xref: /openbmc/linux/samples/vfio-mdev/mbochs.c (revision 5b628549)
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_EDID_REGION_INDEX  VFIO_PCI_NUM_REGIONS
75 #define MBOCHS_NUM_REGIONS        (MBOCHS_EDID_REGION_INDEX+1)
76 
77 #define MBOCHS_CONFIG_SPACE_SIZE  0xff
78 #define MBOCHS_MMIO_BAR_OFFSET	  PAGE_SIZE
79 #define MBOCHS_MMIO_BAR_SIZE	  PAGE_SIZE
80 #define MBOCHS_EDID_OFFSET	  (MBOCHS_MMIO_BAR_OFFSET +	\
81 				   MBOCHS_MMIO_BAR_SIZE)
82 #define MBOCHS_EDID_SIZE	  PAGE_SIZE
83 #define MBOCHS_MEMORY_BAR_OFFSET  (MBOCHS_EDID_OFFSET + \
84 				   MBOCHS_EDID_SIZE)
85 
86 #define MBOCHS_EDID_BLOB_OFFSET   (MBOCHS_EDID_SIZE/2)
87 
88 #define STORE_LE16(addr, val)	(*(u16 *)addr = val)
89 #define STORE_LE32(addr, val)	(*(u32 *)addr = val)
90 
91 
92 MODULE_LICENSE("GPL v2");
93 
94 static int max_mbytes = 256;
95 module_param_named(count, max_mbytes, int, 0444);
96 MODULE_PARM_DESC(mem, "megabytes available to " MBOCHS_NAME " devices");
97 
98 
99 #define MBOCHS_TYPE_1 "small"
100 #define MBOCHS_TYPE_2 "medium"
101 #define MBOCHS_TYPE_3 "large"
102 
103 static const struct mbochs_type {
104 	const char *name;
105 	u32 mbytes;
106 	u32 max_x;
107 	u32 max_y;
108 } mbochs_types[] = {
109 	{
110 		.name	= MBOCHS_CLASS_NAME "-" MBOCHS_TYPE_1,
111 		.mbytes = 4,
112 		.max_x  = 800,
113 		.max_y  = 600,
114 	}, {
115 		.name	= MBOCHS_CLASS_NAME "-" MBOCHS_TYPE_2,
116 		.mbytes = 16,
117 		.max_x  = 1920,
118 		.max_y  = 1440,
119 	}, {
120 		.name	= MBOCHS_CLASS_NAME "-" MBOCHS_TYPE_3,
121 		.mbytes = 64,
122 		.max_x  = 0,
123 		.max_y  = 0,
124 	},
125 };
126 
127 
128 static dev_t		mbochs_devt;
129 static struct class	*mbochs_class;
130 static struct cdev	mbochs_cdev;
131 static struct device	mbochs_dev;
132 static int		mbochs_used_mbytes;
133 
134 struct vfio_region_info_ext {
135 	struct vfio_region_info          base;
136 	struct vfio_region_info_cap_type type;
137 };
138 
139 struct mbochs_mode {
140 	u32 drm_format;
141 	u32 bytepp;
142 	u32 width;
143 	u32 height;
144 	u32 stride;
145 	u32 __pad;
146 	u64 offset;
147 	u64 size;
148 };
149 
150 struct mbochs_dmabuf {
151 	struct mbochs_mode mode;
152 	u32 id;
153 	struct page **pages;
154 	pgoff_t pagecount;
155 	struct dma_buf *buf;
156 	struct mdev_state *mdev_state;
157 	struct list_head next;
158 	bool unlinked;
159 };
160 
161 /* State of each mdev device */
162 struct mdev_state {
163 	u8 *vconfig;
164 	u64 bar_mask[3];
165 	u32 memory_bar_mask;
166 	struct mutex ops_lock;
167 	struct mdev_device *mdev;
168 
169 	const struct mbochs_type *type;
170 	u16 vbe[VBE_DISPI_INDEX_COUNT];
171 	u64 memsize;
172 	struct page **pages;
173 	pgoff_t pagecount;
174 	struct vfio_region_gfx_edid edid_regs;
175 	u8 edid_blob[0x400];
176 
177 	struct list_head dmabufs;
178 	u32 active_id;
179 	u32 next_id;
180 };
181 
182 static const char *vbe_name_list[VBE_DISPI_INDEX_COUNT] = {
183 	[VBE_DISPI_INDEX_ID]               = "id",
184 	[VBE_DISPI_INDEX_XRES]             = "xres",
185 	[VBE_DISPI_INDEX_YRES]             = "yres",
186 	[VBE_DISPI_INDEX_BPP]              = "bpp",
187 	[VBE_DISPI_INDEX_ENABLE]           = "enable",
188 	[VBE_DISPI_INDEX_BANK]             = "bank",
189 	[VBE_DISPI_INDEX_VIRT_WIDTH]       = "virt-width",
190 	[VBE_DISPI_INDEX_VIRT_HEIGHT]      = "virt-height",
191 	[VBE_DISPI_INDEX_X_OFFSET]         = "x-offset",
192 	[VBE_DISPI_INDEX_Y_OFFSET]         = "y-offset",
193 	[VBE_DISPI_INDEX_VIDEO_MEMORY_64K] = "video-mem",
194 };
195 
196 static const char *vbe_name(u32 index)
197 {
198 	if (index < ARRAY_SIZE(vbe_name_list))
199 		return vbe_name_list[index];
200 	return "(invalid)";
201 }
202 
203 static struct page *__mbochs_get_page(struct mdev_state *mdev_state,
204 				      pgoff_t pgoff);
205 static struct page *mbochs_get_page(struct mdev_state *mdev_state,
206 				    pgoff_t pgoff);
207 
208 static const struct mbochs_type *mbochs_find_type(struct kobject *kobj)
209 {
210 	int i;
211 
212 	for (i = 0; i < ARRAY_SIZE(mbochs_types); i++)
213 		if (strcmp(mbochs_types[i].name, kobj->name) == 0)
214 			return mbochs_types + i;
215 	return NULL;
216 }
217 
218 static void mbochs_create_config_space(struct mdev_state *mdev_state)
219 {
220 	STORE_LE16((u16 *) &mdev_state->vconfig[PCI_VENDOR_ID],
221 		   0x1234);
222 	STORE_LE16((u16 *) &mdev_state->vconfig[PCI_DEVICE_ID],
223 		   0x1111);
224 	STORE_LE16((u16 *) &mdev_state->vconfig[PCI_SUBSYSTEM_VENDOR_ID],
225 		   PCI_SUBVENDOR_ID_REDHAT_QUMRANET);
226 	STORE_LE16((u16 *) &mdev_state->vconfig[PCI_SUBSYSTEM_ID],
227 		   PCI_SUBDEVICE_ID_QEMU);
228 
229 	STORE_LE16((u16 *) &mdev_state->vconfig[PCI_COMMAND],
230 		   PCI_COMMAND_IO | PCI_COMMAND_MEMORY);
231 	STORE_LE16((u16 *) &mdev_state->vconfig[PCI_CLASS_DEVICE],
232 		   PCI_CLASS_DISPLAY_OTHER);
233 	mdev_state->vconfig[PCI_CLASS_REVISION] =  0x01;
234 
235 	STORE_LE32((u32 *) &mdev_state->vconfig[PCI_BASE_ADDRESS_0],
236 		   PCI_BASE_ADDRESS_SPACE_MEMORY |
237 		   PCI_BASE_ADDRESS_MEM_TYPE_32	 |
238 		   PCI_BASE_ADDRESS_MEM_PREFETCH);
239 	mdev_state->bar_mask[0] = ~(mdev_state->memsize) + 1;
240 
241 	STORE_LE32((u32 *) &mdev_state->vconfig[PCI_BASE_ADDRESS_2],
