From mboxrd@z Thu Jan 1 00:00:00 1970 From: Will Deacon Subject: Re: [PATCH v6 02/21] KVM: ARM64: Define PMU data structure for each vcpu Date: Tue, 8 Dec 2015 13:53:36 +0000 Message-ID: <20151208135335.GK19612@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> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Shannon Zhao , kvmarm@lists.cs.columbia.edu, christoffer.dall@linaro.org, linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org, alex.bennee@linaro.org, wei@redhat.com, cov@codeaurora.org, shannon.zhao@linaro.org, peter.huangpeng@huawei.com, hangaohuai@huawei.com To: Marc Zyngier Return-path: Received: from foss.arm.com ([217.140.101.70]:43812 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964956AbbLHNxe (ORCPT ); Tue, 8 Dec 2015 08:53:34 -0500 Content-Disposition: inline In-Reply-To: <5666DD0A.5060004@arm.com> Sender: kvm-owner@vger.kernel.org List-ID: 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. Will