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 C4DECC433EF for ; Mon, 14 Feb 2022 02:53:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237844AbiBNCxW (ORCPT ); Sun, 13 Feb 2022 21:53:22 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:39150 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229615AbiBNCxU (ORCPT ); Sun, 13 Feb 2022 21:53:20 -0500 Received: from out30-43.freemail.mail.aliyun.com (out30-43.freemail.mail.aliyun.com [115.124.30.43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1E63D50471 for ; Sun, 13 Feb 2022 18:53:12 -0800 (PST) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R161e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04423;MF=xuanzhuo@linux.alibaba.com;NM=1;PH=DS;RN=4;SR=0;TI=SMTPD_---0V4L2OCN_1644807189; Received: from localhost(mailfrom:xuanzhuo@linux.alibaba.com fp:SMTPD_---0V4L2OCN_1644807189) by smtp.aliyun-inc.com(127.0.0.1); Mon, 14 Feb 2022 10:53:10 +0800 Message-ID: <1644807053.6509683-1-xuanzhuo@linux.alibaba.com> Subject: Re: [PATCH v4 14/14] virtio_pci: queue_reset: support VIRTIO_F_RING_RESET Date: Mon, 14 Feb 2022 10:50:53 +0800 From: Xuan Zhuo To: Jason Wang Cc: "Michael S. Tsirkin" , virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org References: <20220209122901.51790-1-xuanzhuo@linux.alibaba.com> <20220209122901.51790-15-xuanzhuo@linux.alibaba.com> <8b0b5f06-74eb-d6cb-07e2-38249e4cda92@redhat.com> In-Reply-To: <8b0b5f06-74eb-d6cb-07e2-38249e4cda92@redhat.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 11 Feb 2022 15:05:40 +0800, Jason Wang wrote: > > =E5=9C=A8 2022/2/9 =E4=B8=8B=E5=8D=888:29, Xuan Zhuo =E5=86=99=E9=81=93: > > This patch implements virtio pci support for QUEUE RESET. > > > > Performing reset on a queue is divided into these steps: > > > > 1. reset_vq: reset one vq > > 2. recycle the buffer from vq by virtqueue_detach_unused_buf() > > 3. release the ring of the vq by vring_release_virtqueue() > > 4. enable_reset_vq: re-enable the reset queue > > > > This patch implements reset_vq, enable_reset_vq in the pci scenario > > > > Signed-off-by: Xuan Zhuo > > --- > > drivers/virtio/virtio_pci_common.c | 8 +-- > > drivers/virtio/virtio_pci_modern.c | 80 ++++++++++++++++++++++++++++-- > > drivers/virtio/virtio_ring.c | 2 + > > include/linux/virtio.h | 1 + > > 4 files changed, 85 insertions(+), 6 deletions(-) > > > > diff --git a/drivers/virtio/virtio_pci_common.c b/drivers/virtio/virtio= _pci_common.c > > index cb01eb0cb2e4..303637ac4914 100644 > > --- a/drivers/virtio/virtio_pci_common.c > > +++ b/drivers/virtio/virtio_pci_common.c > > @@ -255,9 +255,11 @@ static void vp_del_vq(struct virtqueue *vq) > > struct virtio_pci_vq_info *info =3D 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 d29d40bf0b45..cc45515eda50 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_devic= e *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 */ > > @@ -176,6 +179,70 @@ static void vp_reset(struct virtio_device *vdev) > > vp_disable_cbs(vdev); > > } > > > > +static int vp_modern_reset_vq(struct virtqueue *vq) > > +{ > > + struct virtio_pci_device *vp_dev =3D to_vp_device(vq->vdev); > > + struct virtio_pci_modern_device *mdev =3D &vp_dev->mdev; > > + struct virtio_pci_vq_info *info; > > + unsigned long flags; > > + u16 msix_vec; > > + > > + if (!virtio_has_feature(vq->vdev, VIRTIO_F_RING_RESET)) > > + return -ENOENT; > > + > > + vp_modern_set_queue_reset(mdev, vq->index); > > + > > + info =3D vp_dev->vqs[vq->index]; > > + msix_vec =3D info->msix_vector; > > + > > + /* Disable VQ callback. */ > > + if (vp_dev->per_vq_vectors && msix_vec !