xref: /openbmc/linux/samples/vfio-mdev/mbochs.c (revision 5f66f73b)
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 void mbochs_create_config_space(struct mdev_state *mdev_state)
209 {
210 	STORE_LE16((u16 *) &mdev_state->vconfig[PCI_VENDOR_ID],
211 		   0x1234);
212 	STORE_LE16((u16 *) &mdev_state->vconfig[PCI_DEVICE_ID],
213 		   0x1111);
214 	STORE_LE16((u16 *) &mdev_state->vconfig[PCI_SUBSYSTEM_VENDOR_ID],
215 		   PCI_SUBVENDOR_ID_REDHAT_QUMRANET);
216 	STORE_LE16((u16 *) &mdev_state->vconfig[PCI_SUBSYSTEM_ID],
217 		   PCI_SUBDEVICE_ID_QEMU);
218 
219 	STORE_LE16((u16 *) &mdev_state->vconfig[PCI_COMMAND],
220 		   PCI_COMMAND_IO | PCI_COMMAND_MEMORY);
221 	STORE_LE16((u16 *) &mdev_state->vconfig[PCI_CLASS_DEVICE],
222 		   PCI_CLASS_DISPLAY_OTHER);
223 	mdev_state->vconfig[PCI_CLASS_REVISION] =  0x01;
224 
225 	STORE_LE32((u32 *) &mdev_state->vconfig[PCI_BASE_ADDRESS_0],
226 		   PCI_BASE_ADDRESS_SPACE_MEMORY |
227 		   PCI_BASE_ADDRESS_MEM_TYPE_32	 |
228 		   PCI_BASE_ADDRESS_MEM_PREFETCH);
229 	mdev_state->bar_mask[0] = ~(mdev_state->memsize) + 1;
230 
231 	STORE_LE32((u32 *) &mdev_state->vconfig[PCI_BASE_ADDRESS_2],
232 		   PCI_BASE_ADDRESS_SPACE_MEMORY |
233 		   PCI_BASE_ADDRESS_MEM_TYPE_32);
234 	mdev_state->bar_mask[2] = ~(MBOCHS_MMIO_BAR_SIZE) + 1;
235 }
236 
237 static int mbochs_check_framebuffer(struct mdev_state *mdev_state,
238 				    struct mbochs_mode *mode)
239 {
240 	struct device *dev = mdev_dev(mdev_state->mdev);
241 	u16 *vbe = mdev_state->vbe;
242 	u32 virt_width;
243 
244 	WARN_ON(!mutex_is_locked(&mdev_state->ops_lock));
245 
246 	if (!(vbe[VBE_DISPI_INDEX_ENABLE] & VBE_DISPI_ENABLED))
247 		goto nofb;
248 
249 	memset(mode, 0, sizeof(*mode));
250 	switch (vbe[VBE_DISPI_INDEX_BPP]) {
251 	case 32:
252 		mode->drm_format = DRM_FORMAT_XRGB8888;
253 		mode->bytepp = 4;
254 		break;
255 	default:
256 		dev_info_ratelimited(dev, "%s: bpp %d not supported\n",
257 				     __func__, vbe[VBE_DISPI_INDEX_BPP]);
258 		goto nofb;
259 	}
260 
261 	mode->width  = vbe[VBE_DISPI_INDEX_XRES];
262 	mode->height = vbe[VBE_DISPI_INDEX_YRES];
263 	virt_width  = vbe[VBE_DISPI_INDEX_VIRT_WIDTH];
264 	if (virt_width < mode->width)
265 		virt_width = mode->width;
266 	mode->stride = virt_width * mode->bytepp;
267 	mode->size   = (u64)mode->stride * mode->height;
268 	mode->offset = ((u64)vbe[VBE_DISPI_INDEX_X_OFFSET] * mode->bytepp +
269 		       (u64)vbe[VBE_DISPI_INDEX_Y_OFFSET] * mode->stride);
270 
271 	if (mode->width < 64 || mode->height < 64) {
272 		dev_info_ratelimited(dev, "%s: invalid resolution %dx%d\n",
273 				     __func__, mode->width, mode->height);
274 		goto nofb;
275 	}
276 	if (mode->offset + mode->size > mdev_state->memsize) {
277 		dev_info_ratelimited(dev, "%s: framebuffer memory overflow\n",
278 				     __func__);
279 		goto nofb;
280 	}
281 
282 	return 0;
283 
284 nofb:
285 	memset(mode, 0, sizeof(*mode));
286 	return -EINVAL;
287 }
288 
289 static bool mbochs_modes_equal(struct mbochs_mode *mode1,
290 			       struct mbochs_mode *mode2)
291 {
292 	return memcmp(mode1, mode2, sizeof(struct mbochs_mode)) == 0;
293 }
294 
295 static void handle_pci_cfg_write(struct mdev_state *mdev_state, u16 offset,
296 				 char *buf, u32 count)
297 {
298 	struct device *dev = mdev_dev(mdev_state->mdev);
299 	int index = (offset - PCI_BASE_ADDRESS_0) / 0x04;
300 	u32 cfg_addr;
301 
302 	switch (offset) {
303 	case PCI_BASE_ADDRESS_0:
304 	case PCI_BASE_ADDRESS_2:
305 		cfg_addr = *(u32 *)buf;
306 
307 		if (cfg_addr == 0xffffffff) {
308 			cfg_addr = (cfg_addr & mdev_state->bar_mask[index]);
309 		} else {
310 			cfg_addr &= PCI_BASE_ADDRESS_MEM_MASK;
311 			if (cfg_addr)
312 				dev_info(dev, "BAR #%d @ 0x%x\n",
313 					 index, cfg_addr);
314 		}
315 
316 		cfg_addr |= (mdev_state->vconfig[offset] &
317 			     ~PCI_BASE_ADDRESS_MEM_MASK);
318 		STORE_LE32(&mdev_state->vconfig[offset], cfg_addr);
319 		break;
320 	}
321 }
322 
323 static void handle_mmio_write(struct mdev_state *mdev_state, u16 offset,
324 			      char *buf, u32 count)
325 {
326 	struct device *dev = mdev_dev(mdev_state->mdev);
327 	int index;
328 	u16 reg16;
329 
330 	switch (offset) {
331 	case 0x400 ... 0x41f: /* vga ioports remapped */
332 		goto unhandled;
333 	case 0x500 ... 0x515: /* bochs dispi interface */
334 		if (count != 2)
335 			goto unhandled;
336 		index = (offset - 0x500) / 2;
337 		reg16 = *(u16 *)buf;
338 		if (index < ARRAY_SIZE(mdev_state->vbe))
339 			mdev_state->vbe[index] = reg16;
340 		dev_dbg(dev, "%s: vbe write %d = %d (%s)\n",
341 			__func__, index, reg16, vbe_name(index));
342 		break;
