Commit 30a03dfc authored by Wu Zongyong's avatar Wu Zongyong Committed by Michael S. Tsirkin
Browse files

virtio_vdpa: setup correct vq size with callbacks get_vq_num_{max,min} 



For the devices which implement the get_vq_num_min callback, the driver
should not negotiate with virtqueue size with the backend vdpa device if
the value returned by get_vq_num_min equals to the value returned by
get_vq_num_max.
This is useful for vdpa devices based on legacy virtio specfication.

Signed-off-by: default avatarWu Zongyong <wuzongyong@linux.alibaba.com>
Link: https://lore.kernel.org/r/bc0551cec6c3f3dd9424b678b7c22d882aebab3a.1635493219.git.wuzongyong@linux.alibaba.com


Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent c53e5d1b

drivers/virtio/virtio_vdpa.c

+11 −5
Original line number Diff line number Diff line
@@ -145,7 +145,8 @@ virtio_vdpa_setup_vq(struct virtio_device *vdev, unsigned int index, 
	/* Assume split virtqueue, switch to packed if necessary */

	struct vdpa_vq_state state = {0};

	unsigned long flags;

	u32 align, num;

	u32 align, max_num, min_num = 1;

	bool may_reduce_num = true;

	int err;



	if (!name)
@@ -163,16 +164,21 @@ virtio_vdpa_setup_vq(struct virtio_device *vdev, unsigned int index, 
	if (!info)

		return ERR_PTR(-ENOMEM);



	num = ops->get_vq_num_max(vdpa);

	if (num == 0) {

	max_num = ops->get_vq_num_max(vdpa);

	if (max_num == 0) {

		err = -ENOENT;

		goto error_new_virtqueue;

	}



	if (ops->get_vq_num_min)

		min_num = ops->get_vq_num_min(vdpa);



	may_reduce_num = (max_num == min_num) ? false : true;



	/* Create the vring */

	align = ops->get_vq_align(vdpa);

	vq = vring_create_virtqueue(index, num, align, vdev,

				    true, true, ctx,

	vq = vring_create_virtqueue(index, max_num, align, vdev,

				    true, may_reduce_num, ctx,

				    virtio_vdpa_notify, callback, name);

	if (!vq) {

		err = -ENOMEM;