xref: /linux/samples/vfio-mdev/mbochs.c (revision 79997eda0d31bc68203c95ecb978773ee6ce7a1f)
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_LICENSE("GPL v2");
92 
93 static int max_mbytes = 256;
94 module_param_named(count, max_mbytes, int, 0444);
95 MODULE_PARM_DESC(mem, "megabytes available to " MBOCHS_NAME " devices");
96 
97 
98 #define MBOCHS_TYPE_1 "small"
99 #define MBOCHS_TYPE_2 "medium"
100 #define MBOCHS_TYPE_3 "large"
101 
102 static struct mbochs_type {
103 	struct mdev_type type;
104 	u32 mbytes;
105 	u32 max_x;
106 	u32 max_y;
107 } mbochs_types[] = {
108 	{
109 		.type.sysfs_name	= MBOCHS_TYPE_1,
110 		.type.pretty_name	= MBOCHS_CLASS_NAME "-" MBOCHS_TYPE_1,
111 		.mbytes = 4,
112 		.max_x  = 800,
113 		.max_y  = 600,
114 	}, {
115 		.type.sysfs_name	= MBOCHS_TYPE_2,
116 		.type.pretty_name	= MBOCHS_CLASS_NAME "-" MBOCHS_TYPE_2,
117 		.mbytes = 16,
118 		.max_x  = 1920,
119 		.max_y  = 1440,
120 	}, {
121 		.type.sysfs_name	= MBOCHS_TYPE_3,
122 		.type.pretty_name	= MBOCHS_CLASS_NAME "-" MBOCHS_TYPE_3,
123 		.mbytes = 64,
124 		.max_x  = 0,
125 		.max_y  = 0,
126 	},
127 };
128 
129 static struct mdev_type *mbochs_mdev_types[] = {
130 	&mbochs_types[0].type,
131 	&mbochs_types[1].type,
132 	&mbochs_types[2].type,
133 };
134 
135 static dev_t		mbochs_devt;
136 static struct class	*mbochs_class;
137 static struct cdev	mbochs_cdev;
138 static struct device	mbochs_dev;
139 static struct mdev_parent mbochs_parent;
140 static atomic_t mbochs_avail_mbytes;
141 static const struct vfio_device_ops mbochs_dev_ops;
142 
143 struct vfio_region_info_ext {
144 	struct vfio_region_info          base;
145 	struct vfio_region_info_cap_type type;
146 };
147 
148 struct mbochs_mode {
149 	u32 drm_format;
150 	u32 bytepp;
151 	u32 width;
152 	u32 height;
153 	u32 stride;
154 	u32 __pad;
155 	u64 offset;
156 	u64 size;
157 };
158 
159 struct mbochs_dmabuf {
160 	struct mbochs_mode mode;
161 	u32 id;
162 	struct page **pages;
163 	pgoff_t pagecount;
164 	struct dma_buf *buf;
165 	struct mdev_state *mdev_state;
166 	struct list_head next;
167 	bool unlinked;
168 };
169 
170 /* State of each mdev device */
171 struct mdev_state {
172 	struct vfio_device vdev;
173 	u8 *vconfig;
174 	u64 bar_mask[3];
175 	u32 memory_bar_mask;
176 	struct mutex ops_lock;
177 	struct mdev_device *mdev;
178 
179 	const struct mbochs_type *type;
180 	u16 vbe[VBE_DISPI_INDEX_COUNT];
181 	u64 memsize;
182 	struct page **pages;
183 	pgoff_t pagecount;
184 	struct vfio_region_gfx_edid edid_regs;
185 	u8 edid_blob[0x400];
186 
187 	struct list_head dmabufs;
188 	u32 active_id;
189 	u32 next_id;
190 };
191 
192 static const char *vbe_name_list[VBE_DISPI_INDEX_COUNT] = {
193 	[VBE_DISPI_INDEX_ID]               = "id",
194 	[VBE_DISPI_INDEX_XRES]             = "xres",
195 	[VBE_DISPI_INDEX_YRES]             = "yres",
196 	[VBE_DISPI_INDEX_BPP]              = "bpp",
197 	[VBE_DISPI_INDEX_ENABLE]           = "enable",
198 	[VBE_DISPI_INDEX_BANK]             = "bank",
199 	[VBE_DISPI_INDEX_VIRT_WIDTH]       = "virt-width",
200 	[VBE_DISPI_INDEX_VIRT_HEIGHT]      = "virt-height",
201 	[VBE_DISPI_INDEX_X_OFFSET]         = "x-offset",
202 	[VBE_DISPI_INDEX_Y_OFFSET]         = "y-offset",
203 	[VBE_DISPI_INDEX_VIDEO_MEMORY_64K] = "video-mem",
204 };
205 
206 static const char *vbe_name(u32 index)
207 {
208 	if (index < ARRAY_SIZE(vbe_name_list))
209 		return vbe_name_list[index];
210 	return "(invalid)";
211 }
212 
213 static struct page *__mbochs_get_page(struct mdev_state *mdev_state,
214 				      pgoff_t pgoff);
215 static struct page *mbochs_get_page(struct mdev_state *mdev_state,
216 				    pgoff_t pgoff);
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_state *mdev_state, char *buf,
439 			   size_t count, loff_t pos, bool is_write)
440 {
441 	struct page *pg;
442 	loff_t poff;
443 	char *map;
444 	int ret = 0;
445 
446 	mutex_lock(&mdev_state->ops_lock);
447 
448 	if (pos < MBOCHS_CONFIG_SPACE_SIZE) {
449 		if (is_write)
450 			handle_pci_cfg_write(mdev_state, pos, buf, count);
451 		else
452 			memcpy(buf, (mdev_state->vconfig + pos), count);
453 
454 	} else if (pos >= MBOCHS_MMIO_BAR_OFFSET &&
455 		   pos + count <= (MBOCHS_MMIO_BAR_OFFSET +
456 				   MBOCHS_MMIO_BAR_SIZE)) {
457 		pos -= MBOCHS_MMIO_BAR_OFFSET;
458 		if (is_write)
459 			handle_mmio_write(mdev_state, pos, buf, count);
460 		else
461 			handle_mmio_read(mdev_state, pos, buf, count);
462 
463 	} else if (pos >= MBOCHS_EDID_OFFSET &&
464 		   pos + count <= (MBOCHS_EDID_OFFSET +
465 				   MBOCHS_EDID_SIZE)) {
466 		pos -= MBOCHS_EDID_OFFSET;
467 		if (pos < MBOCHS_EDID_BLOB_OFFSET) {
468 			handle_edid_regs(mdev_state, pos, buf, count, is_write);
469 		} else {
470 			pos -= MBOCHS_EDID_BLOB_OFFSET;
471 			handle_edid_blob(mdev_state, pos, buf, count, is_write);
472 		}
473 
474 	} else if (pos >= MBOCHS_MEMORY_BAR_OFFSET &&
475 		   pos + count <=
476 		   MBOCHS_MEMORY_BAR_OFFSET + mdev_state->memsize) {
477 		pos -= MBOCHS_MMIO_BAR_OFFSET;
478 		poff = pos & ~PAGE_MASK;
479 		pg = __mbochs_get_page(mdev_state, pos >> PAGE_SHIFT);
480 		map = kmap(pg);
481 		if (is_write)
482 			memcpy(map + poff, buf, count);
483 		else
484 			memcpy(buf, map + poff, count);
485 		kunmap(pg);
486 		put_page(pg);
487 
488 	} else {
489 		dev_dbg(mdev_state->vdev.dev, "%s: %s @0x%llx (unhandled)\n",
490 			__func__, is_write ? "WR" : "RD", pos);
491 		ret = -1;
492 		goto accessfailed;
493 	}
494 
495 	ret = count;
496 
497 
498 accessfailed:
499 	mutex_unlock(&mdev_state->ops_lock);
500 
501 	return ret;
502 }
503 
504 static int mbochs_reset(struct mdev_state *mdev_state)
505 {
506 	u32 size64k = mdev_state->memsize / (64 * 1024);
507 	int i;
508 
509 	for (i = 0; i < ARRAY_SIZE(mdev_state->vbe); i++)
510 		mdev_state->vbe[i] = 0;
511 	mdev_state->vbe[VBE_DISPI_INDEX_ID] = VBE_DISPI_ID5;
512 	mdev_state->vbe[VBE_DISPI_INDEX_VIDEO_MEMORY_64K] = size64k;
513 	return 0;
514 }
515 
516 static int mbochs_init_dev(struct vfio_device *vdev)
517 {
518 	struct mdev_state *mdev_state =
519 		container_of(vdev, struct mdev_state, vdev);
520 	struct mdev_device *mdev = to_mdev_device(vdev->dev);
521 	struct mbochs_type *type =
522 		container_of(mdev->type, struct mbochs_type, type);
523 	int avail_mbytes = atomic_read(&mbochs_avail_mbytes);
524 	int ret = -ENOMEM;
525 
526 	do {
527 		if (avail_mbytes < type->mbytes)
528 			return -ENOSPC;
529 	} while (!atomic_try_cmpxchg(&mbochs_avail_mbytes, &avail_mbytes,
530 				     avail_mbytes - type->mbytes));
531 
532 	mdev_state->vconfig = kzalloc(MBOCHS_CONFIG_SPACE_SIZE, GFP_KERNEL);
533 	if (!mdev_state->vconfig)
534 		goto err_avail;
535 
536 	mdev_state->memsize = type->mbytes * 1024 * 1024;
537 	mdev_state->pagecount = mdev_state->memsize >> PAGE_SHIFT;
538 	mdev_state->pages = kcalloc(mdev_state->pagecount,
539 				    sizeof(struct page *),
540 				    GFP_KERNEL);
541 	if (!mdev_state->pages)
542 		goto err_vconfig;
543 
544 	mutex_init(&mdev_state->ops_lock);
545 	mdev_state->mdev = mdev;
546 	INIT_LIST_HEAD(&mdev_state->dmabufs);
547 	mdev_state->next_id = 1;
548 
549 	mdev_state->type = type;
550 	mdev_state->edid_regs.max_xres = type->max_x;
551 	mdev_state->edid_regs.max_yres = type->max_y;
552 	mdev_state->edid_regs.edid_offset = MBOCHS_EDID_BLOB_OFFSET;
553 	mdev_state->edid_regs.edid_max_size = sizeof(mdev_state->edid_blob);
554 	mbochs_create_config_space(mdev_state);
555 	mbochs_reset(mdev_state);
556 
557 	dev_info(vdev->dev, "%s: %s, %d MB, %ld pages\n", __func__,
558 		 type->type.pretty_name, type->mbytes, mdev_state->pagecount);
559 	return 0;
560 
561 err_vconfig:
562 	kfree(mdev_state->vconfig);
563 err_avail:
564 	atomic_add(type->mbytes, &mbochs_avail_mbytes);
565 	return ret;
566 }
567 
568 static int mbochs_probe(struct mdev_device *mdev)
569 {
570 	struct mdev_state *mdev_state;
571 	int ret = -ENOMEM;
572 
573 	mdev_state = vfio_alloc_device(mdev_state, vdev, &mdev->dev,
574 				       &mbochs_dev_ops);
575 	if (IS_ERR(mdev_state))
576 		return PTR_ERR(mdev_state);
577 
578 	ret = vfio_register_emulated_iommu_dev(&mdev_state->vdev);
