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1/*
2 * Xen para-virtual frame buffer device
3 *
4 * Copyright (C) 2005-2006 Anthony Liguori <aliguori@us.ibm.com>
5 * Copyright (C) 2006-2008 Red Hat, Inc., Markus Armbruster <armbru@redhat.com>
6 *
7 * Based on linux/drivers/video/q40fb.c
8 *
9 * This file is subject to the terms and conditions of the GNU General Public
10 * License. See the file COPYING in the main directory of this archive for
11 * more details.
12 */
13
14/*
15 * TODO:
16 *
17 * Switch to grant tables when they become capable of dealing with the
18 * frame buffer.
19 */
20
21#include <linux/console.h>
22#include <linux/kernel.h>
23#include <linux/errno.h>
24#include <linux/fb.h>
25#include <linux/module.h>
26#include <linux/slab.h>
27#include <linux/vmalloc.h>
28#include <linux/mm.h>
29
30#include <asm/xen/hypervisor.h>
31
32#include <xen/xen.h>
33#include <xen/events.h>
34#include <xen/page.h>
35#include <xen/interface/io/fbif.h>
36#include <xen/interface/io/protocols.h>
37#include <xen/xenbus.h>
38
39struct xenfb_info {
40 unsigned char *fb;
41 struct fb_info *fb_info;
42 int x1, y1, x2, y2; /* dirty rectangle,
43 protected by dirty_lock */
44 spinlock_t dirty_lock;
45 int nr_pages;
46 int irq;
47 struct xenfb_page *page;
48 unsigned long *mfns;
49 int update_wanted; /* XENFB_TYPE_UPDATE wanted */
50 int feature_resize; /* XENFB_TYPE_RESIZE ok */
51 struct xenfb_resize resize; /* protected by resize_lock */
52 int resize_dpy; /* ditto */
53 spinlock_t resize_lock;
54
55 struct xenbus_device *xbdev;
56};
57
58#define XENFB_DEFAULT_FB_LEN (XENFB_WIDTH * XENFB_HEIGHT * XENFB_DEPTH / 8)
59
60enum { KPARAM_MEM, KPARAM_WIDTH, KPARAM_HEIGHT, KPARAM_CNT };
61static int video[KPARAM_CNT] = { 2, XENFB_WIDTH, XENFB_HEIGHT };
62module_param_array(video, int, NULL, 0);
63MODULE_PARM_DESC(video,
64 "Video memory size in MB, width, height in pixels (default 2,800,600)");
65
66static void xenfb_make_preferred_console(void);
67static int xenfb_remove(struct xenbus_device *);
68static void xenfb_init_shared_page(struct xenfb_info *, struct fb_info *);
69static int xenfb_connect_backend(struct xenbus_device *, struct xenfb_info *);
70static void xenfb_disconnect_backend(struct xenfb_info *);
71
72static void xenfb_send_event(struct xenfb_info *info,
73 union xenfb_out_event *event)
74{
75 u32 prod;
76
77 prod = info->page->out_prod;
78 /* caller ensures !xenfb_queue_full() */
79 mb(); /* ensure ring space available */
80 XENFB_OUT_RING_REF(info->page, prod) = *event;
81 wmb(); /* ensure ring contents visible */
82 info->page->out_prod = prod + 1;
83
84 notify_remote_via_irq(info->irq);
85}
86
87static void xenfb_do_update(struct xenfb_info *info,
88 int x, int y, int w, int h)
89{
90 union xenfb_out_event event;
91
92 memset(&event, 0, sizeof(event));
93 event.type = XENFB_TYPE_UPDATE;
94 event.update.x = x;
95 event.update.y = y;
96 event.update.width = w;
97 event.update.height = h;
98
99 /* caller ensures !xenfb_queue_full() */
100 xenfb_send_event(info, &event);
101}
102
103static void xenfb_do_resize(struct xenfb_info *info)
104{
105 union xenfb_out_event event;
106
107 memset(&event, 0, sizeof(event));
108 event.resize = info->resize;
