xref: /linux/samples/vfio-mdev/mbochs.c (revision f879306834818ebd1722a4372079610cdd466fec)
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/kernel.h>
25 #include <linux/slab.h>
26 #include <linux/vmalloc.h>
27 #include <linux/cdev.h>
28 #include <linux/vfio.h>
29 #include <linux/iommu.h>
30 #include <linux/sysfs.h>
31 #include <linux/mdev.h>
32 #include <linux/pci.h>
33 #include <linux/dma-buf.h>
34 #include <linux/highmem.h>
35 #include <drm/drm_fourcc.h>
36 #include <drm/drm_rect.h>
37 #include <drm/drm_modeset_lock.h>
38 #include <drm/drm_property.h>
39 #include <drm/drm_plane.h>
40 
41 
42 #define VBE_DISPI_INDEX_ID		0x0
43 #define VBE_DISPI_INDEX_XRES		0x1
44 #define VBE_DISPI_INDEX_YRES		0x2
45 #define VBE_DISPI_INDEX_BPP		0x3
46 #define VBE_DISPI_INDEX_ENABLE		0x4
47 #define VBE_DISPI_INDEX_BANK		0x5
48 #define VBE_DISPI_INDEX_VIRT_WIDTH	0x6
49 #define VBE_DISPI_INDEX_VIRT_HEIGHT	0x7
50 #define VBE_DISPI_INDEX_X_OFFSET	0x8
51 #define VBE_DISPI_INDEX_Y_OFFSET	0x9
52 #define VBE_DISPI_INDEX_VIDEO_MEMORY_64K 0xa
53 #define VBE_DISPI_INDEX_COUNT		0xb
54 
55 #define VBE_DISPI_ID0			0xB0C0
56 #define VBE_DISPI_ID1			0xB0C1
57 #define VBE_DISPI_ID2			0xB0C2
58 #define VBE_DISPI_ID3			0xB0C3
59 #define VBE_DISPI_ID4			0xB0C4
60 #define VBE_DISPI_ID5			0xB0C5
61 
62 #define VBE_DISPI_DISABLED		0x00
63 #define VBE_DISPI_ENABLED		0x01
64 #define VBE_DISPI_GETCAPS		0x02
65 #define VBE_DISPI_8BIT_DAC		0x20
66 #define VBE_DISPI_LFB_ENABLED		0x40
67 #define VBE_DISPI_NOCLEARMEM		0x80
68 
69 
70 #define MBOCHS_NAME		  "mbochs"
71 #define MBOCHS_CLASS_NAME	  "mbochs"
72 
73 #define MBOCHS_EDID_REGION_INDEX  VFIO_PCI_NUM_REGIONS
74 #define MBOCHS_NUM_REGIONS        (MBOCHS_EDID_REGION_INDEX+1)
75 
76 #define MBOCHS_CONFIG_SPACE_SIZE  0xff
77 #define MBOCHS_MMIO_BAR_OFFSET	  PAGE_SIZE
78 #define MBOCHS_MMIO_BAR_SIZE	  PAGE_SIZE
79 #define MBOCHS_EDID_OFFSET	  (MBOCHS_MMIO_BAR_OFFSET +	\
80 				   MBOCHS_MMIO_BAR_SIZE)
81 #define MBOCHS_EDID_SIZE	  PAGE_SIZE
82 #define MBOCHS_MEMORY_BAR_OFFSET  (MBOCHS_EDID_OFFSET + \
83 				   MBOCHS_EDID_SIZE)
84 
85 #define MBOCHS_EDID_BLOB_OFFSET   (MBOCHS_EDID_SIZE/2)
86 
87 #define STORE_LE16(addr, val)	(*(u16 *)addr = val)
88 #define STORE_LE32(addr, val)	(*(u32 *)addr = val)
89 
90 
91 MODULE_DESCRIPTION("Mediated virtual PCI display host device driver");
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 struct mbochs_type {
104 	struct mdev_type type;
105 	u32 mbytes;
106 	u32 max_x;
107 	u32 max_y;
108 } mbochs_types[] = {
109 	{
110 		.type.sysfs_name	= MBOCHS_TYPE_1,
111 		.type.pretty_name	= MBOCHS_CLASS_NAME "-" MBOCHS_TYPE_1,
112 		.mbytes = 4,
113 		.max_x  = 800,
114 		.max_y  = 600,
115 	}, {
116 		.type.sysfs_name	= MBOCHS_TYPE_2,
117 		.type.pretty_name	= MBOCHS_CLASS_NAME "-" MBOCHS_TYPE_2,
118 		.mbytes = 16,
119 		.max_x  = 1920,
120 		.max_y  = 1440,
121 	}, {
122 		.type.sysfs_name	= MBOCHS_TYPE_3,
123 		.type.pretty_name	= MBOCHS_CLASS_NAME "-" MBOCHS_TYPE_3,
124 		.mbytes = 64,
125 		.max_x  = 0,
126 		.max_y  = 0,
127 	},
128 };
129 
130 static struct mdev_type *mbochs_mdev_types[] = {
131 	&mbochs_types[0].type,
132 	&mbochs_types[1].type,
133 	&mbochs_types[2].type,
134 };
135 
136 static dev_t		mbochs_devt;
137 static const struct class mbochs_class = {
138 	.name = MBOCHS_CLASS_NAME,
139 };
140 static struct cdev	mbochs_cdev;
141 static struct device	mbochs_dev;
142 static struct mdev_parent mbochs_parent;
143 static atomic_t mbochs_avail_mbytes;
144 static const struct vfio_device_ops mbochs_dev_ops;
145 
146 struct vfio_region_info_ext {
147 	struct vfio_region_info          base;
148 	struct vfio_region_info_cap_type type;
149 };
150 
151 struct mbochs_mode {
152 	u32 drm_format;
153 	u32 bytepp;
154 	u32 width;
155 	u32 height;
156 	u32 stride;
157 	u32 __pad;
158 	u64 offset;
159 	u64 size;
160 };
161 
162 struct mbochs_dmabuf {
163 	struct mbochs_mode mode;
164 	u32 id;
165 	struct page **pages;
166 	pgoff_t pagecount;
167 	struct dma_buf *buf;
168 	struct mdev_state *mdev_state;
169 	struct list_head next;
170 	bool unlinked;
171 };
172 
173 /* State of each mdev device */
174 struct mdev_state {
175 	struct vfio_device vdev;
176 	u8 *vconfig;
177 	u64 bar_mask[3];
178 	u32 memory_bar_mask;
179 	struct mutex ops_lock;
180 	struct mdev_device *mdev;
181 
182 	const struct mbochs_type *type;
183 	u16 vbe[VBE_DISPI_INDEX_COUNT];
184 	u64 memsize;
185 	struct page **pages;
186 	pgoff_t pagecount;
187 	struct vfio_region_gfx_edid edid_regs;
188 	u8 edid_blob[0x400];
189 
190 	struct list_head dmabufs;
191 	u32 active_id;
192 	u32 next_id;
193 };
194 
195 static const char *vbe_name_list[VBE_DISPI_INDEX_COUNT] = {
196 	[VBE_DISPI_INDEX_ID]               = "id",
197 	[VBE_DISPI_INDEX_XRES]             = "xres",
198 	[VBE_DISPI_INDEX_YRES]             = "yres",
199 	[VBE_DISPI_INDEX_BPP]              = "bpp",
200 	[VBE_DISPI_INDEX_ENABLE]           = "enable",
201 	[VBE_DISPI_INDEX_BANK]             = "bank",
202 	[VBE_DISPI_INDEX_VIRT_WIDTH]       = "virt-width",
203 	[VBE_DISPI_INDEX_VIRT_HEIGHT]      = "virt-height",
204 	[VBE_DISPI_INDEX_X_OFFSET]         = "x-offset",
205 	[VBE_DISPI_INDEX_Y_OFFSET]         = "y-offset",
206 	[VBE_DISPI_INDEX_VIDEO_MEMORY_64K] = "video-mem",
