vdpa_sim_blk: handle VIRTIO_BLK_T_GET_ID

Handle VIRTIO_BLK_T_GET_ID request, always answering the
"vdpa_blk_sim" string.
Acked-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Link: https://lore.kernel.org/r/20210315163450.254396-14-sgarzare@redhat.comSigned-off-by: Michael S. Tsirkin <mst@redhat.com>

drivers/vdpa/vdpa_sim/vdpa_sim_blk.c

@@ -38,6 +38,7 @@
 #define VDPASIM_BLK_VQ_NUM	1
 
 static struct vdpasim *vdpasim_blk_dev;
+static char vdpasim_blk_id[VIRTIO_BLK_ID_BYTES] = "vdpa_blk_sim";
 
 static bool vdpasim_blk_check_range(u64 start_sector, size_t range_size)
 {
@@ -153,6 +154,20 @@ static bool vdpasim_blk_handle_req(struct vdpasim *vdpasim,
 		}
 		break;
 
+	case VIRTIO_BLK_T_GET_ID:
+		bytes = vringh_iov_push_iotlb(&vq->vring, &vq->in_iov,
+					      vdpasim_blk_id,
+					      VIRTIO_BLK_ID_BYTES);
+		if (bytes < 0) {
+			dev_err(&vdpasim->vdpa.dev,
+				"vringh_iov_push_iotlb() error: %zd\n", bytes);
+			status = VIRTIO_BLK_S_IOERR;
+			break;
+		}
+
+		pushed += bytes;
+		break;
+
 	default:
 		dev_warn(&vdpasim->vdpa.dev,
 			 "Unsupported request type %d\n", type);