xref: /openbmc/linux/samples/vfio-mdev/mbochs.c (revision 965f22bc)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Mediated virtual PCI display host device driver
4  *
5  * Emulate enough of qemu stdvga to make bochs-drm.ko happy.  That is
6  * basically the vram memory bar and the bochs dispi interface vbe
7  * registers in the mmio register bar.	Specifically it does *not*
8  * include any legacy vga stuff.  Device looks a lot like "qemu -device
9  * secondary-vga".
10  *
11  *   (c) Gerd Hoffmann <kraxel@redhat.com>
12  *
13  * based on mtty driver which is:
14  *   Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved.
15  *	 Author: Neo Jia <cjia@nvidia.com>
16  *		 Kirti Wankhede <kwankhede@nvidia.com>
17  *
18  * This program is free software; you can redistribute it and/or modify
19  * it under the terms of the GNU General Public License version 2 as
20  * published by the Free Software Foundation.
21  */
22 #include <linux/init.h>
23 #include <linux/module.h>
24 #include <linux/device.h>
25 #include <linux/kernel.h>
26 #include <linux/slab.h>
27 #include <linux/vmalloc.h>
28 #include <linux/cdev.h>
29 #include <linux/vfio.h>
30 #include <linux/iommu.h>
31 #include <linux/sysfs.h>
32 #include <linux/mdev.h>
33 #include <linux/pci.h>
34 #include <linux/dma-buf.h>
35 #include <linux/highmem.h>
36 #include <drm/drm_fourcc.h>
37 #include <drm/drm_rect.h>
38 #include <drm/drm_modeset_lock.h>
39 #include <drm/drm_property.h>
40 #include <drm/drm_plane.h>
41 
42 
43 #define VBE_DISPI_INDEX_ID		0x0
44 #define VBE_DISPI_INDEX_XRES		0x1
45 #define VBE_DISPI_INDEX_YRES		0x2
46 #define VBE_DISPI_INDEX_BPP		0x3
47 #define VBE_DISPI_INDEX_ENABLE		0x4
48 #define VBE_DISPI_INDEX_BANK		0x5
49 #define VBE_DISPI_INDEX_VIRT_WIDTH	0x6
50 #define VBE_DISPI_INDEX_VIRT_HEIGHT	0x7
51 #define VBE_DISPI_INDEX_X_OFFSET	0x8
52 #define VBE_DISPI_INDEX_Y_OFFSET	0x9
53 #define VBE_DISPI_INDEX_VIDEO_MEMORY_64K 0xa
54 #define VBE_DISPI_INDEX_COUNT		0xb
55 
56 #define VBE_DISPI_ID0			0xB0C0
57 #define VBE_DISPI_ID1			0xB0C1
58 #define VBE_DISPI_ID2			0xB0C2
59 #define VBE_DISPI_ID3			0xB0C3
60 #define VBE_DISPI_ID4			0xB0C4
61 #define VBE_DISPI_ID5			0xB0C5
62 
63 #define VBE_DISPI_DISABLED		0x00
64 #define VBE_DISPI_ENABLED		0x01
65 #define VBE_DISPI_GETCAPS		0x02
66 #define VBE_DISPI_8BIT_DAC		0x20
67 #define VBE_DISPI_LFB_ENABLED		0x40
68 #define VBE_DISPI_NOCLEARMEM		0x80
69 
70 
71 #define MBOCHS_NAME		  "mbochs"
72 #define MBOCHS_CLASS_NAME	  "mbochs"
73 
74 #define MBOCHS_CONFIG_SPACE_SIZE  0xff
75 #define MBOCHS_MMIO_BAR_OFFSET	  PAGE_SIZE
76 #define MBOCHS_MMIO_BAR_SIZE	  PAGE_SIZE
77 #define MBOCHS_MEMORY_BAR_OFFSET  (MBOCHS_MMIO_BAR_OFFSET + \
78 				   MBOCHS_MMIO_BAR_SIZE)
79 
80 #define STORE_LE16(addr, val)	(*(u16 *)addr = val)
81 #define STORE_LE32(addr, val)	(*(u32 *)addr = val)
82 
83 
84 MODULE_LICENSE("GPL v2");
85 
86 static int max_mbytes = 256;
87 module_param_named(count, max_mbytes, int, 0444);
88 MODULE_PARM_DESC(mem, "megabytes available to " MBOCHS_NAME " devices");
89 
90 
91 #define MBOCHS_TYPE_1 "small"
92 #define MBOCHS_TYPE_2 "medium"
93 #define MBOCHS_TYPE_3 "large"
94 
95 static const struct mbochs_type {
96 	const char *name;
97 	u32 mbytes;
98 } mbochs_types[] = {
99 	{
100 		.name	= MBOCHS_CLASS_NAME "-" MBOCHS_TYPE_1,
101 		.mbytes = 4,
102 	}, {
103 		.name	= MBOCHS_CLASS_NAME "-" MBOCHS_TYPE_2,
104 		.mbytes = 16,
105 	}, {
106 		.name	= MBOCHS_CLASS_NAME "-" MBOCHS_TYPE_3,
107 		.mbytes = 64,
108 	},
109 };
110 
111 
112 static dev_t		mbochs_devt;
113 static struct class	*mbochs_class;
114 static struct cdev	mbochs_cdev;
115 static struct device	mbochs_dev;
116 static int		mbochs_used_mbytes;
117 
118 struct mbochs_mode {
119 	u32 drm_format;
120 	u32 bytepp;
121 	u32 width;
122 	u32 height;
123 	u32 stride;
124 	u32 __pad;
125 	u64 offset;
126 	u64 size;
127 };
128 
129 struct mbochs_dmabuf {
130 	struct mbochs_mode mode;
131 	u32 id;
132 	struct page **pages;
133 	pgoff_t pagecount;
134 	struct dma_buf *buf;
135 	struct mdev_state *mdev_state;
136 	struct list_head next;
137 	bool unlinked;
138 };
139 
140 /* State of each mdev device */
141 struct mdev_state {
142 	u8 *vconfig;
143 	u64 bar_mask[3];
144 	u32 memory_bar_mask;
145 	struct mutex ops_lock;
146 	struct mdev_device *mdev;
147 	struct vfio_device_info dev_info;
148 
149 	const struct mbochs_type *type;
150 	u16 vbe[VBE_DISPI_INDEX_COUNT];
151 	u64 memsize;
152 	struct page **pages;
153 	pgoff_t pagecount;
154 
155 	struct list_head dmabufs;
156 	u32 active_id;
157 	u32 next_id;
158 };
159 
160 static const char *vbe_name_list[VBE_DISPI_INDEX_COUNT] = {
161 	[VBE_DISPI_INDEX_ID]               = "id",
162 	[VBE_DISPI_INDEX_XRES]             = "xres",
163 	[VBE_DISPI_INDEX_YRES]             = "yres",
164 	[VBE_DISPI_INDEX_BPP]              = "bpp",
165 	[VBE_DISPI_INDEX_ENABLE]           = "enable",
166 	[VBE_DISPI_INDEX_BANK]             = "bank",
167 	[VBE_DISPI_INDEX_VIRT_WIDTH]       = "virt-width",
168 	[VBE_DISPI_INDEX_VIRT_HEIGHT]      = "virt-height",