343 	case 0x600 ... 0x607: /* qemu extended regs */
344 		goto unhandled;
345 	default:
346 unhandled:
347 		dev_dbg(dev, "%s: @0x%03x, count %d (unhandled)\n",
348 			__func__, offset, count);
349 		break;
350 	}
351 }
352 
353 static void handle_mmio_read(struct mdev_state *mdev_state, u16 offset,
354 			     char *buf, u32 count)
355 {
356 	struct device *dev = mdev_dev(mdev_state->mdev);
357 	struct vfio_region_gfx_edid *edid;
358 	u16 reg16 = 0;
359 	int index;
360 
361 	switch (offset) {
362 	case 0x000 ... 0x3ff: /* edid block */
363 		edid = &mdev_state->edid_regs;
364 		if (edid->link_state != VFIO_DEVICE_GFX_LINK_STATE_UP ||
365 		    offset >= edid->edid_size) {
366 			memset(buf, 0, count);
367 			break;
368 		}
369 		memcpy(buf, mdev_state->edid_blob + offset, count);
370 		break;
371 	case 0x500 ... 0x515: /* bochs dispi interface */
372 		if (count != 2)
373 			goto unhandled;
374 		index = (offset - 0x500) / 2;
375 		if (index < ARRAY_SIZE(mdev_state->vbe))
376 			reg16 = mdev_state->vbe[index];
377 		dev_dbg(dev, "%s: vbe read %d = %d (%s)\n",
378 			__func__, index, reg16, vbe_name(index));
379 		*(u16 *)buf = reg16;
380 		break;
381 	default:
382 unhandled:
383 		dev_dbg(dev, "%s: @0x%03x, count %d (unhandled)\n",
384 			__func__, offset, count);
385 		memset(buf, 0, count);
386 		break;
387 	}
388 }
389 
390 static void handle_edid_regs(struct mdev_state *mdev_state, u16 offset,
391 			     char *buf, u32 count, bool is_write)
392 {
393 	char *regs = (void *)&mdev_state->edid_regs;
394 
395 	if (offset + count > sizeof(mdev_state->edid_regs))
396 		return;
397 	if (count != 4)
398 		return;
399 	if (offset % 4)
400 		return;
401 
402 	if (is_write) {
403 		switch (offset) {
404 		case offsetof(struct vfio_region_gfx_edid, link_state):
405 		case offsetof(struct vfio_region_gfx_edid, edid_size):
406 			memcpy(regs + offset, buf, count);
407 			break;
408 		default:
409 			/* read-only regs */
410 			break;
411 		}
412 	} else {
413 		memcpy(buf, regs + offset, count);
414 	}
415 }
416 
417 static void handle_edid_blob(struct mdev_state *mdev_state, u16 offset,
418 			     char *buf, u32 count, bool is_write)
419 {
420 	if (offset + count > mdev_state->edid_regs.edid_max_size)
421 		return;
422 	if (is_write)
423 		memcpy(mdev_state->edid_blob + offset, buf, count);
424 	else
425 		memcpy(buf, mdev_state->edid_blob + offset, count);
426 }
427 
428 static ssize_t mdev_access(struct mdev_device *mdev, char *buf, size_t count,
429 			   loff_t pos, bool is_write)
430 {
431 	struct mdev_state *mdev_state = mdev_get_drvdata(mdev);
432 	struct device *dev = mdev_dev(mdev);
433 	struct page *pg;
434 	loff_t poff;
435 	char *map;
436 	int ret = 0;
437 
438 	mutex_lock(&mdev_state->ops_lock);
439 
440 	if (pos < MBOCHS_CONFIG_SPACE_SIZE) {
441 		if (is_write)
442 			handle_pci_cfg_write(mdev_state, pos, buf, count);
443 		else
444 			memcpy(buf, (mdev_state->vconfig + pos), count);
445 
446 	} else if (pos >= MBOCHS_MMIO_BAR_OFFSET &&
447 		   pos + count <= (MBOCHS_MMIO_BAR_OFFSET +
448 				   MBOCHS_MMIO_BAR_SIZE)) {
449 		pos -= MBOCHS_MMIO_BAR_OFFSET;
450 		if (is_write)
451 			handle_mmio_write(mdev_state, pos, buf, count);
452 		else
453 			handle_mmio_read(mdev_state, pos, buf, count);
454 
455 	} else if (pos >= MBOCHS_EDID_OFFSET &&
456 		   pos + count <= (MBOCHS_EDID_OFFSET +
457 				   MBOCHS_EDID_SIZE)) {
458 		pos -= MBOCHS_EDID_OFFSET;
459 		if (pos < MBOCHS_EDID_BLOB_OFFSET) {
460 			handle_edid_regs(mdev_state, pos, buf, count, is_write);
461 		} else {
462 			pos -= MBOCHS_EDID_BLOB_OFFSET;
463 			handle_edid_blob(mdev_state, pos, buf, count, is_write);
464 		}
465 
466 	} else if (pos >= MBOCHS_MEMORY_BAR_OFFSET &&
467 		   pos + count <=
468 		   MBOCHS_MEMORY_BAR_OFFSET + mdev_state->memsize) {
469 		pos -= MBOCHS_MMIO_BAR_OFFSET;
470 		poff = pos & ~PAGE_MASK;
471 		pg = __mbochs_get_page(mdev_state, pos >> PAGE_SHIFT);
472 		map = kmap(pg);
473 		if (is_write)
474 			memcpy(map + poff, buf, count);
475 		else
476 			memcpy(buf, map + poff, count);
477 		kunmap(pg);
478 		put_page(pg);
479 
480 	} else {
481 		dev_dbg(dev, "%s: %s @0x%llx (unhandled)\n",
482 			__func__, is_write ? "WR" : "RD", pos);
483 		ret = -1;
484 		goto accessfailed;
485 	}
486 
487 	ret = count;
488 
489 
490 accessfailed:
491 	mutex_unlock(&mdev_state->ops_lock);
492 
493 	return ret;
494 }
495 
496 static int mbochs_reset(struct mdev_device *mdev)
497 {
498 	struct mdev_state *mdev_state = mdev_get_drvdata(mdev);
499 	u32 size64k = mdev_state->memsize / (64 * 1024);
500 	int i;
501 
502 	for (i = 0; i < ARRAY_SIZE(mdev_state->vbe); i++)
