From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7DE7EC43381 for ; Mon, 18 Feb 2019 09:39:56 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 48F0C20855 for ; Mon, 18 Feb 2019 09:39:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="YSsbCWK8" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 48F0C20855 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=OEUs4i4qxe9DGhDX4UVKidJuMOKVD6ODyKZPToV+gGM=; b=YSsbCWK8kycmZO 9sRz7VR9yx5TacXHzW7TwU/zJwQmVcBJ1Ei8mVI7GCMl9kGYPSYD6AilWf1GXggoEDd6JUMoEGw6n DMRPSn9tJdu1eRGgZHKkB6C/ZUFXf3g77NKSKRxk3pKoDPNMu6T2o85WQ80TverveV88B0M4u3PCh LSrqqAj5VU3ekI2tjhklPSlciUX32YHoL8zpdn+I3qUXVR39kf1XhOiExP0Pa0FAWhpXJoiQ60SaP mHeyg0TAsUg8Is+9m0gZCb8Q2rRMSYhys5TTjc/6SIT8j0vjZsvHJkoeQP8uT8OEAcNUPt/4xtQyN dYw/3Tv5I3XoYlkFtrgg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gvfOz-0003yH-Po; Mon, 18 Feb 2019 09:39:53 +0000 Received: from foss.arm.com ([217.140.101.70]) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gvfOv-0003vw-3T for linux-arm-kernel@lists.infradead.org; Mon, 18 Feb 2019 09:39:50 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 1DE3080D; Mon, 18 Feb 2019 01:39:47 -0800 (PST) Received: from localhost (unknown [10.37.6.16]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 81B633F589; Mon, 18 Feb 2019 01:39:46 -0800 (PST) Date: Mon, 18 Feb 2019 09:39:44 +0000 From: Andrew Murray To: Suzuki K Poulose Subject: Re: [PATCH v2 3/5] KVM: arm/arm64: re-create event when setting counter value Message-ID: <20190218093944.GE54124@e119886-lin.cambridge.arm.com> References: <1549299218-44714-1-git-send-email-andrew.murray@arm.com> <1549299218-44714-4-git-send-email-andrew.murray@arm.com> <3adc7d31-9d5a-d66b-21ee-9b4da986d24f@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <3adc7d31-9d5a-d66b-21ee-9b4da986d24f@arm.com> User-Agent: Mutt/1.10.1+81 (426a6c1) (2018-08-26) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190218_013949_148154_8A23CDED X-CRM114-Status: GOOD ( 21.76 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: marc.zyngier@arm.com, julien.thierry@arm.com, christoffer.dall@arm.com, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, Feb 13, 2019 at 02:28:51PM +0000, Suzuki K Poulose wrote: > Hi Andrew, > > On 04/02/2019 16:53, Andrew Murray wrote: > > The perf event sample_period is currently set based upon the current > > counter value, when PMXEVTYPER is written to and the perf event is created. > > However the user may choose to write the type before the counter value in > > which case sample_period will be set incorrectly. Let's instead decouple > > event creation from PMXEVTYPER and (re)create the event in either > > suitation. > > > > Signed-off-by: Andrew Murray > > --- > > virt/kvm/arm/pmu.c | 40 +++++++++++++++++++++++++++++++--------- > > 1 file changed, 31 insertions(+), 9 deletions(-) > > > > diff --git a/virt/kvm/arm/pmu.c b/virt/kvm/arm/pmu.c > > index 6e7c179..95d74ec 100644 > > --- a/virt/kvm/arm/pmu.c > > +++ b/virt/kvm/arm/pmu.c > > @@ -24,6 +24,7 @@ > > #include > > #include > > +static void kvm_pmu_create_perf_event(struct kvm_vcpu *vcpu, u64 select_idx); > > /** > > * kvm_pmu_get_counter_value - get PMU counter value > > * @vcpu: The vcpu pointer > > @@ -62,6 +63,9 @@ void kvm_pmu_set_counter_value(struct kvm_vcpu *vcpu, u64 select_idx, u64 val) > > reg = (select_idx == ARMV8_PMU_CYCLE_IDX) > > ? PMCCNTR_EL0 : PMEVCNTR0_EL0 + select_idx; > > __vcpu_sys_reg(vcpu, reg) += (s64)val - kvm_pmu_get_counter_value(vcpu, select_idx); > > + > > + /* Recreate the perf event to reflect the updated sample_period */ > > + kvm_pmu_create_perf_event(vcpu, select_idx); > > } > > /** > > @@ -378,23 +382,22 @@ static bool kvm_pmu_counter_is_enabled(struct kvm_vcpu *vcpu, u64 select_idx) > > } > > /** > > - * kvm_pmu_set_counter_event_type - set selected counter to monitor some event > > + * kvm_pmu_create_perf_event - create a perf event for a counter > > * @vcpu: The vcpu pointer > > - * @data: The data guest writes to PMXEVTYPER_EL0 > > + * @data: Type of event as per PMXEVTYPER_EL0 format > > * @select_idx: The number of selected counter > > nit: data no longer exists. > Thanks for the review, Andrew Murray > > > - * > > - * When OS accesses PMXEVTYPER_EL0, that means it wants to set a PMC to count an > > - * event with given hardware event number. Here we call perf_event API to > > - * emulate this action and create a kernel perf event for it. > > */ > > -void kvm_pmu_set_counter_event_type(struct kvm_vcpu *vcpu, u64 data, > > - u64 select_idx) > > +static void kvm_pmu_create_perf_event(struct kvm_vcpu *vcpu, u64 select_idx) > > { > > With the comment from Julien addressed, > > Reviewed-by: Suzuki K Poulose _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel