From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc Zyngier Subject: Re: [PATCH v6 02/21] KVM: ARM64: Define PMU data structure for each vcpu Date: Tue, 08 Dec 2015 13:37:14 +0000 Message-ID: <5666DD0A.5060004@arm.com> References: <1449578860-15808-1-git-send-email-zhaoshenglong@huawei.com> <1449578860-15808-3-git-send-email-zhaoshenglong@huawei.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id D3BB741145 for ; Tue, 8 Dec 2015 08:35:29 -0500 (EST) Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id MA7wBhPgKyoz for ; Tue, 8 Dec 2015 08:35:28 -0500 (EST) Received: from foss.arm.com (foss.arm.com [217.140.101.70]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 5978D407A6 for ; Tue, 8 Dec 2015 08:35:28 -0500 (EST) In-Reply-To: <1449578860-15808-3-git-send-email-zhaoshenglong@huawei.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu To: Shannon Zhao , kvmarm@lists.cs.columbia.edu, christoffer.dall@linaro.org Cc: kvm@vger.kernel.org, will.deacon@arm.com, linux-arm-kernel@lists.infradead.org, shannon.zhao@linaro.org List-Id: kvmarm@lists.cs.columbia.edu On 08/12/15 12:47, Shannon Zhao wrote: > From: Shannon Zhao > > 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 > --- > arch/arm64/include/asm/kvm_host.h | 2 ++ > arch/arm64/kvm/Kconfig | 8 ++++++++ > include/kvm/arm_pmu.h | 40 +++++++++++++++++++++++++++++++++++++++ > 3 files changed, 50 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 > #include > +#include > > #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 What if HW_PERF_EVENTS is not selected? Also, selecting HW_PERF_EVENTS is not enough, and you probably need PERF_EVENTS as well, So this should probably read: select KVM_ARM_PMU if (HW_PERF_EVENTS && PERF_EVENTS) > ---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 and this line should be dropped. > + ---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..dea78f8 > --- /dev/null > +++ b/include/kvm/arm_pmu.h > @@ -0,0 +1,40 @@ > +/* > + * Copyright (C) 2015 Linaro Ltd. > + * Author: Shannon Zhao > + * > + * 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 . > + */ > + > +#ifndef __ASM_ARM_KVM_PMU_H > +#define __ASM_ARM_KVM_PMU_H > + > +#include > +#ifdef CONFIG_KVM_ARM_PMU > +#include > +#endif > + > +struct kvm_pmc { > + u8 idx;/* index into the pmu->pmc array */ > + struct perf_event *perf_event; > + 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 > The repetition of #ifdef CONFIG_KVM_ARM_PMU is a bit ugly. How about something like this instead: #ifndef __ASM_ARM_KVM_PMU_H #define __ASM_ARM_KVM_PMU_H #ifdef CONFIG_KVM_ARM_PMU #include #include struct kvm_pmc { u8 idx;/* index into the pmu->pmc array */ struct perf_event *perf_event; u64 bitmask; }; struct kvm_pmu { /* PMU IRQ Number per VCPU */ int irq_num; struct kvm_pmc pmc[ARMV8_MAX_COUNTERS]; }; #else struct kvm_pmu { }; #endif #endif and you can then populate the rest of the function prototype and stubs where needed. Thanks, M. -- Jazz is not dead. It just smells funny...