207 };
208 
209 static const char *vbe_name(u32 index)
210 {
211 	if (index < ARRAY_SIZE(vbe_name_list))
212 		return vbe_name_list[index];
213 	return "(invalid)";
214 }
215 
216 static struct page *__mbochs_get_page(struct mdev_state *mdev_state,
217 				      pgoff_t pgoff);
218 static struct page *mbochs_get_page(struct mdev_state *mdev_state,
219 				    pgoff_t pgoff);
220 
221 static void mbochs_create_config_space(struct mdev_state *mdev_state)
222 {
223 	STORE_LE16((u16 *) &mdev_state->vconfig[PCI_VENDOR_ID],
224 		   0x1234);
225 	STORE_LE16((u16 *) &mdev_state->vconfig[PCI_DEVICE_ID],
226 		   0x1111);
227 	STORE_LE16((u16 *) &mdev_state->vconfig[PCI_SUBSYSTEM_VENDOR_ID],
228 		   PCI_SUBVENDOR_ID_REDHAT_QUMRANET);
229 	STORE_LE16((u16 *) &mdev_state->vconfig[PCI_SUBSYSTEM_ID],
230 		   PCI_SUBDEVICE_ID_QEMU);
231 
232 	STORE_LE16((u16 *) &mdev_state->vconfig[PCI_COMMAND],
233 		   PCI_COMMAND_IO | PCI_COMMAND_MEMORY);
234 	STORE_LE16((u16 *) &mdev_state->vconfig[PCI_CLASS_DEVICE],
235 		   PCI_CLASS_DISPLAY_OTHER);
236 	mdev_state->vconfig[PCI_CLASS_REVISION] =  0x01;
237 
238 	STORE_LE32((u32 *) &mdev_state->vconfig[PCI_BASE_ADDRESS_0],
239 		   PCI_BASE_ADDRESS_SPACE_MEMORY |
240 		   PCI_BASE_ADDRESS_MEM_TYPE_32	 |
241 		   PCI_BASE_ADDRESS_MEM_PREFETCH);
242 	mdev_state->bar_mask[0] = ~(mdev_state->memsize) + 1;
243 
244 	STORE_LE32((u32 *) &mdev_state->vconfig[PCI_BASE_ADDRESS_2],
245 		   PCI_BASE_ADDRESS_SPACE_MEMORY |
246 		   PCI_BASE_ADDRESS_MEM_TYPE_32);
247 	mdev_state->bar_mask[2] = ~(MBOCHS_MMIO_BAR_SIZE) + 1;
248 }
249 
250 static int mbochs_check_framebuffer(struct mdev_state *mdev_state,
251 				    struct mbochs_mode *mode)
252 {
253 	struct device *dev = mdev_dev(mdev_state->mdev);
254 	u16 *vbe = mdev_state->vbe;
255 	u32 virt_width;
256 
257 	WARN_ON(!mutex_is_locked(&mdev_state->ops_lock));
258 
259 	if (!(vbe[VBE_DISPI_INDEX_ENABLE] & VBE_DISPI_ENABLED))
260 		goto nofb;
261 
262 	memset(mode, 0, sizeof(*mode));
263 	switch (vbe[VBE_DISPI_INDEX_BPP]) {
264 	case 32:
265 		mode->drm_format = DRM_FORMAT_XRGB8888;
266 		mode->bytepp = 4;
267 		break;
268 	default:
269 		dev_info_ratelimited(dev, "%s: bpp %d not supported\n",
270 				     __func__, vbe[VBE_DISPI_INDEX_BPP]);
271 		goto nofb;
272 	}
273 
274 	mode->width  = vbe[VBE_DISPI_INDEX_XRES];
275 	mode->height = vbe[VBE_DISPI_INDEX_YRES];
276 	virt_width  = vbe[VBE_DISPI_INDEX_VIRT_WIDTH];
277 	if (virt_width < mode->width)
278 		virt_width = mode->width;
279 	mode->stride = virt_width * mode->bytepp;
280 	mode->size   = (u64)mode->stride * mode->height;
281 	mode->offset = ((u64)vbe[VBE_DISPI_INDEX_X_OFFSET] * mode->bytepp +
282 		       (u64)vbe[VBE_DISPI_INDEX_Y_OFFSET] * mode->stride);
283 
284 	if (mode->width < 64 || mode->height < 64) {
285 		dev_info_ratelimited(dev, "%s: invalid resolution %dx%d\n",
286 				     __func__, mode->width, mode->height);
287 		goto nofb;
288 	}
289 	if (mode->offset + mode->size > mdev_state->memsize) {
290 		dev_info_ratelimited(dev, "%s: framebuffer memory overflow\n",
291 				     __func__);
292 		goto nofb;
293 	}
294 
295 	return 0;
296 
297 nofb:
298 	memset(mode, 0, sizeof(*mode));
299 	return -EINVAL;
300 }
301 
302 static bool mbochs_modes_equal(struct mbochs_mode *mode1,
303 			       struct mbochs_mode *mode2)
304 {
305 	return memcmp(mode1, mode2, sizeof(struct mbochs_mode)) == 0;
306 }
307 
308 static void handle_pci_cfg_write(struct mdev_state *mdev_state, u16 offset,
309 				 char *buf, u32 count)
310 {
311 	struct device *dev = mdev_dev(mdev_state->mdev);
312 	int index = (offset - PCI_BASE_ADDRESS_0) / 0x04;
313 	u32 cfg_addr;
314 
315 	switch (offset) {
316 	case PCI_BASE_ADDRESS_0:
317 	case PCI_BASE_ADDRESS_2:
318 		cfg_addr = *(u32 *)buf;
319 
320 		if (cfg_addr == 0xffffffff) {
321 			cfg_addr = (cfg_addr & mdev_state->bar_mask[index]);
322 		} else {
323 			cfg_addr &= PCI_BASE_ADDRESS_MEM_MASK;
324 			if (cfg_addr)
325 				dev_info(dev, "BAR #%d @ 0x%x\n",
326 					 index, cfg_addr);
327 		}
328 
329 		cfg_addr |= (mdev_state->vconfig[offset] &
330 			     ~PCI_BASE_ADDRESS_MEM_MASK);
331 		STORE_LE32(&mdev_state->vconfig[offset], cfg_addr);
332 		break;
333 	}
334 }
335 
336 static void handle_mmio_write(struct mdev_state *mdev_state, u16 offset,
337 			      char *buf, u32 count)
338 {
339 	struct device *dev = mdev_dev(mdev_state->mdev);
340 	int index;
341 	u16 reg16;
342 
343 	switch (offset) {
344 	case 0x400 ... 0x41f: /* vga ioports remapped */
345 		goto unhandled;
346 	case 0x500 ... 0x515: /* bochs dispi interface */
347 		if (count != 2)
348 			goto unhandled;
349 		index = (offset - 0x500) / 2;
350 		reg16 = *(u16 *)buf;
351 		if (index < ARRAY_SIZE(mdev_state->vbe))
352 			mdev_state->vbe[index] = reg16;
353 		dev_dbg(dev, "%s: vbe write %d = %d (%s)\n",
354 			__func__, index, reg16, vbe_name(index));
355 		break;
356 	case 0x600 ... 0x607: /* qemu extended regs */
357 		goto unhandled;
358 	default:
359 unhandled:
360 		dev_dbg(dev, "%s: @0x%03x, count %d (unhandled)\n",
361 			__func__, offset, count);
362 		break;
363 	}
364 }
365 
366 static void handle_mmio_read(struct mdev_state *mdev_state, u16 offset,
367 			     char *buf, u32 count)
