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=-9.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=unavailable 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 495C0C3B1BD for ; Fri, 14 Feb 2020 18:36:36 +0000 (UTC) Received: from mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by mail.kernel.org (Postfix) with ESMTP id F127920848 for ; Fri, 14 Feb 2020 18:36:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="eJhR293p" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F127920848 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvmarm-bounces@lists.cs.columbia.edu Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id AEE3C4AEB5; Fri, 14 Feb 2020 13:36:35 -0500 (EST) X-Virus-Scanned: at lists.cs.columbia.edu Authentication-Results: mm01.cs.columbia.edu (amavisd-new); dkim=softfail (fail, message has been altered) header.i=@kernel.org Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id YO+gBTL--yK7; Fri, 14 Feb 2020 13:36:34 -0500 (EST) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 1DCFC4AEA5; Fri, 14 Feb 2020 13:36:34 -0500 (EST) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 5E0924AE9E for ; Fri, 14 Feb 2020 13:36:32 -0500 (EST) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id gTV4jfJP+zka for ; Fri, 14 Feb 2020 13:36:31 -0500 (EST) Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by mm01.cs.columbia.edu (Postfix) with ESMTPS id 00CEF4AE96 for ; Fri, 14 Feb 2020 13:36:30 -0500 (EST) Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 27CE1222C2; Fri, 14 Feb 2020 18:36:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581705390; bh=U47Cim1m36ncRf1F2X4HkjZI4B/fxmPv0g5AophOpgA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=eJhR293pkuXcdRUeLf+A+a5MOkH+eBfFE4Kwin/ZWZlOCyHu6DIus/kBknxlwLH58 tH2aUPG3KcPyZtTScRIDdIRvnIIrIqLgah7CS70dF4/bqz+Mf2n1buxSD3En2Qzhh3 2k2rqsfuW1010yFz/XHAZSuvJndRy49pEJckG08I= Received: from 78.163-31-62.static.virginmediabusiness.co.uk ([62.31.163.78] helo=why.lan) by disco-boy.misterjones.org with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1j2fpE-005J5c-Gy; Fri, 14 Feb 2020 18:36:28 +0000 From: Marc Zyngier To: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org Subject: [PATCH 1/2] KVM: arm64: Add PMU event filtering infrastructure Date: Fri, 14 Feb 2020 18:36:14 +0000 Message-Id: <20200214183615.25498-2-maz@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200214183615.25498-1-maz@kernel.org> References: <20200214183615.25498-1-maz@kernel.org> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 62.31.163.78 X-SA-Exim-Rcpt-To: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, james.morse@arm.com, julien.thierry.kdev@gmail.com, suzuki.poulose@arm.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false X-BeenThere: kvmarm@lists.cs.columbia.edu X-Mailman-Version: 2.1.14 Precedence: list List-Id: Where KVM/ARM decisions are made List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu It can be desirable to expose a PMU to a guest, and yet not want the guest to be able to count some of the implemented events (because this would give information on shared resources, for example. For this, let's extend the PMUv3 device API, and offer a way to setup a bitmap of the allowed events (the default being no bitmap, and thus no filtering). Userspace can thus allow/deny ranges of event. The default policy depends on the "polarity" of the first filter setup (default deny if the filter allows events, and default allow if the filter denies events). This allows to setup exactly what is allowed for a given guest. Note that although the ioctl is per-vcpu, the map of allowed events is global to the VM (it can be setup from any vcpu until the vcpu PMU is initialized). Signed-off-by: Marc Zyngier --- arch/arm64/include/asm/kvm_host.h | 6 +++ arch/arm64/include/uapi/asm/kvm.h | 16 +++++++ virt/kvm/arm/arm.c | 2 + virt/kvm/arm/pmu.c | 76 ++++++++++++++++++++++++++----- 4 files changed, 88 insertions(+), 12 deletions(-) diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index d87aa609d2b6..b594c604215f 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -91,6 +91,12 @@ struct kvm_arch { * supported. */ bool return_nisv_io_abort_to_user; + + /* + * VM-wide PMU filter, implemented as a bitmap and big enough + * for up to 65536 events + */ + unsigned long *pmu_filter; }; #define KVM_NR_MEM_OBJS 40 diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h index ba85bb23f060..7b1511d6ce44 100644 --- a/arch/arm64/include/uapi/asm/kvm.h +++ b/arch/arm64/include/uapi/asm/kvm.h @@ -159,6 +159,21 @@ struct kvm_sync_regs { struct kvm_arch_memory_slot { }; +/* + * PMU filter structure. Describe