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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A5825C4332F for ; Fri, 11 Mar 2022 05:06:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240482AbiCKFHM (ORCPT ); Fri, 11 Mar 2022 00:07:12 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47152 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237879AbiCKFHK (ORCPT ); Fri, 11 Mar 2022 00:07:10 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 1B6471AC2AD for ; Thu, 10 Mar 2022 21:06:07 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1646975164; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Fv0x+1VoYiMUKdKtNJKiJ1SoB5j1+sfzfwwiDTV8v0U=; b=goI1wucyfhrRjb2LqdhjZG9vbdQLBH5/8UG7Mgl8m46EbR14NS03hpZOOJB0dIXb6TFL0Y b3HYZNFovqx/dixROdco0UQiuTDuL4OdY6XCreGOvRghfl0x26Wvsqs56Z71EjoZb/dzm/ SAKEKRgB/2jbHhMMiC/G/mXzVbWPj6Q= Received: from mail-pg1-f200.google.com (mail-pg1-f200.google.com [209.85.215.200]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-179-qKpzCvD1PKS9pjQNzwpVmA-1; Fri, 11 Mar 2022 00:06:03 -0500 X-MC-Unique: qKpzCvD1PKS9pjQNzwpVmA-1 Received: by mail-pg1-f200.google.com with SMTP id 1-20020a630c41000000b00378d9d6bd91so4164402pgm.17 for ; Thu, 10 Mar 2022 21:06:03 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=Fv0x+1VoYiMUKdKtNJKiJ1SoB5j1+sfzfwwiDTV8v0U=; b=byURXPon80DiL5PL/tAlCCZnSdCpxmlZ1HtcA0MobUuevAjju1kxf27g0SD1isBJCo mhboct8sb7O1PMu+8g7txA9feaXdADB5GV5VV5uNT1iJRmiZhn4SviFsKAIdv+FIPYMK NspC5tcIpjqMk7wLwgIE747thx/VQK3VR8EuYHqb/dU5JexrxlcMbUIxKl/PhGkTuNaW kBY69TVPrEN3nVMz3EXNbloCyIYKDAAHrUJ8FL5qX6QEuhJpTdebQ+6onrmtsUbkVLNc F16owmccQN/FGOETVRHfQ7ZpgvIw4jU1EKEpNE7bE1Ls/MvEcbauGoAW3AVIRaE3X/yw cXZA== X-Gm-Message-State: AOAM530v4tqUeHP7DA+SWDEVx/T8dFqAIanYQpgRBBxlgK1tyRWcJjl8 kIEiH5+TMrFq6D+Gn4yAICd9irIwsdqkaroaJDJnWEPeP6PXJh/tl842LuSZqgQOxbraswyXzX7 WoLtFjTPWHmSyR47ihnSVKQ== X-Received: by 2002:a65:6943:0:b0:376:333b:1025 with SMTP id w3-20020a656943000000b00376333b1025mr6951055pgq.164.1646975162519; Thu, 10 Mar 2022 21:06:02 -0800 (PST) X-Google-Smtp-Source: ABdhPJxD3Bx61otH/mEyxC9XMtKu0q2dVWdhVfXlDv+iqZjtIoCxQvw239yb0wy+o8Y5dbByJp1/ng== X-Received: by 2002:a65:6943:0:b0:376:333b:1025 with SMTP id w3-20020a656943000000b00376333b1025mr6951009pgq.164.1646975162136; Thu, 10 Mar 2022 21:06:02 -0800 (PST) Received: from [10.72.13.226] ([209.132.188.80]) by smtp.gmail.com with ESMTPSA id g15-20020a056a0023cf00b004e17e11cb17sm9537352pfc.111.2022.03.10.21.05.53 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 10 Mar 2022 21:06:01 -0800 (PST) Message-ID: <55348e9d-2b8f-4e32-682f-2218c2fb517a@redhat.com> Date: Fri, 11 Mar 2022 13:05:51 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:91.0) Gecko/20100101 Thunderbird/91.6.2 Subject: Re: [PATCH v7 17/26] virtio_pci: queue_reset: support VIRTIO_F_RING_RESET Content-Language: en-US To: Xuan Zhuo Cc: Jeff Dike , Richard Weinberger , Anton Ivanov , "Michael S. Tsirkin" , "David S. Miller" , Jakub Kicinski , Hans de Goede , Mark Gross , Vadim Pasternak , Bjorn Andersson , Mathieu Poirier , Cornelia Huck , Halil Pasic , Heiko Carstens , Vasily Gorbik , Christian Borntraeger , Alexander Gordeev , Sven Schnelle , Alexei Starovoitov , Daniel Borkmann , Jesper Dangaard Brouer , John Fastabend , Johannes Berg , Vincent Whitchurch , linux-um@lists.infradead.org, platform-driver-x86@vger.kernel.org, linux-remoteproc@vger.kernel.org, linux-s390@vger.kernel.org, kvm@vger.kernel.org, bpf@vger.kernel.