503 		mdev_state->vbe[i] = 0;
504 	mdev_state->vbe[VBE_DISPI_INDEX_ID] = VBE_DISPI_ID5;
505 	mdev_state->vbe[VBE_DISPI_INDEX_VIDEO_MEMORY_64K] = size64k;
506 	return 0;
507 }
508 
509 static int mbochs_create(struct mdev_device *mdev)
510 {
511 	const struct mbochs_type *type =
512 		&mbochs_types[mdev_get_type_group_id(mdev)];
513 	struct device *dev = mdev_dev(mdev);
514 	struct mdev_state *mdev_state;
515 
516 	if (!type)
517 		type = &mbochs_types[0];
518 	if (type->mbytes + mbochs_used_mbytes > max_mbytes)
519 		return -ENOMEM;
520 
521 	mdev_state = kzalloc(sizeof(struct mdev_state), GFP_KERNEL);
522 	if (mdev_state == NULL)
523 		return -ENOMEM;
524 
525 	mdev_state->vconfig = kzalloc(MBOCHS_CONFIG_SPACE_SIZE, GFP_KERNEL);
526 	if (mdev_state->vconfig == NULL)
527 		goto err_mem;
528 
529 	mdev_state->memsize = type->mbytes * 1024 * 1024;
530 	mdev_state->pagecount = mdev_state->memsize >> PAGE_SHIFT;
531 	mdev_state->pages = kcalloc(mdev_state->pagecount,
532 				    sizeof(struct page *),
533 				    GFP_KERNEL);
534 	if (!mdev_state->pages)
535 		goto err_mem;
536 
537 	dev_info(dev, "%s: %s, %d MB, %ld pages\n", __func__,
538 		 type->name, type->mbytes, mdev_state->pagecount);
539 
540 	mutex_init(&mdev_state->ops_lock);
541 	mdev_state->mdev = mdev;
542 	mdev_set_drvdata(mdev, mdev_state);
543 	INIT_LIST_HEAD(&mdev_state->dmabufs);
544 	mdev_state->next_id = 1;
545 
546 	mdev_state->type = type;
547 	mdev_state->edid_regs.max_xres = type->max_x;
548 	mdev_state->edid_regs.max_yres = type->max_y;
549 	mdev_state->edid_regs.edid_offset = MBOCHS_EDID_BLOB_OFFSET;
550 	mdev_state->edid_regs.edid_max_size = sizeof(mdev_state->edid_blob);
551 	mbochs_create_config_space(mdev_state);
552 	mbochs_reset(mdev);
553 
554 	mbochs_used_mbytes += type->mbytes;
555 	return 0;
556 
557 err_mem:
558 	kfree(mdev_state->vconfig);
559 	kfree(mdev_state);
560 	return -ENOMEM;
561 }
562 
563 static int mbochs_remove(struct mdev_device *mdev)
564 {
565 	struct mdev_state *mdev_state = mdev_get_drvdata(mdev);
566 
567 	mbochs_used_mbytes -= mdev_state->type->mbytes;
568 	mdev_set_drvdata(mdev, NULL);
569 	kfree(mdev_state->pages);
570 	kfree(mdev_state->vconfig);
571 	kfree(mdev_state);
572 	return 0;
573 }
574 
575 static ssize_t mbochs_read(struct mdev_device *mdev, char __user *buf,
576 			   size_t count, loff_t *ppos)
577 {
578 	unsigned int done = 0;
579 	int ret;
580 
581 	while (count) {
582 		size_t filled;
583 
584 		if (count >= 4 && !(*ppos % 4)) {
585 			u32 val;
586 
587 			ret =  mdev_access(mdev, (char *)&val, sizeof(val),
588 					   *ppos, false);
589 			if (ret <= 0)
590 				goto read_err;
591 
592 			if (copy_to_user(buf, &val, sizeof(val)))
593 				goto read_err;
594 
595 			filled = 4;
596 		} else if (count >= 2 && !(*ppos % 2)) {
597 			u16 val;
598 
599 			ret = mdev_access(mdev, (char *)&val, sizeof(val),
600 					  *ppos, false);
601 			if (ret <= 0)
602 				goto read_err;
603 
604 			if (copy_to_user(buf, &val, sizeof(val)))
605 				goto read_err;
606 
607 			filled = 2;
608 		} else {
609 			u8 val;
610 
611 			ret = mdev_access(mdev, (char *)&val, sizeof(val),
612 					  *ppos, false);
613 			if (ret <= 0)
614 				goto read_err;
615 
616 			if (copy_to_user(buf, &val, sizeof(val)))
617 				goto read_err;
618 
619 			filled = 1;
620 		}
621 
622 		count -= filled;
623 		done += filled;
624 		*ppos += filled;
625 		buf += filled;
626 	}
627 
628 	return done;
629 
630 read_err:
631 	return -EFAULT;
632 }
633 
634 static ssize_t mbochs_write(struct mdev_device *mdev, const char __user *buf,
635 			    size_t count, loff_t *ppos)
636 {
637 	unsigned int done = 0;
638 	int ret;
639 
640 	while (count) {
641 		size_t filled;
642 
643 		if (count >= 4 && !(*ppos % 4)) {
644 			u32 val;
645 
646 			if (copy_from_user(&val, buf, sizeof(val)))
647 				goto write_err;
648 
649 			ret = mdev_access(mdev, (char *)&val, sizeof(val),
650 					  *ppos, true);
651 			if (ret <= 0)
652 				goto write_err;
653 
654 			filled = 4;
655 		} else if (count >= 2 && !(*ppos % 2)) {
656 			u16 val;
657 
658 			if (copy_from_user(&val, buf, sizeof(val)))
659 				goto write_err;
660 
661 			ret = mdev_access(mdev, (char *)&val, sizeof(val),
662 					  *ppos, true);
663 			if (ret <= 0)
664 				goto write_err;
665 
666 			filled = 2;
667 		} else {
668 			u8 val;
669 
670 			if (copy_from_user(&val, buf, sizeof(val)))
671 				goto write_err;
672 
673 			ret = mdev_access(mdev, (char *)&val, sizeof(val),
674 					  *ppos, true);
675 			if (ret <= 0)
676 				goto write_err;
677 
678 			filled = 1;
679 		}
680 		count -= filled;