368 {
369 	struct device *dev = mdev_dev(mdev_state->mdev);
370 	struct vfio_region_gfx_edid *edid;
371 	u16 reg16 = 0;
372 	int index;
373 
374 	switch (offset) {
375 	case 0x000 ... 0x3ff: /* edid block */
376 		edid = &mdev_state->edid_regs;
377 		if (edid->link_state != VFIO_DEVICE_GFX_LINK_STATE_UP ||
378 		    offset >= edid->edid_size) {
379 			memset(buf, 0, count);
380 			break;
381 		}
382 		memcpy(buf, mdev_state->edid_blob + offset, count);
383 		break;
384 	case 0x500 ... 0x515: /* bochs dispi interface */
385 		if (count != 2)
386 			goto unhandled;
387 		index = (offset - 0x500) / 2;
388 		if (index < ARRAY_SIZE(mdev_state->vbe))
389 			reg16 = mdev_state->vbe[index];
390 		dev_dbg(dev, "%s: vbe read %d = %d (%s)\n",
391 			__func__, index, reg16, vbe_name(index));
392 		*(u16 *)buf = reg16;
393 		break;
394 	default:
395 unhandled:
396 		dev_dbg(dev, "%s: @0x%03x, count %d (unhandled)\n",
397 			__func__, offset, count);
398 		memset(buf, 0, count);
399 		break;
400 	}
401 }
402 
403 static void handle_edid_regs(struct mdev_state *mdev_state, u16 offset,
404 			     char *buf, u32 count, bool is_write)
405 {
406 	char *regs = (void *)&mdev_state->edid_regs;
407 
408 	if (offset + count > sizeof(mdev_state->edid_regs))
409 		return;
410 	if (count != 4)
411 		return;
412 	if (offset % 4)
413 		return;
414 
415 	if (is_write) {
416 		switch (offset) {
417 		case offsetof(struct vfio_region_gfx_edid, link_state):
418 		case offsetof(struct vfio_region_gfx_edid, edid_size):
419 			memcpy(regs + offset, buf, count);
420 			break;
421 		default:
422 			/* read-only regs */
423 			break;
424 		}
425 	} else {
426 		memcpy(buf, regs + offset, count);
427 	}
428 }
429 
430 static void handle_edid_blob(struct mdev_state *mdev_state, u16 offset,
431 			     char *buf, u32 count, bool is_write)
432 {
433 	if (offset + count > mdev_state->edid_regs.edid_max_size)
434 		return;
435 	if (is_write)
436 		memcpy(mdev_state->edid_blob + offset, buf, count);
437 	else
438 		memcpy(buf, mdev_state->edid_blob + offset, count);
439 }
440 
441 static ssize_t mdev_access(struct mdev_state *mdev_state, char *buf,
442 			   size_t count, loff_t pos, bool is_write)
443 {
444 	struct page *pg;
445 	loff_t poff;
446 	char *map;
447 	int ret = 0;
448 
449 	mutex_lock(&mdev_state->ops_lock);
450 
451 	if (pos < MBOCHS_CONFIG_SPACE_SIZE) {
452 		if (is_write)
453 			handle_pci_cfg_write(mdev_state, pos, buf, count);
454 		else
455 			memcpy(buf, (mdev_state->vconfig + pos), count);
456 
457 	} else if (pos >= MBOCHS_MMIO_BAR_OFFSET &&
458 		   pos + count <= (MBOCHS_MMIO_BAR_OFFSET +
459 				   MBOCHS_MMIO_BAR_SIZE)) {
460 		pos -= MBOCHS_MMIO_BAR_OFFSET;
461 		if (is_write)
462 			handle_mmio_write(mdev_state, pos, buf, count);
463 		else
464 			handle_mmio_read(mdev_state, pos, buf, count);
465 
466 	} else if (pos >= MBOCHS_EDID_OFFSET &&
467 		   pos + count <= (MBOCHS_EDID_OFFSET +
468 				   MBOCHS_EDID_SIZE)) {
469 		pos -= MBOCHS_EDID_OFFSET;
470 		if (pos < MBOCHS_EDID_BLOB_OFFSET) {
471 			handle_edid_regs(mdev_state, pos, buf, count, is_write);
472 		} else {
473 			pos -= MBOCHS_EDID_BLOB_OFFSET;
474 			handle_edid_blob(mdev_state, pos, buf, count, is_write);
475 		}
476 
477 	} else if (pos >= MBOCHS_MEMORY_BAR_OFFSET &&
478 		   pos + count <=
479 		   MBOCHS_MEMORY_BAR_OFFSET + mdev_state->memsize) {
480 		pos -= MBOCHS_MMIO_BAR_OFFSET;
481 		poff = pos & ~PAGE_MASK;
482 		pg = __mbochs_get_page(mdev_state, pos >> PAGE_SHIFT);
483 		map = kmap(pg);
484 		if (is_write)
485 			memcpy(map + poff, buf, count);
486 		else
487 			memcpy(buf, map + poff, count);
488 		kunmap(pg);
489 		put_page(pg);
490 
491 	} else {
492 		dev_dbg(mdev_state->vdev.dev, "%s: %s @0x%llx (unhandled)\n",
493 			__func__, is_write ? "WR" : "RD", pos);
494 		ret = -1;
495 		goto accessfailed;
496 	}
497 
498 	ret = count;
499 
500 
501 accessfailed:
502 	mutex_unlock(&mdev_state->ops_lock);
503 
504 	return ret;
505 }
506 
507 static int mbochs_reset(struct mdev_state *mdev_state)
508 {
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_init_dev(struct vfio_device *vdev)
520 {
521 	struct mdev_state *mdev_state =
522 		container_of(vdev, struct mdev_state, vdev);
523 	struct mdev_device *mdev = to_mdev_device(vdev->dev);
524 	struct mbochs_type *type =
525 		container_of(mdev->type, struct mbochs_type, type);
526 	int avail_mbytes = atomic_read(&mbochs_avail_mbytes);
527 	int ret = -ENOMEM;
528 
529 	do {
530 		if (avail_mbytes < type->mbytes)
531 			return -ENOSPC;
532 	} while (!atomic_try_cmpxchg(&mbochs_avail_mbytes, &avail_mbytes,
533 				     avail_mbytes - type->mbytes));
534 
535 	mdev_state->vconfig = kzalloc(MBOCHS_CONFIG_SPACE_SIZE, GFP_KERNEL);
536 	if (!mdev_state->vconfig)
537 		goto err_avail;
538 
539 	mdev_state->memsize = type->mbytes * 1024 * 1024;
540 	mdev_state->pagecount = mdev_state->memsize >> PAGE_SHIFT;
541 	mdev_state->pages = kcalloc(mdev_state->pagecount,
542 				    sizeof(struct page *),
543 				    GFP_KERNEL);
544 	if (!mdev_state->pages)
545 		goto err_vconfig;
546 
547 	mutex_init(&mdev_state->ops_lock);
548 	mdev_state->mdev = mdev;
549 	INIT_LIST_HEAD(&mdev_state->dmabufs);
550 	mdev_state->next_id = 1;
