1/*
2 * Copyright 2014, 2015 Red Hat.
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * on the rights to use, copy, modify, merge, publish, distribute, sub
8 * license, and/or sell copies of the Software, and to permit persons to whom
9 * the Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
13 * Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHOR(S) AND/OR THEIR SUPPLIERS BE LIABLE FOR ANY CLAIM,
19 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
20 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
21 * USE OR OTHER DEALINGS IN THE SOFTWARE.
22 */
23#include <stdio.h>
24#include "util/u_memory.h"
25#include "util/u_format.h"
26#include "util/u_inlines.h"
27#include "os/os_time.h"
28#include "state_tracker/sw_winsys.h"
29
30#include "virgl_vtest_winsys.h"
31#include "virgl_vtest_public.h"
32
33static void *virgl_vtest_resource_map(struct virgl_winsys *vws,
34                                      struct virgl_hw_res *res);
35static void virgl_vtest_resource_unmap(struct virgl_winsys *vws,
36                                       struct virgl_hw_res *res);
37
38static inline boolean can_cache_resource(struct virgl_hw_res *res)
39{
40   return res->cacheable == TRUE;
41}
42
43static uint32_t vtest_get_transfer_size(struct virgl_hw_res *res,
44                                        const struct pipe_box *box,
45                                        uint32_t stride, uint32_t layer_stride,
46                                        uint32_t level, uint32_t *valid_stride_p)
47{
48   uint32_t valid_stride, valid_layer_stride;
49
50   valid_stride = util_format_get_stride(res->format, box->width);
51   if (stride) {
52      if (box->height > 1)
53         valid_stride = stride;
54   }
55
56   valid_layer_stride = util_format_get_2d_size(res->format, valid_stride,
57                                                box->height);
58   if (layer_stride) {
59      if (box->depth > 1)
60         valid_layer_stride = layer_stride;
61   }
62
63   *valid_stride_p = valid_stride;
64   return valid_layer_stride * box->depth;
65}
66
67static int
68virgl_vtest_transfer_put(struct virgl_winsys *vws,
69                         struct virgl_hw_res *res,
70                         const struct pipe_box *box,
71                         uint32_t stride, uint32_t layer_stride,
72                         uint32_t buf_offset, uint32_t level)
73{
74   struct virgl_vtest_winsys *vtws = virgl_vtest_winsys(vws);
75   uint32_t size;
76   void *ptr;
77   uint32_t valid_stride;
78
79   size = vtest_get_transfer_size(res, box, stride, layer_stride, level,
80                                  &valid_stride);
81
82   virgl_vtest_send_transfer_cmd(vtws, VCMD_TRANSFER_PUT, res->res_handle,
83                                 level, stride, layer_stride,
84                                 box, size);
85   ptr = virgl_vtest_resource_map(vws, res);
86   virgl_vtest_send_transfer_put_data(vtws, ptr + buf_offset, size);
87   virgl_vtest_resource_unmap(vws, res);
88   return 0;
89}
90
91static int
92virgl_vtest_transfer_get(struct virgl_winsys *vws,
93                         struct virgl_hw_res *res,
94                         const struct pipe_box *box,
95                         uint32_t stride, uint32_t layer_stride,
96                         uint32_t buf_offset, uint32_t level)
97{
98   struct virgl_vtest_winsys *vtws = virgl_vtest_winsys(vws);
99   uint32_t size;
100   void *ptr;
101   uint32_t valid_stride;
102
103   size = vtest_get_transfer_size(res, box, stride, layer_stride, level,
104                                  &valid_stride);
105
106   virgl_vtest_send_transfer_cmd(vtws, VCMD_TRANSFER_GET, res->res_handle,
107                                 level, stride, layer_stride,
108                                 box, size);
