From patchwork Wed Jul 31 17:36:46 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Zyngier X-Patchwork-Id: 11068939 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 12E1314DB for ; Wed, 31 Jul 2019 17:37:13 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E9E9B22638 for ; Wed, 31 Jul 2019 17:37:12 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id DDE6E232A7; Wed, 31 Jul 2019 17:37:12 +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=unavailable 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 7D5DF22638 for ; Wed, 31 Jul 2019 17:37:12 +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=pAuquxCRH7iePLsrukCQCz42PcJ786kXVOh8uKQitpQ=; b=snY8kXC+GkHosA auM0oiF+L0cTM6SrZXrU4KmyXexelUsPxQe0qGifwGSfLDdSwUKdq78vRVqzpD/WRyJFuirjyNpUy VokFCI/GHC32M83JVt8hy4q4KD9c0AA5zaNXX3ob+8lsZjrLwfn6JAXGlIWU/Z8bDF/L+7A6WnmfC MYOULkpmvkeo1/AHwthjkkDOoXbdBCtqxxDDrJ7CO5/cGwA2FFHN2BHatl2Jm4jJac62N3ZGZo0rM 8sDIgWnCkp+JBZ1b6UwqS7qp3jZLUPL59sgGrI+PIbM+I3xvOxa0IzVzRwS0Ey3EnM/q7tAy6Or1x lZpJFTUxl8XdGEtRzwEA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hssXH-0004nE-AE; Wed, 31 Jul 2019 17:37:11 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hssX9-0004dR-Ll for linux-arm-kernel@lists.infradead.org; Wed, 31 Jul 2019 17:37:05 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id B49B31570; Wed, 31 Jul 2019 10:37:02 -0700 (PDT) Received: from big-swifty.lan (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id CDB553F71F; Wed, 31 Jul 2019 10:36:59 -0700 (PDT) From: Marc Zyngier To: Paolo Bonzini , =?utf-8?b?UmFkaW0gS3LEjW3DocWZ?= Subject: [PATCH 1/5] KVM: arm/arm64: Introduce kvm_pmu_vcpu_init() to setup PMU counter index Date: Wed, 31 Jul 2019 18:36:46 +0100 Message-Id: <20190731173650.12627-2-maz@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190731173650.12627-1-maz@kernel.org> References: <20190731173650.12627-1-maz@kernel.org> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190731_103703_876686_79F537F4 X-CRM114-Status: GOOD ( 13.10 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Anders Roxell , kvm@vger.kernel.org, Suzuki K Poulose , Julien Thierry , James Morse , Zenghui Yu , Andrew Murray , kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org 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 From: Zenghui Yu We use "pmc->idx" and the "chained" bitmap to determine if the pmc is chained, in kvm_pmu_pmc_is_chained(). But idx might be uninitialized (and random) when we doing this decision, through a KVM_ARM_VCPU_INIT ioctl -> kvm_pmu_vcpu_reset(). And the test_bit() against this random idx will potentially hit a KASAN BUG [1]. In general, idx is the static property of a PMU counter that is not expected to be modified across resets, as suggested by Julien. It looks more reasonable if we can setup the PMU counter idx for a vcpu in its creation time. Introduce a new function - kvm_pmu_vcpu_init() for this basic setup. Oh, and the KASAN BUG will get fixed this way. [1] https://www.spinics.net/lists/kvm-arm/msg36700.html Fixes: 80f393a23be6 ("KVM: arm/arm64: Support chained PMU counters") Suggested-by: Andrew Murray Suggested-by: Julien Thierry Acked-by: Julien Thierry Signed-off-by: Zenghui Yu Signed-off-by: Marc Zyngier --- include/kvm/arm_pmu.h | 2 ++ virt/kvm/arm/arm.c | 2 ++ virt/kvm/arm/pmu.c | 18 +++++++++++++++--- 3 files changed, 19 insertions(+), 3 deletions(-) diff --git a/include/kvm/arm_pmu.h b/include/kvm/arm_pmu.h index 16c769a7f979..6db030439e29 100644 --- a/include/kvm/arm_pmu.h +++ b/include/kvm/arm_pmu.h @@ -34,6 +34,7 @@ struct kvm_pmu { u64 kvm_pmu_get_counter_value(struct kvm_vcpu *vcpu, u64 select_idx); void kvm_pmu_set_counter_value(struct kvm_vcpu *vcpu, u64 select_idx, u64 val); u64 kvm_pmu_valid_counter_mask(struct kvm_vcpu *vcpu); +void kvm_pmu_vcpu_init(struct kvm_vcpu *vcpu); void kvm_pmu_vcpu_reset(struct kvm_vcpu *vcpu); void kvm_pmu_vcpu_destroy(struct kvm_vcpu *vcpu); void kvm_pmu_disable_counter_mask(struct kvm_vcpu *vcpu, u64 val); @@ -71,6 +72,7 @@ static inline u64 kvm_pmu_valid_counter_mask(struct kvm_vcpu *vcpu) { return 0; } +static inline void kvm_pmu_vcpu_init(struct kvm_vcpu *vcpu) {} static inline void kvm_pmu_vcpu_reset(struct kvm_vcpu *vcpu) {} static inline void kvm_pmu_vcpu_destroy(struct kvm_vcpu *vcpu) {} static inline void kvm_pmu_disable_counter_mask(struct kvm_vcpu *vcpu, u64 val) {} diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c index f645c0fbf7ec..c704fa696184 100644 --- a/virt/kvm/arm/arm.c +++ b/virt/kvm/arm/arm.c @@ -340,6 +340,8 @@ int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu) /* Set up the timer */ kvm_timer_vcpu_init(vcpu); + kvm_pmu_vcpu_init(vcpu); + kvm_arm_reset_debug_ptr(vcpu); return kvm_vgic_vcpu_init(vcpu); diff --git a/virt/kvm/arm/pmu.c b/virt/kvm/arm/pmu.c index 3dd8238ed246..362a01886bab 100644 --- a/virt/kvm/arm/pmu.c +++ b/virt/kvm/arm/pmu.c @@ -214,6 +214,20 @@ static void kvm_pmu_stop_counter(struct kvm_vcpu *vcpu, struct kvm_pmc *pmc) kvm_pmu_release_perf_event(pmc); } +/** + * kvm_pmu_vcpu_init - assign pmu counter idx for cpu + * @vcpu: The vcpu pointer + * + */ +void kvm_pmu_vcpu_init(struct kvm_vcpu *vcpu) +{ + int i; + struct kvm_pmu *pmu = &vcpu->arch.pmu; + + for (i = 0; i < ARMV8_PMU_MAX_COUNTERS; i++) + pmu->pmc[i].idx = i; +} + /** * kvm_pmu_vcpu_reset - reset pmu state for cpu * @vcpu: The vcpu pointer @@ -224,10 +238,8 @@ void kvm_pmu_vcpu_reset(struct kvm_vcpu *vcpu) int i; struct kvm_pmu *pmu = &vcpu->arch.pmu; - for (i = 0; i < ARMV8_PMU_MAX_COUNTERS; i++) { + for (i = 0; i < ARMV8_PMU_MAX_COUNTERS; i++) kvm_pmu_stop_counter(vcpu, &pmu->pmc[i]); - pmu->pmc[i].idx = i; - } bitmap_zero(vcpu->arch.pmu.chained, ARMV8_PMU_MAX_COUNTER_PAIRS); }