551 
552 	mdev_state->type = type;
553 	mdev_state->edid_regs.max_xres = type->max_x;
554 	mdev_state->edid_regs.max_yres = type->max_y;
555 	mdev_state->edid_regs.edid_offset = MBOCHS_EDID_BLOB_OFFSET;
556 	mdev_state->edid_regs.edid_max_size = sizeof(mdev_state->edid_blob);
557 	mbochs_create_config_space(mdev_state);
558 	mbochs_reset(mdev_state);
559 
560 	dev_info(vdev->dev, "%s: %s, %d MB, %ld pages\n", __func__,
561 		 type->type.pretty_name, type->mbytes, mdev_state->pagecount);
562 	return 0;
563 
564 err_vconfig:
565 	kfree(mdev_state->vconfig);
566 err_avail:
567 	atomic_add(type->mbytes, &mbochs_avail_mbytes);
568 	return ret;
569 }
570 
571 static int mbochs_probe(struct mdev_device *mdev)
572 {
573 	struct mdev_state *mdev_state;
574 	int ret = -ENOMEM;
575 
576 	mdev_state = vfio_alloc_device(mdev_state, vdev, &mdev->dev,
577 				       &mbochs_dev_ops);
578 	if (IS_ERR(mdev_state))
579 		return PTR_ERR(mdev_state);
580 
581 	ret = vfio_register_emulated_iommu_dev(&mdev_state->vdev);
582 	if (ret)
583 		goto err_put_vdev;
584 	dev_set_drvdata(&mdev->dev, mdev_state);
585 	return 0;
586 
587 err_put_vdev:
588 	vfio_put_device(&mdev_state->vdev);
589 	return ret;
590 }
591 
592 static void mbochs_release_dev(struct vfio_device *vdev)
593 {
594 	struct mdev_state *mdev_state =
595 		container_of(vdev, struct mdev_state, vdev);
596 
597 	atomic_add(mdev_state->type->mbytes, &mbochs_avail_mbytes);
598 	kfree(mdev_state->pages);
599 	kfree(mdev_state->vconfig);
600 }
601 
602 static void mbochs_remove(struct mdev_device *mdev)
603 {
604 	struct mdev_state *mdev_state = dev_get_drvdata(&mdev->dev);
605 
606 	vfio_unregister_group_dev(&mdev_state->vdev);
607 	vfio_put_device(&mdev_state->vdev);
608 }
609 
610 static ssize_t mbochs_read(struct vfio_device *vdev, char __user *buf,
611 			   size_t count, loff_t *ppos)
612 {
613 	struct mdev_state *mdev_state =
614 		container_of(vdev, struct mdev_state, vdev);
615 	unsigned int done = 0;
616 	int ret;
617 
618 	while (count) {
619 		size_t filled;
620 
621 		if (count >= 4 && !(*ppos % 4)) {
622 			u32 val;
623 
624 			ret =  mdev_access(mdev_state, (char *)&val, sizeof(val),
625 					   *ppos, false);
626 			if (ret <= 0)
627 				goto read_err;
628 
629 			if (copy_to_user(buf, &val, sizeof(val)))
630 				goto read_err;
631 
632 			filled = 4;
633 		} else if (count >= 2 && !(*ppos % 2)) {
634 			u16 val;
635 
636 			ret = mdev_access(mdev_state, (char *)&val, sizeof(val),
637 					  *ppos, false);
638 			if (ret <= 0)
639 				goto read_err;
640 
641 			if (copy_to_user(buf, &val, sizeof(val)))
642 				goto read_err;
643 
644 			filled = 2;
645 		} else {
646 			u8 val;
647 
648 			ret = mdev_access(mdev_state, (char *)&val, sizeof(val),
649 					  *ppos, false);
650 			if (ret <= 0)
651 				goto read_err;
652 
653 			if (copy_to_user(buf, &val, sizeof(val)))
654 				goto read_err;
655 
656 			filled = 1;
657 		}
658 
659 		count -= filled;
660 		done += filled;
661 		*ppos += filled;
662 		buf += filled;
663 	}
664 
665 	return done;
666 
667 read_err:
668 	return -EFAULT;
669 }
670 
671 static ssize_t mbochs_write(struct vfio_device *vdev, const char __user *buf,
672 			    size_t count, loff_t *ppos)
673 {
674 	struct mdev_state *mdev_state =
675 		container_of(vdev, struct mdev_state, vdev);
676 	unsigned int done = 0;
677 	int ret;
678 
679 	while (count) {
680 		size_t filled;
681 
682 		if (count >= 4 && !(*ppos % 4)) {
683 			u32 val;
684 
685 			if (copy_from_user(&val, buf, sizeof(val)))
686 				goto write_err;
687 
688 			ret = mdev_access(mdev_state, (char *)&val, sizeof(val),
689 					  *ppos, true);
690 			if (ret <= 0)
691 				goto write_err;
692 
693 			filled = 4;
694 		} else if (count >= 2 && !(*ppos % 2)) {
695 			u16 val;
696 
697 			if (copy_from_user(&val, buf, sizeof(val)))
698 				goto write_err;
699 
700 			ret = mdev_access(mdev_state, (char *)&val, sizeof(val),
701 					  *ppos, true);
702 			if (ret <= 0)
703 				goto write_err;
704 
705 			filled = 2;
706 		} else {
707 			u8 val;
708 
709 			if (copy_from_user(&val, buf, sizeof(val)))
710 				goto write_err;
711 
712 			ret = mdev_access(mdev_state, (char *)&val, sizeof(val),
713 					  *ppos, true);
714 			if (ret <= 0)
715 				goto write_err;
716 
717 			filled = 1;
718 		}
719 		count -= filled;
720 		done += filled;
721 		*ppos += filled;
722 		buf += filled;
723 	}
724 
725 	return done;
726 write_err:
727 	return -EFAULT;
728 }
729 
730 static struct page *__mbochs_get_page(struct mdev_state *mdev_state,
731 				      pgoff_t pgoff)
732 {
733 	WARN_ON(!mutex_is_locked(&mdev_state->ops_lock));
734 
735 	if (!mdev_state->pages[pgoff]) {
736 		mdev_state->pages[pgoff] =
737 			alloc_pages(GFP_HIGHUSER | __GFP_ZERO, 0);
738 		if (!mdev_state->pages[pgoff])
739 			return NULL;
740 	}
741 
742 	get_page(mdev_state->pages[pgoff]);
743 	return mdev_state->pages[pgoff];
744 }
745 
746 static struct page *mbochs_get_page(struct mdev_state *mdev_state,
747 				    pgoff_t pgoff)
748 {
749 	struct page *page;
750 
751 	if (WARN_ON(pgoff >= mdev_state->pagecount))
752 		return NULL;
753 
754 	mutex_lock(&mdev_state->ops_lock);
755 	page = __mbochs_get_page(mdev_state, pgoff);
