xref: /linux/samples/vfio-mdev/mbochs.c (revision a3ebb59eee2e558e8f8f27fc3f75cd367f17cd8e)
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 mbochs_mode {
147 	u32 drm_format;
148 	u32 bytepp;
149 	u32 width;
150 	u32 height;
151 	u32 stride;
152 	u32 __pad;
153 	u64 offset;
154 	u64 size;
155 };
156 
157 struct mbochs_dmabuf {
158 	struct mbochs_mode mode;
159 	u32 id;
160 	struct page **pages;
161 	pgoff_t pagecount;
162 	struct dma_buf *buf;
163 	struct mdev_state *mdev_state;
164 	struct list_head next;
165 	bool unlinked;
166 };
167 
168 /* State of each mdev device */
169 struct mdev_state {
170 	struct vfio_device vdev;
171 	u8 *vconfig;
172 	u64 bar_mask[3];
173 	u32 memory_bar_mask;
174 	struct mutex ops_lock;
175 	struct mdev_device *mdev;
176 
177 	const struct mbochs_type *type;
178 	u16 vbe[VBE_DISPI_INDEX_COUNT];
179 	u64 memsize;
180 	struct page **pages;
181 	pgoff_t pagecount;
182 	struct vfio_region_gfx_edid edid_regs;
183 	u8 edid_blob[0x400];
184 
185 	struct list_head dmabufs;
186 	u32 active_id;
187 	u32 next_id;
188 };
189 
190 static const char *vbe_name_list[VBE_DISPI_INDEX_COUNT] = {
191 	[VBE_DISPI_INDEX_ID]               = "id",
192 	[VBE_DISPI_INDEX_XRES]             = "xres",
193 	[VBE_DISPI_INDEX_YRES]             = "yres",
194 	[VBE_DISPI_INDEX_BPP]              = "bpp",
195 	[VBE_DISPI_INDEX_ENABLE]           = "enable",
196 	[VBE_DISPI_INDEX_BANK]             = "bank",
197 	[VBE_DISPI_INDEX_VIRT_WIDTH]       = "virt-width",
198 	[VBE_DISPI_INDEX_VIRT_HEIGHT]      = "virt-height",
199 	[VBE_DISPI_INDEX_X_OFFSET]         = "x-offset",
200 	[VBE_DISPI_INDEX_Y_OFFSET]         = "y-offset",
201 	[VBE_DISPI_INDEX_VIDEO_MEMORY_64K] = "video-mem",
202 };
203 
vbe_name(u32 index)204 static const char *vbe_name(u32 index)
205 {
206 	if (index < ARRAY_SIZE(vbe_name_list))
207 		return vbe_name_list[index];
208 	return "(invalid)";
209 }
210 
211 static struct page *__mbochs_get_page(struct mdev_state *mdev_state,
212 				      pgoff_t pgoff);
213 static struct page *mbochs_get_page(struct mdev_state *mdev_state,
214 				    pgoff_t pgoff);
215 
mbochs_create_config_space(struct mdev_state * mdev_state)216 static void mbochs_create_config_space(struct mdev_state *mdev_state)
217 {
218 	STORE_LE16((u16 *) &mdev_state->vconfig[PCI_VENDOR_ID],
219 		   0x1234);
220 	STORE_LE16((u16 *) &mdev_state->vconfig[PCI_DEVICE_ID],
221 		   0x1111);
222 	STORE_LE16((u16 *) &mdev_state->vconfig[PCI_SUBSYSTEM_VENDOR_ID],
223 		   PCI_SUBVENDOR_ID_REDHAT_QUMRANET);
224 	STORE_LE16((u16 *) &mdev_state->vconfig[PCI_SUBSYSTEM_ID],
225 		   PCI_SUBDEVICE_ID_QEMU);
226 
227 	STORE_LE16((u16 *) &mdev_state->vconfig[PCI_COMMAND],
228 		   PCI_COMMAND_IO | PCI_COMMAND_MEMORY);
229 	STORE_LE16((u16 *) &mdev_state->vconfig[PCI_CLASS_DEVICE],
230 		   PCI_CLASS_DISPLAY_OTHER);
231 	mdev_state->vconfig[PCI_CLASS_REVISION] =  0x01;
232 
233 	STORE_LE32((u32 *) &mdev_state->vconfig[PCI_BASE_ADDRESS_0],
234 		   PCI_BASE_ADDRESS_SPACE_MEMORY |
235 		   PCI_BASE_ADDRESS_MEM_TYPE_32	 |
236 		   PCI_BASE_ADDRESS_MEM_PREFETCH);
237 	mdev_state->bar_mask[0] = ~(mdev_state->memsize) + 1;
238 
239 	STORE_LE32((u32 *) &mdev_state->vconfig[PCI_BASE_ADDRESS_2],
