| Message ID | 1449123091-20252-3-git-send-email-zhaoshenglong@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 03/12/15 06:11, Shannon Zhao wrote: > From: Shannon Zhao <shannon.zhao@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. > > Since this only supports ARM64 (or PMUv3), add a separate config symbol > for it. > > Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org> > --- > arch/arm64/include/asm/kvm_host.h | 2 ++ > arch/arm64/kvm/Kconfig | 8 ++++++++ > include/kvm/arm_pmu.h | 41 +++++++++++++++++++++++++++++++++++++++ > 3 files changed, 51 insertions(+) > create mode 100644 include/kvm/arm_pmu.h > > diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h > index a35ce72..42e15bb 100644 > --- a/arch/arm64/include/asm/kvm_host.h > +++ b/arch/arm64/include/asm/kvm_host.h > @@ -37,6 +37,7 @@ > > #include <kvm/arm_vgic.h> > #include <kvm/arm_arch_timer.h> > +#include <kvm/arm_pmu.h> > > #define KVM_MAX_VCPUS VGIC_V3_MAX_CPUS > > @@ -132,6 +133,7 @@ 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/kvm/Kconfig b/arch/arm64/kvm/Kconfig > index a5272c0..66da9a2 100644 > --- a/arch/arm64/kvm/Kconfig > +++ b/arch/arm64/kvm/Kconfig > @@ -36,6 +36,7 @@ config KVM > select HAVE_KVM_EVENTFD > select HAVE_KVM_IRQFD > select KVM_ARM_VGIC_V3 > + select KVM_ARM_PMU > ---help--- > Support hosting virtualized guest machines. > We don't support KVM with 16K page tables yet, due to the multiple > @@ -48,6 +49,13 @@ config KVM_ARM_HOST > ---help--- > Provides host support for ARM processors. > > +config KVM_ARM_PMU > + bool > + depends on KVM_ARM_HOST && HW_PERF_EVENTS > + ---help--- > + Adds support for a virtual Performance Monitoring Unit (PMU) in > + virtual machines. > + > source drivers/vhost/Kconfig > > endif # VIRTUALIZATION > diff --git a/include/kvm/arm_pmu.h b/include/kvm/arm_pmu.h > new file mode 100644 > index 0000000..0c13470 > --- /dev/null > +++ b/include/kvm/arm_pmu.h > @@ -0,0 +1,41 @@ > +/* > + * Copyright (C) 2015 Linaro Ltd. > + * Author: Shannon Zhao <shannon.zhao@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 <linux/perf_event.h> > +#ifdef CONFIG_KVM_ARM_PMU > +#include <asm/pmu.h> > +#endif > + > +struct kvm_pmc { > + u8 idx;/* index into the pmu->pmc array */ > + struct perf_event *perf_event; > + struct kvm_vcpu *vcpu; Why do you need this? If you have the pointer to a kvm_pmc structure, it is very cheap to compute the address of the vcpu: static inline kvm_vcpu *kvm_pmc_to_vcpu(struct kvm_pmc *pmc) { struct kvm_pmu *pmu; pmc -= pmc->idx; pmu = container_of(pmc, struct kvm_pmu, pmc); return container_of(pmu, struct kvm_vcpu, pmu); } All of which the compiler will happily optimize for you. > + u64 bitmask; Looking at the code in pmu.c, there seem to be some confusion between u64 and unsigned long (see kvm_pmu_get_counter_value). Please make sure this is uniform. > +}; > + > +struct kvm_pmu { > +#ifdef CONFIG_KVM_ARM_PMU > + /* PMU IRQ Number per VCPU */ > + int irq_num; > + struct kvm_pmc pmc[ARMV8_MAX_COUNTERS]; > +#endif > +}; > + > +#endif > Thanks, M.
