vDPA: introduce get_vq_size to vdpa_config_ops

This commit introduces a new interface get_vq_size to
vDPA config ops, this new interface intends to report
the size of a specific virtqueue

Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Message-Id: <20240202163905.8834-3-lingshan.zhu@intel.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
index aef92a7c57f3fd58a2bf40a49d7bf9011ae08ba1..ba52d128aeb76bc1d52b375707f12875915bc7e6 100644 (file)
--- a/drivers/vhost/vdpa.c
+++ b/drivers/vhost/vdpa.c
@@ -687,6 +687,14 @@ static long vhost_vdpa_vring_ioctl(struct vhost_vdpa *v, unsigned int cmd,
                if (!ops->set_group_asid)
                        return -EOPNOTSUPP;
                return ops->set_group_asid(vdpa, idx, s.num);
+       case VHOST_VDPA_GET_VRING_SIZE:
+               if (!ops->get_vq_size)
+                       return -EOPNOTSUPP;
+               s.index = idx;
+               s.num = ops->get_vq_size(vdpa, idx);
+               if (copy_to_user(argp, &s, sizeof(s)))
+                       return -EFAULT;
+               return 0;
        case VHOST_GET_VRING_BASE:
                r = ops->get_vq_state(v->vdpa, idx, &vq_state);
                if (r)

diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h
index db15ac07f8a6a453bfbe35df555eea6efc83e0d8..4097e8e92860befe6912cdda2b3e89baad9afee5 100644 (file)
--- a/include/linux/vdpa.h
+++ b/include/linux/vdpa.h
@@ -195,6 +195,10 @@ struct vdpa_map_file {
  *                             @idx: virtqueue index
  *                             Returns int: irq number of a virtqueue,
  *                             negative number if no irq assigned.
+ * @get_vq_size:               Get the size of a specific virtqueue (optional)
+ *                             @vdev: vdpa device
+ *                             @idx: virtqueue index
+ *                             Return u16: the size of the virtqueue
  * @get_vq_align:              Get the virtqueue align requirement
  *                             for the device
  *                             @vdev: vdpa device
@@ -386,6 +390,7 @@ struct vdpa_config_ops {
        (*get_vq_notification)(struct vdpa_device *vdev, u16 idx);
        /* vq irq is not expected to be changed once DRIVER_OK is set */
        int (*get_vq_irq)(struct vdpa_device *vdev, u16 idx);
+       u16 (*get_vq_size)(struct vdpa_device *vdev, u16 idx);
 
        /* Device ops */
        u32 (*get_vq_align)(struct vdpa_device *vdev);