169 	[VBE_DISPI_INDEX_X_OFFSET]         = "x-offset",
170 	[VBE_DISPI_INDEX_Y_OFFSET]         = "y-offset",
171 	[VBE_DISPI_INDEX_VIDEO_MEMORY_64K] = "video-mem",
172 };
173 
174 static const char *vbe_name(u32 index)
175 {
176 	if (index < ARRAY_SIZE(vbe_name_list))
177 		return vbe_name_list[index];
178 	return "(invalid)";
179 }
180 
181 static struct page *__mbochs_get_page(struct mdev_state *mdev_state,
182 				      pgoff_t pgoff);
183 static struct page *mbochs_get_page(struct mdev_state *mdev_state,
184 				    pgoff_t pgoff);
185 
186 static const struct mbochs_type *mbochs_find_type(struct kobject *kobj)
187 {
188 	int i;
189 
190 	for (i = 0; i < ARRAY_SIZE(mbochs_types); i++)
191 		if (strcmp(mbochs_types[i].name, kobj->name) == 0)
192 			return mbochs_types + i;
193 	return NULL;
194 }
195 
196 static void mbochs_create_config_space(struct mdev_state *mdev_state)
197 {
198 	STORE_LE16((u16 *) &mdev_state->vconfig[PCI_VENDOR_ID],
199 		   0x1234);
200 	STORE_LE16((u16 *) &mdev_state->vconfig[PCI_DEVICE_ID],
201 		   0x1111);
202 	STORE_LE16((u16 *) &mdev_state->vconfig[PCI_SUBSYSTEM_VENDOR_ID],
203 		   PCI_SUBVENDOR_ID_REDHAT_QUMRANET);
204 	STORE_LE16((u16 *) &mdev_state->vconfig[PCI_SUBSYSTEM_ID],
205 		   PCI_SUBDEVICE_ID_QEMU);
206 
207 	STORE_LE16((u16 *) &mdev_state->vconfig[PCI_COMMAND],
208 		   PCI_COMMAND_IO | PCI_COMMAND_MEMORY);
209 	STORE_LE16((u16 *) &mdev_state->vconfig[PCI_CLASS_DEVICE],
210 		   PCI_CLASS_DISPLAY_OTHER);
211 	mdev_state->vconfig[PCI_CLASS_REVISION] =  0x01;
212 
213 	STORE_LE32((u32 *) &mdev_state->vconfig[PCI_BASE_ADDRESS_0],
214 		   PCI_BASE_ADDRESS_SPACE_MEMORY |
215 		   PCI_BASE_ADDRESS_MEM_TYPE_32	 |
216 		   PCI_BASE_ADDRESS_MEM_PREFETCH);
217 	mdev_state->bar_mask[0] = ~(mdev_state->memsize) + 1;
218 
219 	STORE_LE32((u32 *) &mdev_state->vconfig[PCI_BASE_ADDRESS_2],
220 		   PCI_BASE_ADDRESS_SPACE_MEMORY |
221 		   PCI_BASE_ADDRESS_MEM_TYPE_32);
222 	mdev_state->bar_mask[2] = ~(MBOCHS_MMIO_BAR_SIZE) + 1;
223 }
224 
225 static int mbochs_check_framebuffer(struct mdev_state *mdev_state,
226 				    struct mbochs_mode *mode)
227 {
228 	struct device *dev = mdev_dev(mdev_state->mdev);
229 	u16 *vbe = mdev_state->vbe;
230 	u32 virt_width;
231 
232 	WARN_ON(!mutex_is_locked(&mdev_state->ops_lock));
233 
234 	if (!(vbe[VBE_DISPI_INDEX_ENABLE] & VBE_DISPI_ENABLED))
235 		goto nofb;
236 
237 	memset(mode, 0, sizeof(*mode));
238 	switch (vbe[VBE_DISPI_INDEX_BPP]) {
239 	case 32:
240 		mode->drm_format = DRM_FORMAT_XRGB8888;
241 		mode->bytepp = 4;
242 		break;
243 	default:
244 		dev_info_ratelimited(dev, "%s: bpp %d not supported\n",
245 				     __func__, vbe[VBE_DISPI_INDEX_BPP]);
246 		goto nofb;
247 	}
248 
249 	mode->width  = vbe[VBE_DISPI_INDEX_XRES];
250 	mode->height = vbe[VBE_DISPI_INDEX_YRES];
251 	virt_width  = vbe[VBE_DISPI_INDEX_VIRT_WIDTH];
252 	if (virt_width < mode->width)
253 		virt_width = mode->width;
254 	mode->stride = virt_width * mode->bytepp;
255 	mode->size   = (u64)mode->stride * mode->height;
256 	mode->offset = ((u64)vbe[VBE_DISPI_INDEX_X_OFFSET] * mode->bytepp +
257 		       (u64)vbe[VBE_DISPI_INDEX_Y_OFFSET] * mode->stride);
258 
259 	if (mode->width < 64 || mode->height < 64) {
260 		dev_info_ratelimited(dev, "%s: invalid resolution %dx%d\n",
261 				     __func__, mode->width, mode->height);
262 		goto nofb;
263 	}
264 	if (mode->offset + mode->size > mdev_state->memsize) {
265 		dev_info_ratelimited(dev, "%s: framebuffer memory overflow\n",
266 				     __func__);
267 		goto nofb;
268 	}
269 
270 	return 0;
271 
272 nofb:
273 	memset(mode, 0, sizeof(*mode));
274 	return -EINVAL;
275 }
276 
277 static bool mbochs_modes_equal(struct mbochs_mode *mode1,
278 			       struct mbochs_mode *mode2)
279 {
280 	return memcmp(mode1, mode2, sizeof(struct mbochs_mode)) == 0;
281 }
282 
283 static void handle_pci_cfg_write(struct mdev_state *mdev_state, u16 offset,
284 				 char *buf, u32 count)
285 {
286 	struct device *dev = mdev_dev(mdev_state->mdev);
287 	int index = (offset - PCI_BASE_ADDRESS_0) / 0x04;
288 	u32 cfg_addr;
289 
290 	switch (offset) {
291 	case PCI_BASE_ADDRESS_0:
292 	case PCI_BASE_ADDRESS_2:
293 		cfg_addr = *(u32 *)buf;
294 
295 		if (cfg_addr == 0xffffffff) {
296 			cfg_addr = (cfg_addr & mdev_state->bar_mask[index]);
297 		} else {
298 			cfg_addr &= PCI_BASE_ADDRESS_MEM_MASK;
299 			if (cfg_addr)
300 				dev_info(dev, "BAR #%d @ 0x%x\n",
301 					 index, cfg_addr);
302 		}
303 
304 		cfg_addr |= (mdev_state->vconfig[offset] &
305 			     ~PCI_BASE_ADDRESS_MEM_MASK);
306 		STORE_LE32(&mdev_state->vconfig[offset], cfg_addr);
307 		break;
308 	}
309 }
310 
311 static void handle_mmio_write(struct mdev_state *mdev_state, u16 offset,
312 			      char *buf, u32 count)
313 {
314 	struct device *dev = mdev_dev(mdev_state->mdev);
315 	int index;
316 	u16 reg16;
317 
318 	switch (offset) {
319 	case 0x400 ... 0x41f: /* vga ioports remapped */
320 		goto unhandled;
321 	case 0x500 ... 0x515: /* bochs dispi interface */