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org References: <20220308123518.33800-1-xuanzhuo@linux.alibaba.com> <20220308123518.33800-18-xuanzhuo@linux.alibaba.com> <8b9d337d-71c2-07b4-8e65-6f83cf09bf7a@redhat.com> <1646818328.2590482-9-xuanzhuo@linux.alibaba.com> From: Jason Wang In-Reply-To: <1646818328.2590482-9-xuanzhuo@linux.alibaba.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-s390@vger.kernel.org 在 2022/3/9 下午5:32, Xuan Zhuo 写道: > On Wed, 9 Mar 2022 16:54:10 +0800, Jason Wang wrote: >> 在 2022/3/8 下午8:35, Xuan Zhuo 写道: >>> This patch implements virtio pci support for QUEUE RESET. >>> >>> Performing reset on a queue is divided into these steps: >>> >>> 1. virtio_reset_vq() - notify the device to reset the queue >>> 2. virtqueue_detach_unused_buf() - recycle the buffer submitted >>> 3. virtqueue_reset_vring() - reset the vring (may re-alloc) >>> 4. virtio_enable_resetq() - mmap vring to device, and enable the queue >>> >>> This patch implements virtio_reset_vq(), virtio_enable_resetq() in the >>> pci scenario. >>> >>> Signed-off-by: Xuan Zhuo >>> --- >>> drivers/virtio/virtio_pci_common.c | 8 +-- >>> drivers/virtio/virtio_pci_modern.c | 83 ++++++++++++++++++++++++++++++ >>> 2 files changed, 88 insertions(+), 3 deletions(-) >>> >>> diff --git a/drivers/virtio/virtio_pci_common.c b/drivers/virtio/virtio_pci_common.c >>> index fdbde1db5ec5..863d3a8a0956 100644 >>> --- a/drivers/virtio/virtio_pci_common.c >>> +++ b/drivers/virtio/virtio_pci_common.c >>> @@ -248,9 +248,11 @@ static void vp_del_vq(struct virtqueue *vq) >>> struct virtio_pci_vq_info *info = vp_dev->vqs[vq->index]; >>> unsigned long flags; >>> >>> - spin_lock_irqsave(&vp_dev->lock, flags); >>> - list_del(&info->node); >>> - spin_unlock_irqrestore(&vp_dev->lock, flags); >>> + if (!vq->reset) { >>> + spin_lock_irqsave(&vp_dev->lock, flags); >>> + list_del(&info->node); >>> + spin_unlock_irqrestore(&vp_dev->lock, flags); >>> + } >>> >>> vp_dev->del_vq(info); >>> kfree(info); >>> diff --git a/drivers/virtio/virtio_pci_modern.c b/drivers/virtio/virtio_pci_modern.c >>> index 49a4493732cf..3c67d3607802 100644 >>> --- a/drivers/virtio/virtio_pci_modern.c >>> +++ b/drivers/virtio/virtio_pci_modern.c >>> @@ -34,6 +34,9 @@ static void vp_transport_features(struct virtio_device *vdev, u64 features) >>> if ((features & BIT_ULL(VIRTIO_F_SR_IOV)) && >>> pci_find_ext_capability(pci_dev, PCI_EXT_CAP_ID_SRIOV)) >>> __virtio_set_bit(vdev, VIRTIO_F_SR_IOV); >>> + >>> + if (features & BIT_ULL(VIRTIO_F_RING_RESET)) >>> + __virtio_set_bit(vdev, VIRTIO_F_RING_RESET); >>> } >>> >>> /* virtio config->finalize_features() implementation */ >>> @@ -199,6 +202,82 @@ static int vp_active_vq(struct virtqueue *vq, u16 msix_vec) >>> return 0; >>> } >>> >>> +static int vp_modern_reset_vq(struct virtqueue *vq) >>> +{ >>> + struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev); >>> + struct virtio_pci_modern_device *mdev = &vp_dev->mdev; >>> + struct virtio_pci_vq_info *info; >>> + unsigned long flags; >>> + unsigned int irq; >>> + >>> + if (!virtio_has_feature(vq->vdev, VIRTIO_F_RING_RESET)) >>> + return -ENOENT; >>> + >>> + vp_modern_set_queue_reset(mdev, vq->index); >>> + >>> + info = vp_dev->vqs[vq->index]; >>> + >>> + /* delete vq from irq handler */ >>> + spin_lock_irqsave(&vp_dev->lock, flags); >>> + list_del(&info->node); >>> + spin_unlock_irqrestore(&vp_dev->lock, flags); >>> + >>> + INIT_LIST_HEAD(&info->node); >>> + >>> + vq->reset = VIRTIO_VQ_RESET_STEP_DEVICE; >>> + >>> + /* sync irq callback. */ >>> + if (vp_dev->intx_enabled) { >>> + irq = vp_dev->pci_dev->irq; >>> + >>> + } else { >>> + if (info->msix_vector == VIRTIO_MSI_NO_VECTOR) >>> + return 0; >>> + >>> + irq = pci_irq_vector(vp_dev->pci_dev, info->msix_vector); >>> + } >>> + >>> + synchronize_irq(irq); >> >> Synchronize_irq() is not sufficient here since it breaks the effort of >> the interrupt hardening which is done by commits: >> >> 080cd7c3ac87 virtio-pci: harden INTX interrupts >> 9e35276a5344 virtio_pci: harden MSI-X interrupts >> >> Unfortunately  080cd7c3ac87 introduces an issue that disable_irq() were >> used for the affinity managed irq but we're discussing a fix. > I need to understand it first. > >> >>> + >>> + return 0; >>> +} >>> + >>> +static int vp_modern_enable_reset_vq(struct virtqueue *vq) >>> +{ >>> + struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev); >>> + struct virtio_pci_modern_device *mdev = &vp_dev->mdev; >>> + struct virtio_pci_vq_info *info; >>> + unsigned long flags, index; >>> + int err; >>> + >>> + if (vq->reset != VIRTIO_VQ_RESET_STEP_VRING_ATTACH) >>> + return -EBUSY; >>> + >>> + index = vq->index; >>> + info = vp_dev->vqs[index]; >>> + >>> + /* check queue reset status */ >>> + if (vp_modern_get_queue_reset(mdev, index) != 1) >>> + return -EBUSY; >>> + >>> + err = vp_active_vq(vq, info->msix_vector); >>> + if (err) >>> + return err; >>> + >>> + if (vq->callback) { >>> + spin_lock_irqsave(&vp_dev->lock, flags); >>> + list_add(&info->node, &vp_dev->virtqueues); >>> + spin_unlock_irqrestore(&vp_dev->lock, flags); >>> + } else { >>> + INIT_LIST_HEAD(&info->node); >>> + } >>> + >>> + vp_modern_set_queue_enable(&vp_dev->mdev, index, true); >> >> Any reason we need to check queue_enable() here? > The purpose of this function is to enable a reset vq, so call queue_enable() to > activate it. Ok, this is what spec mandate. Thanks > > Thanks. > >> Thanks >> >> >>> + vq->reset = VIRTIO_VQ_RESET_STEP_NONE; >>> + >>> + return 0; >>> +} >>> + >>> static u16 vp_config_vector(struct virtio_pci_device *vp_dev, u16 vector) >>> { >>> return vp_modern_config_vector(&vp_dev->mdev, vector); >>> @@ -407,6 +486,8 @@ static const struct virtio_config_ops virtio_pci_config_nodev_ops = { >>> .set_vq_affinity = vp_set_vq_affinity, >>> .get_vq_affinity = vp_get_vq_affinity, >>> .get_shm_region = vp_get_shm_region, >>> + .reset_vq = vp_modern_reset_vq, >>> + .enable_reset_vq = vp_modern_enable_reset_vq, >>> }; >>> >>> static const struct virtio_config_ops virtio_pci_config_ops = { >>> @@ -425,6 +506,8 @@ static const struct virtio_config_ops virtio_pci_config_ops = { >>> .set_vq_affinity = vp_set_vq_affinity, >>> .get_vq_affinity = vp_get_vq_affinity, >>> .get_shm_region = vp_get_shm_region, >>> + .reset_vq = vp_modern_reset_vq, >>> + .enable_reset_vq = vp_modern_enable_reset_vq, >>> }; >>> >>> /* the PCI probing function */