+ if (whandle->offset != 0) {
+ fprintf(stderr, "Attempt to import unsupported winsys offset %u\n",
+ whandle->offset);
+ return NULL;
+ }
+
+ ret = vmw_ioctl_gb_surface_ref(vws, whandle, &flags, format,
+ &mip_levels, &handle, &desc.region);
+
+ if (ret) {
+ fprintf(stderr, "Failed referencing shared surface. SID %d.\n"
+ "Error %d (%s).\n",
+ whandle->handle, ret, strerror(-ret));
+ return NULL;
+ }
+
+ if (mip_levels != 1) {
+ fprintf(stderr, "Incorrect number of mipmap levels on shared surface."
+ " SID %d, levels %d\n",
+ whandle->handle, mip_levels);
+ goto out_mip;
+ }
+
+ vsrf = CALLOC_STRUCT(vmw_svga_winsys_surface);
+ if (!vsrf)
+ goto out_mip;
+
+ pipe_reference_init(&vsrf->refcnt, 1);
+ p_atomic_set(&vsrf->validated, 0);
+ vsrf->screen = vws;
+ vsrf->sid = handle;
+ vsrf->size = vmw_region_size(desc.region);
+
+ /*
+ * Synchronize backing buffers of shared surfaces using the
+ * kernel, since we don't pass fence objects around between
+ * processes.
+ */
+ desc.pb_desc.alignment = 4096;
+ desc.pb_desc.usage = VMW_BUFFER_USAGE_SHARED | VMW_BUFFER_USAGE_SYNC;
+ pb_buf = provider->create_buffer(provider, vsrf->size, &desc.pb_desc);
+ vsrf->buf = vmw_svga_winsys_buffer_wrap(pb_buf);
+ if (!vsrf->buf)
+ goto out_no_buf;
+ ssrf = svga_winsys_surface(vsrf);
+
+ return ssrf;
+
+out_no_buf:
+ FREE(vsrf);
+out_mip:
+ vmw_ioctl_region_destroy(desc.region);
+ vmw_ioctl_surface_destroy(vws, whandle->handle);
+ return NULL;