From 04ca0b0b16f11faf74fa92468dab51b8372586cd Mon Sep 17 00:00:00 2001 From: Xuan Zhuo Date: Mon, 1 Aug 2022 14:38:52 +0800 Subject: [PATCH] virtio_pci: support VIRTIO_F_RING_RESET This patch implements virtio pci support for QUEUE RESET. Performing reset on a queue is divided into these steps: 1. notify the device to reset the queue 2. recycle the buffer submitted 3. reset the vring (may re-alloc) 4. 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 Acked-by: Jason Wang Message-Id: <20220801063902.129329-33-xuanzhuo@linux.alibaba.com> Signed-off-by: Michael S. Tsirkin --- drivers/virtio/virtio_pci_common.c | 12 ++++-- drivers/virtio/virtio_pci_modern.c | 88 ++++++++++++++++++++++++++++++++++++++ 2 files changed, 97 insertions(+), 3 deletions(-) diff --git a/drivers/virtio/virtio_pci_common.c b/drivers/virtio/virtio_pci_common.c index ca51fcc..ad258a9 100644 --- a/drivers/virtio/virtio_pci_common.c +++ b/drivers/virtio/virtio_pci_common.c @@ -214,9 +214,15 @@ 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 it fails during re-enable reset vq. This way we won't rejoin + * info->node to the queue. Prevent unexpected irqs. + */ + 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 9041d9a..c3b9f27 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 +202,87 @@ static int vp_active_vq(struct virtqueue *vq, u16 msix_vec) return 0; } +static int vp_modern_disable_vq_and_reset(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; + + 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); + +#ifdef CONFIG_VIRTIO_HARDEN_NOTIFICATION + __virtqueue_break(vq); +#endif + + /* For the case where vq has an exclusive irq, call synchronize_irq() to + * wait for completion. + * + * note: We can't use disable_irq() since it conflicts with the affinity + * managed IRQ that is used by some drivers. + */ + if (vp_dev->per_vq_vectors && info->msix_vector != VIRTIO_MSI_NO_VECTOR) + synchronize_irq(pci_irq_vector(vp_dev->pci_dev, info->msix_vector)); + + vq->reset = true; + + return 0; +} + +static int vp_modern_enable_vq_after_reset(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) + return -EBUSY; + + index = vq->index; + info = vp_dev->vqs[index]; + + if (vp_modern_get_queue_reset(mdev, index)) + return -EBUSY; + + if (vp_modern_get_queue_enable(mdev, index)) + 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); + } + +#ifdef CONFIG_VIRTIO_HARDEN_NOTIFICATION + __virtqueue_unbreak(vq); +#endif + + vp_modern_set_queue_enable(&vp_dev->mdev, index, true); + vq->reset = false; + + return 0; +} + static u16 vp_config_vector(struct virtio_pci_device *vp_dev, u16 vector) { return vp_modern_config_vector(&vp_dev->mdev, vector); @@ -413,6 +497,8 @@ 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, + .disable_vq_and_reset = vp_modern_disable_vq_and_reset, + .enable_vq_after_reset = vp_modern_enable_vq_after_reset, }; static const struct virtio_config_ops virtio_pci_config_ops = { @@ -431,6 +517,8 @@ 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, + .disable_vq_and_reset = vp_modern_disable_vq_and_reset, + .enable_vq_after_reset = vp_modern_enable_vq_after_reset, }; /* the PCI probing function */ -- 2.7.4