756 	mutex_unlock(&mdev_state->ops_lock);
757 
758 	return page;
759 }
760 
761 static void mbochs_put_pages(struct mdev_state *mdev_state)
762 {
763 	struct device *dev = mdev_dev(mdev_state->mdev);
764 	int i, count = 0;
765 
766 	WARN_ON(!mutex_is_locked(&mdev_state->ops_lock));
767 
768 	for (i = 0; i < mdev_state->pagecount; i++) {
769 		if (!mdev_state->pages[i])
770 			continue;
771 		put_page(mdev_state->pages[i]);
772 		mdev_state->pages[i] = NULL;
773 		count++;
774 	}
775 	dev_dbg(dev, "%s: %d pages released\n", __func__, count);
776 }
777 
778 static vm_fault_t mbochs_region_vm_fault(struct vm_fault *vmf)
779 {
780 	struct vm_area_struct *vma = vmf->vma;
781 	struct mdev_state *mdev_state = vma->vm_private_data;
782 	pgoff_t page_offset = (vmf->address - vma->vm_start) >> PAGE_SHIFT;
783 
784 	if (page_offset >= mdev_state->pagecount)
785 		return VM_FAULT_SIGBUS;
786 
787 	vmf->page = mbochs_get_page(mdev_state, page_offset);
788 	if (!vmf->page)
789 		return VM_FAULT_SIGBUS;
790 
791 	return 0;
792 }
793 
794 static const struct vm_operations_struct mbochs_region_vm_ops = {
795 	.fault = mbochs_region_vm_fault,
796 };
797 
798 static int mbochs_mmap(struct vfio_device *vdev, struct vm_area_struct *vma)
799 {
800 	struct mdev_state *mdev_state =
801 		container_of(vdev, struct mdev_state, vdev);
802 
803 	if (vma->vm_pgoff != MBOCHS_MEMORY_BAR_OFFSET >> PAGE_SHIFT)
804 		return -EINVAL;
805 	if (vma->vm_end < vma->vm_start)
806 		return -EINVAL;
807 	if (vma->vm_end - vma->vm_start > mdev_state->memsize)
808 		return -EINVAL;
809 	if ((vma->vm_flags & VM_SHARED) == 0)
810 		return -EINVAL;
811 
812 	vma->vm_ops = &mbochs_region_vm_ops;
813 	vma->vm_private_data = mdev_state;
814 	return 0;
815 }
816 
817 static vm_fault_t mbochs_dmabuf_vm_fault(struct vm_fault *vmf)
818 {
819 	struct vm_area_struct *vma = vmf->vma;
820 	struct mbochs_dmabuf *dmabuf = vma->vm_private_data;
821 
822 	if (WARN_ON(vmf->pgoff >= dmabuf->pagecount))
823 		return VM_FAULT_SIGBUS;
824 
825 	vmf->page = dmabuf->pages[vmf->pgoff];
826 	get_page(vmf->page);
827 	return 0;
828 }
829 
830 static const struct vm_operations_struct mbochs_dmabuf_vm_ops = {
831 	.fault = mbochs_dmabuf_vm_fault,
832 };
833 
834 static int mbochs_mmap_dmabuf(struct dma_buf *buf, struct vm_area_struct *vma)
835 {
836 	struct mbochs_dmabuf *dmabuf = buf->priv;
837 	struct device *dev = mdev_dev(dmabuf->mdev_state->mdev);
838 
839 	dev_dbg(dev, "%s: %d\n", __func__, dmabuf->id);
840 
841 	if ((vma->vm_flags & VM_SHARED) == 0)
842 		return -EINVAL;
843 
844 	vma->vm_ops = &mbochs_dmabuf_vm_ops;
845 	vma->vm_private_data = dmabuf;
846 	return 0;
847 }
848 
849 static void mbochs_print_dmabuf(struct mbochs_dmabuf *dmabuf,
850 				const char *prefix)
851 {
852 	struct device *dev = mdev_dev(dmabuf->mdev_state->mdev);
853 	u32 fourcc = dmabuf->mode.drm_format;
854 
855 	dev_dbg(dev, "%s/%d: %c%c%c%c, %dx%d, stride %d, off 0x%llx, size 0x%llx, pages %ld\n",
856 		prefix, dmabuf->id,
857 		fourcc ? ((fourcc >>  0) & 0xff) : '-',
858 		fourcc ? ((fourcc >>  8) & 0xff) : '-',
859 		fourcc ? ((fourcc >> 16) & 0xff) : '-',
860 		fourcc ? ((fourcc >> 24) & 0xff) : '-',
861 		dmabuf->mode.width, dmabuf->mode.height, dmabuf->mode.stride,
862 		dmabuf->mode.offset, dmabuf->mode.size, dmabuf->pagecount);
863 }
864 
865 static struct sg_table *mbochs_map_dmabuf(struct dma_buf_attachment *at,
866 					  enum dma_data_direction direction)
867 {
868 	struct mbochs_dmabuf *dmabuf = at->dmabuf->priv;
869 	struct device *dev = mdev_dev(dmabuf->mdev_state->mdev);
870 	struct sg_table *sg;
871 
872 	dev_dbg(dev, "%s: %d\n", __func__, dmabuf->id);
873 
874 	sg = kzalloc(sizeof(*sg), GFP_KERNEL);
875 	if (!sg)
876 		goto err1;
877 	if (sg_alloc_table_from_pages(sg, dmabuf->pages, dmabuf->pagecount,
878 				      0, dmabuf->mode.size, GFP_KERNEL) < 0)
879 		goto err2;
880 	if (dma_map_sgtable(at->dev, sg, direction, 0))
881 		goto err3;
882 
883 	return sg;
884 
885 err3:
886 	sg_free_table(sg);
887 err2:
888 	kfree(sg);
889 err1:
890 	return ERR_PTR(-ENOMEM);
891 }
892 
893 static void mbochs_unmap_dmabuf(struct dma_buf_attachment *at,
894 				struct sg_table *sg,
895 				enum dma_data_direction direction)
896 {
897 	struct mbochs_dmabuf *dmabuf = at->dmabuf->priv;
898 	struct device *dev = mdev_dev(dmabuf->mdev_state->mdev);
899 
900 	dev_dbg(dev, "%s: %d\n", __func__, dmabuf->id);
901 
902 	dma_unmap_sgtable(at->dev, sg, direction, 0);
903 	sg_free_table(sg);
904 	kfree(sg);
905 }
906 
907 static void mbochs_release_dmabuf(struct dma_buf *buf)
908 {
909 	struct mbochs_dmabuf *dmabuf = buf->priv;
910 	struct mdev_state *mdev_state = dmabuf->mdev_state;
911 	struct device *dev = mdev_dev(mdev_state->mdev);
912 	pgoff_t pg;
913 
914 	dev_dbg(dev, "%s: %d\n", __func__, dmabuf->id);
915 
916 	for (pg = 0; pg < dmabuf->pagecount; pg++)
917 		put_page(dmabuf->pages[pg]);
918 
919 	mutex_lock(&mdev_state->ops_lock);
920 	dmabuf->buf = NULL;
921 	if (dmabuf->unlinked)
922 		kfree(dmabuf);
923 	mutex_unlock(&mdev_state->ops_lock);
924 }
925 
926 static struct dma_buf_ops mbochs_dmabuf_ops = {
927 	.map_dma_buf	  = mbochs_map_dmabuf,
928 	.unmap_dma_buf	  = mbochs_unmap_dmabuf,
929 	.release	  = mbochs_release_dmabuf,