322 		if (count != 2)
323 			goto unhandled;
324 		index = (offset - 0x500) / 2;
325 		reg16 = *(u16 *)buf;
326 		if (index < ARRAY_SIZE(mdev_state->vbe))
327 			mdev_state->vbe[index] = reg16;
328 		dev_dbg(dev, "%s: vbe write %d = %d (%s)\n",
329 			__func__, index, reg16, vbe_name(index));
330 		break;
331 	case 0x600 ... 0x607: /* qemu extended regs */
332 		goto unhandled;
333 	default:
334 unhandled:
335 		dev_dbg(dev, "%s: @0x%03x, count %d (unhandled)\n",
336 			__func__, offset, count);
337 		break;
338 	}
339 }
340 
341 static void handle_mmio_read(struct mdev_state *mdev_state, u16 offset,
342 			     char *buf, u32 count)
343 {
344 	struct device *dev = mdev_dev(mdev_state->mdev);
345 	u16 reg16 = 0;
346 	int index;
347 
348 	switch (offset) {
349 	case 0x500 ... 0x515: /* bochs dispi interface */
350 		if (count != 2)
351 			goto unhandled;
352 		index = (offset - 0x500) / 2;
353 		if (index < ARRAY_SIZE(mdev_state->vbe))
354 			reg16 = mdev_state->vbe[index];
355 		dev_dbg(dev, "%s: vbe read %d = %d (%s)\n",
356 			__func__, index, reg16, vbe_name(index));
357 		*(u16 *)buf = reg16;
358 		break;
359 	default:
360 unhandled:
361 		dev_dbg(dev, "%s: @0x%03x, count %d (unhandled)\n",
362 			__func__, offset, count);
363 		memset(buf, 0, count);
364 		break;
365 	}
366 }
367 
368 static ssize_t mdev_access(struct mdev_device *mdev, char *buf, size_t count,
369 			   loff_t pos, bool is_write)
370 {
371 	struct mdev_state *mdev_state = mdev_get_drvdata(mdev);
372 	struct device *dev = mdev_dev(mdev);
373 	struct page *pg;
374 	loff_t poff;
375 	char *map;
376 	int ret = 0;
377 
378 	mutex_lock(&mdev_state->ops_lock);
379 
380 	if (pos < MBOCHS_CONFIG_SPACE_SIZE) {
381 		if (is_write)
382 			handle_pci_cfg_write(mdev_state, pos, buf, count);
383 		else
384 			memcpy(buf, (mdev_state->vconfig + pos), count);
385 
386 	} else if (pos >= MBOCHS_MMIO_BAR_OFFSET &&
387 		   pos + count <= MBOCHS_MEMORY_BAR_OFFSET) {
388 		pos -= MBOCHS_MMIO_BAR_OFFSET;
389 		if (is_write)
390 			handle_mmio_write(mdev_state, pos, buf, count);
391 		else
392 			handle_mmio_read(mdev_state, pos, buf, count);
393 
394 	} else if (pos >= MBOCHS_MEMORY_BAR_OFFSET &&
395 		   pos + count <=
396 		   MBOCHS_MEMORY_BAR_OFFSET + mdev_state->memsize) {
397 		pos -= MBOCHS_MMIO_BAR_OFFSET;
398 		poff = pos & ~PAGE_MASK;
399 		pg = __mbochs_get_page(mdev_state, pos >> PAGE_SHIFT);
400 		map = kmap(pg);
401 		if (is_write)
402 			memcpy(map + poff, buf, count);
403 		else
404 			memcpy(buf, map + poff, count);
405 		kunmap(pg);
406 		put_page(pg);
407 
408 	} else {
409 		dev_dbg(dev, "%s: %s @0x%llx (unhandled)\n",
410 			__func__, is_write ? "WR" : "RD", pos);
411 		ret = -1;
412 		goto accessfailed;
413 	}
414 
415 	ret = count;
416 
417 
418 accessfailed:
419 	mutex_unlock(&mdev_state->ops_lock);
420 
421 	return ret;
422 }
423 
424 static int mbochs_reset(struct mdev_device *mdev)
425 {
426 	struct mdev_state *mdev_state = mdev_get_drvdata(mdev);
427 	u32 size64k = mdev_state->memsize / (64 * 1024);
428 	int i;
429 
430 	for (i = 0; i < ARRAY_SIZE(mdev_state->vbe); i++)
431 		mdev_state->vbe[i] = 0;
432 	mdev_state->vbe[VBE_DISPI_INDEX_ID] = VBE_DISPI_ID5;
433 	mdev_state->vbe[VBE_DISPI_INDEX_VIDEO_MEMORY_64K] = size64k;
434 	return 0;
435 }
436 
437 static int mbochs_create(struct kobject *kobj, struct mdev_device *mdev)
438 {
439 	const struct mbochs_type *type = mbochs_find_type(kobj);
440 	struct device *dev = mdev_dev(mdev);
441 	struct mdev_state *mdev_state;
442 
443 	if (!type)
444 		type = &mbochs_types[0];
445 	if (type->mbytes + mbochs_used_mbytes > max_mbytes)
446 		return -ENOMEM;
447 
448 	mdev_state = kzalloc(sizeof(struct mdev_state), GFP_KERNEL);
449 	if (mdev_state == NULL)
450 		return -ENOMEM;
451 
452 	mdev_state->vconfig = kzalloc(MBOCHS_CONFIG_SPACE_SIZE, GFP_KERNEL);
453 	if (mdev_state->vconfig == NULL)
454 		goto err_mem;
455 
456 	mdev_state->memsize = type->mbytes * 1024 * 1024;
457 	mdev_state->pagecount = mdev_state->memsize >> PAGE_SHIFT;
458 	mdev_state->pages = kcalloc(mdev_state->pagecount,
459 				    sizeof(struct page *),
460 				    GFP_KERNEL);
461 	if (!mdev_state->pages)
462 		goto err_mem;
463 
464 	dev_info(dev, "%s: %s, %d MB, %ld pages\n", __func__,
465 		 kobj->name, type->mbytes, mdev_state->pagecount);
466 
467 	mutex_init(&mdev_state->ops_lock);
468 	mdev_state->mdev = mdev;
469 	mdev_set_drvdata(mdev, mdev_state);
470 	INIT_LIST_HEAD(&mdev_state->dmabufs);
471 	mdev_state->next_id = 1;
472 
473 	mdev_state->type = type;
474 	mbochs_create_config_space(mdev_state);
475 	mbochs_reset(mdev);
476 
477 	mbochs_used_mbytes += type->mbytes;
478 	return 0;
479 
480 err_mem:
481 	kfree(mdev_state->vconfig);
482 	kfree(mdev_state);
483 	return -ENOMEM;
484 }
485 
486 static int mbochs_remove(struct mdev_device *mdev)
487 {
488 	struct mdev_state *mdev_state = mdev_get_drvdata(mdev);
489 
490 	mbochs_used_mbytes -= mdev_state->type->mbytes;
491 	mdev_set_drvdata(mdev, NULL);
492 	kfree(mdev_state->pages);
493 	kfree(mdev_state->vconfig);
494 	kfree(mdev_state);
495 	return 0;
496 }
497 
498 static ssize_t mbochs_read(struct mdev_device *mdev, char __user *buf,
499 			   size_t count, loff_t *ppos)
500 {
501 	unsigned int done = 0;
502 	int ret;
503 
504 	while (count) {
505 		size_t filled;
506 
507 		if (count >= 4 && !(*ppos % 4)) {
508 			u32 val;
509 
510 			ret =  mdev_access(mdev, (char *)&val, sizeof(val),
511 					   *ppos, false);
512 			if (ret <= 0)
513 				goto read_err;
514 
515 			if (copy_to_user(buf, &val, sizeof(val)))
516 				goto read_err;
517 
518 			filled = 4;
519 		} else if (count >= 2 && !(*ppos % 2)) {
520 			u16 val;
521 
522 			ret = mdev_access(mdev, (char *)&val, sizeof(val),
523 					  *ppos, false);
524 			if (ret <= 0)
525 				goto read_err;
526 
527 			if (copy_to_user(buf, &val, sizeof(val)))
528 				goto read_err;
529 
530 			filled = 2;
531 		} else {
532 			u8 val;
533 
534 			ret = mdev_access(mdev, (char *)&val, sizeof(val),
535 					  *ppos, false);
536 			if (ret <= 0)
537 				goto read_err;
538 
539 			if (copy_to_user(buf, &val, sizeof(val)))
540 				goto read_err;
541 
542 			filled = 1;
543 		}
544 
545 		count -= filled;
546 		done += filled;
547 		*ppos += filled;
548 		buf += filled;
549 	}
550 
551 	return done;
552 
553 read_err:
554 	return -EFAULT;
555 }
556 
557 static ssize_t mbochs_write(struct mdev_device *mdev, const char __user *buf,
558 			    size_t count, loff_t *ppos)
559 {
560 	unsigned int done = 0;
561 	int ret;
562 
563 	while (count) {
564 		size_t filled;
565 
566 		if (count >= 4 && !(*ppos % 4)) {
567 			u32 val;
568 
569 			if (copy_from_user(&val, buf, sizeof(val)))
570 				goto write_err;
571 
572 			ret = mdev_access(mdev, (char *)&val, sizeof(val),
573 					  *ppos, true);
574 			if (ret <= 0)
575 				goto write_err;
576 
577 			filled = 4;
578 		} else if (count >= 2 && !(*ppos % 2)) {
579 			u16 val;
580 
581 			if (copy_from_user(&val, buf, sizeof(val)))
582 				goto write_err;
583 
584 			ret = mdev_access(mdev, (char *)&val, sizeof(val),
585 					  *ppos, true);
586 			if (ret <= 0)
587 				goto write_err;
588 
589 			filled = 2;
590 		} else {
591 			u8 val;
592 
593 			if (copy_from_user(&val, buf, sizeof(val)))
594 				goto write_err;
595 
596 			ret = mdev_access(mdev, (char *)&val, sizeof(val),
597 					  *ppos, true);
598 			if (ret <= 0)
599 				goto write_err;
600 
601 			filled = 1;
602 		}
603 		count -= filled;
604 		done += filled;
605 		*ppos += filled;
606 		buf += filled;
607 	}
608 
609 	return done;
610 write_err:
611 	return -EFAULT;
612 }
613 
614 static struct page *__mbochs_get_page(struct mdev_state *mdev_state,
615 				      pgoff_t pgoff)
616 {
617 	WARN_ON(!mutex_is_locked(&mdev_state->ops_lock));
618 
619 	if (!mdev_state->pages[pgoff]) {
620 		mdev_state->pages[pgoff] =
621 			alloc_pages(GFP_HIGHUSER | __GFP_ZERO, 0);
622 		if (!mdev_state->pages[pgoff])
623 			return NULL;
624 	}
625 
626 	get_page(mdev_state->pages[pgoff]);
627 	return mdev_state->pages[pgoff];
628 }
629 
630 static struct page *mbochs_get_page(struct mdev_state *mdev_state,
631 				    pgoff_t pgoff)
632 {
633 	struct page *page;
634 
635 	if (WARN_ON(pgoff >= mdev_state->pagecount))
636 		return NULL;
637 
638 	mutex_lock(&mdev_state->ops_lock);
639 	page = __mbochs_get_page(mdev_state, pgoff);
640 	mutex_unlock(&mdev_state->ops_lock);
641 
642 	return page;
643 }
644 
645 static void mbochs_put_pages(struct mdev_state *mdev_state)
646 {
647 	struct device *dev = mdev_dev(mdev_state->mdev);
648 	int i, count = 0;
649 
650 	WARN_ON(!mutex_is_locked(&mdev_state->ops_lock));
651 
652 	for (i = 0; i < mdev_state->pagecount; i++) {
653 		if (!mdev_state->pages[i])
654 			continue;
655 		put_page(mdev_state->pages[i]);
656 		mdev_state->pages[i] = NULL;
657 		count++;
658 	}
659 	dev_dbg(dev, "%s: %d pages released\n", __func__, count);
660 }
661 
662 static vm_fault_t mbochs_region_vm_fault(struct vm_fault *vmf)
663 {
664 	struct vm_area_struct *vma = vmf->vma;
665 	struct mdev_state *mdev_state = vma->vm_private_data;
666 	pgoff_t page_offset = (vmf->address - vma->vm_start) >> PAGE_SHIFT;
667 
668 	if (page_offset >= mdev_state->pagecount)
669 		return VM_FAULT_SIGBUS;
670 
671 	vmf->page = mbochs_get_page(mdev_state, page_offset);
672 	if (!vmf->page)
673 		return VM_FAULT_SIGBUS;
674 
675 	return 0;
676 }
677 
678 static const struct vm_operations_struct mbochs_region_vm_ops = {
679 	.fault = mbochs_region_vm_fault,
680 };
681 
682 static int mbochs_mmap(struct mdev_device *mdev, struct vm_area_struct *vma)
683 {
684 	struct mdev_state *mdev_state = mdev_get_drvdata(mdev);
685 
686 	if (vma->vm_pgoff != MBOCHS_MEMORY_BAR_OFFSET >> PAGE_SHIFT)
687 		return -EINVAL;
688 	if (vma->vm_end < vma->vm_start)
689 		return -EINVAL;
690 	if (vma->vm_end - vma->vm_start > mdev_state->memsize)
691 		return -EINVAL;
692 	if ((vma->vm_flags & VM_SHARED) == 0)
693 		return -EINVAL;
694 
695 	vma->vm_ops = &mbochs_region_vm_ops;
696 	vma->vm_private_data = mdev_state;
697 	return 0;
698 }
699 
700 static vm_fault_t mbochs_dmabuf_vm_fault(struct vm_fault *vmf)
701 {
702 	struct vm_area_struct *vma = vmf->vma;
703 	struct mbochs_dmabuf *dmabuf = vma->vm_private_data;
704 
705 	if (WARN_ON(vmf->pgoff >= dmabuf->pagecount))
706 		return VM_FAULT_SIGBUS;
707 
708 	vmf->page = dmabuf->pages[vmf->pgoff];
709 	get_page(vmf->page);
710 	return 0;
711 }
712 
713 static const struct vm_operations_struct mbochs_dmabuf_vm_ops = {
714 	.fault = mbochs_dmabuf_vm_fault,
715 };
716 
717 static int mbochs_mmap_dmabuf(struct dma_buf *buf, struct vm_area_struct *vma)
718 {
719 	struct mbochs_dmabuf *dmabuf = buf->priv;
720 	struct device *dev = mdev_dev(dmabuf->mdev_state->mdev);
721 
722 	dev_dbg(dev, "%s: %d\n", __func__, dmabuf->id);
723 
724 	if ((vma->vm_flags & VM_SHARED) == 0)
725 		return -EINVAL;
726 
727 	vma->vm_ops = &mbochs_dmabuf_vm_ops;
728 	vma->vm_private_data = dmabuf;
729 	return 0;
730 }
731 
732 static void mbochs_print_dmabuf(struct mbochs_dmabuf *dmabuf,
733 				const char *prefix)
734 {
735 	struct device *dev = mdev_dev(dmabuf->mdev_state->mdev);
736 	u32 fourcc = dmabuf->mode.drm_format;
737 
738 	dev_dbg(dev, "%s/%d: %c%c%c%c, %dx%d, stride %d, off 0x%llx, size 0x%llx, pages %ld\n",
739 		prefix, dmabuf->id,
740 		fourcc ? ((fourcc >>  0) & 0xff) : '-',
741 		fourcc ? ((fourcc >>  8) & 0xff) : '-',
742 		fourcc ? ((fourcc >> 16) & 0xff) : '-',
743 		fourcc ? ((fourcc >> 24) & 0xff) : '-',
744 		dmabuf->mode.width, dmabuf->mode.height, dmabuf->mode.stride,
745 		dmabuf->mode.offset, dmabuf->mode.size, dmabuf->pagecount);
746 }
747 
748 static struct sg_table *mbochs_map_dmabuf(struct dma_buf_attachment *at,
749 					  enum dma_data_direction direction)
750 {
751 	struct mbochs_dmabuf *dmabuf = at->dmabuf->priv;
752 	struct device *dev = mdev_dev(dmabuf->mdev_state->mdev);
753 	struct sg_table *sg;
754 
755 	dev_dbg(dev, "%s: %d\n", __func__, dmabuf->id);
756 
757 	sg = kzalloc(sizeof(*sg), GFP_KERNEL);
758 	if (!sg)
759 		goto err1;
760 	if (sg_alloc_table_from_pages(sg, dmabuf->pages, dmabuf->pagecount,
761 				      0, dmabuf->mode.size, GFP_KERNEL) < 0)
762 		goto err2;
763 	if (!dma_map_sg(at->dev, sg->sgl, sg->nents, direction))
764 		goto err3;
765 
766 	return sg;
767 
768 err3:
769 	sg_free_table(sg);
770 err2:
771 	kfree(sg);
772 err1:
773 	return ERR_PTR(-ENOMEM);
774 }
775 
776 static void mbochs_unmap_dmabuf(struct dma_buf_attachment *at,
777 				struct sg_table *sg,
778 				enum dma_data_direction direction)
779 {
780 	struct mbochs_dmabuf *dmabuf = at->dmabuf->priv;
781 	struct device *dev = mdev_dev(dmabuf->mdev_state->mdev);
782 
783 	dev_dbg(dev, "%s: %d\n", __func__, dmabuf->id);
784 
785 	sg_free_table(sg);
786 	kfree(sg);
787 }
788 
789 static void mbochs_release_dmabuf(struct dma_buf *buf)
790 {
791 	struct mbochs_dmabuf *dmabuf = buf->priv;
792 	struct mdev_state *mdev_state = dmabuf->mdev_state;
793 	struct device *dev = mdev_dev(mdev_state->mdev);
794 	pgoff_t pg;
795 
796 	dev_dbg(dev, "%s: %d\n", __func__, dmabuf->id);
797 
798 	for (pg = 0; pg < dmabuf->pagecount; pg++)
799 		put_page(dmabuf->pages[pg]);
800 
801 	mutex_lock(&mdev_state->ops_lock);
802 	dmabuf->buf = NULL;
803 	if (dmabuf->unlinked)
804 		kfree(dmabuf);
805 	mutex_unlock(&mdev_state->ops_lock);
806 }
807 
808 static void *mbochs_kmap_dmabuf(struct dma_buf *buf, unsigned long page_num)
809 {
810 	struct mbochs_dmabuf *dmabuf = buf->priv;
811 	struct page *page = dmabuf->pages[page_num];
812 
813 	return kmap(page);
814 }
815 
816 static void mbochs_kunmap_dmabuf(struct dma_buf *buf, unsigned long page_num,
817 				 void *vaddr)
818 {
819 	kunmap(vaddr);
820 }
821 
822 static struct dma_buf_ops mbochs_dmabuf_ops = {
823 	.map_dma_buf	  = mbochs_map_dmabuf,
824 	.unmap_dma_buf	  = mbochs_unmap_dmabuf,
825 	.release	  = mbochs_release_dmabuf,
826 	.map		  = mbochs_kmap_dmabuf,
827 	.unmap		  = mbochs_kunmap_dmabuf,
828 	.mmap		  = mbochs_mmap_dmabuf,
829 };
830 
831 static struct mbochs_dmabuf *mbochs_dmabuf_alloc(struct mdev_state *mdev_state,
832 						 struct mbochs_mode *mode)
833 {
834 	struct mbochs_dmabuf *dmabuf;
835 	pgoff_t page_offset, pg;
836 
837 	WARN_ON(!mutex_is_locked(&mdev_state->ops_lock));
838 
839 	dmabuf = kzalloc(sizeof(struct mbochs_dmabuf), GFP_KERNEL);
840 	if (!dmabuf)
841 		return NULL;
842 
843 	dmabuf->mode = *mode;
844 	dmabuf->id = mdev_state->next_id++;
845 	dmabuf->pagecount = DIV_ROUND_UP(mode->size, PAGE_SIZE);
846 	dmabuf->pages = kcalloc(dmabuf->pagecount, sizeof(struct page *),
847 				GFP_KERNEL);
848 	if (!dmabuf->pages)
849 		goto err_free_dmabuf;
850 
851 	page_offset = dmabuf->mode.offset >> PAGE_SHIFT;
852 	for (pg = 0; pg < dmabuf->pagecount; pg++) {
853 		dmabuf->pages[pg] = __mbochs_get_page(mdev_state,
854 						      page_offset + pg);
855 		if (!dmabuf->pages[pg])
856 			goto err_free_pages;
857 	}
858 
859 	dmabuf->mdev_state = mdev_state;
860 	list_add(&dmabuf->next, &mdev_state->dmabufs);
861 
862 	mbochs_print_dmabuf(dmabuf, __func__);