240 		   PCI_BASE_ADDRESS_SPACE_MEMORY |
241 		   PCI_BASE_ADDRESS_MEM_TYPE_32);
242 	mdev_state->bar_mask[2] = ~(MBOCHS_MMIO_BAR_SIZE) + 1;
243 }
244 
mbochs_check_framebuffer(struct mdev_state * mdev_state,struct mbochs_mode * mode)245 static int mbochs_check_framebuffer(struct mdev_state *mdev_state,
246 				    struct mbochs_mode *mode)
247 {
248 	struct device *dev = mdev_dev(mdev_state->mdev);
249 	u16 *vbe = mdev_state->vbe;
250 	u32 virt_width;
251 
252 	WARN_ON(!mutex_is_locked(&mdev_state->ops_lock));
253 
254 	if (!(vbe[VBE_DISPI_INDEX_ENABLE] & VBE_DISPI_ENABLED))
255 		goto nofb;
256 
257 	memset(mode, 0, sizeof(*mode));
258 	switch (vbe[VBE_DISPI_INDEX_BPP]) {
259 	case 32:
260 		mode->drm_format = DRM_FORMAT_XRGB8888;
261 		mode->bytepp = 4;
262 		break;
263 	default:
264 		dev_info_ratelimited(dev, "%s: bpp %d not supported\n",
265 				     __func__, vbe[VBE_DISPI_INDEX_BPP]);
266 		goto nofb;
267 	}
268 
269 	mode->width  = vbe[VBE_DISPI_INDEX_XRES];
270 	mode->height = vbe[VBE_DISPI_INDEX_YRES];
271 	virt_width  = vbe[VBE_DISPI_INDEX_VIRT_WIDTH];
272 	if (virt_width < mode->width)
273 		virt_width = mode->width;
274 	mode->stride = virt_width * mode->bytepp;
275 	mode->size   = (u64)mode->stride * mode->height;
276 	mode->offset = ((u64)vbe[VBE_DISPI_INDEX_X_OFFSET] * mode->bytepp +
277 		       (u64)vbe[VBE_DISPI_INDEX_Y_OFFSET] * mode->stride);
278 
279 	if (mode->width < 64 || mode->height < 64) {
280 		dev_info_ratelimited(dev, "%s: invalid resolution %dx%d\n",
281 				     __func__, mode->width, mode->height);
282 		goto nofb;
283 	}
284 	if (mode->offset + mode->size > mdev_state->memsize) {
285 		dev_info_ratelimited(dev, "%s: framebuffer memory overflow\n",
286 				     __func__);
287 		goto nofb;
288 	}
289 
290 	return 0;
291 
292 nofb:
293 	memset(mode, 0, sizeof(*mode));
294 	return -EINVAL;
295 }
296 
mbochs_modes_equal(struct mbochs_mode * mode1,struct mbochs_mode * mode2)297 static bool mbochs_modes_equal(struct mbochs_mode *mode1,
298 			       struct mbochs_mode *mode2)
299 {
300 	return memcmp(mode1, mode2, sizeof(struct mbochs_mode)) == 0;
301 }
302 
handle_pci_cfg_write(struct mdev_state * mdev_state,u16 offset,char * buf,u32 count)303 static void handle_pci_cfg_write(struct mdev_state *mdev_state, u16 offset,
304 				 char *buf, u32 count)
305 {
306 	struct device *dev = mdev_dev(mdev_state->mdev);
307 	int index = (offset - PCI_BASE_ADDRESS_0) / 0x04;
308 	u32 cfg_addr;
309 
310 	switch (offset) {
311 	case PCI_BASE_ADDRESS_0:
312 	case PCI_BASE_ADDRESS_2:
313 		cfg_addr = *(u32 *)buf;
314 
315 		if (cfg_addr == 0xffffffff) {
316 			cfg_addr = (cfg_addr & mdev_state->bar_mask[index]);
317 		} else {
318 			cfg_addr &= PCI_BASE_ADDRESS_MEM_MASK;
319 			if (cfg_addr)
320 				dev_info(dev, "BAR #%d @ 0x%x\n",
321 					 index, cfg_addr);
322 		}
323 
324 		cfg_addr |= (mdev_state->vconfig[offset] &
325 			     ~PCI_BASE_ADDRESS_MEM_MASK);
326 		STORE_LE32(&mdev_state->vconfig[offset], cfg_addr);
327 		break;
328 	}
329 }
330 
handle_mmio_write(struct mdev_state * mdev_state,u16 offset,char * buf,u32 count)331 static void handle_mmio_write(struct mdev_state *mdev_state, u16 offset,
332 			      char *buf, u32 count)
333 {