242 		   PCI_BASE_ADDRESS_SPACE_MEMORY |
243 		   PCI_BASE_ADDRESS_MEM_TYPE_32);
244 	mdev_state->bar_mask[2] = ~(MBOCHS_MMIO_BAR_SIZE) + 1;
245 }
246 
247 static int mbochs_check_framebuffer(struct mdev_state *mdev_state,
248 				    struct mbochs_mode *mode)
249 {
250 	struct device *dev = mdev_dev(mdev_state->mdev);
251 	u16 *vbe = mdev_state->vbe;
252 	u32 virt_width;
253 
254 	WARN_ON(!mutex_is_locked(&mdev_state->ops_lock));
255 
256 	if (!(vbe[VBE_DISPI_INDEX_ENABLE] & VBE_DISPI_ENABLED))
257 		goto nofb;
258 
259 	memset(mode, 0, sizeof(*mode));
260 	switch (vbe[VBE_DISPI_INDEX_BPP]) {
261 	case 32:
262 		mode->drm_format = DRM_FORMAT_XRGB8888;
263 		mode->bytepp = 4;
264 		break;
265 	default:
266 		dev_info_ratelimited(dev, "%s: bpp %d not supported\n",
267 				     __func__, vbe[VBE_DISPI_INDEX_BPP]);
268 		goto nofb;
269 	}
270 
271 	mode->width  = vbe[VBE_DISPI_INDEX_XRES];
272 	mode->height = vbe[VBE_DISPI_INDEX_YRES];
273 	virt_width  = vbe[VBE_DISPI_INDEX_VIRT_WIDTH];
274 	if (virt_width < mode->width)
275 		virt_width = mode->width;
276 	mode->stride = virt_width * mode->bytepp;
277 	mode->size   = (u64)mode->stride * mode->height;
278 	mode->offset = ((u64)vbe[VBE_DISPI_INDEX_X_OFFSET] * mode->bytepp +
279 		       (u64)vbe[VBE_DISPI_INDEX_Y_OFFSET] * mode->stride);
280 
281 	if (mode->width < 64 || mode->height < 64) {
282 		dev_info_ratelimited(dev, "%s: invalid resolution %dx%d\n",
283 				     __func__, mode->width, mode->height);
284 		goto nofb;
285 	}
286 	if (mode->offset + mode->size > mdev_state->memsize) {
287 		dev_info_ratelimited(dev, "%s: framebuffer memory overflow\n",
288 				     __func__);
289 		goto nofb;
290 	}
291 
292 	return 0;
293 
294 nofb:
295 	memset(mode, 0, sizeof(*mode));
296 	return -EINVAL;
297 }
298 
299 static bool mbochs_modes_equal(struct mbochs_mode *mode1,
300 			       struct mbochs_mode *mode2)
301 {
302 	return memcmp(mode1, mode2, sizeof(struct mbochs_mode)) == 0;
303 }
304 
305 static void handle_pci_cfg_write(struct mdev_state *mdev_state, u16 offset,
306 				 char *buf, u32 count)
307 {
308 	struct device *dev = mdev_dev(mdev_state->mdev);
309 	int index = (offset - PCI_BASE_ADDRESS_0) / 0x04;
310 	u32 cfg_addr;
311 
312 	switch (offset) {
313 	case PCI_BASE_ADDRESS_0:
314 	case PCI_BASE_ADDRESS_2:
315 		cfg_addr = *(u32 *)buf;
316 
317 		if (cfg_addr == 0xffffffff) {
318 			cfg_addr = (cfg_addr & mdev_state->bar_mask[index]);
319 		} else {
320 			cfg_addr &= PCI_BASE_ADDRESS_MEM_MASK;
321 			if (cfg_addr)
322 				dev_info(dev, "BAR #%d @ 0x%x\n",
323 					 index, cfg_addr);
324 		}
325 
326 		cfg_addr |= (mdev_state->vconfig[offset] &
327 			     ~PCI_BASE_ADDRESS_MEM_MASK);
328 		STORE_LE32(&mdev_state->vconfig[offset], cfg_addr);
329 		break;
330 	}
331 }
332 
333 static void handle_mmio_write(struct mdev_state *mdev_state, u16 offset,
334 			      char *buf, u32 count)
335 {
336 	struct device *dev = mdev_dev(mdev_state->mdev);
337 	int index;
338 	u16 reg16;
339 
340 	switch (offset) {
341 	case 0x400 ... 0x41f: /* vga ioports remapped */
342 		goto unhandled;
343 	case 0x500 ... 0x515: /* bochs dispi interface */
344 		if (count != 2)
345 			goto unhandled;
346 		index = (offset - 0x500) / 2;
347 		reg16 = *(u16 *)buf;
348 		if (index < ARRAY_SIZE(mdev_state->vbe))
349 			mdev_state->vbe[index] = reg16;
350 		dev_dbg(dev, "%s: vbe write %d = %d (%s)\n",
351 			__func__, index, reg16, vbe_name(index));
352 		break;
353 	case 0x600 ... 0x607: /* qemu extended regs */
354 		goto unhandled;
355 	default:
356 unhandled:
357 		dev_dbg(dev, "%s: @0x%03x, count %d (unhandled)\n",
358 			__func__, offset, count);
359 		break;
360 	}
361 }
362 
363 static void handle_mmio_read(struct mdev_state *mdev_state, u16 offset,
364 			     char *buf, u32 count)
365 {
366 	struct device *dev = mdev_dev(mdev_state->mdev);
367 	struct vfio_region_gfx_edid *edid;
368 	u16 reg16 = 0;
369 	int index;
370 
371 	switch (offset) {
372 	case 0x000 ... 0x3ff: /* edid block */
373 		edid = &mdev_state->edid_regs;
374 		if (edid->link_state != VFIO_DEVICE_GFX_LINK_STATE_UP ||
375 		    offset >= edid->edid_size) {
376 			memset(buf, 0, count);
377 			break;
378 		}
379 		memcpy(buf, mdev_state->edid_blob + offset, count);
380 		break;
381 	case 0x500 ... 0x515: /* bochs dispi interface */
382 		if (count != 2)
383 			goto unhandled;
384 		index = (offset - 0x500) / 2;
385 		if (index < ARRAY_SIZE(mdev_state->vbe))
386 			reg16 = mdev_state->vbe[index];
387 		dev_dbg(dev, "%s: vbe read %d = %d (%s)\n",
388 			__func__, index, reg16, vbe_name(index));
389 		*(u16 *)buf = reg16;
390 		break;
391 	default:
392 unhandled:
393 		dev_dbg(dev, "%s: @0x%03x, count %d (unhandled)\n",
394 			__func__, offset, count);
395 		memset(buf, 0, count);
396 		break;
397 	}
398 }
399 
400 static void handle_edid_regs(struct mdev_state *mdev_state, u16 offset,
401 			     char *buf, u32 count, bool is_write)
402 {
403 	char *regs = (void *)&mdev_state->edid_regs;
404 
405 	if (offset + count > sizeof(mdev_state->edid_regs))
406 		return;
407 	if (count != 4)
408 		return;
409 	if (offset % 4)
410 		return;