579 	if (ret)
580 		goto err_put_vdev;
581 	dev_set_drvdata(&mdev->dev, mdev_state);
582 	return 0;
583 
584 err_put_vdev:
585 	vfio_put_device(&mdev_state->vdev);
586 	return ret;
587 }
588 
589 static void mbochs_release_dev(struct vfio_device *vdev)
590 {
591 	struct mdev_state *mdev_state =
592 		container_of(vdev, struct mdev_state, vdev);
593 
594 	atomic_add(mdev_state->type->mbytes, &mbochs_avail_mbytes);
595 	kfree(mdev_state->pages);
596 	kfree(mdev_state->vconfig);
597 }
598 
599 static void mbochs_remove(struct mdev_device *mdev)
600 {
601 	struct mdev_state *mdev_state = dev_get_drvdata(&mdev->dev);
602 
603 	vfio_unregister_group_dev(&mdev_state->vdev);
604 	vfio_put_device(&mdev_state->vdev);
605 }
606 
607 static ssize_t mbochs_read(struct vfio_device *vdev, char __user *buf,
608 			   size_t count, loff_t *ppos)
609 {
610 	struct mdev_state *mdev_state =
611 		container_of(vdev, struct mdev_state, vdev);
612 	unsigned int done = 0;
613 	int ret;
614 
615 	while (count) {
616 		size_t filled;
617 
618 		if (count >= 4 && !(*ppos % 4)) {
619 			u32 val;
620 
621 			ret =  mdev_access(mdev_state, (char *)&val, sizeof(val),
622 					   *ppos, false);
623 			if (ret <= 0)
624 				goto read_err;
625 
626 			if (copy_to_user(buf, &val, sizeof(val)))
627 				goto read_err;
628 
629 			filled = 4;
630 		} else if (count >= 2 && !(*ppos % 2)) {
631 			u16 val;
632 
633 			ret = mdev_access(mdev_state, (char *)&val, sizeof(val),
634 					  *ppos, false);
635 			if (ret <= 0)
636 				goto read_err;
637 
638 			if (copy_to_user(buf, &val, sizeof(val)))
639 				goto read_err;
640 
641 			filled = 2;
642 		} else {
643 			u8 val;
644 
645 			ret = mdev_access(mdev_state, (char *)&val, sizeof(val),
646 					  *ppos, false);
647 			if (ret <= 0)
648 				goto read_err;
649 
650 			if (copy_to_user(buf, &val, sizeof(val)))
651 				goto read_err;
652 
653 			filled = 1;
654 		}
655 
656 		count -= filled;
657 		done += filled;
658 		*ppos += filled;
659 		buf += filled;
660 	}
661 
662 	return done;
663 
664 read_err:
665 	return -EFAULT;
666 }
667 
668 static ssize_t mbochs_write(struct vfio_device *vdev, const char __user *buf,
669 			    size_t count, loff_t *ppos)
670 {
671 	struct mdev_state *mdev_state =
672 		container_of(vdev, struct mdev_state, vdev);
673 	unsigned int done = 0;
674 	int ret;
675 
676 	while (count) {
677 		size_t filled;
678 
679 		if (count >= 4 && !(*ppos % 4)) {
680 			u32 val;
681 
682 			if (copy_from_user(&val, buf, sizeof(val)))
683 				goto write_err;
684 
685 			ret = mdev_access(mdev_state, (char *)&val, sizeof(val),
686 					  *ppos, true);
687 			if (ret <= 0)
688 				goto write_err;
689 
690 			filled = 4;
691 		} else if (count >= 2 && !(*ppos % 2)) {
692 			u16 val;
693 
694 			if (copy_from_user(&val, buf, sizeof(val)))
695 				goto write_err;
696 
697 			ret = mdev_access(mdev_state, (char *)&val, sizeof(val),
698 					  *ppos, true);
699 			if (ret <= 0)
700 				goto write_err;
701 
702 			filled = 2;
703 		} else {
704 			u8 val;
705 
706 			if (copy_from_user(&val, buf, sizeof(val)))
707 				goto write_err;
708 
709 			ret = mdev_access(mdev_state, (char *)&val, sizeof(val),
710 					  *ppos, true);
711 			if (ret <= 0)
712 				goto write_err;
713 
714 			filled = 1;
715 		}
716 		count -= filled;
717 		done += filled;
718 		*ppos += filled;
719 		buf += filled;
720 	}
721 
722 	return done;
723 write_err:
724 	return -EFAULT;
725 }
726 
727 static struct page *__mbochs_get_page(struct mdev_state *mdev_state,
728 				      pgoff_t pgoff)
729 {
730 	WARN_ON(!mutex_is_locked(&mdev_state->ops_lock));
731 
732 	if (!mdev_state->pages[pgoff]) {
733 		mdev_state->pages[pgoff] =
734 			alloc_pages(GFP_HIGHUSER | __GFP_ZERO, 0);
735 		if (!mdev_state->pages[pgoff])
736 			return NULL;
737 	}
738 
739 	get_page(mdev_state->pages[pgoff]);
740 	return mdev_state->pages[pgoff];
741 }
742 
743 static struct page *mbochs_get_page(struct mdev_state *mdev_state,
744 				    pgoff_t pgoff)
745 {
746 	struct page *page;
747 