109
110 /* caller ensures !xenfb_queue_full() */
111 xenfb_send_event(info, &event);
112}
113
114static int xenfb_queue_full(struct xenfb_info *info)
115{
116 u32 cons, prod;
117
118 prod = info->page->out_prod;
119 cons = info->page->out_cons;
120 return prod - cons == XENFB_OUT_RING_LEN;
121}
122
123static void xenfb_handle_resize_dpy(struct xenfb_info *info)
124{
125 unsigned long flags;
126
127 spin_lock_irqsave(&info->resize_lock, flags);
128 if (info->resize_dpy) {
129 if (!xenfb_queue_full(info)) {
130 info->resize_dpy = 0;
131 xenfb_do_resize(info);
132 }
133 }
134 spin_unlock_irqrestore(&info->resize_lock, flags);
135}
136
137static void xenfb_refresh(struct xenfb_info *info,
138 int x1, int y1, int w, int h)
139{
140 unsigned long flags;
141 int x2 = x1 + w - 1;
142 int y2 = y1 + h - 1;
143
144 xenfb_handle_resize_dpy(info);
145
146 if (!info->update_wanted)
147 return;
148
149 spin_lock_irqsave(&info->dirty_lock, flags);
150
151 /* Combine with dirty rectangle: */
152 if (info->y1 < y1)
153 y1 = info->y1;
154 if (info->y2 > y2)
155 y2 = info->y2;
156 if (info->x1 < x1)
157 x1 = info->x1;
158 if (info->x2 > x2)
159 x2 = info->x2;
160
161 if (xenfb_queue_full(info)) {
162 /* Can't send right now, stash it in the dirty rectangle */
163 info->x1 = x1;
164 info->x2 = x2;
165 info->y1 = y1;
166 info->y2 = y2;
167 spin_unlock_irqrestore(&info->dirty_lock, flags);
168 return;
169 }
170
171 /* Clear dirty rectangle: */
172 info->x1 = info->y1 = INT_MAX;
173 info->x2 = info->y2 = 0;
174
175 spin_unlock_irqrestore(&info->dirty_lock, flags);
176
177 if (x1 <= x2 && y1 <= y2)
178 xenfb_do_update(info, x1, y1, x2 - x1 + 1, y2 - y1 + 1);
179}
180
181static void xenfb_deferred_io(struct fb_info *fb_info,
182 struct list_head *pagelist)
183{
184 struct xenfb_info *info = fb_info->par;
185 struct page *page;
186 unsigned long beg, end;
187 int y1, y2, miny, maxy;
188
189 miny = INT_MAX;
190 maxy = 0;
191 list_for_each_entry(page, pagelist, lru) {
192 beg = page->index << PAGE_SHIFT;
193 end = beg + PAGE_SIZE - 1;
194 y1 = beg / fb_info->fix.line_length;
195 y2 = end / fb_info->fix.line_length;
196 if (y2 >= fb_info->var.yres)
197 y2 = fb_info->var.yres - 1;
198 if (miny > y1)
199 miny = y1;
200 if (maxy < y2)
201 maxy = y2;
202 }
203 xenfb_refresh(info, 0, miny, fb_info->var.xres, maxy - miny + 1);
204}
205
206static struct fb_deferred_io xenfb_defio = {
207 .delay = HZ / 20,
208 .deferred_io = xenfb_deferred_io,
209};
210
211static int xenfb_setcolreg(unsigned regno, unsigned red, unsigned green,
212 unsigned blue, unsigned transp,
213 struct fb_info *info)
214{
215 u32 v;
216
217 if (regno > info->cmap.len)
218 return 1;
219
220#define CNVT_TOHW(val, width) ((((val)<<(width))+0x7FFF-(val))>>16)
221 red = CNVT_TOHW(red, info->var.red.length);
222 green = CNVT_TOHW(green, info->var.green.length);
223 blue = CNVT_TOHW(blue, info->var.blue.length);
224 transp = CNVT_TOHW(transp, info->var.transp.length);
225#undef CNVT_TOHW
226
227 v = (red << info->var.red.offset) |
228 (green << info->var.green.offset) |
229 (blue << info->var.blue.offset);
230
231 switch (info->var.bits_per_pixel) {
232 case 16:
233 case 24:
234 case 32:
235 ((u32 *)info->pseudo_palette)[regno] = v;
236 break;
237 }
238
239 return 0;
240}
241
242static void xenfb_fillrect(struct fb_info *p, const struct fb_fillrect *rect)
243{
244 struct xenfb_info *info = p->par;
245
246 sys_fillrect(p, rect);
247 xenfb_refresh(info, rect->dx, rect->dy, rect->width, rect->height);
248}
249
250static void xenfb_imageblit(struct fb_info *p, const struct fb_image *image)
251{
252 struct xenfb_info *info = p->par;
253
254 sys_imageblit(p, image);
255 xenfb_refresh(info, image->dx, image->dy, image->width, image->height);
256}
257
258static void xenfb_copyarea(struct fb_info *p, const struct fb_copyarea *area)
259{
260 struct xenfb_info *info = p->par;
261
262 sys_copyarea(p, area);
263 xenfb_refresh(info, area->dx, area->dy, area->width, area->height);
264}
265
266static ssize_t xenfb_write(struct fb_info *p, const char __user *buf,
267 size_t count, loff_t *ppos)
268{
269 struct xenfb_info *info = p->par;
270 ssize_t res;
271
272 res = fb_sys_write(p, buf, count, ppos);
273 xenfb_refresh(info, 0, 0, info->page->width, info->page->height);
274 return res;
275}
276
277static int
278xenfb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
279{
280 struct xenfb_info *xenfb_info;
281 int required_mem_len;
282
283 xenfb_info = info->par;
284
285 if (!xenfb_info->feature_resize) {
286 if (var->xres == video[KPARAM_WIDTH] &&
287 var->yres == video[KPARAM_HEIGHT] &&
288 var->bits_per_pixel == xenfb_info->page->depth) {
289 return 0;
290 }
291 return -EINVAL;
292 }
293
294 /* Can't resize past initial width and height */
295 if (var->xres > video[KPARAM_WIDTH] || var->yres > video[KPARAM_HEIGHT])
296 return -EINVAL;
297
298 required_mem_len = var->xres * var->yres * xenfb_info->page->depth / 8;
299 if (var->bits_per_pixel == xenfb_info->page->depth &&
300 var->xres <= info->fix.line_length / (XENFB_DEPTH / 8) &&
301 required_mem_len <= info->fix.smem_len) {
302 var->xres_virtual = var->xres;
303 var->yres_virtual = var->yres;
304 return 0;
305 }
306 return -EINVAL;
307}
308
309static int xenfb_set_par(struct fb_info *info)
310{
311 struct xenfb_info *xenfb_info;
312 unsigned long flags;
313
314 xenfb_info = info->par;
315
316 spin_lock_irqsave(&xenfb_info->resize_lock, flags);
317 xenfb_info->resize.type = XENFB_TYPE_RESIZE;
318 xenfb_info->resize.width = info->var.xres;
319 xenfb_info->resize.height = info->var.yres;
320 xenfb_info->resize.stride = info->fix.line_length;
321 xenfb_info->resize.depth = info->var.bits_per_pixel;
322 xenfb_info->resize.offset = 0;
323 xenfb_info->resize_dpy = 1;
324 spin_unlock_irqrestore(&xenfb_info->resize_lock, flags);
325 return 0;
326}
327
328static struct fb_ops xenfb_fb_ops = {
329 .owner = THIS_MODULE,
330 .fb_read = fb_sys_read,
331 .fb_write = xenfb_write,
332 .fb_setcolreg = xenfb_setcolreg,
333 .fb_fillrect = xenfb_fillrect,
334 .fb_copyarea = xenfb_copyarea,
335 .fb_imageblit = xenfb_imageblit,
336 .fb_check_var = xenfb_check_var,
337 .fb_set_par = xenfb_set_par,
338};
339
340static irqreturn_t xenfb_event_handler(int rq, void *dev_id)
341{
342 /*
343 * No in events recognized, simply ignore them all.
344 * If you need to recognize some, see xen-kbdfront's
345 * input_handler() for how to do that.