681 		done += filled;
682 		*ppos += filled;
683 		buf += filled;
684 	}
685 
686 	return done;
687 write_err:
688 	return -EFAULT;
689 }
690 
691 static struct page *__mbochs_get_page(struct mdev_state *mdev_state,
692 				      pgoff_t pgoff)
693 {
694 	WARN_ON(!mutex_is_locked(&mdev_state->ops_lock));
695 
696 	if (!mdev_state->pages[pgoff]) {
697 		mdev_state->pages[pgoff] =
698 			alloc_pages(GFP_HIGHUSER | __GFP_ZERO, 0);
699 		if (!mdev_state->pages[pgoff])
700 			return NULL;
701 	}
702 
703 	get_page(mdev_state->pages[pgoff]);
704 	return mdev_state->pages[pgoff];
705 }
706 
707 static struct page *mbochs_get_page(struct mdev_state *mdev_state,
708 				    pgoff_t pgoff)
709 {
710 	struct page *page;
711 
712 	if (WARN_ON(pgoff >= mdev_state->pagecount))
713 		return NULL;
714 
715 	mutex_lock(&mdev_state->ops_lock);
716 	page = __mbochs_get_page(mdev_state, pgoff);
717 	mutex_unlock(&mdev_state->ops_lock);
718 
719 	return page;
720 }
721 
722 static void mbochs_put_pages(struct mdev_state *mdev_state)
723 {
724 	struct device *dev = mdev_dev(mdev_state->mdev);
725 	int i, count = 0;
726 
727 	WARN_ON(!mutex_is_locked(&mdev_state->ops_lock));
728 
729 	for (i = 0; i < mdev_state->pagecount; i++) {
730 		if (!mdev_state->pages[i])
731 			continue;
732 		put_page(mdev_state->pages[i]);
733 		mdev_state->pages[i] = NULL;
734 		count++;
735 	}
736 	dev_dbg(dev, "%s: %d pages released\n", __func__, count);
737 }
738 
739 static vm_fault_t mbochs_region_vm_fault(struct vm_fault *vmf)
740 {
741 	struct vm_area_struct *vma = vmf->vma;
742 	struct mdev_state *mdev_state = vma->vm_private_data;
743 	pgoff_t page_offset = (vmf->address - vma->vm_start) >> PAGE_SHIFT;
744 
745 	if (page_offset >= mdev_state->pagecount)
746 		return VM_FAULT_SIGBUS;
747 
748 	vmf->page = mbochs_get_page(mdev_state, page_offset);
749 	if (!vmf->page)
750 		return VM_FAULT_SIGBUS;
751 
752 	return 0;
753 }
754 
755 static const struct vm_operations_struct mbochs_region_vm_ops = {
756 	.fault = mbochs_region_vm_fault,
757 };
758 
759 static int mbochs_mmap(struct mdev_device *mdev, struct vm_area_struct *vma)
760 {
761 	struct mdev_state *mdev_state = mdev_get_drvdata(mdev);
762 
763 	if (vma->vm_pgoff != MBOCHS_MEMORY_BAR_OFFSET >> PAGE_SHIFT)
764 		return -EINVAL;
765 	if (vma->vm_end < vma->vm_start)
766 		return -EINVAL;
767 	if (vma->vm_end - vma->vm_start > mdev_state->memsize)
768 		return -EINVAL;
769 	if ((vma->vm_flags & VM_SHARED) == 0)
770 		return -EINVAL;
771 
772 	vma->vm_ops = &mbochs_region_vm_ops;
773 	vma->vm_private_data = mdev_state;
774 	return 0;
775 }
776 
777 static vm_fault_t mbochs_dmabuf_vm_fault(struct vm_fault *vmf)
778 {
779 	struct vm_area_struct *vma = vmf->vma;
780 	struct mbochs_dmabuf *dmabuf = vma->vm_private_data;
781 
782 	if (WARN_ON(vmf->pgoff >= dmabuf->pagecount))
783 		return VM_FAULT_SIGBUS;
784 
785 	vmf->page = dmabuf->pages[vmf->pgoff];
786 	get_page(vmf->page);
787 	return 0;
788 }
789 
790 static const struct vm_operations_struct mbochs_dmabuf_vm_ops = {
791 	.fault = mbochs_dmabuf_vm_fault,
792 };
793 
794 static int mbochs_mmap_dmabuf(struct dma_buf *buf, struct vm_area_struct *vma)
795 {
796 	struct mbochs_dmabuf *dmabuf = buf->priv;
797 	struct device *dev = mdev_dev(dmabuf->mdev_state->mdev);
798 
799 	dev_dbg(dev, "%s: %d\n", __func__, dmabuf->id);
800 
801 	if ((vma->vm_flags & VM_SHARED) == 0)
802 		return -EINVAL;
803 
804 	vma->vm_ops = &mbochs_dmabuf_vm_ops;
805 	vma->vm_private_data = dmabuf;
806 	return 0;
807 }
808 
809 static void mbochs_print_dmabuf(struct mbochs_dmabuf *dmabuf,
810 				const char *prefix)
811 {
812 	struct device *dev = mdev_dev(dmabuf->mdev_state->mdev);
813 	u32 fourcc = dmabuf->mode.drm_format;
814 
815 	dev_dbg(dev, "%s/%d: %c%c%c%c, %dx%d, stride %d, off 0x%llx, size 0x%llx, pages %ld\n",
816 		prefix, dmabuf->id,
817 		fourcc ? ((fourcc >>  0) & 0xff) : '-',
818 		fourcc ? ((fourcc >>  8) & 0xff) : '-',
819 		fourcc ? ((fourcc >> 16) & 0xff) : '-',
820 		fourcc ? ((fourcc >> 24) & 0xff) : '-',
821 		dmabuf->mode.width, dmabuf->mode.height, dmabuf->mode.stride,
822 		dmabuf->mode.offset, dmabuf->mode.size, dmabuf->pagecount);
823 }
824 
825 static struct sg_table *mbochs_map_dmabuf(struct dma_buf_attachment *at,
826 					  enum dma_data_direction direction)
827 {
828 	struct mbochs_dmabuf *dmabuf = at->dmabuf->priv;
829 	struct device *dev = mdev_dev(dmabuf->mdev_state->mdev);
830 	struct sg_table *sg;
831 
832 	dev_dbg(dev, "%s: %d\n", __func__, dmabuf->id);
833 
834 	sg = kzalloc(sizeof(*sg), GFP_KERNEL);
835 	if (!sg)
836 		goto err1;
837 	if (sg_alloc_table_from_pages(sg, dmabuf->pages, dmabuf->pagecount,
838 				      0, dmabuf->mode.size, GFP_KERNEL) < 0)
839 		goto err2;
840 	if (dma_map_sgtable(at->dev, sg, direction, 0))
841 		goto err3;
842 
843 	return sg;
844 
845 err3:
846 	sg_free_table(sg);
847 err2:
848 	kfree(sg);
849 err1:
850 	return ERR_PTR(-ENOMEM);
851 }
852 
853 static void mbochs_unmap_dmabuf(struct dma_buf_attachment *at,
854 				struct sg_table *sg,
855 				enum dma_data_direction direction)
856 {
857 	struct mbochs_dmabuf *dmabuf = at->dmabuf->priv;
858 	struct device *dev = mdev_dev(dmabuf->mdev_state->mdev);
859 
860 	dev_dbg(dev, "%s: %d\n", __func__, dmabuf->id);
861 
862 	dma_unmap_sgtable(at->dev, sg, direction, 0);
863 	sg_free_table(sg);
864 	kfree(sg);
865 }
866 
867 static void mbochs_release_dmabuf(struct dma_buf *buf)
868 {
869 	struct mbochs_dmabuf *dmabuf = buf->priv;
870 	struct mdev_state *mdev_state = dmabuf->mdev_state;
871 	struct device *dev = mdev_dev(mdev_state->mdev);
872 	pgoff_t pg;
873 
874 	dev_dbg(dev, "%s: %d\n", __func__, dmabuf->id);
875 
876 	for (pg = 0; pg < dmabuf->pagecount; pg++)
877 		put_page(dmabuf->pages[pg]);
878 
879 	mutex_lock(&mdev_state->ops_lock);
880 	dmabuf->buf = NULL;
881 	if (dmabuf->unlinked)
882 		kfree(dmabuf);
883 	mutex_unlock(&mdev_state->ops_lock);
884 }
885 
886 static struct dma_buf_ops mbochs_dmabuf_ops = {
887 	.map_dma_buf	  = mbochs_map_dmabuf,
888 	.unmap_dma_buf	  = mbochs_unmap_dmabuf,
889 	.release	  = mbochs_release_dmabuf,
890 	.mmap		  = mbochs_mmap_dmabuf,
891 };
892 
893 static struct mbochs_dmabuf *mbochs_dmabuf_alloc(struct mdev_state *mdev_state,
894 						 struct mbochs_mode *mode)
895 {
896 	struct mbochs_dmabuf *dmabuf;
897 	pgoff_t page_offset, pg;
898 
899 	WARN_ON(!mutex_is_locked(&mdev_state->ops_lock));
900 
901 	dmabuf = kzalloc(sizeof(struct mbochs_dmabuf), GFP_KERNEL);
902 	if (!dmabuf)
903 		return NULL;
904 
905 	dmabuf->mode = *mode;
906 	dmabuf->id = mdev_state->next_id++;
907 	dmabuf->pagecount = DIV_ROUND_UP(mode->size, PAGE_SIZE);
908 	dmabuf->pages = kcalloc(dmabuf->pagecount, sizeof(struct page *),
909 				GFP_KERNEL);
910 	if (!dmabuf->pages)
911 		goto err_free_dmabuf;
912 
913 	page_offset = dmabuf->mode.offset >> PAGE_SHIFT;
914 	for (pg = 0; pg < dmabuf->pagecount; pg++) {
915 		dmabuf->pages[pg] = __mbochs_get_page(mdev_state,
916 						      page_offset + pg);
917 		if (!dmabuf->pages[pg])
918 			goto err_free_pages;
919 	}
920 
921 	dmabuf->mdev_state = mdev_state;
922 	list_add(&dmabuf->next, &mdev_state->dmabufs);
923 
924 	mbochs_print_dmabuf(dmabuf, __func__);
925 	return dmabuf;
926 
927 err_free_pages:
928 	while (pg > 0)
929 		put_page(dmabuf->pages[--pg]);
930 	kfree(dmabuf->pages);
931 err_free_dmabuf:
932 	kfree(dmabuf);
933 	return NULL;
934 }
935 
936 static struct mbochs_dmabuf *
937 mbochs_dmabuf_find_by_mode(struct mdev_state *mdev_state,
938 			   struct mbochs_mode *mode)
939 {
940 	struct mbochs_dmabuf *dmabuf;
941 
942 	WARN_ON(!mutex_is_locked(&mdev_state->ops_lock));
943 
944 	list_for_each_entry(dmabuf, &mdev_state->dmabufs, next)
945 		if (mbochs_modes_equal(&dmabuf->mode, mode))
946 			return dmabuf;
947 
948 	return NULL;
949 }
950 
951 static struct mbochs_dmabuf *
952 mbochs_dmabuf_find_by_id(struct mdev_state *mdev_state, u32 id)
953 {
954 	struct mbochs_dmabuf *dmabuf;
955 
956 	WARN_ON(!mutex_is_locked(&mdev_state->ops_lock));
957 
958 	list_for_each_entry(dmabuf, &mdev_state->dmabufs, next)
959 		if (dmabuf->id == id)
960 			return dmabuf;
961 
962 	return NULL;
963 }
964 
965 static int mbochs_dmabuf_export(struct mbochs_dmabuf *dmabuf)
966 {
967 	struct mdev_state *mdev_state = dmabuf->mdev_state;
968 	struct device *dev = mdev_dev(mdev_state->mdev);
969 	DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
970 	struct dma_buf *buf;
971 
972 	WARN_ON(!mutex_is_locked(&mdev_state->ops_lock));
973 
974 	if (!IS_ALIGNED(dmabuf->mode.offset, PAGE_SIZE)) {
975 		dev_info_ratelimited(dev, "%s: framebuffer not page-aligned\n",
976 				     __func__);
977 		return -EINVAL;
978 	}
979 
980 	exp_info.ops = &mbochs_dmabuf_ops;
981 	exp_info.size = dmabuf->mode.size;
982 	exp_info.priv = dmabuf;
983 
984 	buf = dma_buf_export(&exp_info);
985 	if (IS_ERR(buf)) {
986 		dev_info_ratelimited(dev, "%s: dma_buf_export failed: %ld\n",
987 				     __func__, PTR_ERR(buf));
988 		return PTR_ERR(buf);
989 	}
990 
991 	dmabuf->buf = buf;
992 	dev_dbg(dev, "%s: %d\n", __func__, dmabuf->id);
993 	return 0;
994 }
995 
996 static int mbochs_get_region_info(struct mdev_device *mdev,
997 				  struct vfio_region_info_ext *ext)