411 
412 	if (is_write) {
413 		switch (offset) {
414 		case offsetof(struct vfio_region_gfx_edid, link_state):
415 		case offsetof(struct vfio_region_gfx_edid, edid_size):
416 			memcpy(regs + offset, buf, count);
417 			break;
418 		default:
419 			/* read-only regs */
420 			break;
421 		}
422 	} else {
423 		memcpy(buf, regs + offset, count);
424 	}
425 }
426 
427 static void handle_edid_blob(struct mdev_state *mdev_state, u16 offset,
428 			     char *buf, u32 count, bool is_write)
429 {
430 	if (offset + count > mdev_state->edid_regs.edid_max_size)
431 		return;
432 	if (is_write)
433 		memcpy(mdev_state->edid_blob + offset, buf, count);
434 	else
435 		memcpy(buf, mdev_state->edid_blob + offset, count);
436 }
437 
438 static ssize_t mdev_access(struct mdev_device *mdev, char *buf, size_t count,
439 			   loff_t pos, bool is_write)
440 {
441 	struct mdev_state *mdev_state = mdev_get_drvdata(mdev);
442 	struct device *dev = mdev_dev(mdev);
443 	struct page *pg;
444 	loff_t poff;
445 	char *map;
446 	int ret = 0;
447 
448 	mutex_lock(&mdev_state->ops_lock);
449 
450 	if (pos < MBOCHS_CONFIG_SPACE_SIZE) {
451 		if (is_write)
452 			handle_pci_cfg_write(mdev_state, pos, buf, count);
453 		else
454 			memcpy(buf, (mdev_state->vconfig + pos), count);
455 
456 	} else if (pos >= MBOCHS_MMIO_BAR_OFFSET &&
457 		   pos + count <= (MBOCHS_MMIO_BAR_OFFSET +
458 				   MBOCHS_MMIO_BAR_SIZE)) {
459 		pos -= MBOCHS_MMIO_BAR_OFFSET;
460 		if (is_write)
461 			handle_mmio_write(mdev_state, pos, buf, count);
462 		else
463 			handle_mmio_read(mdev_state, pos, buf, count);
464 
465 	} else if (pos >= MBOCHS_EDID_OFFSET &&
466 		   pos + count <= (MBOCHS_EDID_OFFSET +
467 				   MBOCHS_EDID_SIZE)) {
468 		pos -= MBOCHS_EDID_OFFSET;
469 		if (pos < MBOCHS_EDID_BLOB_OFFSET) {
470 			handle_edid_regs(mdev_state, pos, buf, count, is_write);
471 		} else {
472 			pos -= MBOCHS_EDID_BLOB_OFFSET;
473 			handle_edid_blob(mdev_state, pos, buf, count, is_write);
474 		}
475 
476 	} else if (pos >= MBOCHS_MEMORY_BAR_OFFSET &&
477 		   pos + count <=
478 		   MBOCHS_MEMORY_BAR_OFFSET + mdev_state->memsize) {
479 		pos -= MBOCHS_MMIO_BAR_OFFSET;
480 		poff = pos & ~PAGE_MASK;
481 		pg = __mbochs_get_page(mdev_state, pos >> PAGE_SHIFT);
482 		map = kmap(pg);
483 		if (is_write)
484 			memcpy(map + poff, buf, count);
485 		else
486 			memcpy(buf, map + poff, count);
487 		kunmap(pg);
488 		put_page(pg);
489 
490 	} else {
491 		dev_dbg(dev, "%s: %s @0x%llx (unhandled)\n",
492 			__func__, is_write ? "WR" : "RD", pos);
493 		ret = -1;
494 		goto accessfailed;
495 	}
496 
497 	ret = count;
498 
499 
500 accessfailed:
501 	mutex_unlock(&mdev_state->ops_lock);
502 
503 	return ret;
504 }
505 
506 static int mbochs_reset(struct mdev_device *mdev)
507 {
508 	struct mdev_state *mdev_state = mdev_get_drvdata(mdev);
509 	u32 size64k = mdev_state->memsize / (64 * 1024);
510 	int i;
511 
512 	for (i = 0; i < ARRAY_SIZE(mdev_state->vbe); i++)
513 		mdev_state->vbe[i] = 0;
514 	mdev_state->vbe[VBE_DISPI_INDEX_ID] = VBE_DISPI_ID5;
515 	mdev_state->vbe[VBE_DISPI_INDEX_VIDEO_MEMORY_64K] = size64k;
516 	return 0;
517 }
518 
519 static int mbochs_create(struct kobject *kobj, struct mdev_device *mdev)
520 {
521 	const struct mbochs_type *type = mbochs_find_type(kobj);
522 	struct device *dev = mdev_dev(mdev);
523 	struct mdev_state *mdev_state;
524 
525 	if (!type)
526 		type = &mbochs_types[0];
527 	if (type->mbytes + mbochs_used_mbytes > max_mbytes)
528 		return -ENOMEM;
529 
530 	mdev_state = kzalloc(sizeof(struct mdev_state), GFP_KERNEL);
531 	if (mdev_state == NULL)
532 		return -ENOMEM;
533 
534 	mdev_state->vconfig = kzalloc(MBOCHS_CONFIG_SPACE_SIZE, GFP_KERNEL);
535 	if (mdev_state->vconfig == NULL)
536 		goto err_mem;
537 
538 	mdev_state->memsize = type->mbytes * 1024 * 1024;
539 	mdev_state->pagecount = mdev_state->memsize >> PAGE_SHIFT;
540 	mdev_state->pages = kcalloc(mdev_state->pagecount,
541 				    sizeof(struct page *),
542 				    GFP_KERNEL);
543 	if (!mdev_state->pages)
544 		goto err_mem;
545 
546 	dev_info(dev, "%s: %s, %d MB, %ld pages\n", __func__,
547 		 kobj->name, type->mbytes, mdev_state->pagecount);
548 
549 	mutex_init(&mdev_state->ops_lock);
550 	mdev_state->mdev = mdev;
551 	mdev_set_drvdata(mdev, mdev_state);
552 	INIT_LIST_HEAD(&mdev_state->dmabufs);
553 	mdev_state->next_id = 1;
554 
555 	mdev_state->type = type;
556 	mdev_state->edid_regs.max_xres = type->max_x;
557 	mdev_state->edid_regs.max_yres = type->max_y;
558 	mdev_state->edid_regs.edid_offset = MBOCHS_EDID_BLOB_OFFSET;
559 	mdev_state->edid_regs.edid_max_size = sizeof(mdev_state->edid_blob);
560 	mbochs_create_config_space(mdev_state);
561 	mbochs_reset(mdev);
562 
563 	mbochs_used_mbytes += type->mbytes;
564 	return 0;
565 
566 err_mem:
567 	kfree(mdev_state->vconfig);
568 	kfree(mdev_state);
569 	return -ENOMEM;
570 }
571 
572 static int mbochs_remove(struct mdev_device *mdev)
573 {
574 	struct mdev_state *mdev_state = mdev_get_drvdata(mdev);
575 
576 	mbochs_used_mbytes -= mdev_state->type->mbytes;
577 	mdev_set_drvdata(mdev, NULL);
578 	kfree(mdev_state->pages);
579 	kfree(mdev_state->vconfig);
580 	kfree(mdev_state);
581 	return 0;
582 }
583 
584 static ssize_t mbochs_read(struct mdev_device *mdev, char __user *buf,
585 			   size_t count, loff_t *ppos)
586 {
587 	unsigned int done = 0;
588 	int ret;
589 
590 	while (count) {
591 		size_t filled;
592 
593 		if (count >= 4 && !(*ppos % 4)) {
594 			u32 val;
595 
596 			ret =  mdev_access(mdev, (char *)&val, sizeof(val),
597 					   *ppos, false);
598 			if (ret <= 0)
599 				goto read_err;
600 
601 			if (copy_to_user(buf, &val, sizeof(val)))
602 				goto read_err;
603 
604 			filled = 4;
605 		} else if (count >= 2 && !(*ppos % 2)) {
606 			u16 val;
607 
608 			ret = mdev_access(mdev, (char *)&val, sizeof(val),
609 					  *ppos, false);
610 			if (ret <= 0)
611 				goto read_err;
612 
613 			if (copy_to_user(buf, &val, sizeof(val)))
614 				goto read_err;
615 
616 			filled = 2;
617 		} else {
618 			u8 val;
619 
620 			ret = mdev_access(mdev, (char *)&val, sizeof(val),
621 					  *ppos, false);
622 			if (ret <= 0)
623 				goto read_err;
624 
625 			if (copy_to_user(buf, &val, sizeof(val)))
626 				goto read_err;
627 
628 			filled = 1;
629 		}
630 
631 		count -= filled;
632 		done += filled;
633 		*ppos += filled;
634 		buf += filled;
635 	}
636 
637 	return done;
638 
639 read_err:
640 	return -EFAULT;
641 }
642 
643 static ssize_t mbochs_write(struct mdev_device *mdev, const char __user *buf,
644 			    size_t count, loff_t *ppos)
645 {
646 	unsigned int done = 0;
647 	int ret;
648 
649 	while (count) {
650 		size_t filled;
651 
652 		if (count >= 4 && !(*ppos % 4)) {
653 			u32 val;
654 
655 			if (copy_from_user(&val, buf, sizeof(val)))
656 				goto write_err;
657 
658 			ret = mdev_access(mdev, (char *)&val, sizeof(val),
659 					  *ppos, true);
660 			if (ret <= 0)
661 				goto write_err;
662 
663 			filled = 4;
664 		} else if (count >= 2 && !(*ppos % 2)) {
665 			u16 val;
666 
667 			if (copy_from_user(&val, buf, sizeof(val)))
668 				goto write_err;
669 
670 			ret = mdev_access(mdev, (char *)&val, sizeof(val),
671 					  *ppos, true);
672 			if (ret <= 0)
673 				goto write_err;
674 
675 			filled = 2;
676 		} else {
677 			u8 val;
678 
679 			if (copy_from_user(&val, buf, sizeof(val)))
680 				goto write_err;
681 
682 			ret = mdev_access(mdev, (char *)&val, sizeof(val),
683 					  *ppos, true);
684 			if (ret <= 0)
685 				goto write_err;
686 
687 			filled = 1;
688 		}
689 		count -= filled;
690 		done += filled;
691 		*ppos += filled;
692 		buf += filled;
693 	}
694 
695 	return done;
696 write_err:
697 	return -EFAULT;
698 }
699 
700 static struct page *__mbochs_get_page(struct mdev_state *mdev_state,
701 				      pgoff_t pgoff)
702 {
703 	WARN_ON(!mutex_is_locked(&mdev_state->ops_lock));
704 
705 	if (!mdev_state->pages[pgoff]) {
706 		mdev_state->pages[pgoff] =
707 			alloc_pages(GFP_HIGHUSER | __GFP_ZERO, 0);
708 		if (!mdev_state->pages[pgoff])
709 			return NULL;
710 	}
711 
712 	get_page(mdev_state->pages[pgoff]);
713 	return mdev_state->pages[pgoff];
714 }
715 
716 static struct page *mbochs_get_page(struct mdev_state *mdev_state,
717 				    pgoff_t pgoff)
718 {
719 	struct page *page;
720 
721 	if (WARN_ON(pgoff >= mdev_state->pagecount))
722 		return NULL;
723 
724 	mutex_lock(&mdev_state->ops_lock);
725 	page = __mbochs_get_page(mdev_state, pgoff);
726 	mutex_unlock(&mdev_state->ops_lock);
727 
728 	return page;
729 }
730 
731 static void mbochs_put_pages(struct mdev_state *mdev_state)
732 {
733 	struct device *dev = mdev_dev(mdev_state->mdev);
734 	int i, count = 0;
735 
736 	WARN_ON(!mutex_is_locked(&mdev_state->ops_lock));
737 
738 	for (i = 0; i < mdev_state->pagecount; i++) {
739 		if (!mdev_state->pages[i])
740 			continue;
741 		put_page(mdev_state->pages[i]);
742 		mdev_state->pages[i] = NULL;
743 		count++;
744 	}
745 	dev_dbg(dev, "%s: %d pages released\n", __func__, count);
746 }
747 
748 static vm_fault_t mbochs_region_vm_fault(struct vm_fault *vmf)
749 {
750 	struct vm_area_struct *vma = vmf->vma;
751 	struct mdev_state *mdev_state = vma->vm_private_data;
752 	pgoff_t page_offset = (vmf->address - vma->vm_start) >> PAGE_SHIFT;
753 
754 	if (page_offset >= mdev_state->pagecount)
755 		return VM_FAULT_SIGBUS;
756 
757 	vmf->page = mbochs_get_page(mdev_state, page_offset);
758 	if (!vmf->page)
759 		return VM_FAULT_SIGBUS;
760 
761 	return 0;
762 }
763 
764 static const struct vm_operations_struct mbochs_region_vm_ops = {
765 	.fault = mbochs_region_vm_fault,
766 };
767 
768 static int mbochs_mmap(struct mdev_device *mdev, struct vm_area_struct *vma)
769 {
770 	struct mdev_state *mdev_state = mdev_get_drvdata(mdev);
771 
772 	if (vma->vm_pgoff != MBOCHS_MEMORY_BAR_OFFSET >> PAGE_SHIFT)
773 		return -EINVAL;
774 	if (vma->vm_end < vma->vm_start)
775 		return -EINVAL;
776 	if (vma->vm_end - vma->vm_start > mdev_state->memsize)
777 		return -EINVAL;
778 	if ((vma->vm_flags & VM_SHARED) == 0)
779 		return -EINVAL;
780 
781 	vma->vm_ops = &mbochs_region_vm_ops;
782 	vma->vm_private_data = mdev_state;
783 	return 0;
784 }
785 
786 static vm_fault_t mbochs_dmabuf_vm_fault(struct vm_fault *vmf)
787 {
788 	struct vm_area_struct *vma = vmf->vma;