748 	if (WARN_ON(pgoff >= mdev_state->pagecount))
749 		return NULL;
750 
751 	mutex_lock(&mdev_state->ops_lock);
752 	page = __mbochs_get_page(mdev_state, pgoff);
753 	mutex_unlock(&mdev_state->ops_lock);
754 
755 	return page;
756 }
757 
758 static void mbochs_put_pages(struct mdev_state *mdev_state)
759 {
760 	struct device *dev = mdev_dev(mdev_state->mdev);
761 	int i, count = 0;
762 
763 	WARN_ON(!mutex_is_locked(&mdev_state->ops_lock));
764 
765 	for (i = 0; i < mdev_state->pagecount; i++) {
766 		if (!mdev_state->pages[i])
767 			continue;
768 		put_page(mdev_state->pages[i]);
769 		mdev_state->pages[i] = NULL;
770 		count++;
771 	}
772 	dev_dbg(dev, "%s: %d pages released\n", __func__, count);
773 }
774 
775 static vm_fault_t mbochs_region_vm_fault(struct vm_fault *vmf)
776 {
777 	struct vm_area_struct *vma = vmf->vma;
778 	struct mdev_state *mdev_state = vma->vm_private_data;
779 	pgoff_t page_offset = (vmf->address - vma->vm_start) >> PAGE_SHIFT;
780 
781 	if (page_offset >= mdev_state->pagecount)
782 		return VM_FAULT_SIGBUS;
783 
784 	vmf->page = mbochs_get_page(mdev_state, page_offset);
785 	if (!vmf->page)
786 		return VM_FAULT_SIGBUS;
787 
788 	return 0;
789 }
790 
791 static const struct vm_operations_struct mbochs_region_vm_ops = {
792 	.fault = mbochs_region_vm_fault,
793 };
794 
795 static int mbochs_mmap(struct vfio_device *vdev, struct vm_area_struct *vma)
796 {
797 	struct mdev_state *mdev_state =
798 		container_of(vdev, struct mdev_state, vdev);
799 
800 	if (vma->vm_pgoff != MBOCHS_MEMORY_BAR_OFFSET >> PAGE_SHIFT)
801 		return -EINVAL;
802 	if (vma->vm_end < vma->vm_start)
803 		return -EINVAL;
804 	if (vma->vm_end - vma->vm_start > mdev_state->memsize)
805 		return -EINVAL;
806 	if ((vma->vm_flags & VM_SHARED) == 0)
807 		return -EINVAL;
808 
809 	vma->vm_ops = &mbochs_region_vm_ops;
810 	vma->vm_private_data = mdev_state;
811 	return 0;
812 }
813 
814 static vm_fault_t mbochs_dmabuf_vm_fault(struct vm_fault *vmf)
815 {
816 	struct vm_area_struct *vma = vmf->vma;
817 	struct mbochs_dmabuf *dmabuf = vma->vm_private_data;
818 
819 	if (WARN_ON(vmf->pgoff >= dmabuf->pagecount))
820 		return VM_FAULT_SIGBUS;
821 
822 	vmf->page = dmabuf->pages[vmf->pgoff];
823 	get_page(vmf->page);
824 	return 0;
825 }
826 
827 static const struct vm_operations_struct mbochs_dmabuf_vm_ops = {
828 	.fault = mbochs_dmabuf_vm_fault,
829 };
830 
831 static int mbochs_mmap_dmabuf(struct dma_buf *buf, struct vm_area_struct *vma)
832 {
833 	struct mbochs_dmabuf *dmabuf = buf->priv;
834 	struct device *dev = mdev_dev(dmabuf->mdev_state->mdev);
835 
836 	dev_dbg(dev, "%s: %d\n", __func__, dmabuf->id);
837 
838 	if ((vma->vm_flags & VM_SHARED) == 0)
839 		return -EINVAL;
840 
841 	vma->vm_ops = &mbochs_dmabuf_vm_ops;
842 	vma->vm_private_data = dmabuf;
843 	return 0;
844 }
845 
846 static void mbochs_print_dmabuf(struct mbochs_dmabuf *dmabuf,
847 				const char *prefix)
848 {
849 	struct device *dev = mdev_dev(dmabuf->mdev_state->mdev);
850 	u32 fourcc = dmabuf->mode.drm_format;
851 
852 	dev_dbg(dev, "%s/%d: %c%c%c%c, %dx%d, stride %d, off 0x%llx, size 0x%llx, pages %ld\n",
853 		prefix, dmabuf->id,
854 		fourcc ? ((fourcc >>  0) & 0xff) : '-',
855 		fourcc ? ((fourcc >>  8) & 0xff) : '-',
856 		fourcc ? ((fourcc >> 16) & 0xff) : '-',
857 		fourcc ? ((fourcc >> 24) & 0xff) : '-',
858 		dmabuf->mode.width, dmabuf->mode.height, dmabuf->mode.stride,
859 		dmabuf->mode.offset, dmabuf->mode.size, dmabuf->pagecount);
860 }
861 
862 static struct sg_table *mbochs_map_dmabuf(struct dma_buf_attachment *at,
863 					  enum dma_data_direction direction)
864 {
865 	struct mbochs_dmabuf *dmabuf = at->dmabuf->priv;
866 	struct device *dev = mdev_dev(dmabuf->mdev_state->mdev);
867 	struct sg_table *sg;
868 
869 	dev_dbg(dev, "%s: %d\n", __func__, dmabuf->id);
870 
871 	sg = kzalloc(sizeof(*sg), GFP_KERNEL);
872 	if (!sg)
873 		goto err1;
874 	if (sg_alloc_table_from_pages(sg, dmabuf->pages, dmabuf->pagecount,
875 				      0, dmabuf->mode.size, GFP_KERNEL) < 0)
876 		goto err2;