a range of events with a particular + * action. To be used with KVM_ARM_VCPU_PMU_V3_FILTER. + */ +struct kvm_pmu_event_filter { + __u16 base_event; + __u16 nevents; + +#define KVM_PMU_EVENT_ALLOW 0 +#define KVM_PMU_EVENT_DENY 1 + + __u8 action; + __u8 pad[3]; +}; + /* for KVM_GET/SET_VCPU_EVENTS */ struct kvm_vcpu_events { struct { @@ -329,6 +344,7 @@ struct kvm_vcpu_events { #define KVM_ARM_VCPU_PMU_V3_CTRL 0 #define KVM_ARM_VCPU_PMU_V3_IRQ 0 #define KVM_ARM_VCPU_PMU_V3_INIT 1 +#define KVM_ARM_VCPU_PMU_V3_FILTER 2 #define KVM_ARM_VCPU_TIMER_CTRL 1 #define KVM_ARM_VCPU_TIMER_IRQ_VTIMER 0 #define KVM_ARM_VCPU_TIMER_IRQ_PTIMER 1 diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c index d65a0faa46d8..9132f7508975 100644 --- a/virt/kvm/arm/arm.c +++ b/virt/kvm/arm/arm.c @@ -164,6 +164,8 @@ void kvm_arch_destroy_vm(struct kvm *kvm) free_percpu(kvm->arch.last_vcpu_ran); kvm->arch.last_vcpu_ran = NULL; + bitmap_free(kvm->arch.pmu_filter); + for (i = 0; i < KVM_MAX_VCPUS; ++i) { if (kvm->vcpus[i]) { kvm_vcpu_destroy(kvm->vcpus[i]); diff --git a/virt/kvm/arm/pmu.c b/virt/kvm/arm/pmu.c index f0d0312c0a55..817f341ed9ad 100644 --- a/virt/kvm/arm/pmu.c +++ b/virt/kvm/arm/pmu.c @@ -585,6 +585,14 @@ static void kvm_pmu_create_perf_event(struct kvm_vcpu *vcpu, u64 select_idx) pmc->idx != ARMV8_PMU_CYCLE_IDX) return; + /* + * If we have a filter in place and that the event isn't allowed, do + * not install a perf event either. + */ + if (vcpu->kvm->arch.pmu_filter && + !test_bit(eventsel, vcpu->kvm->arch.pmu_filter)) + return; + memset(&attr, 0, sizeof(struct perf_event_attr)); attr.type = PERF_TYPE_RAW; attr.size = sizeof(attr); @@ -735,15 +743,6 @@ int kvm_arm_pmu_v3_enable(struct kvm_vcpu *vcpu) static int kvm_arm_pmu_v3_init(struct kvm_vcpu *vcpu) { - if (!kvm_arm_support_pmu_v3()) - return -ENODEV; - - if (!test_bit(KVM_ARM_VCPU_PMU_V3, vcpu->arch.features)) - return -ENXIO; - - if (vcpu->arch.pmu.created) - return -EBUSY; - if (irqchip_in_kernel(vcpu->kvm)) { int ret; @@ -794,8 +793,19 @@ static bool pmu_irq_is_valid(struct kvm *kvm, int irq) return true; } +#define NR_EVENTS (ARMV8_PMU_EVTYPE_EVENT + 1) + int kvm_arm_pmu_v3_set_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr) { + if (!kvm_arm_support_pmu_v3()) + return -ENODEV; + + if (!test_bit(KVM_ARM_VCPU_PMU_V3, vcpu->arch.features)) + return -ENODEV; + + if (vcpu->arch.pmu.created) + return -EBUSY; + switch (attr->attr) { case KVM_ARM_VCPU_PMU_V3_IRQ: { int __user *uaddr = (int __user *)(long)attr->addr; @@ -804,9 +814,6 @@ int kvm_arm_pmu_v3_set_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr) if (!irqchip_in_kernel(vcpu->kvm)) return -EINVAL; - if (!test_bit(KVM_ARM_VCPU_PMU_V3, vcpu->arch.features)) - return -ENODEV; - if (get_user(irq, uaddr)) return -EFAULT; @@ -824,6 +831,50 @@ int kvm_arm_pmu_v3_set_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr) vcpu->arch.pmu.irq_num = irq; return 0; } + case KVM_ARM_VCPU_PMU_V3_FILTER: { + struct kvm_pmu_event_filter __user *uaddr; + struct kvm_pmu_event_filter filter; + + uaddr = (struct kvm_pmu_event_filter __user *)(long)attr->addr; + + if (copy_from_user(&filter, uaddr, sizeof(filter))) + return -EFAULT; + + if (((u32)filter.base_event + filter.nevents) > NR_EVENTS || + (filter.action != KVM_PMU_EVENT_ALLOW && + filter.action != KVM_PMU_EVENT_DENY)) + return -EINVAL; + + mutex_lock(&vcpu->kvm->lock); + + if (!vcpu->kvm->arch.pmu_filter) { + vcpu->kvm->arch.pmu_filter = bitmap_alloc(NR_EVENTS, GFP_KERNEL); + if (!vcpu->kvm->arch.pmu_filter) { + mutex_unlock(&vcpu->kvm->lock); + return -ENOMEM; + } + + /* + * The default depends on the first applied filter. + * If it allows events, the default is to deny. + * Conversely, if the first filter denies a set of + * events, the default is to allow. + */ + if (filter.action == KVM_PMU_EVENT_ALLOW) + bitmap_zero(vcpu->kvm->arch.pmu_filter, NR_EVENTS); + else + bitmap_fill(vcpu->kvm->arch.pmu_filter, NR_EVENTS); + } + + if (filter.action == KVM_PMU_EVENT_ALLOW) + bitmap_set(vcpu->kvm->arch.pmu_filter, filter.base_event, filter.nevents); + else + bitmap_clear(vcpu->kvm->arch.pmu_filter, filter.base_event, filter.nevents); + + mutex_unlock(&vcpu->kvm->lock); + + return 0; + } case KVM_ARM_VCPU_PMU_V3_INIT: return kvm_arm_pmu_v3_init(vcpu); } @@ -860,6 +911,7 @@ int kvm_arm_pmu_v3_has_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr) switch (attr->attr) { case KVM_ARM_VCPU_PMU_V3_IRQ: case KVM_ARM_VCPU_PMU_V3_INIT: + case KVM_ARM_VCPU_PMU_V3_FILTER: if (kvm_arm_support_pmu_v3() && test_bit(KVM_ARM_VCPU_PMU_V3, vcpu->arch.features)) return 0; -- 2.20.1 _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm