vhost-vdpa: uAPI to get virtqueue group id

Follows the support for virtqueue group in vDPA. This patches
introduces uAPI to get the virtqueue group ID for a specific virtqueue
in vhost-vdpa.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Gautam Dawar <gdawar@xilinx.com>
Message-Id: <20220330180436.24644-14-gdawar@xilinx.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
index a017011..aa5cacd 100644 (file)
--- a/drivers/vhost/vdpa.c
+++ b/drivers/vhost/vdpa.c
@@ -465,6 +465,14 @@ static long vhost_vdpa_vring_ioctl(struct vhost_vdpa *v, unsigned int cmd,
                        return -EFAULT;
                ops->set_vq_ready(vdpa, idx, s.num);
                return 0;
+       case VHOST_VDPA_GET_VRING_GROUP:
+               s.index = idx;
+               s.num = ops->get_vq_group(vdpa, idx);
+               if (s.num >= vdpa->ngroups)
+                       return -EIO;
+               else 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/uapi/linux/vhost.h b/include/uapi/linux/vhost.h
index 5132200..668914c 100644 (file)
--- a/include/uapi/linux/vhost.h
+++ b/include/uapi/linux/vhost.h
@@ -156,4 +156,12 @@
 
 /* Get the number of address spaces. */
 #define VHOST_VDPA_GET_AS_NUM          _IOR(VHOST_VIRTIO, 0x7A, unsigned int)
+
+/* Get the group for a virtqueue: read index, write group in num,
+ * The virtqueue index is stored in the index field of
+ * vhost_vring_state. The group for this specific virtqueue is
+ * returned via num field of vhost_vring_state.
+ */
+#define VHOST_VDPA_GET_VRING_GROUP     _IOWR(VHOST_VIRTIO, 0x7B,       \
+                                             struct vhost_vring_state)
 #endif