877 	if (dma_map_sgtable(at->dev, sg, direction, 0))
878 		goto err3;
879 
880 	return sg;
881 
882 err3:
883 	sg_free_table(sg);
884 err2:
885 	kfree(sg);
886 err1:
887 	return ERR_PTR(-ENOMEM);
888 }
889 
890 static void mbochs_unmap_dmabuf(struct dma_buf_attachment *at,
891 				struct sg_table *sg,
892 				enum dma_data_direction direction)
893 {
894 	struct mbochs_dmabuf *dmabuf = at->dmabuf->priv;
895 	struct device *dev = mdev_dev(dmabuf->mdev_state->mdev);
896 
897 	dev_dbg(dev, "%s: %d\n", __func__, dmabuf->id);
898 
899 	dma_unmap_sgtable(at->dev, sg, direction, 0);
900 	sg_free_table(sg);
901 	kfree(sg);
902 }
903 
904 static void mbochs_release_dmabuf(struct dma_buf *buf)
905 {
906 	struct mbochs_dmabuf *dmabuf = buf->priv;
907 	struct mdev_state *mdev_state = dmabuf->mdev_state;
908 	struct device *dev = mdev_dev(mdev_state->mdev);
909 	pgoff_t pg;
910 
911 	dev_dbg(dev, "%s: %d\n", __func__, dmabuf->id);
912 
913 	for (pg = 0; pg < dmabuf->pagecount; pg++)
914 		put_page(dmabuf->pages[pg]);
915 
916 	mutex_lock(&mdev_state->ops_lock);
917 	dmabuf->buf = NULL;
918 	if (dmabuf->unlinked)
919 		kfree(dmabuf);
920 	mutex_unlock(&mdev_state->ops_lock);
921 }
922 
923 static struct dma_buf_ops mbochs_dmabuf_ops = {
924 	.map_dma_buf	  = mbochs_map_dmabuf,
925 	.unmap_dma_buf	  = mbochs_unmap_dmabuf,
926 	.release	  = mbochs_release_dmabuf,
927 	.mmap		  = mbochs_mmap_dmabuf,
928 };
929 
930 static struct mbochs_dmabuf *mbochs_dmabuf_alloc(struct mdev_state *mdev_state,
931 						 struct mbochs_mode *mode)
932 {
933 	struct mbochs_dmabuf *dmabuf;
934 	pgoff_t page_offset, pg;
935 
936 	WARN_ON(!mutex_is_locked(&mdev_state->ops_lock));
937 
938 	dmabuf = kzalloc(sizeof(struct mbochs_dmabuf), GFP_KERNEL);
939 	if (!dmabuf)
940 		return NULL;
941 
942 	dmabuf->mode = *mode;
943 	dmabuf->id = mdev_state->next_id++;
944 	dmabuf->pagecount = DIV_ROUND_UP(mode->size, PAGE_SIZE);
945 	dmabuf->pages = kcalloc(dmabuf->pagecount, sizeof(struct page *),
946 				GFP_KERNEL);
947 	if (!dmabuf->pages)
948 		goto err_free_dmabuf;
949 
950 	page_offset = dmabuf->mode.offset >> PAGE_SHIFT;
951 	for (pg = 0; pg < dmabuf->pagecount; pg++) {
952 		dmabuf->pages[pg] = __mbochs_get_page(mdev_state,
953 						      page_offset + pg);
954 		if (!dmabuf->pages[pg])
955 			goto err_free_pages;
956 	}
957 
958 	dmabuf->mdev_state = mdev_state;
959 	list_add(&dmabuf->next, &mdev_state->dmabufs);
960 
961 	mbochs_print_dmabuf(dmabuf, __func__);
962 	return dmabuf;
963 
964 err_free_pages:
965 	while (pg > 0)
966 		put_page(dmabuf->pages[--pg]);
967 	kfree(dmabuf->pages);
968 err_free_dmabuf:
969 	kfree(dmabuf);
970 	return NULL;
971 }
972 
973 static struct mbochs_dmabuf *
974 mbochs_dmabuf_find_by_mode(struct mdev_state *mdev_state,
975 			   struct mbochs_mode *mode)
976 {
977 	struct mbochs_dmabuf *dmabuf;
978 
979 	WARN_ON(!mutex_is_locked(&mdev_state->ops_lock));
980 
981 	list_for_each_entry(dmabuf, &mdev_state->dmabufs, next)
982 		if (mbochs_modes_equal(&dmabuf->mode, mode))
983 			return dmabuf;
984 
985 	return NULL;
986 }
987 
988 static struct mbochs_dmabuf *
989 mbochs_dmabuf_find_by_id(struct mdev_state *mdev_state, u32 id)
990 {
991 	struct mbochs_dmabuf *dmabuf;
992 
993 	WARN_ON(!mutex_is_locked(&mdev_state->ops_lock));
994 
995 	list_for_each_entry(dmabuf, &mdev_state->dmabufs, next)
996 		if (dmabuf->id == id)
997 			return dmabuf;
998 
999 	return NULL;
1000 }
1001 
1002 static int mbochs_dmabuf_export(struct mbochs_dmabuf *dmabuf)
1003 {
1004 	struct mdev_state *mdev_state = dmabuf->mdev_state;
1005 	struct device *dev = mdev_state->vdev.dev;
1006 	DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
1007 	struct dma_buf *buf;
1008 
1009 	WARN_ON(!mutex_is_locked(&mdev_state->ops_lock));
1010 
1011 	if (!IS_ALIGNED(dmabuf->mode.offset, PAGE_SIZE)) {
1012 		dev_info_ratelimited(dev, "%s: framebuffer not page-aligned\n",
1013 				     __func__);
1014 		return -EINVAL;
1015 	}
1016 
1017 	exp_info.ops = &mbochs_dmabuf_ops;
1018 	exp_info.size = dmabuf->mode.size;
1019 	exp_info.priv = dmabuf;