863 	return dmabuf;
864 
865 err_free_pages:
866 	while (pg > 0)
867 		put_page(dmabuf->pages[--pg]);
868 	kfree(dmabuf->pages);
869 err_free_dmabuf:
870 	kfree(dmabuf);
871 	return NULL;
872 }
873 
874 static struct mbochs_dmabuf *
875 mbochs_dmabuf_find_by_mode(struct mdev_state *mdev_state,
876 			   struct mbochs_mode *mode)
877 {
878 	struct mbochs_dmabuf *dmabuf;
879 
880 	WARN_ON(!mutex_is_locked(&mdev_state->ops_lock));
881 
882 	list_for_each_entry(dmabuf, &mdev_state->dmabufs, next)
883 		if (mbochs_modes_equal(&dmabuf->mode, mode))
884 			return dmabuf;
885 
886 	return NULL;
887 }
888 
889 static struct mbochs_dmabuf *
890 mbochs_dmabuf_find_by_id(struct mdev_state *mdev_state, u32 id)
891 {
892 	struct mbochs_dmabuf *dmabuf;
893 
894 	WARN_ON(!mutex_is_locked(&mdev_state->ops_lock));
895 
896 	list_for_each_entry(dmabuf, &mdev_state->dmabufs, next)
897 		if (dmabuf->id == id)
898 			return dmabuf;
899 
900 	return NULL;
901 }
902 
903 static int mbochs_dmabuf_export(struct mbochs_dmabuf *dmabuf)
904 {
905 	struct mdev_state *mdev_state = dmabuf->mdev_state;
906 	struct device *dev = mdev_dev(mdev_state->mdev);
907 	DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
908 	struct dma_buf *buf;
909 
910 	WARN_ON(!mutex_is_locked(&mdev_state->ops_lock));
911 
912 	if (!IS_ALIGNED(dmabuf->mode.offset, PAGE_SIZE)) {
913 		dev_info_ratelimited(dev, "%s: framebuffer not page-aligned\n",
914 				     __func__);
915 		return -EINVAL;
916 	}
917 
918 	exp_info.ops = &mbochs_dmabuf_ops;
919 	exp_info.size = dmabuf->mode.size;
920 	exp_info.priv = dmabuf;
921 
922 	buf = dma_buf_export(&exp_info);
923 	if (IS_ERR(buf)) {
924 		dev_info_ratelimited(dev, "%s: dma_buf_export failed: %ld\n",
925 				     __func__, PTR_ERR(buf));
926 		return PTR_ERR(buf);
927 	}
928 
929 	dmabuf->buf = buf;
930 	dev_dbg(dev, "%s: %d\n", __func__, dmabuf->id);
931 	return 0;
932 }
933 
934 static int mbochs_get_region_info(struct mdev_device *mdev,
935 				  struct vfio_region_info *region_info,
936 				  u16 *cap_type_id, void **cap_type)
937 {
938 	struct mdev_state *mdev_state;
939 
940 	mdev_state = mdev_get_drvdata(mdev);
941 	if (!mdev_state)
942 		return -EINVAL;
943 
944 	if (region_info->index >= VFIO_PCI_NUM_REGIONS)
945 		return -EINVAL;
946 
947 	switch (region_info->index) {
948 	case VFIO_PCI_CONFIG_REGION_INDEX:
949 		region_info->offset = 0;
950 		region_info->size   = MBOCHS_CONFIG_SPACE_SIZE;
951 		region_info->flags  = (VFIO_REGION_INFO_FLAG_READ |
952 				       VFIO_REGION_INFO_FLAG_WRITE);
953 		break;
954 	case VFIO_PCI_BAR0_REGION_INDEX:
955 		region_info->offset = MBOCHS_MEMORY_BAR_OFFSET;
956 		region_info->size   = mdev_state->memsize;
957 		region_info->flags  = (VFIO_REGION_INFO_FLAG_READ  |
958 				       VFIO_REGION_INFO_FLAG_WRITE |
959 				       VFIO_REGION_INFO_FLAG_MMAP);
960 		break;
961 	case VFIO_PCI_BAR2_REGION_INDEX:
962 		region_info->offset = MBOCHS_MMIO_BAR_OFFSET;
963 		region_info->size   = MBOCHS_MMIO_BAR_SIZE;
964 		region_info->flags  = (VFIO_REGION_INFO_FLAG_READ  |
965 				       VFIO_REGION_INFO_FLAG_WRITE);
966 		break;
967 	default:
968 		region_info->size   = 0;
969 		region_info->offset = 0;
970 		region_info->flags  = 0;
971 	}
972 
973 	return 0;
974 }
975 
976 static int mbochs_get_irq_info(struct mdev_device *mdev,
977 			       struct vfio_irq_info *irq_info)
978 {
979 	irq_info->count = 0;
980 	return 0;
981 }
982 
983 static int mbochs_get_device_info(struct mdev_device *mdev,
984 				  struct vfio_device_info *dev_info)
985 {
986 	dev_info->flags = VFIO_DEVICE_FLAGS_PCI;
987 	dev_info->num_regions = VFIO_PCI_NUM_REGIONS;
988 	dev_info->num_irqs = VFIO_PCI_NUM_IRQS;
989 	return 0;
990 }
991 
992 static int mbochs_query_gfx_plane(struct mdev_device *mdev,
993 				  struct vfio_device_gfx_plane_info *plane)
994 {
995 	struct mdev_state *mdev_state = mdev_get_drvdata(mdev);
996 	struct device *dev = mdev_dev(mdev);
997 	struct mbochs_dmabuf *dmabuf;
998 	struct mbochs_mode mode;
999 	int ret;
1000 
1001 	if (plane->flags & VFIO_GFX_PLANE_TYPE_PROBE) {
1002 		if (plane->flags == (VFIO_GFX_PLANE_TYPE_PROBE |
1003 				     VFIO_GFX_PLANE_TYPE_DMABUF))
1004 			return 0;
1005 		return -EINVAL;
1006 	}
1007 
1008 	if (plane->flags != VFIO_GFX_PLANE_TYPE_DMABUF)
1009 		return -EINVAL;
1010 
1011 	plane->drm_format_mod = 0;
1012 	plane->x_pos	      = 0;
1013 	plane->y_pos	      = 0;
1014 	plane->x_hot	      = 0;
1015 	plane->y_hot	      = 0;
1016 
1017 	mutex_lock(&mdev_state->ops_lock);
1018 
1019 	ret = -EINVAL;
1020 	if (plane->drm_plane_type == DRM_PLANE_TYPE_PRIMARY)
1021 		ret = mbochs_check_framebuffer(mdev_state, &mode);
1022 	if (ret < 0) {
1023 		plane->drm_format     = 0;
1024 		plane->width	      = 0;
1025 		plane->height	      = 0;
1026 		plane->stride	      = 0;
1027 		plane->size	      = 0;
1028 		plane->dmabuf_id      = 0;
1029 		goto done;
1030 	}
1031 
1032 	dmabuf = mbochs_dmabuf_find_by_mode(mdev_state, &mode);
1033 	if (!dmabuf)
1034 		mbochs_dmabuf_alloc(mdev_state, &mode);