930 	.mmap		  = mbochs_mmap_dmabuf,
931 };
932 
933 static struct mbochs_dmabuf *mbochs_dmabuf_alloc(struct mdev_state *mdev_state,
934 						 struct mbochs_mode *mode)
935 {
936 	struct mbochs_dmabuf *dmabuf;
937 	pgoff_t page_offset, pg;
938 
939 	WARN_ON(!mutex_is_locked(&mdev_state->ops_lock));
940 
941 	dmabuf = kzalloc(sizeof(struct mbochs_dmabuf), GFP_KERNEL);
942 	if (!dmabuf)
943 		return NULL;
944 
945 	dmabuf->mode = *mode;
946 	dmabuf->id = mdev_state->next_id++;
947 	dmabuf->pagecount = DIV_ROUND_UP(mode->size, PAGE_SIZE);
948 	dmabuf->pages = kcalloc(dmabuf->pagecount, sizeof(struct page *),
949 				GFP_KERNEL);
950 	if (!dmabuf->pages)
951 		goto err_free_dmabuf;
952 
953 	page_offset = dmabuf->mode.offset >> PAGE_SHIFT;
954 	for (pg = 0; pg < dmabuf->pagecount; pg++) {
955 		dmabuf->pages[pg] = __mbochs_get_page(mdev_state,
956 						      page_offset + pg);
957 		if (!dmabuf->pages[pg])
958 			goto err_free_pages;
959 	}
960 
961 	dmabuf->mdev_state = mdev_state;
962 	list_add(&dmabuf->next, &mdev_state->dmabufs);
963 
964 	mbochs_print_dmabuf(dmabuf, __func__);
965 	return dmabuf;
966 
967 err_free_pages:
968 	while (pg > 0)
969 		put_page(dmabuf->pages[--pg]);
970 	kfree(dmabuf->pages);
971 err_free_dmabuf:
972 	kfree(dmabuf);
973 	return NULL;
974 }
975 
976 static struct mbochs_dmabuf *
977 mbochs_dmabuf_find_by_mode(struct mdev_state *mdev_state,
978 			   struct mbochs_mode *mode)
979 {
980 	struct mbochs_dmabuf *dmabuf;
981 
982 	WARN_ON(!mutex_is_locked(&mdev_state->ops_lock));
983 
984 	list_for_each_entry(dmabuf, &mdev_state->dmabufs, next)
985 		if (mbochs_modes_equal(&dmabuf->mode, mode))
986 			return dmabuf;
987 
988 	return NULL;
989 }
990 
991 static struct mbochs_dmabuf *
992 mbochs_dmabuf_find_by_id(struct mdev_state *mdev_state, u32 id)
993 {
994 	struct mbochs_dmabuf *dmabuf;
995 
996 	WARN_ON(!mutex_is_locked(&mdev_state->ops_lock));
997 
998 	list_for_each_entry(dmabuf, &mdev_state->dmabufs, next)
999 		if (dmabuf->id == id)
1000 			return dmabuf;
1001 
1002 	return NULL;
1003 }
1004 
1005 static int mbochs_dmabuf_export(struct mbochs_dmabuf *dmabuf)
1006 {
1007 	struct mdev_state *mdev_state = dmabuf->mdev_state;
1008 	struct device *dev = mdev_state->vdev.dev;
1009 	DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
1010 	struct dma_buf *buf;
1011 
1012 	WARN_ON(!mutex_is_locked(&mdev_state->ops_lock));
1013 
1014 	if (!IS_ALIGNED(dmabuf->mode.offset, PAGE_SIZE)) {
1015 		dev_info_ratelimited(dev, "%s: framebuffer not page-aligned\n",
1016 				     __func__);
1017 		return -EINVAL;
1018 	}
1019 
1020 	exp_info.ops = &mbochs_dmabuf_ops;
1021 	exp_info.size = dmabuf->mode.size;
1022 	exp_info.priv = dmabuf;
1023 
1024 	buf = dma_buf_export(&exp_info);
1025 	if (IS_ERR(buf)) {
1026 		dev_info_ratelimited(dev, "%s: dma_buf_export failed: %ld\n",
1027 				     __func__, PTR_ERR(buf));
1028 		return PTR_ERR(buf);
1029 	}
1030 
1031 	dmabuf->buf = buf;
1032 	dev_dbg(dev, "%s: %d\n", __func__, dmabuf->id);
1033 	return 0;
1034 }
1035 
1036 static int mbochs_get_region_info(struct mdev_state *mdev_state,
1037 				  struct vfio_region_info_ext *ext)
1038 {
1039 	struct vfio_region_info *region_info = &ext->base;
1040 
1041 	if (region_info->index >= MBOCHS_NUM_REGIONS)
1042 		return -EINVAL;
1043 
1044 	switch (region_info->index) {
1045 	case VFIO_PCI_CONFIG_REGION_INDEX:
1046 		region_info->offset = 0;
1047 		region_info->size   = MBOCHS_CONFIG_SPACE_SIZE;
1048 		region_info->flags  = (VFIO_REGION_INFO_FLAG_READ |
1049 				       VFIO_REGION_INFO_FLAG_WRITE);
1050 		break;
1051 	case VFIO_PCI_BAR0_REGION_INDEX:
1052 		region_info->offset = MBOCHS_MEMORY_BAR_OFFSET;
1053 		region_info->size   = mdev_state->memsize;
1054 		region_info->flags  = (VFIO_REGION_INFO_FLAG_READ  |
1055 				       VFIO_REGION_INFO_FLAG_WRITE |
1056 				       VFIO_REGION_INFO_FLAG_MMAP);
1057 		break;
1058 	case VFIO_PCI_BAR2_REGION_INDEX:
1059 		region_info->offset = MBOCHS_MMIO_BAR_OFFSET;
1060 		region_info->size   = MBOCHS_MMIO_BAR_SIZE;
1061 		region_info->flags  = (VFIO_REGION_INFO_FLAG_READ  |
1062 				       VFIO_REGION_INFO_FLAG_WRITE);
1063 		break;
1064 	case MBOCHS_EDID_REGION_INDEX:
1065 		ext->base.argsz = sizeof(*ext);
1066 		ext->base.offset = MBOCHS_EDID_OFFSET;
1067 		ext->base.size = MBOCHS_EDID_SIZE;
1068 		ext->base.flags = (VFIO_REGION_INFO_FLAG_READ  |
1069 				   VFIO_REGION_INFO_FLAG_WRITE |
1070 				   VFIO_REGION_INFO_FLAG_CAPS);
1071 		ext->base.cap_offset = offsetof(typeof(*ext), type);
1072 		ext->type.header.id = VFIO_REGION_INFO_CAP_TYPE;
1073 		ext->type.header.version = 1;
1074 		ext->type.header.next = 0;
1075 		ext->type.type = VFIO_REGION_TYPE_GFX;
1076 		ext->type.subtype = VFIO_REGION_SUBTYPE_GFX_EDID;
1077 		break;
1078 	default:
1079 		region_info->size   = 0;
1080 		region_info->offset = 0;
1081 		region_info->flags  = 0;
1082 	}
1083 
1084 	return 0;
1085 }
1086 
1087 static int mbochs_get_irq_info(struct vfio_irq_info *irq_info)
1088 {
1089 	irq_info->count = 0;
1090 	return 0;
1091 }
1092 
1093 static int mbochs_get_device_info(struct vfio_device_info *dev_info)
1094 {
1095 	dev_info->flags = VFIO_DEVICE_FLAGS_PCI;
1096 	dev_info->num_regions = MBOCHS_NUM_REGIONS;