334 	struct device *dev = mdev_dev(mdev_state->mdev);
335 	int index;
336 	u16 reg16;
337 
338 	switch (offset) {
339 	case 0x400 ... 0x41f: /* vga ioports remapped */
340 		goto unhandled;
341 	case 0x500 ... 0x515: /* bochs dispi interface */
342 		if (count != 2)
343 			goto unhandled;
344 		index = (offset - 0x500) / 2;
345 		reg16 = *(u16 *)buf;
346 		if (index < ARRAY_SIZE(mdev_state->vbe))
347 			mdev_state->vbe[index] = reg16;
348 		dev_dbg(dev, "%s: vbe write %d = %d (%s)\n",
349 			__func__, index, reg16, vbe_name(index));
350 		break;
351 	case 0x600 ... 0x607: /* qemu extended regs */
352 		goto unhandled;
353 	default:
354 unhandled:
355 		dev_dbg(dev, "%s: @0x%03x, count %d (unhandled)\n",
356 			__func__, offset, count);
357 		break;
358 	}
359 }
360 
handle_mmio_read(struct mdev_state * mdev_state,u16 offset,char * buf,u32 count)361 static void handle_mmio_read(struct mdev_state *mdev_state, u16 offset,
362 			     char *buf, u32 count)
363 {
364 	struct device *dev = mdev_dev(mdev_state->mdev);
365 	struct vfio_region_gfx_edid *edid;
366 	u16 reg16 = 0;
367 	int index;
368 
369 	switch (offset) {
370 	case 0x000 ... 0x3ff: /* edid block */
371 		edid = &mdev_state->edid_regs;
372 		if (edid->link_state != VFIO_DEVICE_GFX_LINK_STATE_UP ||
373 		    offset >= edid->edid_size) {
374 			memset(buf, 0, count);
375 			break;
376 		}
377 		memcpy(buf, mdev_state->edid_blob + offset, count);
378 		break;
379 	case 0x500 ... 0x515: /* bochs dispi interface */
380 		if (count != 2)
381 			goto unhandled;
382 		index = (offset - 0x500) / 2;
383 		if (index < ARRAY_SIZE(mdev_state->vbe))
384 			reg16 = mdev_state->vbe[index];
385 		dev_dbg(dev, "%s: vbe read %d = %d (%s)\n",
386 			__func__, index, reg16, vbe_name(index));
387 		*(u16 *)buf = reg16;
388 		break;
389 	default:
390 unhandled:
391 		dev_dbg(dev, "%s: @0x%03x, count %d (unhandled)\n",
392 			__func__, offset, count);
393 		memset(buf, 0, count);
394 		break;
395 	}
396 }
397 
handle_edid_regs(struct mdev_state * mdev_state,u16 offset,char * buf,u32 count,bool is_write)398 static void handle_edid_regs(struct mdev_state *mdev_state, u16 offset,
399 			     char *buf, u32 count, bool is_write)
400 {
401 	char *regs = (void *)&mdev_state->edid_regs;
402 
403 	if (offset + count > sizeof(mdev_state->edid_regs))
404 		return;
405 	if (count != 4)
406 		return;
407 	if (offset % 4)
408 		return;
409 
410 	if (is_write) {
411 		switch (offset) {
412 		case offsetof(struct vfio_region_gfx_edid, link_state):
413 		case offsetof(struct vfio_region_gfx_edid, edid_size):
414 			memcpy(regs + offset, buf, count);
415 			break;
416 		default:
417 			/* read-only regs */
418 			break;
419 		}
420 	} else {
421 		memcpy(buf, regs + offset, count);
422 	}
423 }
424 
handle_edid_blob(struct mdev_state * mdev_state,u16 offset,char * buf,u32 count,bool is_write)425 static void handle_edid_blob(struct mdev_state *mdev_state, u16 offset,
426 			     char *buf, u32 count, bool is_write)
427 {
428 	if (offset + count > mdev_state->edid_regs.edid_max_size)
429 		return;
430 	if (is_write)
431 		memcpy(mdev_state->edid_blob + offset, buf, count);
432 	else
433 		memcpy(buf, mdev_state->edid_blob + offset, count);
434 }
435 
