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 8CBF2C433EF for ; Wed, 9 Mar 2022 08:54:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231565AbiCIIz2 (ORCPT ); Wed, 9 Mar 2022 03:55:28 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57964 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231561AbiCIIz1 (ORCPT ); Wed, 9 Mar 2022 03:55:27 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 4BC8C13D577 for ; Wed, 9 Mar 2022 00:54:28 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1646816067; 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=+ZhhBbOUupAA6M+k9Rz4Ll5OHg5ZJcNqZJUdl8Vkv/g=; b=FCEQXqhDLbaInIadnjKzfk0UDGsC4aGC2Q7HgE9kgXjZsu20rjV3Oyv1gnz1P1UuIO6SBd e2L22Ym8cNz3MHvWqCRceGav1FYCiqEIfYcyLP4sYOyYkuMS0aOTTKDiH3NshmhpYcHGhN AbH68JXhk4v9cFSdyU/IUgFfvN04ne8= Received: from mail-pg1-f198.google.com (mail-pg1-f198.google.com [209.85.215.198]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-454-NKx3gRz_POitZZU7gxbcOQ-1; Wed, 09 Mar 2022 03:54:26 -0500 X-MC-Unique: NKx3gRz_POitZZU7gxbcOQ-1 Received: by mail-pg1-f198.google.com with SMTP id t62-20020a635f41000000b0037c9ae5fb8bso936277pgb.19 for ; Wed, 09 Mar 2022 00:54:26 -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=+ZhhBbOUupAA6M+k9Rz4Ll5OHg5ZJcNqZJUdl8Vkv/g=; b=lOhTSlKDCGvRD8pICybrUMOGZCbx1PGvd9N2sfkGmAwwOFfcnGQ2dUTZjzap56NpYw BHQStPBACV26yYub2b6HMvOp3X5xosFDU+mGLlEQjyT1fvq6RCohCPRTb1uwP3bhMjq8 6B9i2vbco1kr2yrtDYVq0UYBFvQb5Ditdcn+gKgCstuYJShU0EG+y+62arb88Cd3PdIE vYqXlthQjCvXARy4J1AJjBR1ALCtUGSrRizerj8MxwHQEkJfw/8oqwO/TN3Ui3fA3CFe arSIUYH3GS1gJGV1/Dcsbm7mxkf+Fn9KldJFC/ZzteCp8iu5DqQS06EJf2cPEyfFvkfg guPA== X-Gm-Message-State: AOAM530e1SqWap3b337MLUfpTpsnv8eCSql/jmWu8Zt2Uvyzjy1ccHI1 iWcwXAdgTeuAkybwqJkYPBH6QL3QrrXPJDiY6JfF4pkguhOvX7H5dkjlM79rxf9vXQCHJRk4RPR PZZP0Sqtpf6Dr+1RgRS1miA== X-Received: by 2002:a05:6a00:b92:b0:4f6:dfe0:9abb with SMTP id g18-20020a056a000b9200b004f6dfe09abbmr19856129pfj.68.1646816065156; Wed, 09 Mar 2022 00:54:25 -0800 (PST) X-Google-Smtp-Source: ABdhPJzyRePfc4L0AEaEhCl772NZ5fZoJQRardXXak7jcB75evudlHCNm1wIaBIuQxq5B0gxMurNvg== X-Received: by 2002:a05:6a00:b92:b0:4f6:dfe0:9abb with SMTP id g18-20020a056a000b9200b004f6dfe09abbmr19856114pfj.68.1646816064828; Wed, 09 Mar 2022 00:54:24 -0800 (PST) Received: from [10.72.12.183] ([209.132.188.80]) by smtp.gmail.com with ESMTPSA id pi16-20020a17090b1e5000b001bd1ffaf2basm1829407pjb.0.2022.03.09.00.54.15 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 09 Mar 2022 00:54:24 -0800 (PST) Message-ID: <8b9d337d-71c2-07b4-8e65-6f83cf09bf7a@redhat.com> Date: Wed, 9 Mar 2022 16:54:10 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:91.0) Gecko/20100101 Thunderbird/91.6.1 Subject: Re: [PATCH v7 17/26] virtio_pci: queue_reset: support VIRTIO_F_RING_RESET Content-Language: en-US To: Xuan Zhuo , virtualization@lists.linux-foundation.org, netdev@vger.kernel.org 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 References: <20220308123518.33800-1-xuanzhuo@linux.alibaba.com> <20220308123518.33800-18-xuanzhuo@linux.alibaba.com> From: Jason Wang In-Reply-To: <20220308123518.33800-18-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 2022/3/8 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. > + > + 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? 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 */