998 {
999 	struct vfio_region_info *region_info = &ext->base;
1000 	struct mdev_state *mdev_state;
1001 
1002 	mdev_state = mdev_get_drvdata(mdev);
1003 	if (!mdev_state)
1004 		return -EINVAL;
1005 
1006 	if (region_info->index >= MBOCHS_NUM_REGIONS)
1007 		return -EINVAL;
1008 
1009 	switch (region_info->index) {
1010 	case VFIO_PCI_CONFIG_REGION_INDEX:
1011 		region_info->offset = 0;
1012 		region_info->size   = MBOCHS_CONFIG_SPACE_SIZE;
1013 		region_info->flags  = (VFIO_REGION_INFO_FLAG_READ |
1014 				       VFIO_REGION_INFO_FLAG_WRITE);
1015 		break;
1016 	case VFIO_PCI_BAR0_REGION_INDEX:
1017 		region_info->offset = MBOCHS_MEMORY_BAR_OFFSET;
1018 		region_info->size   = mdev_state->memsize;
1019 		region_info->flags  = (VFIO_REGION_INFO_FLAG_READ  |
1020 				       VFIO_REGION_INFO_FLAG_WRITE |
1021 				       VFIO_REGION_INFO_FLAG_MMAP);
1022 		break;
1023 	case VFIO_PCI_BAR2_REGION_INDEX:
1024 		region_info->offset = MBOCHS_MMIO_BAR_OFFSET;
1025 		region_info->size   = MBOCHS_MMIO_BAR_SIZE;
1026 		region_info->flags  = (VFIO_REGION_INFO_FLAG_READ  |
1027 				       VFIO_REGION_INFO_FLAG_WRITE);
1028 		break;
1029 	case MBOCHS_EDID_REGION_INDEX:
1030 		ext->base.argsz = sizeof(*ext);
1031 		ext->base.offset = MBOCHS_EDID_OFFSET;
1032 		ext->base.size = MBOCHS_EDID_SIZE;
1033 		ext->base.flags = (VFIO_REGION_INFO_FLAG_READ  |
1034 				   VFIO_REGION_INFO_FLAG_WRITE |
1035 				   VFIO_REGION_INFO_FLAG_CAPS);
1036 		ext->base.cap_offset = offsetof(typeof(*ext), type);
1037 		ext->type.header.id = VFIO_REGION_INFO_CAP_TYPE;
1038 		ext->type.header.version = 1;
1039 		ext->type.header.next = 0;
1040 		ext->type.type = VFIO_REGION_TYPE_GFX;
1041 		ext->type.subtype = VFIO_REGION_SUBTYPE_GFX_EDID;
1042 		break;
1043 	default:
1044 		region_info->size   = 0;
1045 		region_info->offset = 0;
1046 		region_info->flags  = 0;
1047 	}
1048 
1049 	return 0;
1050 }
1051 
1052 static int mbochs_get_irq_info(struct mdev_device *mdev,
1053 			       struct vfio_irq_info *irq_info)
1054 {
1055 	irq_info->count = 0;
1056 	return 0;
1057 }
1058 
1059 static int mbochs_get_device_info(struct mdev_device *mdev,
1060 				  struct vfio_device_info *dev_info)
1061 {
1062 	dev_info->flags = VFIO_DEVICE_FLAGS_PCI;
1063 	dev_info->num_regions = MBOCHS_NUM_REGIONS;
1064 	dev_info->num_irqs = VFIO_PCI_NUM_IRQS;
1065 	return 0;
1066 }
1067 
1068 static int mbochs_query_gfx_plane(struct mdev_device *mdev,
1069 				  struct vfio_device_gfx_plane_info *plane)
1070 {
1071 	struct mdev_state *mdev_state = mdev_get_drvdata(mdev);
1072 	struct device *dev = mdev_dev(mdev);
1073 	struct mbochs_dmabuf *dmabuf;
1074 	struct mbochs_mode mode;
1075 	int ret;
1076 
1077 	if (plane->flags & VFIO_GFX_PLANE_TYPE_PROBE) {
1078 		if (plane->flags == (VFIO_GFX_PLANE_TYPE_PROBE |
1079 				     VFIO_GFX_PLANE_TYPE_DMABUF))
1080 			return 0;
1081 		return -EINVAL;
1082 	}
1083 
1084 	if (plane->flags != VFIO_GFX_PLANE_TYPE_DMABUF)
1085 		return -EINVAL;
1086 
1087 	plane->drm_format_mod = 0;
1088 	plane->x_pos	      = 0;
1089 	plane->y_pos	      = 0;
1090 	plane->x_hot	      = 0;
1091 	plane->y_hot	      = 0;
1092 
1093 	mutex_lock(&mdev_state->ops_lock);
1094 
1095 	ret = -EINVAL;
1096 	if (plane->drm_plane_type == DRM_PLANE_TYPE_PRIMARY)
1097 		ret = mbochs_check_framebuffer(mdev_state, &mode);
1098 	if (ret < 0) {
1099 		plane->drm_format     = 0;
1100 		plane->width	      = 0;
1101 		plane->height	      = 0;
1102 		plane->stride	      = 0;
1103 		plane->size	      = 0;
1104 		plane->dmabuf_id      = 0;
1105 		goto done;
1106 	}
1107 
1108 	dmabuf = mbochs_dmabuf_find_by_mode(mdev_state, &mode);
1109 	if (!dmabuf)
1110 		mbochs_dmabuf_alloc(mdev_state, &mode);
1111 	if (!dmabuf) {
1112 		mutex_unlock(&mdev_state->ops_lock);
1113 		return -ENOMEM;
1114 	}
1115 
1116 	plane->drm_format     = dmabuf->mode.drm_format;
1117 	plane->width	      = dmabuf->mode.width;
1118 	plane->height	      = dmabuf->mode.height;
1119 	plane->stride	      = dmabuf->mode.stride;
1120 	plane->size	      = dmabuf->mode.size;
1121 	plane->dmabuf_id      = dmabuf->id;
1122 
1123 done:
1124 	if (plane->drm_plane_type == DRM_PLANE_TYPE_PRIMARY &&
1125 	    mdev_state->active_id != plane->dmabuf_id) {
1126 		dev_dbg(dev, "%s: primary: %d => %d\n", __func__,
1127 			mdev_state->active_id, plane->dmabuf_id);
1128 		mdev_state->active_id = plane->dmabuf_id;
1129 	}
1130 	mutex_unlock(&mdev_state->ops_lock);
1131 	return 0;
1132 }
1133 
1134 static int mbochs_get_gfx_dmabuf(struct mdev_device *mdev,
1135 				 u32 id)
1136 {
1137 	struct mdev_state *mdev_state = mdev_get_drvdata(mdev);