789 	struct mbochs_dmabuf *dmabuf = vma->vm_private_data;
790 
791 	if (WARN_ON(vmf->pgoff >= dmabuf->pagecount))
792 		return VM_FAULT_SIGBUS;
793 
794 	vmf->page = dmabuf->pages[vmf->pgoff];
795 	get_page(vmf->page);
796 	return 0;
797 }
798 
799 static const struct vm_operations_struct mbochs_dmabuf_vm_ops = {
800 	.fault = mbochs_dmabuf_vm_fault,
801 };
802 
803 static int mbochs_mmap_dmabuf(struct dma_buf *buf, struct vm_area_struct *vma)
804 {
805 	struct mbochs_dmabuf *dmabuf = buf->priv;
806 	struct device *dev = mdev_dev(dmabuf->mdev_state->mdev);
807 
808 	dev_dbg(dev, "%s: %d\n", __func__, dmabuf->id);
809 
810 	if ((vma->vm_flags & VM_SHARED) == 0)
811 		return -EINVAL;
812 
813 	vma->vm_ops = &mbochs_dmabuf_vm_ops;
814 	vma->vm_private_data = dmabuf;
815 	return 0;
816 }
817 
818 static void mbochs_print_dmabuf(struct mbochs_dmabuf *dmabuf,
819 				const char *prefix)
820 {
821 	struct device *dev = mdev_dev(dmabuf->mdev_state->mdev);
822 	u32 fourcc = dmabuf->mode.drm_format;
823 
824 	dev_dbg(dev, "%s/%d: %c%c%c%c, %dx%d, stride %d, off 0x%llx, size 0x%llx, pages %ld\n",
825 		prefix, dmabuf->id,
826 		fourcc ? ((fourcc >>  0) & 0xff) : '-',
827 		fourcc ? ((fourcc >>  8) & 0xff) : '-',
828 		fourcc ? ((fourcc >> 16) & 0xff) : '-',
829 		fourcc ? ((fourcc >> 24) & 0xff) : '-',
830 		dmabuf->mode.width, dmabuf->mode.height, dmabuf->mode.stride,
831 		dmabuf->mode.offset, dmabuf->mode.size, dmabuf->pagecount);
832 }
833 
834 static struct sg_table *mbochs_map_dmabuf(struct dma_buf_attachment *at,
835 					  enum dma_data_direction direction)
836 {
837 	struct mbochs_dmabuf *dmabuf = at->dmabuf->priv;
838 	struct device *dev = mdev_dev(dmabuf->mdev_state->mdev);
839 	struct sg_table *sg;
840 
841 	dev_dbg(dev, "%s: %d\n", __func__, dmabuf->id);
842 
843 	sg = kzalloc(sizeof(*sg), GFP_KERNEL);
844 	if (!sg)
845 		goto err1;
846 	if (sg_alloc_table_from_pages(sg, dmabuf->pages, dmabuf->pagecount,
847 				      0, dmabuf->mode.size, GFP_KERNEL) < 0)
848 		goto err2;
849 	if (!dma_map_sg(at->dev, sg->sgl, sg->nents, direction))
850 		goto err3;
851 
852 	return sg;
853 
854 err3:
855 	sg_free_table(sg);
856 err2:
857 	kfree(sg);
858 err1:
859 	return ERR_PTR(-ENOMEM);
860 }
861 
862 static void mbochs_unmap_dmabuf(struct dma_buf_attachment *at,
863 				struct sg_table *sg,
864 				enum dma_data_direction direction)
865 {
866 	struct mbochs_dmabuf *dmabuf = at->dmabuf->priv;
867 	struct device *dev = mdev_dev(dmabuf->mdev_state->mdev);
868 
869 	dev_dbg(dev, "%s: %d\n", __func__, dmabuf->id);
870 
871 	sg_free_table(sg);
872 	kfree(sg);
873 }
874 
875 static void mbochs_release_dmabuf(struct dma_buf *buf)
876 {
877 	struct mbochs_dmabuf *dmabuf = buf->priv;
878 	struct mdev_state *mdev_state = dmabuf->mdev_state;
879 	struct device *dev = mdev_dev(mdev_state->mdev);
880 	pgoff_t pg;
881 
882 	dev_dbg(dev, "%s: %d\n", __func__, dmabuf->id);
883 
884 	for (pg = 0; pg < dmabuf->pagecount; pg++)
885 		put_page(dmabuf->pages[pg]);
886 
887 	mutex_lock(&mdev_state->ops_lock);
888 	dmabuf->buf = NULL;
889 	if (dmabuf->unlinked)
890 		kfree(dmabuf);
891 	mutex_unlock(&mdev_state->ops_lock);
892 }
893 
894 static void *mbochs_kmap_dmabuf(struct dma_buf *buf, unsigned long page_num)
895 {
896 	struct mbochs_dmabuf *dmabuf = buf->priv;
897 	struct page *page = dmabuf->pages[page_num];
898 
899 	return kmap(page);
900 }
901 
902 static void mbochs_kunmap_dmabuf(struct dma_buf *buf, unsigned long page_num,
903 				 void *vaddr)
904 {
905 	kunmap(vaddr);
906 }
907 
908 static struct dma_buf_ops mbochs_dmabuf_ops = {
909 	.map_dma_buf	  = mbochs_map_dmabuf,
910 	.unmap_dma_buf	  = mbochs_unmap_dmabuf,
911 	.release	  = mbochs_release_dmabuf,
912 	.map		  = mbochs_kmap_dmabuf,
913 	.unmap		  = mbochs_kunmap_dmabuf,
914 	.mmap		  = mbochs_mmap_dmabuf,
915 };
916 
917 static struct mbochs_dmabuf *mbochs_dmabuf_alloc(struct mdev_state *mdev_state,
918 						 struct mbochs_mode *mode)
919 {
920 	struct mbochs_dmabuf *dmabuf;
921 	pgoff_t page_offset, pg;
922 
923 	WARN_ON(!mutex_is_locked(&mdev_state->ops_lock));
924 
925 	dmabuf = kzalloc(sizeof(struct mbochs_dmabuf), GFP_KERNEL);
926 	if (!dmabuf)
927 		return NULL;
928 
929 	dmabuf->mode = *mode;
930 	dmabuf->id = mdev_state->next_id++;
931 	dmabuf->pagecount = DIV_ROUND_UP(mode->size, PAGE_SIZE);
932 	dmabuf->pages = kcalloc(dmabuf->pagecount, sizeof(struct page *),
933 				GFP_KERNEL);
934 	if (!dmabuf->pages)
935 		goto err_free_dmabuf;
936 
937 	page_offset = dmabuf->mode.offset >> PAGE_SHIFT;
938 	for (pg = 0; pg < dmabuf->pagecount; pg++) {
939 		dmabuf->pages[pg] = __mbochs_get_page(mdev_state,
940 						      page_offset + pg);
941 		if (!dmabuf->pages[pg])
942 			goto err_free_pages;
943 	}
944 
945 	dmabuf->mdev_state = mdev_state;
946 	list_add(&dmabuf->next, &mdev_state->dmabufs);
947 
948 	mbochs_print_dmabuf(dmabuf, __func__);
949 	return dmabuf;
950 
951 err_free_pages:
952 	while (pg > 0)
953 		put_page(dmabuf->pages[--pg]);
954 	kfree(dmabuf->pages);
955 err_free_dmabuf:
956 	kfree(dmabuf);
957 	return NULL;
958 }
959 
960 static struct mbochs_dmabuf *
961 mbochs_dmabuf_find_by_mode(struct mdev_state *mdev_state,
962 			   struct mbochs_mode *mode)
963 {
964 	struct mbochs_dmabuf *dmabuf;
965 
966 	WARN_ON(!mutex_is_locked(&mdev_state->ops_lock));
967 
968 	list_for_each_entry(dmabuf, &mdev_state->dmabufs, next)
969 		if (mbochs_modes_equal(&dmabuf->mode, mode))
970 			return dmabuf;
971 
972 	return NULL;
973 }
974 
975 static struct mbochs_dmabuf *
976 mbochs_dmabuf_find_by_id(struct mdev_state *mdev_state, u32 id)
977 {
978 	struct mbochs_dmabuf *dmabuf;
979 
980 	WARN_ON(!mutex_is_locked(&mdev_state->ops_lock));
981 
982 	list_for_each_entry(dmabuf, &mdev_state->dmabufs, next)
983 		if (dmabuf->id == id)
984 			return dmabuf;
985 
986 	return NULL;
987 }
988 
989 static int mbochs_dmabuf_export(struct mbochs_dmabuf *dmabuf)
990 {
991 	struct mdev_state *mdev_state = dmabuf->mdev_state;
992 	struct device *dev = mdev_dev(mdev_state->mdev);
993 	DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
994 	struct dma_buf *buf;
995 
996 	WARN_ON(!mutex_is_locked(&mdev_state->ops_lock));
997 
998 	if (!IS_ALIGNED(dmabuf->mode.offset, PAGE_SIZE)) {
999 		dev_info_ratelimited(dev, "%s: framebuffer not page-aligned\n",
1000 				     __func__);
1001 		return -EINVAL;
1002 	}
1003 
1004 	exp_info.ops = &mbochs_dmabuf_ops;
1005 	exp_info.size = dmabuf->mode.size;
1006 	exp_info.priv = dmabuf;
1007 
1008 	buf = dma_buf_export(&exp_info);
1009 	if (IS_ERR(buf)) {
1010 		dev_info_ratelimited(dev, "%s: dma_buf_export failed: %ld\n",
1011 				     __func__, PTR_ERR(buf));
1012 		return PTR_ERR(buf);
1013 	}
1014 
1015 	dmabuf->buf = buf;
1016 	dev_dbg(dev, "%s: %d\n", __func__, dmabuf->id);
1017 	return 0;
1018 }
1019 
1020 static int mbochs_get_region_info(struct mdev_device *mdev,
1021 				  struct vfio_region_info_ext *ext)
1022 {
1023 	struct vfio_region_info *region_info = &ext->base;
1024 	struct mdev_state *mdev_state;
1025 
1026 	mdev_state = mdev_get_drvdata(mdev);
1027 	if (!mdev_state)
1028 		return -EINVAL;
1029 
1030 	if (region_info->index >= MBOCHS_NUM_REGIONS)
1031 		return -EINVAL;
1032 
1033 	switch (region_info->index) {
1034 	case VFIO_PCI_CONFIG_REGION_INDEX:
1035 		region_info->offset = 0;
1036 		region_info->size   = MBOCHS_CONFIG_SPACE_SIZE;
1037 		region_info->flags  = (VFIO_REGION_INFO_FLAG_READ |
1038 				       VFIO_REGION_INFO_FLAG_WRITE);
1039 		break;
1040 	case VFIO_PCI_BAR0_REGION_INDEX:
1041 		region_info->offset = MBOCHS_MEMORY_BAR_OFFSET;
1042 		region_info->size   = mdev_state->memsize;
1043 		region_info->flags  = (VFIO_REGION_INFO_FLAG_READ  |
1044 				       VFIO_REGION_INFO_FLAG_WRITE |
1045 				       VFIO_REGION_INFO_FLAG_MMAP);
1046 		break;
1047 	case VFIO_PCI_BAR2_REGION_INDEX:
1048 		region_info->offset = MBOCHS_MMIO_BAR_OFFSET;
1049 		region_info->size   = MBOCHS_MMIO_BAR_SIZE;
1050 		region_info->flags  = (VFIO_REGION_INFO_FLAG_READ  |
1051 				       VFIO_REGION_INFO_FLAG_WRITE);
1052 		break;
1053 	case MBOCHS_EDID_REGION_INDEX:
1054 		ext->base.argsz = sizeof(*ext);
1055 		ext->base.offset = MBOCHS_EDID_OFFSET;
1056 		ext->base.size = MBOCHS_EDID_SIZE;
1057 		ext->base.flags = (VFIO_REGION_INFO_FLAG_READ  |
1058 				   VFIO_REGION_INFO_FLAG_WRITE |
1059 				   VFIO_REGION_INFO_FLAG_CAPS);
1060 		ext->base.cap_offset = offsetof(typeof(*ext), type);
1061 		ext->type.header.id = VFIO_REGION_INFO_CAP_TYPE;
1062 		ext->type.header.version = 1;
1063 		ext->type.header.next = 0;
1064 		ext->type.type = VFIO_REGION_TYPE_GFX;
1065 		ext->type.subtype = VFIO_REGION_SUBTYPE_GFX_EDID;
1066 		break;
1067 	default:
1068 		region_info->size   = 0;
1069 		region_info->offset = 0;
1070 		region_info->flags  = 0;
1071 	}
1072 
1073 	return 0;
1074 }
1075 
1076 static int mbochs_get_irq_info(struct mdev_device *mdev,
1077 			       struct vfio_irq_info *irq_info)
1078 {
1079 	irq_info->count = 0;
1080 	return 0;
1081 }
1082 
1083 static int mbochs_get_device_info(struct mdev_device *mdev,
1084 				  struct vfio_device_info *dev_info)
1085 {
1086 	dev_info->flags = VFIO_DEVICE_FLAGS_PCI;
1087 	dev_info->num_regions = MBOCHS_NUM_REGIONS;
1088 	dev_info->num_irqs = VFIO_PCI_NUM_IRQS;
1089 	return 0;
1090 }
1091 
1092 static int mbochs_query_gfx_plane(struct mdev_device *mdev,
1093 				  struct vfio_device_gfx_plane_info *plane)
1094 {
1095 	struct mdev_state *mdev_state = mdev_get_drvdata(mdev);
1096 	struct device *dev = mdev_dev(mdev);
1097 	struct mbochs_dmabuf *dmabuf;
1098 	struct mbochs_mode mode;
1099 	int ret;
1100 
1101 	if (plane->flags & VFIO_GFX_PLANE_TYPE_PROBE) {
1102 		if (plane->flags == (VFIO_GFX_PLANE_TYPE_PROBE |
1103 				     VFIO_GFX_PLANE_TYPE_DMABUF))
1104 			return 0;
1105 		return -EINVAL;
1106 	}
1107 
1108 	if (plane->flags != VFIO_GFX_PLANE_TYPE_DMABUF)
1109 		return -EINVAL;
1110 
1111 	plane->drm_format_mod = 0;
1112 	plane->x_pos	      = 0;
1113 	plane->y_pos	      = 0;
1114 	plane->x_hot	      = 0;
1115 	plane->y_hot	      = 0;
1116 
1117 	mutex_lock(&mdev_state->ops_lock);
1118 
1119 	ret = -EINVAL;
1120 	if (plane->drm_plane_type == DRM_PLANE_TYPE_PRIMARY)
1121 		ret = mbochs_check_framebuffer(mdev_state, &mode);
1122 	if (ret < 0) {
1123 		plane->drm_format     = 0;
1124 		plane->width	      = 0;
1125 		plane->height	      = 0;
1126 		plane->stride	      = 0;
1127 		plane->size	      = 0;
1128 		plane->dmabuf_id      = 0;
1129 		goto done;
1130 	}
1131 
1132 	dmabuf = mbochs_dmabuf_find_by_mode(mdev_state, &mode);
1133 	if (!dmabuf)
1134 		mbochs_dmabuf_alloc(mdev_state, &mode);
1135 	if (!dmabuf) {
1136 		mutex_unlock(&mdev_state->ops_lock);
1137 		return -ENOMEM;
1138 	}
1139 
1140 	plane->drm_format     = dmabuf->mode.drm_format;
1141 	plane->width	      = dmabuf->mode.width;
1142 	plane->height	      = dmabuf->mode.height;
1143 	plane->stride	      = dmabuf->mode.stride;
1144 	plane->size	      = dmabuf->mode.size;
1145 	plane->dmabuf_id      = dmabuf->id;
1146 
1147 done:
1148 	if (plane->drm_plane_type == DRM_PLANE_TYPE_PRIMARY &&
1149 	    mdev_state->active_id != plane->dmabuf_id) {
1150 		dev_dbg(dev, "%s: primary: %d => %d\n", __func__,
1151 			mdev_state->active_id, plane->dmabuf_id);
1152 		mdev_state->active_id = plane->dmabuf_id;
1153 	}
1154 	mutex_unlock(&mdev_state->ops_lock);
1155 	return 0;
1156 }
1157 
1158 static int mbochs_get_gfx_dmabuf(struct mdev_device *mdev,
1159 				 u32 id)
1160 {
1161 	struct mdev_state *mdev_state = mdev_get_drvdata(mdev);
1162 	struct mbochs_dmabuf *dmabuf;
1163 
1164 	mutex_lock(&mdev_state->ops_lock);
1165 
1166 	dmabuf = mbochs_dmabuf_find_by_id(mdev_state, id);
1167 	if (!dmabuf) {
1168 		mutex_unlock(&mdev_state->ops_lock);
1169 		return -ENOENT;
1170 	}
1171 
1172 	if (!dmabuf->buf)
1173 		mbochs_dmabuf_export(dmabuf);
1174 
1175 	mutex_unlock(&mdev_state->ops_lock);
1176 
1177 	if (!dmabuf->buf)
1178 		return -EINVAL;
1179 
1180 	return dma_buf_fd(dmabuf->buf, 0);
1181 }
1182 
1183 static long mbochs_ioctl(struct mdev_device *mdev, unsigned int cmd,
1184 			unsigned long arg)
1185 {
1186 	int ret = 0;
1187 	unsigned long minsz, outsz;
1188 	struct mdev_state *mdev_state;
1189 
1190 	mdev_state = mdev_get_drvdata(mdev);
1191 
1192 	switch (cmd) {
1193 	case VFIO_DEVICE_GET_INFO:
1194 	{
1195 		struct vfio_device_info info;
1196 
1197 		minsz = offsetofend(struct vfio_device_info, num_irqs);
1198 
1199 		if (copy_from_user(&info, (void __user *)arg, minsz))
1200 			return -EFAULT;
1201 
1202 		if (info.argsz < minsz)
1203 			return -EINVAL;
1204 
1205 		ret = mbochs_get_device_info(mdev, &info);
1206 		if (ret)
1207 			return ret;
1208 
1209 		if (copy_to_user((void __user *)arg, &info, minsz))
1210 			return -EFAULT;
1211 
1212 		return 0;
1213 	}
1214 	case VFIO_DEVICE_GET_REGION_INFO:
1215 	{
1216 		struct vfio_region_info_ext info;
1217 
1218 		minsz = offsetofend(typeof(info), base.offset);
1219 
1220 		if (copy_from_user(&info, (void __user *)arg, minsz))
1221 			return -EFAULT;
1222 
1223 		outsz = info.base.argsz;
1224 		if (outsz < minsz)
1225 			return -EINVAL;
1226 		if (outsz > sizeof(info))
1227 			return -EINVAL;
1228 
1229 		ret = mbochs_get_region_info(mdev, &info);
1230 		if (ret)
1231 			return ret;
1232 
1233 		if (copy_to_user((void __user *)arg, &info, outsz))
1234 			return -EFAULT;
1235 
1236 		return 0;
1237 	}
1238 
1239 	case VFIO_DEVICE_GET_IRQ_INFO:
1240 	{
1241 		struct vfio_irq_info info;
1242 
1243 		minsz = offsetofend(struct vfio_irq_info, count);
1244 
1245 		if (copy_from_user(&info, (void __user *)arg, minsz))
1246 			return -EFAULT;
1247 
1248 		if ((info.argsz < minsz) ||
1249 		    (info.index >= VFIO_PCI_NUM_IRQS))
1250 			return -EINVAL;
1251 
1252 		ret = mbochs_get_irq_info(mdev, &info);
1253 		if (ret)
1254 			return ret;
1255 
1256 		if (copy_to_user((void __user *)arg, &info, minsz))
1257 			return -EFAULT;
1258 
1259 		return 0;
1260 	}
1261 
1262 	case VFIO_DEVICE_QUERY_GFX_PLANE:
1263 	{
1264 		struct vfio_device_gfx_plane_info plane;
1265 
1266 		minsz = offsetofend(struct vfio_device_gfx_plane_info,
1267 				    region_index);
1268 
1269 		if (copy_from_user(&plane, (void __user *)arg, minsz))
1270 			return -EFAULT;
1271 
1272 		if (plane.argsz < minsz)
1273 			return -EINVAL;
1274 
1275 		ret = mbochs_query_gfx_plane(mdev, &plane);
1276 		if (ret)
1277 			return ret;
1278 
1279 		if (copy_to_user((void __user *)arg, &plane, minsz))
1280 			return -EFAULT;
1281 
1282 		return 0;
1283 	}
1284 
1285 	case VFIO_DEVICE_GET_GFX_DMABUF:
1286 	{
1287 		u32 dmabuf_id;
1288 
1289 		if (get_user(dmabuf_id, (__u32 __user *)arg))
1290 			return -EFAULT;
1291 
1292 		return mbochs_get_gfx_dmabuf(mdev, dmabuf_id);
1293 	}
1294 
1295 	case VFIO_DEVICE_SET_IRQS:
1296 		return -EINVAL;
1297 
1298 	case VFIO_DEVICE_RESET:
1299 		return mbochs_reset(mdev);
1300 	}
1301 	return -ENOTTY;
1302 }
1303 
1304 static int mbochs_open(struct mdev_device *mdev)
1305 {
1306 	if (!try_module_get(THIS_MODULE))
1307 		return -ENODEV;
1308 
1309 	return 0;
1310 }
1311 
1312 static void mbochs_close(struct mdev_device *mdev)
1313 {
1314 	struct mdev_state *mdev_state = mdev_get_drvdata(mdev);
1315 	struct mbochs_dmabuf *dmabuf, *tmp;
1316 
1317 	mutex_lock(&mdev_state->ops_lock);
1318 
1319 	list_for_each_entry_safe(dmabuf, tmp, &mdev_state->dmabufs, next) {
1320 		list_del(&dmabuf->next);
1321 		if (dmabuf->buf) {
