Commit 04ca0b0b authored by Xuan Zhuo's avatar Xuan Zhuo Committed by Michael S. Tsirkin
Browse files

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: default avatarXuan Zhuo <xuanzhuo@linux.alibaba.com>
Acked-by: default avatarJason Wang <jasowang@redhat.com>
Message-Id: <20220801063902.129329-33-xuanzhuo@linux.alibaba.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent 56bdc061

drivers/virtio/virtio_pci_common.c

+9 −3
Original line number Diff line number Diff line
@@ -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;



	/*

	 * 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);

drivers/virtio/virtio_pci_modern.c

+88 −0
Original line number Diff line number Diff line
@@ -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 */