1020 
1021 	buf = dma_buf_export(&exp_info);
1022 	if (IS_ERR(buf)) {
1023 		dev_info_ratelimited(dev, "%s: dma_buf_export failed: %ld\n",
1024 				     __func__, PTR_ERR(buf));
1025 		return PTR_ERR(buf);
1026 	}
1027 
1028 	dmabuf->buf = buf;
1029 	dev_dbg(dev, "%s: %d\n", __func__, dmabuf->id);
1030 	return 0;
1031 }
1032 
1033 static int mbochs_get_region_info(struct mdev_state *mdev_state,
1034 				  struct vfio_region_info_ext *ext)
1035 {
1036 	struct vfio_region_info *region_info = &ext->base;
1037 
1038 	if (region_info->index >= MBOCHS_NUM_REGIONS)
1039 		return -EINVAL;
1040 
1041 	switch (region_info->index) {
1042 	case VFIO_PCI_CONFIG_REGION_INDEX:
1043 		region_info->offset = 0;
1044 		region_info->size   = MBOCHS_CONFIG_SPACE_SIZE;
1045 		region_info->flags  = (VFIO_REGION_INFO_FLAG_READ |
1046 				       VFIO_REGION_INFO_FLAG_WRITE);
1047 		break;
1048 	case VFIO_PCI_BAR0_REGION_INDEX:
1049 		region_info->offset = MBOCHS_MEMORY_BAR_OFFSET;
1050 		region_info->size   = mdev_state->memsize;
1051 		region_info->flags  = (VFIO_REGION_INFO_FLAG_READ  |
1052 				       VFIO_REGION_INFO_FLAG_WRITE |
1053 				       VFIO_REGION_INFO_FLAG_MMAP);
1054 		break;
1055 	case VFIO_PCI_BAR2_REGION_INDEX:
1056 		region_info->offset = MBOCHS_MMIO_BAR_OFFSET;
1057 		region_info->size   = MBOCHS_MMIO_BAR_SIZE;
1058 		region_info->flags  = (VFIO_REGION_INFO_FLAG_READ  |
1059 				       VFIO_REGION_INFO_FLAG_WRITE);
1060 		break;
1061 	case MBOCHS_EDID_REGION_INDEX:
1062 		ext->base.argsz = sizeof(*ext);
1063 		ext->base.offset = MBOCHS_EDID_OFFSET;
1064 		ext->base.size = MBOCHS_EDID_SIZE;
1065 		ext->base.flags = (VFIO_REGION_INFO_FLAG_READ  |
1066 				   VFIO_REGION_INFO_FLAG_WRITE |
1067 				   VFIO_REGION_INFO_FLAG_CAPS);
1068 		ext->base.cap_offset = offsetof(typeof(*ext), type);
1069 		ext->type.header.id = VFIO_REGION_INFO_CAP_TYPE;
1070 		ext->type.header.version = 1;
1071 		ext->type.header.next = 0;
1072 		ext->type.type = VFIO_REGION_TYPE_GFX;
1073 		ext->type.subtype = VFIO_REGION_SUBTYPE_GFX_EDID;
1074 		break;
1075 	default:
1076 		region_info->size   = 0;
1077 		region_info->offset = 0;
1078 		region_info->flags  = 0;
1079 	}
1080 
1081 	return 0;
1082 }
1083 
1084 static int mbochs_get_irq_info(struct vfio_irq_info *irq_info)
1085 {
1086 	irq_info->count = 0;
1087 	return 0;
1088 }
1089 
1090 static int mbochs_get_device_info(struct vfio_device_info *dev_info)
1091 {
1092 	dev_info->flags = VFIO_DEVICE_FLAGS_PCI;
1093 	dev_info->num_regions = MBOCHS_NUM_REGIONS;
1094 	dev_info->num_irqs = VFIO_PCI_NUM_IRQS;
1095 	return 0;
1096 }
1097 
1098 static int mbochs_query_gfx_plane(struct mdev_state *mdev_state,
1099 				  struct vfio_device_gfx_plane_info *plane)
1100 {
1101 	struct mbochs_dmabuf *dmabuf;
1102 	struct mbochs_mode mode;
1103 	int ret;
1104 
1105 	if (plane->flags & VFIO_GFX_PLANE_TYPE_PROBE) {
1106 		if (plane->flags == (VFIO_GFX_PLANE_TYPE_PROBE |
1107 				     VFIO_GFX_PLANE_TYPE_DMABUF))
1108 			return 0;
1109 		return -EINVAL;
1110 	}
1111 
1112 	if (plane->flags != VFIO_GFX_PLANE_TYPE_DMABUF)
1113 		return -EINVAL;
1114 
1115 	plane->drm_format_mod = 0;
1116 	plane->x_pos	      = 0;
1117 	plane->y_pos	      = 0;
1118 	plane->x_hot	      = 0;
1119 	plane->y_hot	      = 0;
1120 
1121 	mutex_lock(&mdev_state->ops_lock);
1122 
1123 	ret = -EINVAL;
1124 	if (plane->drm_plane_type == DRM_PLANE_TYPE_PRIMARY)
1125 		ret = mbochs_check_framebuffer(mdev_state, &mode);
1126 	if (ret < 0) {
1127 		plane->drm_format     = 0;
1128 		plane->width	      = 0;
1129 		plane->height	      = 0;
1130 		plane->stride	      = 0;
1131 		plane->size	      = 0;
1132 		plane->dmabuf_id      = 0;
1133 		goto done;
1134 	}
1135 
1136 	dmabuf = mbochs_dmabuf_find_by_mode(mdev_state, &mode);
1137 	if (!dmabuf)
1138 		mbochs_dmabuf_alloc(mdev_state, &mode);
1139 	if (!dmabuf) {
1140 		mutex_unlock(&mdev_state->ops_lock);
1141 		return -ENOMEM;
1142 	}
1143 
1144 	plane->drm_format     = dmabuf->mode.drm_format;
1145 	plane->width	      = dmabuf->mode.width;