109
110
111   ptr = virgl_vtest_resource_map(vws, res);
112   virgl_vtest_recv_transfer_get_data(vtws, ptr + buf_offset, size,
113                                      valid_stride, box, res->format);
114   virgl_vtest_resource_unmap(vws, res);
115   return 0;
116}
117
118static void virgl_hw_res_destroy(struct virgl_vtest_winsys *vtws,
119                                 struct virgl_hw_res *res)
120{
121   virgl_vtest_send_resource_unref(vtws, res->res_handle);
122   if (res->dt)
123      vtws->sws->displaytarget_destroy(vtws->sws, res->dt);
124   free(res->ptr);
125   FREE(res);
126}
127
128static boolean virgl_vtest_resource_is_busy(struct virgl_vtest_winsys *vtws,
129                                            struct virgl_hw_res *res)
130{
131   /* implement busy check */
132   int ret;
133   ret = virgl_vtest_busy_wait(vtws, res->res_handle, 0);
134
135   if (ret < 0)
136      return FALSE;
137
138   return ret == 1 ? TRUE : FALSE;
139}
140
141static void
142virgl_cache_flush(struct virgl_vtest_winsys *vtws)
143{
144   struct list_head *curr, *next;
145   struct virgl_hw_res *res;
146
147   pipe_mutex_lock(vtws->mutex);
148   curr = vtws->delayed.next;
149   next = curr->next;
150
151   while (curr != &vtws->delayed) {
152      res = LIST_ENTRY(struct virgl_hw_res, curr, head);
153      LIST_DEL(&res->head);
154      virgl_hw_res_destroy(vtws, res);
155      curr = next;
156      next = curr->next;
157   }
158   pipe_mutex_unlock(vtws->mutex);
159}
160
161static void
162virgl_cache_list_check_free(struct virgl_vtest_winsys *vtws)
163{
164   struct list_head *curr, *next;
165   struct virgl_hw_res *res;
166   int64_t now;
167
168   now = os_time_get();
169   curr = vtws->delayed.next;
170   next = curr->next;
171   while (curr != &vtws->delayed) {
172      res = LIST_ENTRY(struct virgl_hw_res, curr, head);
173      if (!os_time_timeout(res->start, res->end, now))
174         break;
175
176      LIST_DEL(&res->head);
177      virgl_hw_res_destroy(vtws, res);
178      curr = next;
179      next = curr->next;
180   }
181}
182
183static void virgl_vtest_resource_reference(struct virgl_vtest_winsys *vtws,
184                                           struct virgl_hw_res **dres,
185                                           struct virgl_hw_res *sres)
186{
187   struct virgl_hw_res *old = *dres;
188   if (pipe_reference(&(*dres)->reference, &sres->reference)) {
189      if (!can_cache_resource(old)) {
190         virgl_hw_res_destroy(vtws, old);
191      } else {
192         pipe_mutex_lock(vtws->mutex);
193         virgl_cache_list_check_free(vtws);
194
195         old->start = os_time_get();
196         old->end = old->start + vtws->usecs;
197         LIST_ADDTAIL(&old->head, &vtws->delayed);
198         vtws->num_delayed++;
199         pipe_mutex_unlock(vtws->mutex);
200      }
201   }
202   *dres = sres;
203}
204
205static struct virgl_hw_res *
206virgl_vtest_winsys_resource_create(struct virgl_winsys *vws,
207                                   enum pipe_texture_target target,
208                                   uint32_t format,
209                                   uint32_t bind,
210                                   uint32_t width,
211                                   uint32_t height,
212                                   uint32_t depth,
213                                   uint32_t array_size,
214                                   uint32_t last_level,
215                                   uint32_t nr_samples,
216                                   uint32_t size)
217{
218   struct virgl_vtest_winsys *vtws = virgl_vtest_winsys(vws);
219   struct virgl_hw_res *res;
220   static int handle = 1;
221
222   res = CALLOC_STRUCT(virgl_hw_res);
223   if (!res)
224      return NULL;