1138 	struct mbochs_dmabuf *dmabuf;
1139 
1140 	mutex_lock(&mdev_state->ops_lock);
1141 
1142 	dmabuf = mbochs_dmabuf_find_by_id(mdev_state, id);
1143 	if (!dmabuf) {
1144 		mutex_unlock(&mdev_state->ops_lock);
1145 		return -ENOENT;
1146 	}
1147 
1148 	if (!dmabuf->buf)
1149 		mbochs_dmabuf_export(dmabuf);
1150 
1151 	mutex_unlock(&mdev_state->ops_lock);
1152 
1153 	if (!dmabuf->buf)
1154 		return -EINVAL;
1155 
1156 	return dma_buf_fd(dmabuf->buf, 0);
1157 }
1158 
1159 static long mbochs_ioctl(struct mdev_device *mdev, unsigned int cmd,
1160 			unsigned long arg)
1161 {
1162 	int ret = 0;
1163 	unsigned long minsz, outsz;
1164 
1165 	switch (cmd) {
1166 	case VFIO_DEVICE_GET_INFO:
1167 	{
1168 		struct vfio_device_info info;
1169 
1170 		minsz = offsetofend(struct vfio_device_info, num_irqs);
1171 
1172 		if (copy_from_user(&info, (void __user *)arg, minsz))
1173 			return -EFAULT;
1174 
1175 		if (info.argsz < minsz)
1176 			return -EINVAL;
1177 
1178 		ret = mbochs_get_device_info(mdev, &info);
1179 		if (ret)
1180 			return ret;
1181 
1182 		if (copy_to_user((void __user *)arg, &info, minsz))
1183 			return -EFAULT;
1184 
1185 		return 0;
1186 	}
1187 	case VFIO_DEVICE_GET_REGION_INFO:
1188 	{
1189 		struct vfio_region_info_ext info;
1190 
1191 		minsz = offsetofend(typeof(info), base.offset);
1192 
1193 		if (copy_from_user(&info, (void __user *)arg, minsz))
1194 			return -EFAULT;
1195 
1196 		outsz = info.base.argsz;
1197 		if (outsz < minsz)
1198 			return -EINVAL;
1199 		if (outsz > sizeof(info))
1200 			return -EINVAL;
1201 
1202 		ret = mbochs_get_region_info(mdev, &info);
1203 		if (ret)
1204 			return ret;
1205 
1206 		if (copy_to_user((void __user *)arg, &info, outsz))
1207 			return -EFAULT;
1208 
1209 		return 0;
1210 	}
1211 
1212 	case VFIO_DEVICE_GET_IRQ_INFO:
1213 	{
1214 		struct vfio_irq_info info;
1215 
1216 		minsz = offsetofend(struct vfio_irq_info, count);
1217 
1218 		if (copy_from_user(&info, (void __user *)arg, minsz))
1219 			return -EFAULT;
1220 
1221 		if ((info.argsz < minsz) ||
1222 		    (info.index >= VFIO_PCI_NUM_IRQS))
1223 			return -EINVAL;
1224 
1225 		ret = mbochs_get_irq_info(mdev, &info);
1226 		if (ret)
1227 			return ret;
1228 
1229 		if (copy_to_user((void __user *)arg, &info, minsz))
1230 			return -EFAULT;
1231 
1232 		return 0;
1233 	}
1234 
1235 	case VFIO_DEVICE_QUERY_GFX_PLANE:
1236 	{
1237 		struct vfio_device_gfx_plane_info plane;
1238 
1239 		minsz = offsetofend(struct vfio_device_gfx_plane_info,
1240 				    region_index);
1241 
1242 		if (copy_from_user(&plane, (void __user *)arg, minsz))
1243 			return -EFAULT;
1244 
1245 		if (plane.argsz < minsz)
1246 			return -EINVAL;
1247 
1248 		ret = mbochs_query_gfx_plane(mdev, &plane);
1249 		if (ret)
1250 			return ret;
1251 
1252 		if (copy_to_user((void __user *)arg, &plane, minsz))
1253 			return -EFAULT;
1254 
1255 		return 0;
1256 	}
1257 
1258 	case VFIO_DEVICE_GET_GFX_DMABUF:
1259 	{
1260 		u32 dmabuf_id;
1261 
1262 		if (get_user(dmabuf_id, (__u32 __user *)arg))
1263 			return -EFAULT;
1264 
1265 		return mbochs_get_gfx_dmabuf(mdev, dmabuf_id);
1266 	}
1267 
1268 	case VFIO_DEVICE_SET_IRQS:
1269 		return -EINVAL;
1270 
1271 	case VFIO_DEVICE_RESET:
1272 		return mbochs_reset(mdev);
1273 	}
1274 	return -ENOTTY;
1275 }
1276 
1277 static int mbochs_open(struct mdev_device *mdev)
1278 {
1279 	if (!try_module_get(THIS_MODULE))
1280 		return -ENODEV;
1281 
1282 	return 0;
1283 }
1284 
1285 static void mbochs_close(struct mdev_device *mdev)
1286 {
1287 	struct mdev_state *mdev_state = mdev_get_drvdata(mdev);
1288 	struct mbochs_dmabuf *dmabuf, *tmp;
1289 
1290 	mutex_lock(&mdev_state->ops_lock);
1291 
1292 	list_for_each_entry_safe(dmabuf, tmp, &mdev_state->dmabufs, next) {
1293 		list_del(&dmabuf->next);
1294 		if (dmabuf->buf) {
1295 			/* free in mbochs_release_dmabuf() */
1296 			dmabuf->unlinked = true;
1297 		} else {
1298 			kfree(dmabuf);
1299 		}
1300 	}
1301 	mbochs_put_pages(mdev_state);
1302 
1303 	mutex_unlock(&mdev_state->ops_lock);
1304 	module_put(THIS_MODULE);
1305 }
1306 
1307 static ssize_t
1308 memory_show(struct device *dev, struct device_attribute *attr,
1309 	    char *buf)
1310 {
1311 	struct mdev_device *mdev = mdev_from_dev(dev);
1312 	struct mdev_state *mdev_state = mdev_get_drvdata(mdev);
1313 
1314 	return sprintf(buf, "%d MB\n", mdev_state->type->mbytes);
1315 }
1316 static DEVICE_ATTR_RO(memory);
1317 
1318 static struct attribute *mdev_dev_attrs[] = {
1319 	&dev_attr_memory.attr,
1320 	NULL,
1321 };
1322 
1323 static const struct attribute_group mdev_dev_group = {
1324 	.name  = "vendor",