=3D VIRTIO_MSI_NO_VECTOR) > > + disable_irq(pci_irq_vector(vp_dev->pci_dev, msix_vec)); > > > I think we need a comment to explain why per_vq_mode needs to be dealt > with differently. > > > > + > > + /* delete vq */ > > + spin_lock_irqsave(&vp_dev->lock, flags); > > + list_del(&info->node); > > + spin_unlock_irqrestore(&vp_dev->lock, flags); > > > So I don't see where vring is freed and vp_setup_vq() may try to > allocate new memory, won't it be a memory leak in this case? > > Thanks > > > > + > > + vq->reset =3D true; > > + > > + INIT_LIST_HEAD(&info->node); > > + > > + return 0; > > +} > > + > > +static int vp_modern_enable_reset_vq(struct virtqueue *vq, u16 ring_nu= m) > > +{ > > + struct virtio_pci_device *vp_dev =3D to_vp_device(vq->vdev); > > + struct virtio_pci_modern_device *mdev =3D &vp_dev->mdev; > > + struct virtio_pci_vq_info *info; > > + struct virtqueue *_vq; > > + u16 msix_vec; > > + > > + if (!vq->reset) > > + return -EPERM; > > + > > + /* check queue reset status */ > > + if (vp_modern_get_queue_reset(mdev, vq->index) !=3D 1) > > + return -EBUSY; > > + > > + info =3D vp_dev->vqs[vq->index]; > > + _vq =3D vp_setup_vq(vq->vdev, vq->index, NULL, NULL, NULL, > > + info->msix_vector, ring_num); > > + if (IS_ERR(_vq)) { > > + vq->reset =3D true; > > + return PTR_ERR(_vq); > > + } > > + > > + vp_modern_set_queue_enable(&vp_dev->mdev, vq->index, true); > > + > > + msix_vec =3D vp_dev->vqs[vq->index]->msix_vector; > > + if (vp_dev->per_vq_vectors && msix_vec !=3D VIRTIO_MSI_NO_VECTOR) > > + enable_irq(pci_irq_vector(vp_dev->pci_dev, msix_vec)); > > + > > + return 0; > > +} > > + > > static u16 vp_config_vector(struct virtio_pci_device *vp_dev, u16 vec= tor) > > { > > return vp_modern_config_vector(&vp_dev->mdev, vector); > > @@ -231,10 +298,13 @@ static struct virtqueue *setup_vq(struct virtio_p= ci_device *vp_dev, > > virtqueue_get_avail_addr(vq), > > virtqueue_get_used_addr(vq)); > > > > - vq->priv =3D (void __force *)vp_modern_map_vq_notify(mdev, index, NUL= L); > > if (!vq->priv) { > > - err =3D -ENOMEM; > > - goto err_map_notify; > > + vq->priv =3D (void __force *)vp_modern_map_vq_notify(mdev, index, > > + NULL); > > + if (!vq->priv) { > > + err =3D -ENOMEM; > > + goto err_map_notify; > > + } > > > This seems unrelated or an artifact of previous patches? Sorry, I missed this. Since re-enable reset queue will call setup_vq() again. Added check to not = call vp_modern_map_vq_notify() repeatedly, only called when vq->priv =3D=3D NULL. I think it would be better to implement this in a separate patch. Thanks. > > Thanks > > > > } > > > > if (msix_vec !=3D VIRTIO_MSI_NO_VECTOR) { > > @@ -402,6 +472,8 @@ static const struct virtio_config_ops virtio_pci_co= nfig_nodev_ops =3D { > > .set_vq_affinity =3D vp_set_vq_affinity, > > .get_vq_affinity =3D vp_get_vq_affinity, > > .get_shm_region =3D vp_get_shm_region, > > + .reset_vq =3D vp_modern_reset_vq, > > + .enable_reset_vq =3D vp_modern_enable_reset_vq, > > }; > > > > static const struct virtio_config_ops virtio_pci_config_ops =3D { > > @@ -420,6 +492,8 @@ static const struct virtio_config_ops virtio_pci_co= nfig_ops =3D { > > .set_vq_affinity =3D vp_set_vq_affinity, > > .get_vq_affinity =3D vp_get_vq_affinity, > > .get_shm_region =3D vp_get_shm_region, > > + .reset_vq =3D vp_modern_reset_vq, > > + .enable_reset_vq =3D vp_modern_enable_reset_vq, > > }; > > > > /* the PCI probing function */ > > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c > > index b8747df8dc1f..4f6028e1e2d9 100644 > > --- a/drivers/virtio/virtio_ring.c > > +++ b/drivers/virtio/virtio_ring.c > > @@ -1731,6 +1731,7 @@ static struct virtqueue *vring_create_virtqueue_p= acked( > > vq->vq.vdev =3D vdev; > > vq->vq.num_free =3D num; > > vq->vq.index =3D index; > > + vq->vq.reset =3D false; > > vq->we_own_ring =3D true; > > vq->notify =3D notify; > > vq->weak_barriers =3D weak_barriers; > > @@ -2220,6 +2221,7 @@ static int __vring_init_virtqueue(struct virtqueu= e *_vq, > > vq->vq.vdev =3D vdev; > > vq->vq.num_free =3D vring.num; > > vq->vq.index =3D index; > > + vq->vq.reset =3D false; > > vq->we_own_ring =3D false; > > vq->notify =3D notify; > > vq->weak_barriers =3D weak_barriers; > > diff --git a/include/linux/virtio.h b/include/linux/virtio.h > > index dd1657c3a488..5d4817d79f3f 100644 > > --- a/include/linux/virtio.h > > +++ b/include/linux/virtio.h > > @@ -32,6 +32,7 @@ struct virtqueue { > > unsigned int index; > > unsigned int num_free; > > void *priv; > > + bool reset; > > }; > > > > int virtqueue_add_outbuf(struct virtqueue *vq, >