[PATCH 02/18] KVM: ARM64: Add initial support for PMU
shannon.zhao at linaro.org
shannon.zhao at linaro.org
Sun Jul 5 19:17:32 PDT 2015
From: Shannon Zhao <shannon.zhao at linaro.org>
Here we plan to support virtual PMU for guest by full software
emulation, so define some basic structs and functions preparing for
futher steps. Define struct kvm_pmc for performance monitor counter and
struct kvm_pmu for performance monitor unit for each vcpu. According to
ARMv8 spec, the PMU contains at most 32(ARMV8_MAX_COUNTERS) counters.
Initialize PMU for each vcpu when kvm initialize vcpus, while reset PMU
when kvm reset vcpus.
Since this only supports ARM64 (or PMUv3), add a separate config symbol
for it.
Signed-off-by: Shannon Zhao <shannon.zhao at linaro.org>
---
arch/arm/kvm/arm.c | 4 +++
arch/arm64/include/asm/kvm_host.h | 2 ++
arch/arm64/include/asm/pmu.h | 2 ++
arch/arm64/kvm/Kconfig | 7 +++++
arch/arm64/kvm/Makefile | 1 +
arch/arm64/kvm/reset.c | 3 +++
include/kvm/arm_pmu.h | 54 ++++++++++++++++++++++++++++++++++++++
virt/kvm/arm/pmu.c | 55 +++++++++++++++++++++++++++++++++++++++
8 files changed, 128 insertions(+)
create mode 100644 include/kvm/arm_pmu.h
create mode 100644 virt/kvm/arm/pmu.c
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index bc738d2..4e82625 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -28,6 +28,7 @@
#include <linux/sched.h>
#include <linux/kvm.h>
#include <trace/events/kvm.h>
+#include <kvm/arm_pmu.h>
#define CREATE_TRACE_POINTS
#include "trace.h"
@@ -278,6 +279,9 @@ int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
/* Set up the timer */
kvm_timer_vcpu_init(vcpu);
+ /* Set up the PMU */
+ kvm_pmu_init(vcpu);
+
return 0;
}
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 2709db2..3c88873 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -42,6 +42,7 @@
#include <kvm/arm_vgic.h>
#include <kvm/arm_arch_timer.h>
+#include <kvm/arm_pmu.h>
#define KVM_VCPU_MAX_FEATURES 3
@@ -116,6 +117,7 @@ struct kvm_vcpu_arch {
/* VGIC state */
struct vgic_cpu vgic_cpu;
struct arch_timer_cpu timer_cpu;
+ struct kvm_pmu pmu;
/*
* Anything that is not used directly from assembly code goes
diff --git a/arch/arm64/include/asm/pmu.h b/arch/arm64/include/asm/pmu.h
index b9f394a..95681e6 100644
--- a/arch/arm64/include/asm/pmu.h
+++ b/arch/arm64/include/asm/pmu.h
@@ -19,6 +19,8 @@
#ifndef __ASM_PMU_H
#define __ASM_PMU_H
+#include <linux/perf_event.h>
+
#define ARMV8_MAX_COUNTERS 32
#define ARMV8_COUNTER_MASK (ARMV8_MAX_COUNTERS - 1)
diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig
index bfffe8f..eae3a1b 100644
--- a/arch/arm64/kvm/Kconfig
+++ b/arch/arm64/kvm/Kconfig
@@ -31,6 +31,7 @@ config KVM
select KVM_VFIO
select HAVE_KVM_EVENTFD
select HAVE_KVM_IRQFD
+ select KVM_ARM_PMU
---help---
Support hosting virtualized guest machines.
@@ -52,4 +53,10 @@ config KVM_ARM_MAX_VCPUS
large, so only choose a reasonable number that you expect to
actually use.
+config KVM_ARM_PMU
+ bool
+ depends on KVM_ARM_HOST
+ ---help---
+ Adds support for the Performance Monitoring in virtual machines.