mdev_access(struct mdev_state * mdev_state,char * buf,size_t count,loff_t pos,bool is_write)436 static ssize_t mdev_access(struct mdev_state *mdev_state, char *buf,
437 			   size_t count, loff_t pos, bool is_write)
438 {
439 	struct page *pg;
440 	loff_t poff;
441 	char *map;
442 	int ret = 0;
443 
444 	mutex_lock(&mdev_state->ops_lock);
445 
446 	if (pos < MBOCHS_CONFIG_SPACE_SIZE) {
447 		if (is_write)
448 			handle_pci_cfg_write(mdev_state, pos, buf, count);
449 		else
450 			memcpy(buf, (mdev_state->vconfig + pos), count);
451 
452 	} else if (pos >= MBOCHS_MMIO_BAR_OFFSET &&
453 		   pos + count <= (MBOCHS_MMIO_BAR_OFFSET +
454 				   MBOCHS_MMIO_BAR_SIZE)) {
455 		pos -= MBOCHS_MMIO_BAR_OFFSET;
456 		if (is_write)
457 			handle_mmio_write(mdev_state, pos, buf, count);
458 		else
459 			handle_mmio_read(mdev_state, pos, buf, count);
460 
461 	} else if (pos >= MBOCHS_EDID_OFFSET &&
462 		   pos + count <= (MBOCHS_EDID_OFFSET +
463 				   MBOCHS_EDID_SIZE)) {
464 		pos -= MBOCHS_EDID_OFFSET;
465 		if (pos < MBOCHS_EDID_BLOB_OFFSET) {
466 			handle_edid_regs(mdev_state, pos, buf, count, is_write);
467 		} else {
468 			pos -= MBOCHS_EDID_BLOB_OFFSET;
469 			handle_edid_blob(mdev_state, pos, buf, count, is_write);
470 		}
471 
472 	} else if (pos >= MBOCHS_MEMORY_BAR_OFFSET &&
473 		   pos + count <=
474 		   MBOCHS_MEMORY_BAR_OFFSET + mdev_state->memsize) {
475 		pos -= MBOCHS_MMIO_BAR_OFFSET;
476 		poff = pos & ~PAGE_MASK;
477 		pg = __mbochs_get_page(mdev_state, pos >> PAGE_SHIFT);
478 		map = kmap(pg);
479 		if (is_write)
480 			memcpy(map + poff, buf, count);
481 		else
482 			memcpy(buf, map + poff, count);
483 		kunmap(pg);
484 		put_page(pg);
485 
486 	} else {
487 		dev_dbg(mdev_state->vdev.dev, "%s: %s @0x%llx (unhandled)\n",
488 			__func__, is_write ? "WR" : "RD", pos);
489 		ret = -1;
490 		goto accessfailed;
491 	}
492 
493 	ret = count;
494 
495 
496 accessfailed:
497 	mutex_unlock(&mdev_state->ops_lock);
498 
499 	return ret;
500 }
501 
mbochs_reset(struct mdev_state * mdev_state)502 static int mbochs_reset(struct mdev_state *mdev_state)
503 {
504 	u32 size64k = mdev_state->memsize / (64 * 1024);
505 	int i;
506 
507 	for (i = 0; i < ARRAY_SIZE(mdev_state->vbe); i++)
508 		mdev_state->vbe[i] = 0;
509 	mdev_state->vbe[VBE_DISPI_INDEX_ID] = VBE_DISPI_ID5;
510 	mdev_state->vbe[VBE_DISPI_INDEX_VIDEO_MEMORY_64K] = size64k;
511 	return 0;
512 }
513 
mbochs_init_dev(struct vfio_device * vdev)514 static int mbochs_init_dev(struct vfio_device *vdev)
515 {
516 	struct mdev_state *mdev_state =
517 		container_of(vdev, struct mdev_state, vdev);
518 	struct mdev_device *mdev = to_mdev_device(vdev->dev);
519 	struct mbochs_type *type =
520 		container_of(mdev->type, struct mbochs_type, type);
521 	int avail_mbytes = atomic_read(&mbochs_avail_mbytes);
522 	int ret = -ENOMEM;
523 
524 	do {
525 		if (avail_mbytes < type->mbytes)
526 			return -ENOSPC;
527 	} while (!atomic_try_cmpxchg(&mbochs_avail_mbytes, &avail_mbytes,
528 				     avail_mbytes - type->mbytes));
529 
530 	mdev_state->vconfig = kzalloc(MBOCHS_CONFIG_SPACE_SIZE, GFP_KERNEL);
531 	if (!mdev_state->vconfig)
532 		goto err_avail;
533 
534 	mdev_state->memsize = type->mbytes * 1024 * 1024;