1322 			/* free in mbochs_release_dmabuf() */
1323 			dmabuf->unlinked = true;
1324 		} else {
1325 			kfree(dmabuf);
1326 		}
1327 	}
1328 	mbochs_put_pages(mdev_state);
1329 
1330 	mutex_unlock(&mdev_state->ops_lock);
1331 	module_put(THIS_MODULE);
1332 }
1333 
1334 static ssize_t
1335 memory_show(struct device *dev, struct device_attribute *attr,
1336 	    char *buf)
1337 {
1338 	struct mdev_device *mdev = mdev_from_dev(dev);
1339 	struct mdev_state *mdev_state = mdev_get_drvdata(mdev);
1340 
1341 	return sprintf(buf, "%d MB\n", mdev_state->type->mbytes);
1342 }
1343 static DEVICE_ATTR_RO(memory);
1344 
1345 static struct attribute *mdev_dev_attrs[] = {
1346 	&dev_attr_memory.attr,
1347 	NULL,
1348 };
1349 
1350 static const struct attribute_group mdev_dev_group = {
1351 	.name  = "vendor",
1352 	.attrs = mdev_dev_attrs,
1353 };
1354 
1355 const struct attribute_group *mdev_dev_groups[] = {
1356 	&mdev_dev_group,
1357 	NULL,
1358 };
1359 
1360 static ssize_t
1361 name_show(struct kobject *kobj, struct device *dev, char *buf)
1362 {
1363 	return sprintf(buf, "%s\n", kobj->name);
1364 }
1365 MDEV_TYPE_ATTR_RO(name);
1366 
1367 static ssize_t
1368 description_show(struct kobject *kobj, struct device *dev, char *buf)
1369 {
1370 	const struct mbochs_type *type = mbochs_find_type(kobj);
1371 
1372 	return sprintf(buf, "virtual display, %d MB video memory\n",
1373 		       type ? type->mbytes  : 0);
1374 }
1375 MDEV_TYPE_ATTR_RO(description);
1376 
1377 static ssize_t
1378 available_instances_show(struct kobject *kobj, struct device *dev, char *buf)
1379 {
1380 	const struct mbochs_type *type = mbochs_find_type(kobj);
1381 	int count = (max_mbytes - mbochs_used_mbytes) / type->mbytes;
1382 
1383 	return sprintf(buf, "%d\n", count);
1384 }
1385 MDEV_TYPE_ATTR_RO(available_instances);
1386 
1387 static ssize_t device_api_show(struct kobject *kobj, struct device *dev,
1388 			       char *buf)
1389 {
1390 	return sprintf(buf, "%s\n", VFIO_DEVICE_API_PCI_STRING);
1391 }
1392 MDEV_TYPE_ATTR_RO(device_api);
1393 
1394 static struct attribute *mdev_types_attrs[] = {
1395 	&mdev_type_attr_name.attr,
1396 	&mdev_type_attr_description.attr,
1397 	&mdev_type_attr_device_api.attr,
1398 	&mdev_type_attr_available_instances.attr,
1399 	NULL,
1400 };
1401 
1402 static struct attribute_group mdev_type_group1 = {
1403 	.name  = MBOCHS_TYPE_1,
1404 	.attrs = mdev_types_attrs,
1405 };
1406 
1407 static struct attribute_group mdev_type_group2 = {
1408 	.name  = MBOCHS_TYPE_2,
1409 	.attrs = mdev_types_attrs,
1410 };
1411 
1412 static struct attribute_group mdev_type_group3 = {
1413 	.name  = MBOCHS_TYPE_3,
1414 	.attrs = mdev_types_attrs,
1415 };
1416 
1417 static struct attribute_group *mdev_type_groups[] = {
1418 	&mdev_type_group1,
1419 	&mdev_type_group2,
1420 	&mdev_type_group3,
1421 	NULL,
1422 };
1423 
1424 static const struct mdev_parent_ops mdev_fops = {
1425 	.owner			= THIS_MODULE,
1426 	.mdev_attr_groups	= mdev_dev_groups,
1427 	.supported_type_groups	= mdev_type_groups,
1428 	.create			= mbochs_create,
1429 	.remove			= mbochs_remove,
1430 	.open			= mbochs_open,
1431 	.release		= mbochs_close,
1432 	.read			= mbochs_read,
1433 	.write			= mbochs_write,
1434 	.ioctl			= mbochs_ioctl,
1435 	.mmap			= mbochs_mmap,
1436 };
1437 
1438 static const struct file_operations vd_fops = {
1439 	.owner		= THIS_MODULE,
1440 };
1441 
1442 static void mbochs_device_release(struct device *dev)
1443 {
1444 	/* nothing */
1445 }
1446 
1447 static int __init mbochs_dev_init(void)
1448 {
1449 	int ret = 0;
1450 
1451 	ret = alloc_chrdev_region(&mbochs_devt, 0, MINORMASK + 1, MBOCHS_NAME);
1452 	if (ret < 0) {
1453 		pr_err("Error: failed to register mbochs_dev, err: %d\n", ret);
1454 		return ret;
1455 	}
1456 	cdev_init(&mbochs_cdev, &vd_fops);
1457 	cdev_add(&mbochs_cdev, mbochs_devt, MINORMASK + 1);
1458 	pr_info("%s: major %d\n", __func__, MAJOR(mbochs_devt));
1459 
1460 	mbochs_class = class_create(THIS_MODULE, MBOCHS_CLASS_NAME);
1461 	if (IS_ERR(mbochs_class)) {
1462 		pr_err("Error: failed to register mbochs_dev class\n");
1463 		ret = PTR_ERR(mbochs_class);
1464 		goto failed1;
1465 	}
1466 	mbochs_dev.class = mbochs_class;
1467 	mbochs_dev.release = mbochs_device_release;
1468 	dev_set_name(&mbochs_dev, "%s", MBOCHS_NAME);
1469 
1470 	ret = device_register(&mbochs_dev);
1471 	if (ret)
1472 		goto failed2;
1473 
1474 	ret = mdev_register_device(&mbochs_dev, &mdev_fops);
1475 	if (ret)
1476 		goto failed3;
1477 
1478 	return 0;
1479 
1480 failed3:
1481 	device_unregister(&mbochs_dev);
1482 failed2:
1483 	class_destroy(mbochs_class);
1484 failed1:
1485 	cdev_del(&mbochs_cdev);
1486 	unregister_chrdev_region(mbochs_devt, MINORMASK + 1);
1487 	return ret;
1488 }
1489 
1490 static void __exit mbochs_dev_exit(void)
1491 {
1492 	mbochs_dev.bus = NULL;
1493 	mdev_unregister_device(&mbochs_dev);
1494 
1495 	device_unregister(&mbochs_dev);
1496 	cdev_del(&mbochs_cdev);
1497 	unregister_chrdev_region(mbochs_devt, MINORMASK + 1);
1498 	class_destroy(mbochs_class);
1499 	mbochs_class = NULL;
1500 }
1501 
1502 module_init(mbochs_dev_init)
1503 module_exit(mbochs_dev_exit)
1504