1325 	.attrs = mdev_dev_attrs,
1326 };
1327 
1328 static const struct attribute_group *mdev_dev_groups[] = {
1329 	&mdev_dev_group,
1330 	NULL,
1331 };
1332 
1333 static ssize_t name_show(struct mdev_type *mtype,
1334 			 struct mdev_type_attribute *attr, char *buf)
1335 {
1336 	const struct mbochs_type *type =
1337 		&mbochs_types[mtype_get_type_group_id(mtype)];
1338 
1339 	return sprintf(buf, "%s\n", type->name);
1340 }
1341 static MDEV_TYPE_ATTR_RO(name);
1342 
1343 static ssize_t description_show(struct mdev_type *mtype,
1344 				struct mdev_type_attribute *attr, char *buf)
1345 {
1346 	const struct mbochs_type *type =
1347 		&mbochs_types[mtype_get_type_group_id(mtype)];
1348 
1349 	return sprintf(buf, "virtual display, %d MB video memory\n",
1350 		       type ? type->mbytes  : 0);
1351 }
1352 static MDEV_TYPE_ATTR_RO(description);
1353 
1354 static ssize_t available_instances_show(struct mdev_type *mtype,
1355 					struct mdev_type_attribute *attr,
1356 					char *buf)
1357 {
1358 	const struct mbochs_type *type =
1359 		&mbochs_types[mtype_get_type_group_id(mtype)];
1360 	int count = (max_mbytes - mbochs_used_mbytes) / type->mbytes;
1361 
1362 	return sprintf(buf, "%d\n", count);
1363 }
1364 static MDEV_TYPE_ATTR_RO(available_instances);
1365 
1366 static ssize_t device_api_show(struct mdev_type *mtype,
1367 			       struct mdev_type_attribute *attr, char *buf)
1368 {
1369 	return sprintf(buf, "%s\n", VFIO_DEVICE_API_PCI_STRING);
1370 }
1371 static MDEV_TYPE_ATTR_RO(device_api);
1372 
1373 static struct attribute *mdev_types_attrs[] = {
1374 	&mdev_type_attr_name.attr,
1375 	&mdev_type_attr_description.attr,
1376 	&mdev_type_attr_device_api.attr,
1377 	&mdev_type_attr_available_instances.attr,
1378 	NULL,
1379 };
1380 
1381 static struct attribute_group mdev_type_group1 = {
1382 	.name  = MBOCHS_TYPE_1,
1383 	.attrs = mdev_types_attrs,
1384 };
1385 
1386 static struct attribute_group mdev_type_group2 = {
1387 	.name  = MBOCHS_TYPE_2,
1388 	.attrs = mdev_types_attrs,
1389 };
1390 
1391 static struct attribute_group mdev_type_group3 = {
1392 	.name  = MBOCHS_TYPE_3,
1393 	.attrs = mdev_types_attrs,
1394 };
1395 
1396 static struct attribute_group *mdev_type_groups[] = {
1397 	&mdev_type_group1,
1398 	&mdev_type_group2,
1399 	&mdev_type_group3,
1400 	NULL,
1401 };
1402 
1403 static const struct mdev_parent_ops mdev_fops = {
1404 	.owner			= THIS_MODULE,
1405 	.mdev_attr_groups	= mdev_dev_groups,
1406 	.supported_type_groups	= mdev_type_groups,
1407 	.create			= mbochs_create,
1408 	.remove			= mbochs_remove,
1409 	.open			= mbochs_open,
1410 	.release		= mbochs_close,
1411 	.read			= mbochs_read,
1412 	.write			= mbochs_write,
1413 	.ioctl			= mbochs_ioctl,
1414 	.mmap			= mbochs_mmap,
1415 };
1416 
1417 static const struct file_operations vd_fops = {
1418 	.owner		= THIS_MODULE,
1419 };
1420 
1421 static void mbochs_device_release(struct device *dev)
1422 {
1423 	/* nothing */
1424 }
1425 
1426 static int __init mbochs_dev_init(void)
1427 {
1428 	int ret = 0;
1429 
1430 	ret = alloc_chrdev_region(&mbochs_devt, 0, MINORMASK + 1, MBOCHS_NAME);
1431 	if (ret < 0) {
1432 		pr_err("Error: failed to register mbochs_dev, err: %d\n", ret);
1433 		return ret;
1434 	}
1435 	cdev_init(&mbochs_cdev, &vd_fops);
1436 	cdev_add(&mbochs_cdev, mbochs_devt, MINORMASK + 1);
1437 	pr_info("%s: major %d\n", __func__, MAJOR(mbochs_devt));
1438 
1439 	mbochs_class = class_create(THIS_MODULE, MBOCHS_CLASS_NAME);
1440 	if (IS_ERR(mbochs_class)) {
1441 		pr_err("Error: failed to register mbochs_dev class\n");
1442 		ret = PTR_ERR(mbochs_class);
1443 		goto failed1;
1444 	}
1445 	mbochs_dev.class = mbochs_class;
1446 	mbochs_dev.release = mbochs_device_release;
1447 	dev_set_name(&mbochs_dev, "%s", MBOCHS_NAME);
1448 
1449 	ret = device_register(&mbochs_dev);
1450 	if (ret)
1451 		goto failed2;
1452 
1453 	ret = mdev_register_device(&mbochs_dev, &mdev_fops);
1454 	if (ret)
1455 		goto failed3;
1456 
1457 	return 0;
1458 
1459 failed3:
1460 	device_unregister(&mbochs_dev);
1461 failed2:
1462 	class_destroy(mbochs_class);
1463 failed1:
1464 	cdev_del(&mbochs_cdev);
1465 	unregister_chrdev_region(mbochs_devt, MINORMASK + 1);
1466 	return ret;
1467 }
1468 
1469 static void __exit mbochs_dev_exit(void)
1470 {
1471 	mbochs_dev.bus = NULL;
1472 	mdev_unregister_device(&mbochs_dev);
1473 
1474 	device_unregister(&mbochs_dev);
1475 	cdev_del(&mbochs_cdev);
1476 	unregister_chrdev_region(mbochs_devt, MINORMASK + 1);
1477 	class_destroy(mbochs_class);
1478 	mbochs_class = NULL;
1479 }
1480 
1481 module_init(mbochs_dev_init)
1482 module_exit(mbochs_dev_exit)
1483