From patchwork Wed May 1 16:31:29 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Murray X-Patchwork-Id: 10925399 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id E19C0933 for ; Wed, 1 May 2019 16:32:15 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id CEDBA28990 for ; Wed, 1 May 2019 16:32:15 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id C276128D2C; Wed, 1 May 2019 16:32:15 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 4FCCC28990 for ; Wed, 1 May 2019 16:32:15 +0000 (UTC) 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:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=ZAC+AihEg2VnqUziEZD3MU+II2k5VuUvBiHN9HcNHbM=; b=jLa9KE1wA1GfVS ER+tn7zn3yE8Z5y/LMwV09eeWzJnGQ+cJOhrcwZ5JzRCuUY38N+3jEYiZq1L5/r8jSO2wj62yaPq4 LWM/bqWBMfO/j5j/TuMPvJWZIDjTdEk4MehsMvlvMHx7e3WpO7qgIoDD53eEvy9iwxjQRLEDcLQ2u ro5C3aLgi9ROYzW8z67d+xGaLXH9Xs8SDsr9h1tCeNWrAjW1dWePb3Ie1RjVYAKVGurfJgOR/JLm+ MhKFyLTBDUttxCyq7vbeaJnzmPiG/UGWpuQkaFMRiQeK4bt+6Sv99EUJcrqUpGCRl6I0qCSv+nohx 0LBpuEv7TqcX9x1Cclvw==; 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 1hLs9S-0004Nk-W4; Wed, 01 May 2019 16:32:10 +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 1hLs95-0003lI-Vy for linux-arm-kernel@lists.infradead.org; Wed, 01 May 2019 16:31:51 +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 69E72EBD; Wed, 1 May 2019 09:31:47 -0700 (PDT) Received: from e119886-lin.cambridge.arm.com (unknown [10.37.6.20]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id B5BC23F719; Wed, 1 May 2019 09:31:45 -0700 (PDT) From: Andrew Murray To: Christoffer Dall , Marc Zyngier Subject: [PATCH v5 3/5] KVM: arm/arm64: re-create event when setting counter value Date: Wed, 1 May 2019 17:31:29 +0100 Message-Id: <20190501163131.43175-4-andrew.murray@arm.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190501163131.43175-1-andrew.murray@arm.com> References: <20190501163131.43175-1-andrew.murray@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190501_093148_287747_63BAF58D X-CRM114-Status: GOOD ( 14.63 ) 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: Suzuki K Pouloze , James Morse , kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org, Julien Thierry Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP 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 Reviewed-by: Julien Thierry Reviewed-by: Suzuki K Poulose --- virt/kvm/arm/pmu.c | 42 +++++++++++++++++++++++++++++++++--------- 1 file changed, 33 insertions(+), 9 deletions(-) diff --git a/virt/kvm/arm/pmu.c b/virt/kvm/arm/pmu.c index 6e7c179103a6..ae1e886d4a1a 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 +382,21 @@ 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 * @select_idx: The number of selected counter - * - * 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) { struct kvm_pmu *pmu = &vcpu->arch.pmu; struct kvm_pmc *pmc = &pmu->pmc[select_idx]; struct perf_event *event; struct perf_event_attr attr; - u64 eventsel, counter; + u64 eventsel, counter, reg, data; + + reg = (select_idx == ARMV8_PMU_CYCLE_IDX) + ? PMCCFILTR_EL0 : PMEVTYPER0_EL0 + select_idx; + data = __vcpu_sys_reg(vcpu, reg); kvm_pmu_stop_counter(vcpu, pmc); eventsel = data & ARMV8_PMU_EVTYPE_EVENT; @@ -431,6 +433,28 @@ void kvm_pmu_set_counter_event_type(struct kvm_vcpu *vcpu, u64 data, pmc->perf_event = event; } +/** + * kvm_pmu_set_counter_event_type - set selected counter to monitor some event + * @vcpu: The vcpu pointer + * @data: The data guest writes to PMXEVTYPER_EL0 + * @select_idx: The number of selected counter + * + * 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) +{ + u64 reg, event_type = data & ARMV8_PMU_EVTYPE_MASK; + + reg = (select_idx == ARMV8_PMU_CYCLE_IDX) + ? PMCCFILTR_EL0 : PMEVTYPER0_EL0 + select_idx; + + __vcpu_sys_reg(vcpu, reg) = event_type; + kvm_pmu_create_perf_event(vcpu, select_idx); +} + bool kvm_arm_support_pmu_v3(void) { /*