535 	mdev_state->pagecount = mdev_state->memsize >> PAGE_SHIFT;
536 	mdev_state->pages = kcalloc(mdev_state->pagecount,
537 				    sizeof(struct page *),
538 				    GFP_KERNEL);
539 	if (!mdev_state->pages)
540 		goto err_vconfig;
541 
542 	mutex_init(&mdev_state->ops_lock);
543 	mdev_state->mdev = mdev;
544 	INIT_LIST_HEAD(&mdev_state->dmabufs);
545 	mdev_state->next_id = 1;
546 
547 	mdev_state->type = type;
548 	mdev_state->edid_regs.max_xres = type->max_x;
549 	mdev_state->edid_regs.max_yres = type->max_y;
550 	mdev_state->edid_regs.edid_offset = MBOCHS_EDID_BLOB_OFFSET;
551 	mdev_state->edid_regs.edid_max_size = sizeof(mdev_state->edid_blob);
552 	mbochs_create_config_space(mdev_state);
553 	mbochs_reset(mdev_state);
554 
555 	dev_info(vdev->dev, "%s: %s, %d MB, %ld pages\n", __func__,
556 		 type->type.pretty_name, type->mbytes, mdev_state->pagecount);
557 	return 0;
558 
559 err_vconfig:
560 	kfree(mdev_state->vconfig);
561 err_avail:
562 	atomic_add(type->mbytes, &mbochs_avail_mbytes);
563 	return ret;
564 }
565 
mbochs_probe(struct mdev_device * mdev)566 static int mbochs_probe(struct mdev_device *mdev)
567 {
568 	struct mdev_state *mdev_state;
569 	int ret = -ENOMEM;
570 
571 	mdev_state = vfio_alloc_device(mdev_state, vdev, &mdev->dev,
572 				       &mbochs_dev_ops);
573 	if (IS_ERR(mdev_state))
574 		return PTR_ERR(mdev_state);
575 
576 	ret = vfio_register_emulated_iommu_dev(&mdev_state->vdev);
577 	if (ret)
578 		goto err_put_vdev;
579 	dev_set_drvdata(&mdev->dev, mdev_state);
580 	return 0;
581 
582 err_put_vdev:
583 	vfio_put_device(&mdev_state->vdev);
584 	return ret;
585 }
586 
mbochs_release_dev(struct vfio_device * vdev)587 static void mbochs_release_dev(struct vfio_device *vdev)
588 {
589 	struct mdev_state *mdev_state =
590 		container_of(vdev, struct mdev_state, vdev);
591 
592 	atomic_add(mdev_state->type->mbytes, &mbochs_avail_mbytes);
593 	kfree(mdev_state->pages);
594 	kfree(mdev_state->vconfig);
595 }
596 
mbochs_remove(struct mdev_device * mdev)597 static void mbochs_remove(struct mdev_device *mdev)
598 {
599 	struct mdev_state *mdev_state = dev_get_drvdata(&mdev->dev);
600 
601 	vfio_unregister_group_dev(&mdev_state->vdev);
602 	vfio_put_device(&mdev_state->vdev);
603 }
604 
mbochs_read(struct vfio_device * vdev,char __user * buf,size_t count,loff_t * ppos)605 static ssize_t mbochs_read(struct vfio_device *vdev, char __user *buf,
606 			   size_t count, loff_t *ppos)
607 {
608 	struct mdev_state *mdev_state =
609 		container_of(vdev, struct mdev_state, vdev);
610 	unsigned int done = 0;
611 	int ret;
612 
613 	while (count) {
614 		size_t filled;
615 
616 		if (count >= 4 && !(*ppos % 4)) {
617 			u32 val;
618 
619 			ret =  mdev_access(mdev_state, (char *)&val, sizeof(val),
620 					   *ppos, false);
621 			if (ret <= 0)
622 				goto read_err;
623 
624 			if (copy_to_user(buf, &val, sizeof(val)))
625 				goto read_err;
626 
627 			filled = 4;
628 		} else if (count >= 2 && !(*ppos % 2)) {
629 			u16 val;
630 
631 			ret = mdev_access(mdev_state, (char *)&val, sizeof(val),
632 					  *ppos, false);
633 			if (ret <= 0)
634 				goto read_err;
635 
636 			if (copy_to_user(buf, &val, sizeof(val)))
637 				goto read_err;
638 
639 			filled = 2;
640 		} else {
