Alexandru Elisei <alexandru.elisei@arm.com>,
kernel-team@android.com
Subject: [PATCH 1/5] KVM: arm64: Divorce the perf code from oprofile helpers
Date: Wed, 14 Apr 2021 14:44:05 +0100 [thread overview]
Message-ID: <20210414134409.1266357-2-maz@kernel.org> (raw)
In-Reply-To: <20210414134409.1266357-1-maz@kernel.org>
KVM/arm64 is the sole user of perf_num_counters(), and really
could do without it. Stop using the obsolete API by relying on
the existing probing code.
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
arch/arm64/kvm/perf.c | 7 +------
arch/arm64/kvm/pmu-emul.c | 2 +-
include/kvm/arm_pmu.h | 4 ++++
3 files changed, 6 insertions(+), 7 deletions(-)
diff --git a/arch/arm64/kvm/perf.c b/arch/arm64/kvm/perf.c
index 739164324afe..b8b398670ef2 100644
--- a/arch/arm64/kvm/perf.c
+++ b/arch/arm64/kvm/perf.c
@@ -50,12 +50,7 @@ static struct perf_guest_info_callbacks kvm_guest_cbs = {
int kvm_perf_init(void)
{
- /*
- * Check if HW_PERF_EVENTS are supported by checking the number of
- * hardware performance counters. This could ensure the presence of
- * a physical PMU and CONFIG_PERF_EVENT is selected.
- */
- if (IS_ENABLED(CONFIG_ARM_PMU) && perf_num_counters() > 0)
+ if (kvm_pmu_probe_pmuver() != 0xf)
static_branch_enable(&kvm_arm_pmu_available);
return perf_register_guest_info_callbacks(&kvm_guest_cbs);
diff --git a/arch/arm64/kvm/pmu-emul.c b/arch/arm64/kvm/pmu-emul.c
index e32c6e139a09..fd167d4f4215 100644
--- a/arch/arm64/kvm/pmu-emul.c
+++ b/arch/arm64/kvm/pmu-emul.c
@@ -739,7 +739,7 @@ void kvm_pmu_set_counter_event_type(struct kvm_vcpu *vcpu, u64 data,
kvm_pmu_create_perf_event(vcpu, select_idx);
}
-static int kvm_pmu_probe_pmuver(void)
+int kvm_pmu_probe_pmuver(void)
{
struct perf_event_attr attr = { };
struct perf_event *event;
diff --git a/include/kvm/arm_pmu.h b/include/kvm/arm_pmu.h
index 6fd3cda608e4..864b9997efb2 100644
--- a/include/kvm/arm_pmu.h
+++ b/include/kvm/arm_pmu.h
@@ -61,6 +61,7 @@ int kvm_arm_pmu_v3_get_attr(struct kvm_vcpu *vcpu,
int kvm_arm_pmu_v3_has_attr(struct kvm_vcpu *vcpu,
struct kvm_device_attr *attr);
int kvm_arm_pmu_v3_enable(struct kvm_vcpu *vcpu);
+int kvm_pmu_probe_pmuver(void);
#else
struct kvm_pmu {
};
@@ -116,6 +117,9 @@ static inline u64 kvm_pmu_get_pmceid(struct kvm_vcpu *vcpu, bool pmceid1)
{
return 0;
}
+
+static inline int kvm_pmu_probe_pmuver(void) { return 0xf; }
+
#endif
#endif
--
2.29.2
next prev parent reply other threads:[~2021-04-14 13:44 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-14 13:44 [PATCH 0/5] perf: oprofile spring cleanup Marc Zyngier
2021-04-14 13:44 ` Marc Zyngier [this message]
2021-04-15 6:59 ` [PATCH 1/5] KVM: arm64: Divorce the perf code from oprofile helpers Keqian Zhu
[not found] ` <87h7k7n81z.wl-maz@kernel.org>
2021-04-15 11:34 ` Keqian Zhu
2021-04-22 10:43 ` Will Deacon
2021-04-14 13:44 ` [PATCH 2/5] arm64: Get rid of oprofile leftovers Marc Zyngier
2021-04-22 10:45 ` Will Deacon
2021-04-14 13:44 ` [PATCH 3/5] s390: " Marc Zyngier
2021-04-15 10:38 ` Heiko Carstens
2021-04-15 10:47 ` Marc Zyngier
2021-04-15 12:12 ` Heiko Carstens
2021-04-14 13:44 ` [PATCH 4/5] sh: " Marc Zyngier
2021-04-14 19:09 ` Geert Uytterhoeven
2021-04-14 13:44 ` [PATCH 5/5] perf: " Marc Zyngier
2021-04-22 10:47 ` Will Deacon
2021-04-22 12:48 ` [PATCH 0/5] perf: oprofile spring cleanup Marc Zyngier
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