On 2015/7/17 17:58, Christoffer Dall wrote:
On Fri, Jul 17, 2015 at 04:13:35PM +0800, Shannon Zhao wrote:
On 2015/7/17 2:25, Christoffer Dall wrote:
On Mon, Jul 06, 2015 at 10:17:32AM +0800, shannon.zhao@xxxxxxxxxx wrote:
From: Shannon Zhao <shannon.zhao@xxxxxxxxxx>
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@xxxxxxxxxx>
---
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.
Adds support for a virtual Performance Monitoring Unit (PMU) 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@xxxxxxxxxx>
+ *
+ * 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;
which index is this? Does it map to something architecturally or is it
just the array index number?
It's the index of the PMU counter.
sorry, I don't feel this answers my question? ;)
This index is only used for kvm_pmu_perf_overflow to locate the index of
this PMU counter and kvm_pmu_perf_overflow will set the corresponding
bit of overflow_status to show whether this counter overflows.
See patch 17/18:
+static void kvm_pmu_perf_overflow(struct perf_event *perf_event,
+ struct perf_sample_data *data,
+ struct pt_regs *regs)
+{
+ struct kvm_pmc *pmc = perf_event->overflow_handler_context;
+ struct kvm_vcpu *vcpu = pmc->vcpu;
+ struct kvm_pmu *pmu = &vcpu->arch.pmu;
+
+ if (pmc->interrupt == true) {
+ __set_bit(pmc->idx, (unsigned long *)&pmu->overflow_status);
+ u64 counter;
+ u64 eventsel;
does this map to PMEVTYPER<n>_EL0.evtCount?
No, it just stores the event type.
can you specify more clearly what this maps to/how I derive its meaning?
Is this a perf (Linux) event type number, or an architecturally defined
thing?
Yes, it stores a perf event type number. This is used for
kvm_pmu_set_counter_event_type to check whether event type of this time
is same with the previous one. If they are same, it will return and
doesn't create a new perf event for it and just reuses the previous one.
See PATCH 07/18:
+void kvm_pmu_set_counter_event_type(struct kvm_vcpu *vcpu, unsigned
long data,
+ unsigned long select_idx)
+{
+ struct kvm_pmu *pmu = &vcpu->arch.pmu;
+ struct kvm_pmc *pmc = &pmu->pmc[select_idx];
+ struct perf_event *event;
+ struct perf_event_attr attr;
+ unsigned config, type = PERF_TYPE_RAW;
+
+ if ((data & ARMV8_EVTYPE_EVENT) == pmc->eventsel)
+ return;
Thanks,
-Christoffer
--
Shannon
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