641 			u8 val;
642 
643 			ret = mdev_access(mdev_state, (char *)&val, sizeof(val),
644 					  *ppos, false);
645 			if (ret <= 0)
646 				goto read_err;
647 
648 			if (copy_to_user(buf, &val, sizeof(val)))
649 				goto read_err;
650 
651 			filled = 1;
652 		}
653 
654 		count -= filled;
655 		done += filled;
656 		*ppos += filled;
657 		buf += filled;
658 	}
659 
660 	return done;
661 
662 read_err:
663 	return -EFAULT;
664 }
665 
mbochs_write(struct vfio_device * vdev,const char __user * buf,size_t count,loff_t * ppos)666 static ssize_t mbochs_write(struct vfio_device *vdev, const char __user *buf,
667 			    size_t count, loff_t *ppos)
668 {
669 	struct mdev_state *mdev_state =
670 		container_of(vdev, struct mdev_state, vdev);
671 	unsigned int done = 0;
672 	int ret;
673 
674 	while (count) {
675 		size_t filled;
676 
677 		if (count >= 4 && !(*ppos % 4)) {
678 			u32 val;
679 
680 			if (copy_from_user(&val, buf, sizeof(val)))
681 				goto write_err;
682 
683 			ret = mdev_access(mdev_state, (char *)&val, sizeof(val),
684 					  *ppos, true);
685 			if (ret <= 0)
686 				goto write_err;
687 
688 			filled = 4;
689 		} else if (count >= 2 && !(*ppos % 2)) {
690 			u16 val;
691 
692 			if (copy_from_user(&val, buf, sizeof(val)))
693 				goto write_err;
694 
695 			ret = mdev_access(mdev_state, (char *)&val, sizeof(val),
696 					  *ppos, true);
697 			if (ret <= 0)
698 				goto write_err;
699 
700 			filled = 2;
701 		} else {
702 			u8 val;
703 
704 			if (copy_from_user(&val, buf, sizeof(val)))
705 				goto write_err;
706 
707 			ret = mdev_access(mdev_state, (char *)&val, sizeof(val),
708 					  *ppos, true);
709 			if (ret <= 0)
710 				goto write_err;
711 
712 			filled = 1;
713 		}
714 		count -= filled;
715 		done += filled;
716 		*ppos += filled;
717 		buf += filled;
718 	}
719 
720 	return done;
721 write_err:
722 	return -EFAULT;
723 }
724 
__mbochs_get_page(struct mdev_state * mdev_state,pgoff_t pgoff)725 static struct page *__mbochs_get_page(struct mdev_state *mdev_state,
726 				      pgoff_t pgoff)
727 {
728 	WARN_ON(!mutex_is_locked(&mdev_state->ops_lock));
729 
730 	if (!mdev_state->pages[pgoff]) {
731 		mdev_state->pages[pgoff] =
732 			alloc_pages(GFP_HIGHUSER | __GFP_ZERO, 0);
733 		if (!mdev_state->pages[pgoff])
734 			return NULL;
735 	}
736 
737 	get_page(mdev_state->pages[pgoff]);
738 	return mdev_state->pages[pgoff];
739 }
740 
mbochs_get_page(struct mdev_state * mdev_state,pgoff_t pgoff)741 static struct page *mbochs_get_page(struct mdev_state *mdev_state,
742 				    pgoff_t pgoff)
743 {
744 	struct page *page;
745 
746 	if (WARN_ON(pgoff >= mdev_state->pagecount))
747 		return NULL;
748 
749 	mutex_lock(&mdev_state->ops_lock);
750 	page = __mbochs_get_page(mdev_state, pgoff);
751 	mutex_unlock(&mdev_state->ops_lock);
752 
753 	return page;
754 }
755 
mbochs_put_pages(struct mdev_state * mdev_state)756 static void mbochs_put_pages(struct mdev_state *mdev_state)
757 {
758 	struct device *dev = mdev_dev(mdev_state->mdev);
759 	int i, count = 0;
760 
761 	WARN_ON(!mutex_is_locked(&mdev_state->ops_lock));
762 
763 	for (i = 0; i < mdev_state->pagecount; i++) {
764 		if (!mdev_state->pages[i])
765 			continue;
766 		put_page(mdev_state->pages[i]);