1097 	dev_info->num_irqs = VFIO_PCI_NUM_IRQS;
1098 	return 0;
1099 }
1100 
1101 static int mbochs_query_gfx_plane(struct mdev_state *mdev_state,
1102 				  struct vfio_device_gfx_plane_info *plane)
1103 {
1104 	struct mbochs_dmabuf *dmabuf;
1105 	struct mbochs_mode mode;
1106 	int ret;
1107 
1108 	if (plane->flags & VFIO_GFX_PLANE_TYPE_PROBE) {
1109 		if (plane->flags == (VFIO_GFX_PLANE_TYPE_PROBE |
1110 				     VFIO_GFX_PLANE_TYPE_DMABUF))
1111 			return 0;
1112 		return -EINVAL;
1113 	}
1114 
1115 	if (plane->flags != VFIO_GFX_PLANE_TYPE_DMABUF)
1116 		return -EINVAL;
1117 
1118 	plane->drm_format_mod = 0;
1119 	plane->x_pos	      = 0;
1120 	plane->y_pos	      = 0;
1121 	plane->x_hot	      = 0;
1122 	plane->y_hot	      = 0;
1123 
1124 	mutex_lock(&mdev_state->ops_lock);
1125 
1126 	ret = -EINVAL;
1127 	if (plane->drm_plane_type == DRM_PLANE_TYPE_PRIMARY)
1128 		ret = mbochs_check_framebuffer(mdev_state, &mode);
1129 	if (ret < 0) {
1130 		plane->drm_format     = 0;
1131 		plane->width	      = 0;
1132 		plane->height	      = 0;
1133 		plane->stride	      = 0;
1134 		plane->size	      = 0;
1135 		plane->dmabuf_id      = 0;
1136 		goto done;
1137 	}
1138 
1139 	dmabuf = mbochs_dmabuf_find_by_mode(mdev_state, &mode);
1140 	if (!dmabuf)
1141 		mbochs_dmabuf_alloc(mdev_state, &mode);
1142 	if (!dmabuf) {
1143 		mutex_unlock(&mdev_state->ops_lock);
1144 		return -ENOMEM;
1145 	}
1146 
1147 	plane->drm_format     = dmabuf->mode.drm_format;
1148 	plane->width	      = dmabuf->mode.width;
1149 	plane->height	      = dmabuf->mode.height;
1150 	plane->stride	      = dmabuf->mode.stride;
1151 	plane->size	      = dmabuf->mode.size;
1152 	plane->dmabuf_id      = dmabuf->id;
1153 
1154 done:
1155 	if (plane->drm_plane_type == DRM_PLANE_TYPE_PRIMARY &&
1156 	    mdev_state->active_id != plane->dmabuf_id) {
1157 		dev_dbg(mdev_state->vdev.dev, "%s: primary: %d => %d\n",
1158 			__func__, mdev_state->active_id, plane->dmabuf_id);
1159 		mdev_state->active_id = plane->dmabuf_id;
1160 	}
1161 	mutex_unlock(&mdev_state->ops_lock);
1162 	return 0;
1163 }
1164 
1165 static int mbochs_get_gfx_dmabuf(struct mdev_state *mdev_state, u32 id)
1166 {
1167 	struct mbochs_dmabuf *dmabuf;
1168 
1169 	mutex_lock(&mdev_state->ops_lock);
1170 
1171 	dmabuf = mbochs_dmabuf_find_by_id(mdev_state, id);
1172 	if (!dmabuf) {
1173 		mutex_unlock(&mdev_state->ops_lock);
1174 		return -ENOENT;
1175 	}
1176 
1177 	if (!dmabuf->buf)
1178 		mbochs_dmabuf_export(dmabuf);
1179 
1180 	mutex_unlock(&mdev_state->ops_lock);
1181 
1182 	if (!dmabuf->buf)
1183 		return -EINVAL;
1184 
1185 	return dma_buf_fd(dmabuf->buf, 0);
1186 }
1187 
1188 static long mbochs_ioctl(struct vfio_device *vdev, unsigned int cmd,
1189 			 unsigned long arg)
1190 {
1191 	struct mdev_state *mdev_state =
1192 		container_of(vdev, struct mdev_state, vdev);
1193 	int ret = 0;
1194 	unsigned long minsz, outsz;
1195 
1196 	switch (cmd) {
1197 	case VFIO_DEVICE_GET_INFO:
1198 	{
1199 		struct vfio_device_info info;
1200 
1201 		minsz = offsetofend(struct vfio_device_info, num_irqs);
1202 
1203 		if (copy_from_user(&info, (void __user *)arg, minsz))
1204 			return -EFAULT;
1205 
1206 		if (info.argsz < minsz)
1207 			return -EINVAL;
1208 
1209 		ret = mbochs_get_device_info(&info);
1210 		if (ret)
1211 			return ret;
1212 
1213 		if (copy_to_user((void __user *)arg, &info, minsz))
1214 			return -EFAULT;
1215 
1216 		return 0;
1217 	}
1218 	case VFIO_DEVICE_GET_REGION_INFO:
1219 	{
1220 		struct vfio_region_info_ext info;
1221 
1222 		minsz = offsetofend(typeof(info), base.offset);
1223 
1224 		if (copy_from_user(&info, (void __user *)arg, minsz))
1225 			return -EFAULT;
1226 
1227 		outsz = info.base.argsz;
1228 		if (outsz < minsz)
1229 			return -EINVAL;
1230 		if (outsz > sizeof(info))
1231 			return -EINVAL;
1232 
1233 		ret = mbochs_get_region_info(mdev_state, &info);
1234 		if (ret)
1235 			return ret;
1236 
1237 		if (copy_to_user((void __user *)arg, &info, outsz))
1238 			return -EFAULT;
1239 
1240 		return 0;
1241 	}
1242 
1243 	case VFIO_DEVICE_GET_IRQ_INFO:
1244 	{
1245 		struct vfio_irq_info info;
1246 
1247 		minsz = offsetofend(struct vfio_irq_info, count);
1248 
1249 		if (copy_from_user(&info, (void __user *)arg, minsz))
1250 			return -EFAULT;
1251 
1252 		if ((info.argsz < minsz) ||
1253 		    (info.index >= VFIO_PCI_NUM_IRQS))
1254 			return -EINVAL;
1255 
1256 		ret = mbochs_get_irq_info(&info);
1257 		if (ret)
1258 			return ret;
1259 
1260 		if (copy_to_user((void __user *)arg, &info, minsz))
1261 			return -EFAULT;
1262 
1263 		return 0;
1264 	}
1265 
1266 	case VFIO_DEVICE_QUERY_GFX_PLANE:
1267 	{
1268 		struct vfio_device_gfx_plane_info plane = {};
1269 
1270 		minsz = offsetofend(struct vfio_device_gfx_plane_info,
1271 				    region_index);
1272 
1273 		if (copy_from_user(&plane, (void __user *)arg, minsz))
1274 			return -EFAULT;
1275 
1276 		if (plane.argsz < minsz)
1277 			return -EINVAL;
1278 
1279 		ret = mbochs_query_gfx_plane(mdev_state, &plane);
1280 		if (ret)
1281 			return ret;
1282 
1283 		if (copy_to_user((void __user *)arg, &plane, minsz))
1284 			return -EFAULT;
1285 
1286 		return 0;
1287 	}
1288 
1289 	case VFIO_DEVICE_GET_GFX_DMABUF:
1290 	{