1146 	plane->height	      = dmabuf->mode.height;
1147 	plane->stride	      = dmabuf->mode.stride;
1148 	plane->size	      = dmabuf->mode.size;
1149 	plane->dmabuf_id      = dmabuf->id;
1150 
1151 done:
1152 	if (plane->drm_plane_type == DRM_PLANE_TYPE_PRIMARY &&
1153 	    mdev_state->active_id != plane->dmabuf_id) {
1154 		dev_dbg(mdev_state->vdev.dev, "%s: primary: %d => %d\n",
1155 			__func__, mdev_state->active_id, plane->dmabuf_id);
1156 		mdev_state->active_id = plane->dmabuf_id;
1157 	}
1158 	mutex_unlock(&mdev_state->ops_lock);
1159 	return 0;
1160 }
1161 
1162 static int mbochs_get_gfx_dmabuf(struct mdev_state *mdev_state, u32 id)
1163 {
1164 	struct mbochs_dmabuf *dmabuf;
1165 
1166 	mutex_lock(&mdev_state->ops_lock);
1167 
1168 	dmabuf = mbochs_dmabuf_find_by_id(mdev_state, id);
1169 	if (!dmabuf) {
1170 		mutex_unlock(&mdev_state->ops_lock);
1171 		return -ENOENT;
1172 	}
1173 
1174 	if (!dmabuf->buf)
1175 		mbochs_dmabuf_export(dmabuf);
1176 
1177 	mutex_unlock(&mdev_state->ops_lock);
1178 
1179 	if (!dmabuf->buf)
1180 		return -EINVAL;
1181 
1182 	return dma_buf_fd(dmabuf->buf, 0);
1183 }
1184 
1185 static long mbochs_ioctl(struct vfio_device *vdev, unsigned int cmd,
1186 			 unsigned long arg)
1187 {
1188 	struct mdev_state *mdev_state =
1189 		container_of(vdev, struct mdev_state, vdev);
1190 	int ret = 0;
1191 	unsigned long minsz, outsz;
1192 
1193 	switch (cmd) {
1194 	case VFIO_DEVICE_GET_INFO:
1195 	{
1196 		struct vfio_device_info info;
1197 
1198 		minsz = offsetofend(struct vfio_device_info, num_irqs);
1199 
1200 		if (copy_from_user(&info, (void __user *)arg, minsz))
1201 			return -EFAULT;
1202 
1203 		if (info.argsz < minsz)
1204 			return -EINVAL;
1205 
1206 		ret = mbochs_get_device_info(&info);
1207 		if (ret)
1208 			return ret;
1209 
1210 		if (copy_to_user((void __user *)arg, &info, minsz))
1211 			return -EFAULT;
1212 
1213 		return 0;
1214 	}
1215 	case VFIO_DEVICE_GET_REGION_INFO:
1216 	{
1217 		struct vfio_region_info_ext info;
1218 
1219 		minsz = offsetofend(typeof(info), base.offset);
1220 
1221 		if (copy_from_user(&info, (void __user *)arg, minsz))
1222 			return -EFAULT;
1223 
1224 		outsz = info.base.argsz;
1225 		if (outsz < minsz)
1226 			return -EINVAL;
1227 		if (outsz > sizeof(info))
1228 			return -EINVAL;
1229 
1230 		ret = mbochs_get_region_info(mdev_state, &info);
1231 		if (ret)
1232 			return ret;
1233 
1234 		if (copy_to_user((void __user *)arg, &info, outsz))
1235 			return -EFAULT;
1236 
1237 		return 0;
1238 	}
1239 
1240 	case VFIO_DEVICE_GET_IRQ_INFO:
1241 	{
1242 		struct vfio_irq_info info;
1243 
1244 		minsz = offsetofend(struct vfio_irq_info, count);
1245 
1246 		if (copy_from_user(&info, (void __user *)arg, minsz))
1247 			return -EFAULT;
1248 
1249 		if ((info.argsz < minsz) ||
1250 		    (info.index >= VFIO_PCI_NUM_IRQS))
1251 			return -EINVAL;
1252 
1253 		ret = mbochs_get_irq_info(&info);
1254 		if (ret)
1255 			return ret;
1256 
1257 		if (copy_to_user((void __user *)arg, &info, minsz))
1258 			return -EFAULT;
1259 
1260 		return 0;
1261 	}
1262 
1263 	case VFIO_DEVICE_QUERY_GFX_PLANE:
1264 	{
1265 		struct vfio_device_gfx_plane_info plane = {};
1266 
1267 		minsz = offsetofend(struct vfio_device_gfx_plane_info,
1268 				    region_index);
1269 
1270 		if (copy_from_user(&plane, (void __user *)arg, minsz))
1271 			return -EFAULT;
1272 
1273 		if (plane.argsz < minsz)
1274 			return -EINVAL;
1275 
1276 		ret = mbochs_query_gfx_plane(mdev_state, &plane);
1277 		if (ret)
1278 			return ret;
1279 
1280 		if (copy_to_user((void __user *)arg, &plane, minsz))
1281 			return -EFAULT;
1282 
1283 		return 0;
1284 	}
1285 
1286 	case VFIO_DEVICE_GET_GFX_DMABUF:
1287 	{
1288 		u32 dmabuf_id;
1289 
1290 		if (get_user(dmabuf_id, (__u32 __user *)arg))
1291 			return -EFAULT;
1292 
1293 		return mbochs_get_gfx_dmabuf(mdev_state, dmabuf_id);
1294 	}
1295 
1296 	case VFIO_DEVICE_SET_IRQS:
1297 		return -EINVAL;
1298 
1299 	case VFIO_DEVICE_RESET:
1300 		return mbochs_reset(mdev_state);
1301 	}
1302 	return -ENOTTY;
1303 }