767 		mdev_state->pages[i] = NULL;
768 		count++;
769 	}
770 	dev_dbg(dev, "%s: %d pages released\n", __func__, count);
771 }
772 
mbochs_region_vm_fault(struct vm_fault * vmf)773 static vm_fault_t mbochs_region_vm_fault(struct vm_fault *vmf)
774 {
775 	struct vm_area_struct *vma = vmf->vma;
776 	struct mdev_state *mdev_state = vma->vm_private_data;
777 	pgoff_t page_offset = (vmf->address - vma->vm_start) >> PAGE_SHIFT;
778 
779 	if (page_offset >= mdev_state->pagecount)
780 		return VM_FAULT_SIGBUS;
781 
782 	vmf->page = mbochs_get_page(mdev_state, page_offset);
783 	if (!vmf->page)
784 		return VM_FAULT_SIGBUS;
785 
786 	return 0;
787 }
788 
789 static const struct vm_operations_struct mbochs_region_vm_ops = {
790 	.fault = mbochs_region_vm_fault,
791 };
792 
mbochs_mmap(struct vfio_device * vdev,struct vm_area_struct * vma)793 static int mbochs_mmap(struct vfio_device *vdev, struct vm_area_struct *vma)
794 {
795 	struct mdev_state *mdev_state =
796 		container_of(vdev, struct mdev_state, vdev);
797 
798 	if (vma->vm_pgoff != MBOCHS_MEMORY_BAR_OFFSET >> PAGE_SHIFT)
799 		return -EINVAL;
800 	if (vma->vm_end < vma->vm_start)
801 		return -EINVAL;
802 	if (vma->vm_end - vma->vm_start > mdev_state->memsize)
803 		return -EINVAL;
804 	if ((vma->vm_flags & VM_SHARED) == 0)
805 		return -EINVAL;
806 
807 	vma->vm_ops = &mbochs_region_vm_ops;
808 	vma->vm_private_data = mdev_state;
809 	return 0;
810 }
811 
mbochs_dmabuf_vm_fault(struct vm_fault * vmf)812 static vm_fault_t mbochs_dmabuf_vm_fault(struct vm_fault *vmf)
813 {
814 	struct vm_area_struct *vma = vmf->vma;
815 	struct mbochs_dmabuf *dmabuf = vma->vm_private_data;
816 
817 	if (WARN_ON(vmf->pgoff >= dmabuf->pagecount))
818 		return VM_FAULT_SIGBUS;
819 
820 	vmf->page = dmabuf->pages[vmf->pgoff];
821 	get_page(vmf->page);
822 	return 0;
823 }
824 
825 static const struct vm_operations_struct mbochs_dmabuf_vm_ops = {
826 	.fault = mbochs_dmabuf_vm_fault,
827 };
828 
mbochs_mmap_dmabuf(struct dma_buf * buf,struct vm_area_struct * vma)829 static int mbochs_mmap_dmabuf(struct dma_buf *buf, struct vm_area_struct *vma)
830 {
831 	struct mbochs_dmabuf *dmabuf = buf->priv;
832 	struct device *dev = mdev_dev(dmabuf->mdev_state->mdev);
833 
834 	dev_dbg(dev, "%s: %d\n", __func__, dmabuf->id);
835 
836 	if ((vma->vm_flags & VM_SHARED) == 0)
837 		return -EINVAL;
838 
839 	vma->vm_ops = &mbochs_dmabuf_vm_ops;
840 	vma->vm_private_data = dmabuf;
841 	return 0;
842 }
843 
mbochs_print_dmabuf(struct mbochs_dmabuf * dmabuf,const char * prefix)844 static void mbochs_print_dmabuf(struct mbochs_dmabuf *dmabuf,
845 				const char *prefix)
846 {
847 	struct device *dev = mdev_dev(dmabuf->mdev_state->mdev);
848 	u32 fourcc = dmabuf->mode.drm_format;
849 
850 	dev_dbg(dev, "%s/%d: %c%c%c%c, %dx%d, stride %d, off 0x%llx, size 0x%llx, pages %ld\n",
851 		prefix, dmabuf->id,
852 		fourcc ? ((fourcc >>  0) & 0xff) : '-',
853 		fourcc ? ((fourcc >>  8) & 0xff) : '-',
854 		fourcc ? ((fourcc >> 16) & 0xff) : '-',
855 		fourcc ? ((fourcc >> 24) & 0xff) : '-',
856 		dmabuf->mode.width, dmabuf->mode.height, dmabuf->mode.stride,
857 		dmabuf->mode.offset, dmabuf->mode.size, dmabuf->pagecount);
858 }
859 