225
226   if (bind & (VIRGL_BIND_DISPLAY_TARGET | VIRGL_BIND_SCANOUT)) {
227      res->dt = vtws->sws->displaytarget_create(vtws->sws, bind, format,
228                                                width, height, 64, NULL,
229                                                &res->stride);
230
231   } else {
232      res->ptr = align_malloc(size, 64);
233      if (!res->ptr) {
234         FREE(res);
235         return NULL;
236      }
237   }
238
239   res->bind = bind;
240   res->format = format;
241   res->height = height;
242   res->width = width;
243   virgl_vtest_send_resource_create(vtws, handle, target, format, bind,
244                                    width, height, depth, array_size,
245                                    last_level, nr_samples);
246
247   res->res_handle = handle++;
248   pipe_reference_init(&res->reference, 1);
249   return res;
250}
251
252static void virgl_vtest_winsys_resource_unref(struct virgl_winsys *vws,
253                                              struct virgl_hw_res *hres)
254{
255   struct virgl_vtest_winsys *vtws = virgl_vtest_winsys(vws);
256   virgl_vtest_resource_reference(vtws, &hres, NULL);
257}
258
259static void *virgl_vtest_resource_map(struct virgl_winsys *vws,
260                                      struct virgl_hw_res *res)
261{
262   struct virgl_vtest_winsys *vtws = virgl_vtest_winsys(vws);
263
264   if (res->dt) {
265      return vtws->sws->displaytarget_map(vtws->sws, res->dt, 0);
266   } else {
267      res->mapped = res->ptr;
268      return res->mapped;
269   }
270}
271
272static void virgl_vtest_resource_unmap(struct virgl_winsys *vws,
273                                       struct virgl_hw_res *res)
274{
275   struct virgl_vtest_winsys *vtws = virgl_vtest_winsys(vws);
276   if (res->mapped)
277      res->mapped = NULL;
278
279   if (res->dt)
280      vtws->sws->displaytarget_unmap(vtws->sws, res->dt);
281}
282
283static void virgl_vtest_resource_wait(struct virgl_winsys *vws,
284                                      struct virgl_hw_res *res)
285{
286   struct virgl_vtest_winsys *vtws = virgl_vtest_winsys(vws);
287
288   virgl_vtest_busy_wait(vtws, res->res_handle, VCMD_BUSY_WAIT_FLAG_WAIT);
289}
290
291static inline int virgl_is_res_compat(struct virgl_vtest_winsys *vtws,
292                                      struct virgl_hw_res *res,
293                                      uint32_t size, uint32_t bind,
294                                      uint32_t format)
295{
296   if (res->bind != bind)
297      return 0;
298   if (res->format != format)
299      return 0;
300   if (res->size < size)
301      return 0;
302   if (res->size > size * 2)
303      return 0;
304
305   if (virgl_vtest_resource_is_busy(vtws, res)) {
306      return -1;
307   }
308
309   return 1;
310}
311
312static struct virgl_hw_res *
313virgl_vtest_winsys_resource_cache_create(struct virgl_winsys *vws,
314                                         enum pipe_texture_target target,
315                                         uint32_t format,
316                                         uint32_t bind,
317                                         uint32_t width,
318                                         uint32_t height,
319                                         uint32_t depth,
320                                         uint32_t array_size,
321                                         uint32_t last_level,
322                                         uint32_t nr_samples,
323                                         uint32_t size)
324{
325   struct virgl_vtest_winsys *vtws = virgl_vtest_winsys(vws);
326   struct virgl_hw_res *res, *curr_res;
327   struct list_head *curr, *next;
328   int64_t now;
329   int ret;
330
331   /* only store binds for vertex/index/const buffers */