1291 		u32 dmabuf_id;
1292 
1293 		if (get_user(dmabuf_id, (__u32 __user *)arg))
1294 			return -EFAULT;
1295 
1296 		return mbochs_get_gfx_dmabuf(mdev_state, dmabuf_id);
1297 	}
1298 
1299 	case VFIO_DEVICE_SET_IRQS:
1300 		return -EINVAL;
1301 
1302 	case VFIO_DEVICE_RESET:
1303 		return mbochs_reset(mdev_state);
1304 	}
1305 	return -ENOTTY;
1306 }
1307 
1308 static void mbochs_close_device(struct vfio_device *vdev)
1309 {
1310 	struct mdev_state *mdev_state =
1311 		container_of(vdev, struct mdev_state, vdev);
1312 	struct mbochs_dmabuf *dmabuf, *tmp;
1313 
1314 	mutex_lock(&mdev_state->ops_lock);
1315 
1316 	list_for_each_entry_safe(dmabuf, tmp, &mdev_state->dmabufs, next) {
1317 		list_del(&dmabuf->next);
1318 		if (dmabuf->buf) {
1319 			/* free in mbochs_release_dmabuf() */
1320 			dmabuf->unlinked = true;
1321 		} else {
1322 			kfree(dmabuf);
1323 		}
1324 	}
1325 	mbochs_put_pages(mdev_state);
1326 
1327 	mutex_unlock(&mdev_state->ops_lock);
1328 }
1329 
1330 static ssize_t
1331 memory_show(struct device *dev, struct device_attribute *attr,
1332 	    char *buf)
1333 {
1334 	struct mdev_state *mdev_state = dev_get_drvdata(dev);
1335 
1336 	return sprintf(buf, "%d MB\n", mdev_state->type->mbytes);
1337 }
1338 static DEVICE_ATTR_RO(memory);
1339 
1340 static struct attribute *mdev_dev_attrs[] = {
1341 	&dev_attr_memory.attr,
1342 	NULL,
1343 };
1344 
1345 static const struct attribute_group mdev_dev_group = {
1346 	.name  = "vendor",
1347 	.attrs = mdev_dev_attrs,
1348 };
1349 
1350 static const struct attribute_group *mdev_dev_groups[] = {
1351 	&mdev_dev_group,
1352 	NULL,
1353 };
1354 
1355 static ssize_t mbochs_show_description(struct mdev_type *mtype, char *buf)
1356 {
1357 	struct mbochs_type *type =
1358 		container_of(mtype, struct mbochs_type, type);
1359 
1360 	return sprintf(buf, "virtual display, %d MB video memory\n",
1361 		       type ? type->mbytes  : 0);
1362 }
1363 
1364 static unsigned int mbochs_get_available(struct mdev_type *mtype)
1365 {
1366 	struct mbochs_type *type =
1367 		container_of(mtype, struct mbochs_type, type);
1368 
1369 	return atomic_read(&mbochs_avail_mbytes) / type->mbytes;
1370 }
1371 
1372 static const struct vfio_device_ops mbochs_dev_ops = {
1373 	.close_device = mbochs_close_device,
1374 	.init = mbochs_init_dev,
1375 	.release = mbochs_release_dev,
1376 	.read = mbochs_read,
1377 	.write = mbochs_write,
1378 	.ioctl = mbochs_ioctl,
1379 	.mmap = mbochs_mmap,
1380 	.bind_iommufd	= vfio_iommufd_emulated_bind,
1381 	.unbind_iommufd	= vfio_iommufd_emulated_unbind,
1382 	.attach_ioas	= vfio_iommufd_emulated_attach_ioas,
1383 	.detach_ioas	= vfio_iommufd_emulated_detach_ioas,
1384 };
1385 
1386 static struct mdev_driver mbochs_driver = {
1387 	.device_api = VFIO_DEVICE_API_PCI_STRING,
1388 	.driver = {
1389 		.name = "mbochs",
1390 		.owner = THIS_MODULE,
1391 		.mod_name = KBUILD_MODNAME,
1392 		.dev_groups = mdev_dev_groups,
1393 	},
1394 	.probe = mbochs_probe,
1395 	.remove	= mbochs_remove,
1396 	.get_available = mbochs_get_available,
1397 	.show_description = mbochs_show_description,
1398 };
1399 
1400 static const struct file_operations vd_fops = {
1401 	.owner		= THIS_MODULE,
1402 };
1403 
1404 static void mbochs_device_release(struct device *dev)
1405 {
1406 	/* nothing */
1407 }
1408 
1409 static int __init mbochs_dev_init(void)
1410 {
1411 	int ret = 0;
1412 
1413 	atomic_set(&mbochs_avail_mbytes, max_mbytes);
1414 
1415 	ret = alloc_chrdev_region(&mbochs_devt, 0, MINORMASK + 1, MBOCHS_NAME);
1416 	if (ret < 0) {
1417 		pr_err("Error: failed to register mbochs_dev, err: %d\n", ret);
1418 		return ret;
1419 	}
1420 	cdev_init(&mbochs_cdev, &vd_fops);
1421 	cdev_add(&mbochs_cdev, mbochs_devt, MINORMASK + 1);
1422 	pr_info("%s: major %d\n", __func__, MAJOR(mbochs_devt));
1423 
1424 	ret = mdev_register_driver(&mbochs_driver);
1425 	if (ret)
1426 		goto err_cdev;
1427 
1428 	ret = class_register(&mbochs_class);
1429 	if (ret)
1430 		goto err_driver;
1431 	mbochs_dev.class = &mbochs_class;
1432 	mbochs_dev.release = mbochs_device_release;
1433 	dev_set_name(&mbochs_dev, "%s", MBOCHS_NAME);
1434 
1435 	ret = device_register(&mbochs_dev);
1436 	if (ret)
1437 		goto err_put;
1438 
1439 	ret = mdev_register_parent(&mbochs_parent, &mbochs_dev, &mbochs_driver,
1440 				   mbochs_mdev_types,
1441 				   ARRAY_SIZE(mbochs_mdev_types));
1442 	if (ret)
1443 		goto err_device;
1444 
1445 	return 0;
1446 
1447 err_device:
1448 	device_del(&mbochs_dev);
1449 err_put:
1450 	put_device(&mbochs_dev);
1451 	class_unregister(&mbochs_class);
1452 err_driver:
1453 	mdev_unregister_driver(&mbochs_driver);
1454 err_cdev:
1455 	cdev_del(&mbochs_cdev);
1456 	unregister_chrdev_region(mbochs_devt, MINORMASK + 1);
1457 	return ret;
1458 }
1459 
1460 static void __exit mbochs_dev_exit(void)
1461 {
1462 	mbochs_dev.bus = NULL;
1463 	mdev_unregister_parent(&mbochs_parent);
1464 
1465 	device_unregister(&mbochs_dev);
1466 	mdev_unregister_driver(&mbochs_driver);
1467 	cdev_del(&mbochs_cdev);
1468 	unregister_chrdev_region(mbochs_devt, MINORMASK + 1);
1469 	class_unregister(&mbochs_class);
1470 }
1471 
1472 MODULE_IMPORT_NS(DMA_BUF);
1473 module_init(mbochs_dev_init)
1474 module_exit(mbochs_dev_exit)
1475