On 07/12/15 15:05, Marc Zyngier wrote: > On 03/12/15 06:11, Shannon Zhao wrote: >> From: Shannon Zhao <shannon.zhao@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. >> >> Since this only supports ARM64 (or PMUv3), add a separate config symbol >> for it. >> >> Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org> >> --- >> arch/arm64/include/asm/kvm_host.h | 2 ++ >> arch/arm64/kvm/Kconfig | 8 ++++++++ >> include/kvm/arm_pmu.h | 41 +++++++++++++++++++++++++++++++++++++++ >> 3 files changed, 51 insertions(+) >> create mode 100644 include/kvm/arm_pmu.h >> >> diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h >> index a35ce72..42e15bb 100644 >> --- a/arch/arm64/include/asm/kvm_host.h >> +++ b/arch/arm64/include/asm/kvm_host.h >> @@ -37,6 +37,7 @@ >> >> #include <kvm/arm_vgic.h> >> #include <kvm/arm_arch_timer.h> >> +#include <kvm/arm_pmu.h> >> >> #define KVM_MAX_VCPUS VGIC_V3_MAX_CPUS >> >> @@ -132,6 +133,7 @@ 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/kvm/Kconfig b/arch/arm64/kvm/Kconfig >> index a5272c0..66da9a2 100644 >> --- a/arch/arm64/kvm/Kconfig >> +++ b/arch/arm64/kvm/Kconfig >> @@ -36,6 +36,7 @@ config KVM >> select HAVE_KVM_EVENTFD >> select HAVE_KVM_IRQFD >> select KVM_ARM_VGIC_V3 >> + select KVM_ARM_PMU >> ---help--- >> Support hosting virtualized guest machines. >> We don't support KVM with 16K page tables yet, due to the multiple >> @@ -48,6 +49,13 @@ config KVM_ARM_HOST >> ---help--- >> Provides host support for ARM processors. >> >> +config KVM_ARM_PMU >> + bool >> + depends on KVM_ARM_HOST && HW_PERF_EVENTS >> + ---help--- >> + Adds support for a virtual Performance Monitoring Unit (PMU) in >> + virtual machines. >> + >> source drivers/vhost/Kconfig >> >> endif # VIRTUALIZATION >> diff --git a/include/kvm/arm_pmu.h b/include/kvm/arm_pmu.h >> new file mode 100644 >> index 0000000..0c13470 >> --- /dev/null >> +++ b/include/kvm/arm_pmu.h >> @@ -0,0 +1,41 @@ >> +/* >> + * Copyright (C) 2015 Linaro Ltd. >> + * Author: Shannon Zhao <shannon.zhao@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 <linux/perf_event.h> >> +#ifdef CONFIG_KVM_ARM_PMU >> +#include <asm/pmu.h> >> +#endif >> + >> +struct kvm_pmc { >> + u8 idx;/* index into the pmu->pmc array */ >> + struct perf_event *perf_event; >> + struct kvm_vcpu *vcpu; > > Why do you need this? If you have the pointer to a kvm_pmc structure, it > is very cheap to compute the address of the vcpu: > > static inline kvm_vcpu *kvm_pmc_to_vcpu(struct kvm_pmc *pmc) > { > struct kvm_pmu *pmu; > pmc -= pmc->idx; > pmu = container_of(pmc, struct kvm_pmu, pmc); > return container_of(pmu, struct kvm_vcpu, pmu); > } > > All of which the compiler will happily optimize for you. FWIW, actually compiling code looks something like this: static inline struct kvm_vcpu *kvm_pmc_to_vcpu(struct kvm_pmc *pmc) { struct kvm_pmu *pmu; struct kvm_vcpu_arch *vcpu_arch; pmc -= pmc->idx; pmu = container_of(pmc, struct kvm_pmu, pmc[0]); vcpu_arch = container_of(pmu, struct kvm_vcpu_arch, pmu); return container_of(vcpu_arch, struct kvm_vcpu, arch); } which amounts to 4 sub instructions. Thanks, M.
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index a35ce72..42e15bb 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -37,6 +37,7 @@ #include <kvm/arm_vgic.h> #include <kvm/arm_arch_timer.h> +#include <kvm/arm_pmu.h> #define KVM_MAX_VCPUS VGIC_V3_MAX_CPUS @@ -132,6 +133,7 @@ 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/kvm/Kconfig b/arch/arm64/kvm/Kconfig index a5272c0..66da9a2 100644 --- a/arch/arm64/kvm/Kconfig +++ b/arch/arm64/kvm/Kconfig @@ -36,6 +36,7 @@ config KVM select HAVE_KVM_EVENTFD select HAVE_KVM_IRQFD select KVM_ARM_VGIC_V3 + select KVM_ARM_PMU ---help--- Support hosting virtualized guest machines. We don't support KVM with 16K page tables yet, due to the multiple @@ -48,6 +49,13 @@ config KVM_ARM_HOST ---help--- Provides host support for ARM processors. +config KVM_ARM_PMU + bool + depends on KVM_ARM_HOST && HW_PERF_EVENTS + ---help--- + Adds support for a virtual Performance Monitoring Unit (PMU) in + virtual machines. + source drivers/vhost/Kconfig endif # VIRTUALIZATION diff --git a/include/kvm/arm_pmu.h b/include/kvm/arm_pmu.h new file mode 100644 index 0000000..0c13470 --- /dev/null +++ b/include/kvm/arm_pmu.h @@ -0,0 +1,41 @@ +/* + * Copyright (C) 2015 Linaro Ltd. + * Author: Shannon Zhao <shannon.zhao@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 <linux/perf_event.h> +#ifdef CONFIG_KVM_ARM_PMU +#include <asm/pmu.h> +#endif + +struct kvm_pmc { + u8 idx;/* index into the pmu->pmc array */ + struct perf_event *perf_event; + struct kvm_vcpu *vcpu; + u64 bitmask; +}; + +struct kvm_pmu { +#ifdef CONFIG_KVM_ARM_PMU + /* PMU IRQ Number per VCPU */ + int irq_num; + struct kvm_pmc pmc[ARMV8_MAX_COUNTERS]; +#endif +}; + +#endif