332   if (bind != VIRGL_BIND_CONSTANT_BUFFER && bind != VIRGL_BIND_INDEX_BUFFER &&
333       bind != VIRGL_BIND_VERTEX_BUFFER && bind != VIRGL_BIND_CUSTOM)
334      goto alloc;
335
336   pipe_mutex_lock(vtws->mutex);
337
338   res = NULL;
339   curr = vtws->delayed.next;
340   next = curr->next;
341
342   now = os_time_get();
343   while (curr != &vtws->delayed) {
344      curr_res = LIST_ENTRY(struct virgl_hw_res, curr, head);
345
346      if (!res && ((ret = virgl_is_res_compat(vtws, curr_res, size, bind, format)) > 0))
347         res = curr_res;
348      else if (os_time_timeout(curr_res->start, curr_res->end, now)) {
349         LIST_DEL(&curr_res->head);
350         virgl_hw_res_destroy(vtws, curr_res);
351      } else
352         break;
353
354      if (ret == -1)
355         break;
356
357      curr = next;
358      next = curr->next;
359   }
360
361   if (!res && ret != -1) {
362      while (curr != &vtws->delayed) {
363         curr_res = LIST_ENTRY(struct virgl_hw_res, curr, head);
364         ret = virgl_is_res_compat(vtws, curr_res, size, bind, format);
365         if (ret > 0) {
366            res = curr_res;
367            break;
368         }
369         if (ret == -1)
370            break;
371         curr = next;
372         next = curr->next;
373      }
374   }
375
376   if (res) {
377      LIST_DEL(&res->head);
378      --vtws->num_delayed;
379      pipe_mutex_unlock(vtws->mutex);
380      pipe_reference_init(&res->reference, 1);
381      return res;
382   }
383
384   pipe_mutex_unlock(vtws->mutex);
385
386alloc:
387   res = virgl_vtest_winsys_resource_create(vws, target, format, bind,
388                                            width, height, depth, array_size,
389                                            last_level, nr_samples, size);
390   if (bind == VIRGL_BIND_CONSTANT_BUFFER || bind == VIRGL_BIND_INDEX_BUFFER ||
391       bind == VIRGL_BIND_VERTEX_BUFFER)
392      res->cacheable = TRUE;
393   return res;
394}
395
396static struct virgl_cmd_buf *virgl_vtest_cmd_buf_create(struct virgl_winsys *vws)
397{
398   struct virgl_vtest_cmd_buf *cbuf;
399
400   cbuf = CALLOC_STRUCT(virgl_vtest_cmd_buf);
401   if (!cbuf)
402      return NULL;
403
404   cbuf->nres = 512;
405   cbuf->res_bo = CALLOC(cbuf->nres, sizeof(struct virgl_hw_buf*));
406   if (!cbuf->res_bo) {
407      FREE(cbuf);
408      return NULL;
409   }
410   cbuf->ws = vws;
411   cbuf->base.buf = cbuf->buf;
412   return &cbuf->base;
413}
414
415static void virgl_vtest_cmd_buf_destroy(struct virgl_cmd_buf *_cbuf)
416{
417   struct virgl_vtest_cmd_buf *cbuf = virgl_vtest_cmd_buf(_cbuf);
418
419   FREE(cbuf->res_bo);
420   FREE(cbuf);
421}
422
423static boolean virgl_vtest_lookup_res(struct virgl_vtest_cmd_buf *cbuf,
424                                      struct virgl_hw_res *res)
425{
426   unsigned hash = res->res_handle & (sizeof(cbuf->is_handle_added)-1);
427   int i;
428
429   if (cbuf->is_handle_added[hash]) {
430      i = cbuf->reloc_indices_hashlist[hash];
431      if (cbuf->res_bo[i] == res)
432         return true;
433
434      for (i = 0; i < cbuf->cres; i++) {
435         if (cbuf->res_bo[i] == res) {
436            cbuf->reloc_indices_hashlist[hash] = i;
437            return true;
438         }
439      }
440   }
441   return false;
442}
443
444static void virgl_vtest_release_all_res(struct virgl_vtest_winsys *vtws,
445                                        struct virgl_vtest_cmd_buf *cbuf)
446{
447   int i;
448
449   for (i = 0; i < cbuf->cres; i++) {
450      p_atomic_dec(&cbuf->res_bo[i]->num_cs_references);
451      virgl_vtest_resource_reference(vtws, &cbuf->res_bo[i], NULL);
452   }
453   cbuf->cres = 0;
454}
455
456static void virgl_vtest_add_res(struct virgl_vtest_winsys *vtws,
