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?
> + u64 counter;
> + u64 eventsel;
does this map to PMEVTYPER<n>_EL0.evtCount?
> + bool interrupt;
is this that an interrupt which is pending or which is enabled?
> + 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@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/>.
> + */
> +
> +#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
how is this both global and per VCPU?
> + * @vcpu: The vcpu pointer
> + *
> + * Initialize PMC and Set all the PMU IRQ numbers to invalid
s/Set/set/
> + * 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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