346 */
347 struct xenfb_info *info = dev_id;
348 struct xenfb_page *page = info->page;
349
350 if (page->in_cons != page->in_prod) {
351 info->page->in_cons = info->page->in_prod;
352 notify_remote_via_irq(info->irq);
353 }
354
355 /* Flush dirty rectangle: */
356 xenfb_refresh(info, INT_MAX, INT_MAX, -INT_MAX, -INT_MAX);
357
358 return IRQ_HANDLED;
359}
360
361static int __devinit xenfb_probe(struct xenbus_device *dev,
362 const struct xenbus_device_id *id)
363{
364 struct xenfb_info *info;
365 struct fb_info *fb_info;
366 int fb_size;
367 int val;
368 int ret = 0;
369
370 info = kzalloc(sizeof(*info), GFP_KERNEL);
371 if (info == NULL) {
372 xenbus_dev_fatal(dev, -ENOMEM, "allocating info structure");
373 return -ENOMEM;
374 }
375
376 /* Limit kernel param videoram amount to what is in xenstore */
377 if (xenbus_scanf(XBT_NIL, dev->otherend, "videoram", "%d", &val) == 1) {
378 if (val < video[KPARAM_MEM])
379 video[KPARAM_MEM] = val;
380 }
381
382 /* If requested res does not fit in available memory, use default */
383 fb_size = video[KPARAM_MEM] * 1024 * 1024;
384 if (video[KPARAM_WIDTH] * video[KPARAM_HEIGHT] * XENFB_DEPTH / 8
385 > fb_size) {
386 video[KPARAM_WIDTH] = XENFB_WIDTH;
387 video[KPARAM_HEIGHT] = XENFB_HEIGHT;
388 fb_size = XENFB_DEFAULT_FB_LEN;
389 }
390
391 dev_set_drvdata(&dev->dev, info);
392 info->xbdev = dev;
393 info->irq = -1;
394 info->x1 = info->y1 = INT_MAX;
395 spin_lock_init(&info->dirty_lock);
396 spin_lock_init(&info->resize_lock);
397
398 info->fb = vzalloc(fb_size);
399 if (info->fb == NULL)
400 goto error_nomem;
401
402 info->nr_pages = (fb_size + PAGE_SIZE - 1) >> PAGE_SHIFT;
403
404 info->mfns = vmalloc(sizeof(unsigned long) * info->nr_pages);
405 if (!info->mfns)
406 goto error_nomem;
407
408 /* set up shared page */
409 info->page = (void *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
410 if (!info->page)
411 goto error_nomem;
412
413 /* abusing framebuffer_alloc() to allocate pseudo_palette */
414 fb_info = framebuffer_alloc(sizeof(u32) * 256, NULL);
415 if (fb_info == NULL)
416 goto error_nomem;
417
418 /* complete the abuse: */
419 fb_info->pseudo_palette = fb_info->par;
420 fb_info->par = info;
421
422 fb_info->screen_base = info->fb;
423
424 fb_info->fbops = &xenfb_fb_ops;
425 fb_info->var.xres_virtual = fb_info->var.xres = video[KPARAM_WIDTH];
426 fb_info->var.yres_virtual = fb_info->var.yres = video[KPARAM_HEIGHT];
427 fb_info->var.bits_per_pixel = XENFB_DEPTH;
428
429 fb_info->var.red = (struct fb_bitfield){16, 8, 0};
430 fb_info->var.green = (struct fb_bitfield){8, 8, 0};
431 fb_info->var.blue = (struct fb_bitfield){0, 8, 0};
432
433 fb_info->var.activate = FB_ACTIVATE_NOW;
434 fb_info->var.height = -1;
435 fb_info->var.width = -1;
436 fb_info->var.vmode = FB_VMODE_NONINTERLACED;
437
438 fb_info->fix.visual = FB_VISUAL_TRUECOLOR;
439 fb_info->fix.line_length = fb_info->var.xres * XENFB_DEPTH / 8;
440 fb_info->fix.smem_start = 0;
441 fb_info->fix.smem_len = fb_size;
442 strcpy(fb_info->fix.id, "xen");
443 fb_info->fix.type = FB_TYPE_PACKED_PIXELS;
444 fb_info->fix.accel = FB_ACCEL_NONE;
445
446 fb_info->flags = FBINFO_FLAG_DEFAULT | FBINFO_VIRTFB;
447
448 ret = fb_alloc_cmap(&fb_info->cmap, 256, 0);
449 if (ret < 0) {
450 framebuffer_release(fb_info);
451 xenbus_dev_fatal(dev, ret, "fb_alloc_cmap");
452 goto error;