457                                struct virgl_vtest_cmd_buf *cbuf,
458                                struct virgl_hw_res *res)
459{
460   unsigned hash = res->res_handle & (sizeof(cbuf->is_handle_added)-1);
461
462   if (cbuf->cres > cbuf->nres) {
463      fprintf(stderr,"failure to add relocation\n");
464      return;
465   }
466
467   cbuf->res_bo[cbuf->cres] = NULL;
468   virgl_vtest_resource_reference(vtws, &cbuf->res_bo[cbuf->cres], res);
469   cbuf->is_handle_added[hash] = TRUE;
470
471   cbuf->reloc_indices_hashlist[hash] = cbuf->cres;
472   p_atomic_inc(&res->num_cs_references);
473   cbuf->cres++;
474}
475
476static int virgl_vtest_winsys_submit_cmd(struct virgl_winsys *vws,
477                                         struct virgl_cmd_buf *_cbuf)
478{
479   struct virgl_vtest_winsys *vtws = virgl_vtest_winsys(vws);
480   struct virgl_vtest_cmd_buf *cbuf = virgl_vtest_cmd_buf(_cbuf);
481   int ret;
482
483   if (cbuf->base.cdw == 0)
484      return 0;
485
486   ret = virgl_vtest_submit_cmd(vtws, cbuf);
487
488   virgl_vtest_release_all_res(vtws, cbuf);
489   memset(cbuf->is_handle_added, 0, sizeof(cbuf->is_handle_added));
490   cbuf->base.cdw = 0;
491   return ret;
492}
493
494static void virgl_vtest_emit_res(struct virgl_winsys *vws,
495                                 struct virgl_cmd_buf *_cbuf,
496                                 struct virgl_hw_res *res, boolean write_buf)
497{
498   struct virgl_vtest_winsys *vtws = virgl_vtest_winsys(vws);
499   struct virgl_vtest_cmd_buf *cbuf = virgl_vtest_cmd_buf(_cbuf);
500   boolean already_in_list = virgl_vtest_lookup_res(cbuf, res);
501
502   if (write_buf)
503      cbuf->base.buf[cbuf->base.cdw++] = res->res_handle;
504   if (!already_in_list)
505      virgl_vtest_add_res(vtws, cbuf, res);
506}
507
508static boolean virgl_vtest_res_is_ref(struct virgl_winsys *vws,
509                                      struct virgl_cmd_buf *_cbuf,
510                                      struct virgl_hw_res *res)
511{
512   if (!res->num_cs_references)
513      return FALSE;
514
515   return TRUE;
516}
517
518static int virgl_vtest_get_caps(struct virgl_winsys *vws,
519                                struct virgl_drm_caps *caps)
520{
521   struct virgl_vtest_winsys *vtws = virgl_vtest_winsys(vws);
522   return virgl_vtest_send_get_caps(vtws, caps);
523}
524
525static struct pipe_fence_handle *
526virgl_cs_create_fence(struct virgl_winsys *vws)
527{
528   struct virgl_hw_res *res;
529
530   res = virgl_vtest_winsys_resource_cache_create(vws,
531                                                PIPE_BUFFER,
532                                                PIPE_FORMAT_R8_UNORM,
533                                                PIPE_BIND_CUSTOM,
534                                                8, 1, 1, 0, 0, 0, 8);
535
536   return (struct pipe_fence_handle *)res;
537}
538
539static bool virgl_fence_wait(struct virgl_winsys *vws,
540                             struct pipe_fence_handle *fence,
541                             uint64_t timeout)
542{
543   struct virgl_vtest_winsys *vdws = virgl_vtest_winsys(vws);
544   struct virgl_hw_res *res = virgl_hw_res(fence);
545
546   if (timeout == 0)
547      return !virgl_vtest_resource_is_busy(vdws, res);
548
549   if (timeout != PIPE_TIMEOUT_INFINITE) {
550      int64_t start_time = os_time_get();
551      timeout /= 1000;
552      while (virgl_vtest_resource_is_busy(vdws, res)) {
553         if (os_time_get() - start_time >= timeout)
554            return FALSE;
555         os_time_sleep(10);
556      }
557      return TRUE;
558   }
559   virgl_vtest_resource_wait(vws, res);
560   return TRUE;
561}
562
563static void virgl_fence_reference(struct virgl_winsys *vws,
564                                  struct pipe_fence_handle **dst,
