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: Wu Zongyong <wuzongyong@linux.alibaba.com>
Link: https://lore.kernel.org/r/bc0551cec6c3f3dd9424b678b7c22d882aebab3a.1635493219.git.wuzongyong@linux.alibaba.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Wu Zongyong 2021-10-29 17:14:47 +08:00 committed by Michael S. Tsirkin
parent c53e5d1b5e
commit 30a03dfcbb

View File

@ -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;