453 }
454
455 fb_info->fbdefio = &xenfb_defio;
456 fb_deferred_io_init(fb_info);
457
458 xenfb_init_shared_page(info, fb_info);
459
460 ret = xenfb_connect_backend(dev, info);
461 if (ret < 0) {
462 xenbus_dev_fatal(dev, ret, "xenfb_connect_backend");
463 goto error_fb;
464 }
465
466 ret = register_framebuffer(fb_info);
467 if (ret) {
468 xenbus_dev_fatal(dev, ret, "register_framebuffer");
469 goto error_fb;
470 }
471 info->fb_info = fb_info;
472
473 xenfb_make_preferred_console();
474 return 0;
475
476error_fb:
477 fb_deferred_io_cleanup(fb_info);
478 fb_dealloc_cmap(&fb_info->cmap);
479 framebuffer_release(fb_info);
480error_nomem:
481 if (!ret) {
482 ret = -ENOMEM;
483 xenbus_dev_fatal(dev, ret, "allocating device memory");
484 }
485error:
486 xenfb_remove(dev);
487 return ret;
488}
489
490static __devinit void
491xenfb_make_preferred_console(void)
492{
493 struct console *c;
494
495 if (console_set_on_cmdline)
496 return;
497
498 console_lock();
499 for_each_console(c) {
500 if (!strcmp(c->name, "tty") && c->index == 0)
501 break;
502 }
503 console_unlock();
504 if (c) {
505 unregister_console(c);
506 c->flags |= CON_CONSDEV;
507 c->flags &= ~CON_PRINTBUFFER; /* don't print again */
508 register_console(c);
509 }
510}
511
512static int xenfb_resume(struct xenbus_device *dev)
513{
514 struct xenfb_info *info = dev_get_drvdata(&dev->dev);
515
516 xenfb_disconnect_backend(info);
517 xenfb_init_shared_page(info, info->fb_info);
518 return xenfb_connect_backend(dev, info);
519}
520
521static int xenfb_remove(struct xenbus_device *dev)
522{
523 struct xenfb_info *info = dev_get_drvdata(&dev->dev);
524
525 xenfb_disconnect_backend(info);
526 if (info->fb_info) {
527 fb_deferred_io_cleanup(info->fb_info);
528 unregister_framebuffer(info->fb_info);
529 fb_dealloc_cmap(&info->fb_info->cmap);
530 framebuffer_release(info->fb_info);
531 }
532 free_page((unsigned long)info->page);
533 vfree(info->mfns);
534 vfree(info->fb);
535 kfree(info);
536
537 return 0;
538}
539
540static unsigned long vmalloc_to_mfn(void *address)
541{
542 return pfn_to_mfn(vmalloc_to_pfn(address));
543}
544
545static void xenfb_init_shared_page(struct xenfb_info *info,
546 struct fb_info *fb_info)
547{
548 int i;
549 int epd = PAGE_SIZE / sizeof(info->mfns[0]);
550
551 for (i = 0; i < info->nr_pages; i++)
552 info->mfns[i] = vmalloc_to_mfn(info->fb + i * PAGE_SIZE);
553
554 for (i = 0; i * epd < info->nr_pages; i++)
555 info->page->pd[i] = vmalloc_to_mfn(&info->mfns[i * epd]);
556
557 info->page->width = fb_info->var.xres;
558 info->page->height = fb_info->var.yres;
559 info->page->depth = fb_info->var.bits_per_pixel;
560 info->page->line_length = fb_info->fix.line_length;
561 info->page->mem_length = fb_info->fix.smem_len;
562 info->page->in_cons = info->page->in_prod = 0;
563 info->page->out_cons = info->page->out_prod = 0;
564}
565
566static int xenfb_connect_backend(struct xenbus_device *dev,
567 struct xenfb_info *info)
568{
569 int ret, evtchn, irq;
570 struct xenbus_transaction xbt;
571
572 ret = xenbus_alloc_evtchn(dev, &evtchn);
573 if (ret)
574 return ret;
575 irq = bind_evtchn_to_irqhandler(evtchn, xenfb_event_handler,
576 0, dev->devicetype, info);
577 if (irq < 0) {
578 xenbus_free_evtchn(dev, evtchn);
579 xenbus_dev_fatal(dev, ret, "bind_evtchn_to_irqhandler");
580 return irq;
581 }