1035 	if (!dmabuf) {
1036 		mutex_unlock(&mdev_state->ops_lock);
1037 		return -ENOMEM;
1038 	}
1039 
1040 	plane->drm_format     = dmabuf->mode.drm_format;
1041 	plane->width	      = dmabuf->mode.width;
1042 	plane->height	      = dmabuf->mode.height;
1043 	plane->stride	      = dmabuf->mode.stride;
1044 	plane->size	      = dmabuf->mode.size;
1045 	plane->dmabuf_id      = dmabuf->id;
1046 
1047 done:
1048 	if (plane->drm_plane_type == DRM_PLANE_TYPE_PRIMARY &&
1049 	    mdev_state->active_id != plane->dmabuf_id) {
1050 		dev_dbg(dev, "%s: primary: %d => %d\n", __func__,
1051 			mdev_state->active_id, plane->dmabuf_id);
1052 		mdev_state->active_id = plane->dmabuf_id;
1053 	}
1054 	mutex_unlock(&mdev_state->ops_lock);
1055 	return 0;
1056 }
1057 
1058 static int mbochs_get_gfx_dmabuf(struct mdev_device *mdev,
1059 				 u32 id)
1060 {
1061 	struct mdev_state *mdev_state = mdev_get_drvdata(mdev);
1062 	struct mbochs_dmabuf *dmabuf;
1063 
1064 	mutex_lock(&mdev_state->ops_lock);
1065 
1066 	dmabuf = mbochs_dmabuf_find_by_id(mdev_state, id);
1067 	if (!dmabuf) {
1068 		mutex_unlock(&mdev_state->ops_lock);
1069 		return -ENOENT;
1070 	}
1071 
1072 	if (!dmabuf->buf)
1073 		mbochs_dmabuf_export(dmabuf);
1074 
1075 	mutex_unlock(&mdev_state->ops_lock);
1076 
1077 	if (!dmabuf->buf)
1078 		return -EINVAL;
1079 
1080 	return dma_buf_fd(dmabuf->buf, 0);
1081 }
1082 
1083 static long mbochs_ioctl(struct mdev_device *mdev, unsigned int cmd,
1084 			unsigned long arg)
1085 {
1086 	int ret = 0;
1087 	unsigned long minsz;
1088 	struct mdev_state *mdev_state;
1089 
1090 	mdev_state = mdev_get_drvdata(mdev);
1091 
1092 	switch (cmd) {
1093 	case VFIO_DEVICE_GET_INFO:
1094 	{
1095 		struct vfio_device_info info;
1096 
1097 		minsz = offsetofend(struct vfio_device_info, num_irqs);
1098 
1099 		if (copy_from_user(&info, (void __user *)arg, minsz))
1100 			return -EFAULT;
1101 
1102 		if (info.argsz < minsz)
1103 			return -EINVAL;
1104 
1105 		ret = mbochs_get_device_info(mdev, &info);
1106 		if (ret)
1107 			return ret;
1108 
1109 		memcpy(&mdev_state->dev_info, &info, sizeof(info));
1110 
1111 		if (copy_to_user((void __user *)arg, &info, minsz))
1112 			return -EFAULT;
1113 
1114 		return 0;
1115 	}
1116 	case VFIO_DEVICE_GET_REGION_INFO:
1117 	{
1118 		struct vfio_region_info info;
1119 		u16 cap_type_id = 0;
1120 		void *cap_type = NULL;
1121 
1122 		minsz = offsetofend(struct vfio_region_info, offset);
1123 
1124 		if (copy_from_user(&info, (void __user *)arg, minsz))
1125 			return -EFAULT;
1126 
1127 		if (info.argsz < minsz)
1128 			return -EINVAL;
1129 
1130 		ret = mbochs_get_region_info(mdev, &info, &cap_type_id,
1131 					   &cap_type);
1132 		if (ret)
1133 			return ret;
1134 
1135 		if (copy_to_user((void __user *)arg, &info, minsz))
1136 			return -EFAULT;
1137 
1138 		return 0;
1139 	}
1140 
1141 	case VFIO_DEVICE_GET_IRQ_INFO:
1142 	{
1143 		struct vfio_irq_info info;
1144 
1145 		minsz = offsetofend(struct vfio_irq_info, count);
1146 
1147 		if (copy_from_user(&info, (void __user *)arg, minsz))
1148 			return -EFAULT;
1149 
1150 		if ((info.argsz < minsz) ||
1151 		    (info.index >= mdev_state->dev_info.num_irqs))
1152 			return -EINVAL;
1153 
1154 		ret = mbochs_get_irq_info(mdev, &info);
1155 		if (ret)
1156 			return ret;
1157 
1158 		if (copy_to_user((void __user *)arg, &info, minsz))
1159 			return -EFAULT;
1160 
1161 		return 0;
1162 	}
1163 
1164 	case VFIO_DEVICE_QUERY_GFX_PLANE:
1165 	{
1166 		struct vfio_device_gfx_plane_info plane;
1167 
1168 		minsz = offsetofend(struct vfio_device_gfx_plane_info,
1169 				    region_index);
1170 
1171 		if (copy_from_user(&plane, (void __user *)arg, minsz))
1172 			return -EFAULT;
1173 
1174 		if (plane.argsz < minsz)
1175 			return -EINVAL;
1176 
1177 		ret = mbochs_query_gfx_plane(mdev, &plane);
1178 		if (ret)
1179 			return ret;
1180 
1181 		if (copy_to_user((void __user *)arg, &plane, minsz))
1182 			return -EFAULT;
1183 
1184 		return 0;
1185 	}
1186 
1187 	case VFIO_DEVICE_GET_GFX_DMABUF:
1188 	{
1189 		u32 dmabuf_id;
1190 
1191 		if (get_user(dmabuf_id, (__u32 __user *)arg))
1192 			return -EFAULT;
1193 
1194 		return mbochs_get_gfx_dmabuf(mdev, dmabuf_id);
1195 	}
1196 
1197 	case VFIO_DEVICE_SET_IRQS:
1198 		return -EINVAL;
1199 
1200 	case VFIO_DEVICE_RESET:
1201 		return mbochs_reset(mdev);
1202 	}
1203 	return -ENOTTY;
1204 }
1205 
1206 static int mbochs_open(struct mdev_device *mdev)
1207 {
1208 	if (!try_module_get(THIS_MODULE))
1209 		return -ENODEV;
1210 
1211 	return 0;
1212 }
1213 
1214 static void mbochs_close(struct mdev_device *mdev)
1215 {
1216 	struct mdev_state *mdev_state = mdev_get_drvdata(mdev);
1217 	struct mbochs_dmabuf *dmabuf, *tmp;
1218 
1219 	mutex_lock(&mdev_state->ops_lock);
1220 
1221 	list_for_each_entry_safe(dmabuf, tmp, &mdev_state->dmabufs, next) {
1222 		list_del(&dmabuf->next);
1223 		if (dmabuf->buf) {
1224 			/* free in mbochs_release_dmabuf() */
1225 			dmabuf->unlinked = true;
1226 		} else {
1227 			kfree(dmabuf);