565                                  struct pipe_fence_handle *src)
566{
567   struct virgl_vtest_winsys *vdws = virgl_vtest_winsys(vws);
568   virgl_vtest_resource_reference(vdws, (struct virgl_hw_res **)dst,
569                                  virgl_hw_res(src));
570}
571
572static void virgl_vtest_flush_frontbuffer(struct virgl_winsys *vws,
573                                          struct virgl_hw_res *res,
574                                          unsigned level, unsigned layer,
575                                          void *winsys_drawable_handle,
576                                          struct pipe_box *sub_box)
577{
578   struct virgl_vtest_winsys *vtws = virgl_vtest_winsys(vws);
579   struct pipe_box box;
580   void *map;
581   uint32_t size;
582   uint32_t offset = 0, valid_stride;
583   if (!res->dt)
584      return;
585
586   memset(&box, 0, sizeof(box));
587
588   if (sub_box) {
589      box = *sub_box;
590      offset = box.y / util_format_get_blockheight(res->format) * res->stride +
591               box.x / util_format_get_blockwidth(res->format) * util_format_get_blocksize(res->format);
592   } else {
593      box.z = layer;
594      box.width = res->width;
595      box.height = res->height;
596      box.depth = 1;
597   }
598
599   size = vtest_get_transfer_size(res, &box, res->stride, 0, level, &valid_stride);
600
601   virgl_vtest_busy_wait(vtws, res->res_handle, VCMD_BUSY_WAIT_FLAG_WAIT);
602   map = vtws->sws->displaytarget_map(vtws->sws, res->dt, 0);
603
604   /* execute a transfer */
605   virgl_vtest_send_transfer_cmd(vtws, VCMD_TRANSFER_GET, res->res_handle,
606                                 level, res->stride, 0, &box, size);
607   virgl_vtest_recv_transfer_get_data(vtws, map + offset, size, valid_stride,
608                                      &box, res->format);
609   vtws->sws->displaytarget_unmap(vtws->sws, res->dt);
610
611   vtws->sws->displaytarget_display(vtws->sws, res->dt, winsys_drawable_handle,
612                                    sub_box);
613}
614
615static void
616virgl_vtest_winsys_destroy(struct virgl_winsys *vws)
617{
618   struct virgl_vtest_winsys *vtws = virgl_vtest_winsys(vws);
619
620   virgl_cache_flush(vtws);
621
622   pipe_mutex_destroy(vtws->mutex);
623   FREE(vtws);
624}
625
626struct virgl_winsys *
627virgl_vtest_winsys_wrap(struct sw_winsys *sws)
628{
629   struct virgl_vtest_winsys *vtws;
630
631   vtws = CALLOC_STRUCT(virgl_vtest_winsys);
632   if (!vtws)
633      return NULL;
634
635   virgl_vtest_connect(vtws);
636   vtws->sws = sws;
637
638   vtws->usecs = 1000000;
639   LIST_INITHEAD(&vtws->delayed);
640   pipe_mutex_init(vtws->mutex);
641
642   vtws->base.destroy = virgl_vtest_winsys_destroy;
643
644   vtws->base.transfer_put = virgl_vtest_transfer_put;
645   vtws->base.transfer_get = virgl_vtest_transfer_get;
646
647   vtws->base.resource_create = virgl_vtest_winsys_resource_cache_create;
648   vtws->base.resource_unref = virgl_vtest_winsys_resource_unref;
649   vtws->base.resource_map = virgl_vtest_resource_map;
650   vtws->base.resource_wait = virgl_vtest_resource_wait;
651   vtws->base.cmd_buf_create = virgl_vtest_cmd_buf_create;
652   vtws->base.cmd_buf_destroy = virgl_vtest_cmd_buf_destroy;
653   vtws->base.submit_cmd = virgl_vtest_winsys_submit_cmd;
654
655   vtws->base.emit_res = virgl_vtest_emit_res;
656   vtws->base.res_is_referenced = virgl_vtest_res_is_ref;
657   vtws->base.get_caps = virgl_vtest_get_caps;
658
659   vtws->base.cs_create_fence = virgl_cs_create_fence;
660   vtws->base.fence_wait = virgl_fence_wait;
661   vtws->base.fence_reference = virgl_fence_reference;
662
663   vtws->base.flush_frontbuffer = virgl_vtest_flush_frontbuffer;
664
665   return &vtws->base;
666}
667