582 again:
583 ret = xenbus_transaction_start(&xbt);
584 if (ret) {
585 xenbus_dev_fatal(dev, ret, "starting transaction");
586 goto unbind_irq;
587 }
588 ret = xenbus_printf(xbt, dev->nodename, "page-ref", "%lu",
589 virt_to_mfn(info->page));
590 if (ret)
591 goto error_xenbus;
592 ret = xenbus_printf(xbt, dev->nodename, "event-channel", "%u",
593 evtchn);
594 if (ret)
595 goto error_xenbus;
596 ret = xenbus_printf(xbt, dev->nodename, "protocol", "%s",
597 XEN_IO_PROTO_ABI_NATIVE);
598 if (ret)
599 goto error_xenbus;
600 ret = xenbus_printf(xbt, dev->nodename, "feature-update", "1");
601 if (ret)
602 goto error_xenbus;
603 ret = xenbus_transaction_end(xbt, 0);
604 if (ret) {
605 if (ret == -EAGAIN)
606 goto again;
607 xenbus_dev_fatal(dev, ret, "completing transaction");
608 goto unbind_irq;
609 }
610
611 xenbus_switch_state(dev, XenbusStateInitialised);
612 info->irq = irq;
613 return 0;
614
615 error_xenbus:
616 xenbus_transaction_end(xbt, 1);
617 xenbus_dev_fatal(dev, ret, "writing xenstore");
618 unbind_irq:
619 unbind_from_irqhandler(irq, info);
620 return ret;
621}
622
623static void xenfb_disconnect_backend(struct xenfb_info *info)
624{
625 /* Prevent xenfb refresh */
626 info->update_wanted = 0;
627 if (info->irq >= 0)
628 unbind_from_irqhandler(info->irq, info);
629 info->irq = -1;
630}
631
632static void xenfb_backend_changed(struct xenbus_device *dev,
633 enum xenbus_state backend_state)
634{
635 struct xenfb_info *info = dev_get_drvdata(&dev->dev);
636 int val;
637
638 switch (backend_state) {
639 case XenbusStateInitialising:
640 case XenbusStateInitialised:
641 case XenbusStateReconfiguring:
642 case XenbusStateReconfigured:
643 case XenbusStateUnknown:
644 case XenbusStateClosed:
645 break;
646
647 case XenbusStateInitWait:
648InitWait:
649 xenbus_switch_state(dev, XenbusStateConnected);
650 break;
651
652 case XenbusStateConnected:
653 /*
654 * Work around xenbus race condition: If backend goes
655 * through InitWait to Connected fast enough, we can
656 * get Connected twice here.
657 */
658 if (dev->state != XenbusStateConnected)
659 goto InitWait; /* no InitWait seen yet, fudge it */
660
661 if (xenbus_scanf(XBT_NIL, info->xbdev->otherend,
662 "request-update", "%d", &val) < 0)
663 val = 0;
664 if (val)
665 info->update_wanted = 1;
666
667 if (xenbus_scanf(XBT_NIL, dev->otherend,
668 "feature-resize", "%d", &val) < 0)
669 val = 0;
670 info->feature_resize = val;
671 break;
672
673 case XenbusStateClosing:
674 xenbus_frontend_closed(dev);
675 break;
676 }
677}
678
679static const struct xenbus_device_id xenfb_ids[] = {
680 { "vfb" },
681 { "" }
682};
683
684static DEFINE_XENBUS_DRIVER(xenfb, ,
685 .probe = xenfb_probe,
686 .remove = xenfb_remove,
687 .resume = xenfb_resume,
688 .otherend_changed = xenfb_backend_changed,
689);
690
691static int __init xenfb_init(void)
692{
693 if (!xen_pv_domain())
694 return -ENODEV;
695
696 /* Nothing to do if running in dom0. */
697 if (xen_initial_domain())
698 return -ENODEV;
699
700 return xenbus_register_frontend(&xenfb_driver);
701}
702
703static void __exit xenfb_cleanup(void)
704{
705 xenbus_unregister_driver(&xenfb_driver);
706}
707
708module_init(xenfb_init);
709module_exit(xenfb_cleanup);
710
711MODULE_DESCRIPTION("Xen virtual framebuffer device frontend");
712MODULE_LICENSE("GPL");
713MODULE_ALIAS("xen:vfb");