Re: [PATCH v2 02/22] KVM: ARM64: Define PMU data structure for each vcpu

[Shannon Zhao <zhaoshenglong@huawei.com>]

On 2015/9/11 17:10, Marc Zyngier wrote:
> On 11/09/15 09:54, 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/include/asm/pmu.h      |  2 ++
>>  arch/arm64/kvm/Kconfig            |  8 ++++++++
>>  include/kvm/arm_pmu.h             | 39 +++++++++++++++++++++++++++++++++++++++
>>  4 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 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>
>> +
> 
> This include file seems out of place here, as I don't think anything in
> this file is directly PMU related.
> 
>>  #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..3c7c58d 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 +53,11 @@ 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 a virtual Performance Monitoring Unit (PMU) in
>> +	  virtual machines.
>> +
>>  endif # VIRTUALIZATION
>> diff --git a/include/kvm/arm_pmu.h b/include/kvm/arm_pmu.h
>> new file mode 100644
>> index 0000000..64af88a
>> --- /dev/null
>> +++ b/include/kvm/arm_pmu.h
>> @@ -0,0 +1,39 @@
>> +/*
>> + * 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 <asm/pmu.h>
>> +
>> +struct kvm_pmc {
>> +	u8 idx;/* index into the pmu->pmc array */
>> +	struct perf_event *perf_event;
>> +	struct kvm_vcpu *vcpu;
>> +};
>> +
> 
> Since you have a struct perf_event here, it makes more sense to #include
> linux/perf.h here.
> 

Ok, will fix this.

>> +struct kvm_pmu {
>> +#ifdef CONFIG_KVM_ARM_PMU
>> +	/* PMU IRQ Number per VCPU */
>> +	int irq_num;
>> +	/* IRQ pending flag */
>> +	bool irq_pending;
>> +	struct kvm_pmc pmc[ARMV8_MAX_COUNTERS];
>> +#endif
>> +};
>> +
>> +#endif
>>
> 
> Thanks,
> 
> 	M.
> 

-- 
Shannon