1228 		}
1229 	}
1230 	mbochs_put_pages(mdev_state);
1231 
1232 	mutex_unlock(&mdev_state->ops_lock);
1233 	module_put(THIS_MODULE);
1234 }
1235 
1236 static ssize_t
1237 memory_show(struct device *dev, struct device_attribute *attr,
1238 	    char *buf)
1239 {
1240 	struct mdev_device *mdev = mdev_from_dev(dev);
1241 	struct mdev_state *mdev_state = mdev_get_drvdata(mdev);
1242 
1243 	return sprintf(buf, "%d MB\n", mdev_state->type->mbytes);
1244 }
1245 static DEVICE_ATTR_RO(memory);
1246 
1247 static struct attribute *mdev_dev_attrs[] = {
1248 	&dev_attr_memory.attr,
1249 	NULL,
1250 };
1251 
1252 static const struct attribute_group mdev_dev_group = {
1253 	.name  = "vendor",
1254 	.attrs = mdev_dev_attrs,
1255 };
1256 
1257 const struct attribute_group *mdev_dev_groups[] = {
1258 	&mdev_dev_group,
1259 	NULL,
1260 };
1261 
1262 static ssize_t
1263 name_show(struct kobject *kobj, struct device *dev, char *buf)
1264 {
1265 	return sprintf(buf, "%s\n", kobj->name);
1266 }
1267 MDEV_TYPE_ATTR_RO(name);
1268 
1269 static ssize_t
1270 description_show(struct kobject *kobj, struct device *dev, char *buf)
1271 {
1272 	const struct mbochs_type *type = mbochs_find_type(kobj);
1273 
1274 	return sprintf(buf, "virtual display, %d MB video memory\n",
1275 		       type ? type->mbytes  : 0);
1276 }
1277 MDEV_TYPE_ATTR_RO(description);
1278 
1279 static ssize_t
1280 available_instances_show(struct kobject *kobj, struct device *dev, char *buf)
1281 {
1282 	const struct mbochs_type *type = mbochs_find_type(kobj);
1283 	int count = (max_mbytes - mbochs_used_mbytes) / type->mbytes;
1284 
1285 	return sprintf(buf, "%d\n", count);
1286 }
1287 MDEV_TYPE_ATTR_RO(available_instances);
1288 
1289 static ssize_t device_api_show(struct kobject *kobj, struct device *dev,
1290 			       char *buf)
1291 {
1292 	return sprintf(buf, "%s\n", VFIO_DEVICE_API_PCI_STRING);
1293 }
1294 MDEV_TYPE_ATTR_RO(device_api);
1295 
1296 static struct attribute *mdev_types_attrs[] = {
1297 	&mdev_type_attr_name.attr,
1298 	&mdev_type_attr_description.attr,
1299 	&mdev_type_attr_device_api.attr,
1300 	&mdev_type_attr_available_instances.attr,
1301 	NULL,
1302 };
1303 
1304 static struct attribute_group mdev_type_group1 = {
1305 	.name  = MBOCHS_TYPE_1,
1306 	.attrs = mdev_types_attrs,
1307 };
1308 
1309 static struct attribute_group mdev_type_group2 = {
1310 	.name  = MBOCHS_TYPE_2,
1311 	.attrs = mdev_types_attrs,
1312 };
1313 
1314 static struct attribute_group mdev_type_group3 = {
1315 	.name  = MBOCHS_TYPE_3,
1316 	.attrs = mdev_types_attrs,
1317 };
1318 
1319 static struct attribute_group *mdev_type_groups[] = {
1320 	&mdev_type_group1,
1321 	&mdev_type_group2,
1322 	&mdev_type_group3,
1323 	NULL,
1324 };
1325 
1326 static const struct mdev_parent_ops mdev_fops = {
1327 	.owner			= THIS_MODULE,
1328 	.mdev_attr_groups	= mdev_dev_groups,
1329 	.supported_type_groups	= mdev_type_groups,
1330 	.create			= mbochs_create,
1331 	.remove			= mbochs_remove,
1332 	.open			= mbochs_open,
1333 	.release		= mbochs_close,
1334 	.read			= mbochs_read,
1335 	.write			= mbochs_write,
1336 	.ioctl			= mbochs_ioctl,
1337 	.mmap			= mbochs_mmap,
1338 };
1339 
1340 static const struct file_operations vd_fops = {
1341 	.owner		= THIS_MODULE,
1342 };
1343 
1344 static void mbochs_device_release(struct device *dev)
1345 {
1346 	/* nothing */
1347 }
1348 
1349 static int __init mbochs_dev_init(void)
1350 {
1351 	int ret = 0;
1352 
1353 	ret = alloc_chrdev_region(&mbochs_devt, 0, MINORMASK, MBOCHS_NAME);
1354 	if (ret < 0) {
1355 		pr_err("Error: failed to register mbochs_dev, err: %d\n", ret);
1356 		return ret;
1357 	}
1358 	cdev_init(&mbochs_cdev, &vd_fops);
1359 	cdev_add(&mbochs_cdev, mbochs_devt, MINORMASK);
1360 	pr_info("%s: major %d\n", __func__, MAJOR(mbochs_devt));
1361 
1362 	mbochs_class = class_create(THIS_MODULE, MBOCHS_CLASS_NAME);
1363 	if (IS_ERR(mbochs_class)) {
1364 		pr_err("Error: failed to register mbochs_dev class\n");
1365 		ret = PTR_ERR(mbochs_class);
1366 		goto failed1;
1367 	}
1368 	mbochs_dev.class = mbochs_class;
1369 	mbochs_dev.release = mbochs_device_release;
1370 	dev_set_name(&mbochs_dev, "%s", MBOCHS_NAME);
1371 
1372 	ret = device_register(&mbochs_dev);
1373 	if (ret)
1374 		goto failed2;
1375 
1376 	ret = mdev_register_device(&mbochs_dev, &mdev_fops);
1377 	if (ret)
1378 		goto failed3;
1379 
1380 	return 0;
1381 
1382 failed3:
1383 	device_unregister(&mbochs_dev);
1384 failed2:
1385 	class_destroy(mbochs_class);
1386 failed1:
1387 	cdev_del(&mbochs_cdev);
1388 	unregister_chrdev_region(mbochs_devt, MINORMASK);
1389 	return ret;
1390 }
1391 
1392 static void __exit mbochs_dev_exit(void)
1393 {
1394 	mbochs_dev.bus = NULL;
1395 	mdev_unregister_device(&mbochs_dev);
1396 
1397 	device_unregister(&mbochs_dev);
1398 	cdev_del(&mbochs_cdev);
1399 	unregister_chrdev_region(mbochs_devt, MINORMASK);
1400 	class_destroy(mbochs_class);
1401 	mbochs_class = NULL;
1402 }
1403 
1404 module_init(mbochs_dev_init)
1405 module_exit(mbochs_dev_exit)
1406