From mboxrd@z Thu Jan 1 00:00:00 1970 From: shannon.zhao@linaro.org (Shannon Zhao) Date: Tue, 08 Dec 2015 22:14:29 +0800 Subject: [PATCH v6 02/21] KVM: ARM64: Define PMU data structure for each vcpu In-Reply-To: <5666E4E0.8050504@arm.com> References: <1449578860-15808-1-git-send-email-zhaoshenglong@huawei.com> <1449578860-15808-3-git-send-email-zhaoshenglong@huawei.com> <5666DD0A.5060004@arm.com> <20151208135335.GK19612@arm.com> <5666E4E0.8050504@arm.com> Message-ID: <5666E5C5.5040504@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 2015/12/8 22:10, Marc Zyngier wrote: > On 08/12/15 13:53, Will Deacon wrote: >> On Tue, Dec 08, 2015 at 01:37:14PM +0000, Marc Zyngier wrote: >>> 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/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) >> >> HW_PERF_EVENTS depends on ARM_PMU which in turn depends on PERF_EVENTS. > Yeah, this is the reason why I choose HW_PERF_EVENTS. > in which case, let's make it: > > select KVM_ARM_PMU if HW_PERF_EVENTS > Sure, will do. > which should give us the minimal chain. I hate the kernel config > language! ;-) > > M. > -- Shannon