+
endif # VIRTUALIZATION
diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile
index f90f4aa..78db4ee 100644
--- a/arch/arm64/kvm/Makefile
+++ b/arch/arm64/kvm/Makefile
@@ -27,3 +27,4 @@ kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic-v3.o
kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic-v3-emul.o
kvm-$(CONFIG_KVM_ARM_HOST) += vgic-v3-switch.o
kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/arch_timer.o
+kvm-$(CONFIG_KVM_ARM_PMU) += $(KVM)/arm/pmu.o
diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c
index 0b43265..ee2c2e9 100644
--- a/arch/arm64/kvm/reset.c
+++ b/arch/arm64/kvm/reset.c
@@ -107,5 +107,8 @@ int kvm_reset_vcpu(struct kvm_vcpu *vcpu)
/* Reset timer */
kvm_timer_vcpu_reset(vcpu, cpu_vtimer_irq);
+ /* Reset PMU */
+ kvm_pmu_vcpu_reset(vcpu);
+
return 0;
}
diff --git a/include/kvm/arm_pmu.h b/include/kvm/arm_pmu.h
new file mode 100644
index 0000000..27d14ca
--- /dev/null
+++ b/include/kvm/arm_pmu.h
@@ -0,0 +1,54 @@
+/*
+ * Copyright (C) 2015 Linaro Ltd.
+ * Author: Shannon Zhao <shannon.zhao at linaro.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __ASM_ARM_KVM_PMU_H
+#define __ASM_ARM_KVM_PMU_H
+
+#include <asm/pmu.h>
+#include <linux/irq_work.h>
+
+struct kvm_pmc {
+ u8 idx;
+ u64 counter;
+ u64 eventsel;
+ bool interrupt;
+ bool enable;
+ struct perf_event *perf_event;
+ struct kvm_vcpu *vcpu;
+};
+
+struct kvm_pmu {
+#ifdef CONFIG_KVM_ARM_PMU
+ /* PMU IRQ Number per VCPU */
+ int irq_num;
+ int overflow_status;
+ /* IRQ pending flag */
+ bool irq_pending;
+ struct irq_work irq_work;
+ struct kvm_pmc pmc[ARMV8_MAX_COUNTERS];
+#endif
+};
+
+#ifdef CONFIG_KVM_ARM_PMU
+void kvm_pmu_vcpu_reset(struct kvm_vcpu *vcpu);
+void kvm_pmu_init(struct kvm_vcpu *vcpu);
+#else
+static inline void kvm_pmu_vcpu_reset(struct kvm_vcpu *vcpu) {}
+static inline void kvm_pmu_init(struct kvm_vcpu *vcpu) {}
+#endif
+
+#endif
diff --git a/virt/kvm/arm/pmu.c b/virt/kvm/arm/pmu.c
new file mode 100644
index 0000000..dc252d0
--- /dev/null
+++ b/virt/kvm/arm/pmu.c
@@ -0,0 +1,55 @@
+/*
+ * Copyright (C) 2015 Linaro Ltd.
+ * Author: Shannon Zhao <shannon.zhao at linaro.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/cpu.h>
+#include <linux/kvm.h>
+#include <linux/kvm_host.h>
+#include <kvm/arm_pmu.h>
+
+/**
+ * kvm_pmu_vcpu_reset - reset pmu state for cpu
+ * @vcpu: The vcpu pointer
+ *
+ */
+void kvm_pmu_vcpu_reset(struct kvm_vcpu *vcpu)
+{
+ struct kvm_pmu *pmu = &vcpu->arch.pmu;
+
+ pmu->irq_pending = false;
+}
+
+/**
+ * kvm_pmu_init - Initialize global PMU state for per vcpu
+ * @vcpu: The vcpu pointer
+ *
+ * Initialize PMC and Set all the PMU IRQ numbers to invalid
+ * value so that user space has to explicitly provide PMU
+ * IRQ numbers using set device address ioctl.
+ */
+void kvm_pmu_init(struct kvm_vcpu *vcpu)
+{
+ int i;
+ struct kvm_pmu *pmu = &vcpu->arch.pmu;
+
+ memset(pmu, 0, sizeof(*pmu));
+ for (i = 0; i < ARMV8_MAX_COUNTERS; i++) {
+ pmu->pmc[i].idx = i;
+ pmu->pmc[i].vcpu = vcpu;
+ }
+
+ pmu->irq_num = -1;
+}
--
2.1.0
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