[RFC PATCH 17/24] vhost-vdpa: introduce uAPI to set group ASID

[Jason Wang <jasowang@redhat.com>]

Follows the vDPA support for associating ASID to a specific virtqueue
group. This patch adds a uAPI to support setting them from userspace.

Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 drivers/vhost/vdpa.c       | 8 ++++++++
 include/uapi/linux/vhost.h | 4 ++++
 2 files changed, 12 insertions(+)

diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
index a234d3783e16..978cf97dc03a 100644
--- a/drivers/vhost/vdpa.c
+++ b/drivers/vhost/vdpa.c
@@ -441,6 +441,14 @@ static long vhost_vdpa_vring_ioctl(struct vhost_vdpa *v, unsigned int cmd,
 		else if (copy_to_user(argp, &s, sizeof s))
 			return -EFAULT;
 		return 0;
+	case VHOST_VDPA_SET_GROUP_ASID:
+		if (copy_from_user(&s, argp, sizeof(s)))
+			return -EFAULT;
+		if (s.num >= vdpa->ngroups)
+			return -EINVAL;
+		if (!ops->set_group_asid)
+			return -ENOTSUPP;
+		return ops->set_group_asid(vdpa, idx, s.num);
 	case VHOST_GET_VRING_BASE:
 		r = ops->get_vq_state(v->vdpa, idx, &vq_state);
 		if (r)
diff --git a/include/uapi/linux/vhost.h b/include/uapi/linux/vhost.h
index d1c4b5561fee..f3de9e45c518 100644
--- a/include/uapi/linux/vhost.h
+++ b/include/uapi/linux/vhost.h
@@ -151,4 +151,8 @@
 /* Get the group for a virtqueue: read index, write group in num */
 #define VHOST_VDPA_GET_VRING_GROUP	_IOWR(VHOST_VIRTIO, 0x79,	\
 					      struct vhost_vring_state)
+/* Set the ASID for a virtqueue group. */
+#define VHOST_VDPA_SET_GROUP_ASID	_IOW(VHOST_VIRTIO, 0x7A, \
+					     struct vhost_vring_state)
+
 #endif
-- 
2.20.1