1304 
1305 static void mbochs_close_device(struct vfio_device *vdev)
1306 {
1307 	struct mdev_state *mdev_state =
1308 		container_of(vdev, struct mdev_state, vdev);
1309 	struct mbochs_dmabuf *dmabuf, *tmp;
1310 
1311 	mutex_lock(&mdev_state->ops_lock);
1312 
1313 	list_for_each_entry_safe(dmabuf, tmp, &mdev_state->dmabufs, next) {
1314 		list_del(&dmabuf->next);
1315 		if (dmabuf->buf) {
1316 			/* free in mbochs_release_dmabuf() */
1317 			dmabuf->unlinked = true;
1318 		} else {
1319 			kfree(dmabuf);
1320 		}
1321 	}
1322 	mbochs_put_pages(mdev_state);
1323 
1324 	mutex_unlock(&mdev_state->ops_lock);
1325 }
1326 
1327 static ssize_t
1328 memory_show(struct device *dev, struct device_attribute *attr,
1329 	    char *buf)
1330 {
1331 	struct mdev_state *mdev_state = dev_get_drvdata(dev);
1332 
1333 	return sprintf(buf, "%d MB\n", mdev_state->type->mbytes);
1334 }
1335 static DEVICE_ATTR_RO(memory);
1336 
1337 static struct attribute *mdev_dev_attrs[] = {
1338 	&dev_attr_memory.attr,
1339 	NULL,
1340 };
1341 
1342 static const struct attribute_group mdev_dev_group = {
1343 	.name  = "vendor",
1344 	.attrs = mdev_dev_attrs,
1345 };
1346 
1347 static const struct attribute_group *mdev_dev_groups[] = {
1348 	&mdev_dev_group,
1349 	NULL,
1350 };
1351 
1352 static ssize_t mbochs_show_description(struct mdev_type *mtype, char *buf)
1353 {
1354 	struct mbochs_type *type =
1355 		container_of(mtype, struct mbochs_type, type);
1356 
1357 	return sprintf(buf, "virtual display, %d MB video memory\n",
1358 		       type ? type->mbytes  : 0);
1359 }
1360 
1361 static unsigned int mbochs_get_available(struct mdev_type *mtype)
1362 {
1363 	struct mbochs_type *type =
1364 		container_of(mtype, struct mbochs_type, type);
1365 
1366 	return atomic_read(&mbochs_avail_mbytes) / type->mbytes;
1367 }
1368 
1369 static const struct vfio_device_ops mbochs_dev_ops = {
1370 	.close_device = mbochs_close_device,
1371 	.init = mbochs_init_dev,
1372 	.release = mbochs_release_dev,
1373 	.read = mbochs_read,
1374 	.write = mbochs_write,
1375 	.ioctl = mbochs_ioctl,
1376 	.mmap = mbochs_mmap,
1377 	.bind_iommufd	= vfio_iommufd_emulated_bind,
1378 	.unbind_iommufd	= vfio_iommufd_emulated_unbind,
1379 	.attach_ioas	= vfio_iommufd_emulated_attach_ioas,
1380 	.detach_ioas	= vfio_iommufd_emulated_detach_ioas,
1381 };
1382 
1383 static struct mdev_driver mbochs_driver = {
1384 	.device_api = VFIO_DEVICE_API_PCI_STRING,
1385 	.driver = {
1386 		.name = "mbochs",
1387 		.owner = THIS_MODULE,
1388 		.mod_name = KBUILD_MODNAME,
1389 		.dev_groups = mdev_dev_groups,
1390 	},
1391 	.probe = mbochs_probe,
1392 	.remove	= mbochs_remove,
1393 	.get_available = mbochs_get_available,
1394 	.show_description = mbochs_show_description,
1395 };
1396 
1397 static const struct file_operations vd_fops = {
1398 	.owner		= THIS_MODULE,
1399 };
1400 
1401 static void mbochs_device_release(struct device *dev)
1402 {
1403 	/* nothing */
1404 }
1405 
1406 static int __init mbochs_dev_init(void)
1407 {
1408 	int ret = 0;
1409 
1410 	atomic_set(&mbochs_avail_mbytes, max_mbytes);
1411 
1412 	ret = alloc_chrdev_region(&mbochs_devt, 0, MINORMASK + 1, MBOCHS_NAME);
1413 	if (ret < 0) {
1414 		pr_err("Error: failed to register mbochs_dev, err: %d\n", ret);
1415 		return ret;
1416 	}
1417 	cdev_init(&mbochs_cdev, &vd_fops);
1418 	cdev_add(&mbochs_cdev, mbochs_devt, MINORMASK + 1);
1419 	pr_info("%s: major %d\n", __func__, MAJOR(mbochs_devt));
1420 
1421 	ret = mdev_register_driver(&mbochs_driver);
1422 	if (ret)
1423 		goto err_cdev;
1424 
1425 	mbochs_class = class_create(MBOCHS_CLASS_NAME);
1426 	if (IS_ERR(mbochs_class)) {
1427 		pr_err("Error: failed to register mbochs_dev class\n");
1428 		ret = PTR_ERR(mbochs_class);
1429 		goto err_driver;
1430 	}
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_destroy(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_destroy(mbochs_class);
1470 	mbochs_class = NULL;
1471 }
1472 
1473 MODULE_IMPORT_NS(DMA_BUF);
1474 module_init(mbochs_dev_init)
1475 module_exit(mbochs_dev_exit)
1476