mbochs_map_dmabuf(struct dma_buf_attachment * at,enum dma_data_direction direction)860 static struct sg_table *mbochs_map_dmabuf(struct dma_buf_attachment *at,
861 					  enum dma_data_direction direction)
862 {
863 	struct mbochs_dmabuf *dmabuf = at->dmabuf->priv;
864 	struct device *dev = mdev_dev(dmabuf->mdev_state->mdev);
865 	struct sg_table *sg;
866 
867 	dev_dbg(dev, "%s: %d\n", __func__, dmabuf->id);
868 
869 	sg = kzalloc(sizeof(*sg), GFP_KERNEL);
870 	if (!sg)
871 		goto err1;
872 	if (sg_alloc_table_from_pages(sg, dmabuf->pages, dmabuf->pagecount,
873 				      0, dmabuf->mode.size, GFP_KERNEL) < 0)
874 		goto err2;
875 	if (dma_map_sgtable(at->dev, sg, direction, 0))
876 		goto err3;
877 
878 	return sg;
879 
880 err3:
881 	sg_free_table(sg);
882 err2:
883 	kfree(sg);
884 err1:
885 	return ERR_PTR(-ENOMEM);
886 }
887 
mbochs_unmap_dmabuf(struct dma_buf_attachment * at,struct sg_table * sg,enum dma_data_direction direction)888 static void mbochs_unmap_dmabuf(struct dma_buf_attachment *at,
889 				struct sg_table *sg,
890 				enum dma_data_direction direction)
891 {
892 	struct mbochs_dmabuf *dmabuf = at->dmabuf->priv;
893 	struct device *dev = mdev_dev(dmabuf->mdev_state->mdev);
894 
895 	dev_dbg(dev, "%s: %d\n", __func__, dmabuf->id);
896 
897 	dma_unmap_sgtable(at->dev, sg, direction, 0);
898 	sg_free_table(sg);
899 	kfree(sg);
900 }
901 
mbochs_release_dmabuf(struct dma_buf * buf)902 static void mbochs_release_dmabuf(struct dma_buf *buf)
903 {
904 	struct mbochs_dmabuf *dmabuf = buf->priv;
905 	struct mdev_state *mdev_state = dmabuf->mdev_state;
906 	struct device *dev = mdev_dev(mdev_state->mdev);
907 	pgoff_t pg;
908 
909 	dev_dbg(dev, "%s: %d\n", __func__, dmabuf->id);
910 
911 	for (pg = 0; pg < dmabuf->pagecount; pg++)
912 		put_page(dmabuf->pages[pg]);
913 
914 	mutex_lock(&mdev_state->ops_lock);
915 	dmabuf->buf = NULL;
916 	if (dmabuf->unlinked)
917 		kfree(dmabuf);
918 	mutex_unlock(&mdev_state->ops_lock);
919 }
920 
921 static struct dma_buf_ops mbochs_dmabuf_ops = {
922 	.map_dma_buf	  = mbochs_map_dmabuf,
923 	.unmap_dma_buf	  = mbochs_unmap_dmabuf,
924 	.release	  = mbochs_release_dmabuf,
925 	.mmap		  = mbochs_mmap_dmabuf,
926 };
927 
mbochs_dmabuf_alloc(struct mdev_state * mdev_state,struct mbochs_mode * mode)928 static struct mbochs_dmabuf *mbochs_dmabuf_alloc(struct mdev_state *mdev_state,
929 						 struct mbochs_mode *mode)
930 {
931 	struct mbochs_dmabuf *dmabuf;
932 	pgoff_t page_offset, pg;
933 
934 	WARN_ON(!mutex_is_locked(&mdev_state->ops_lock));
935 
936 	dmabuf = kzalloc(sizeof(struct mbochs_dmabuf), GFP_KERNEL);
937 	if (!dmabuf)
938 		return NULL;
939 
940 	dmabuf->mode = *mode;
941 	dmabuf->id = mdev_state->next_id++;
942 	dmabuf->pagecount = DIV_ROUND_UP(mode->size, PAGE_SIZE);
943 	dmabuf->pages = kcalloc(dmabuf->pagecount, sizeof(struct page *),
944 				GFP_KERNEL);
945 	if (!dmabuf->pages)
946 		goto err_free_dmabuf;
947 
948 	page_offset = dmabuf->mode.offset >> PAGE_SHIFT;
949 	for (pg = 0; pg < dmabuf->pagecount; pg++) {
950 		dmabuf->pages[pg] = __mbochs_get_page(mdev_state,
951 						      page_offset + pg);
952 		if (!dmabuf->pages[pg])
953 			goto err_free_pages;
954 	}
955 
956 	dmabuf->mdev_state = mdev_state;
957 	list_add(&dmabuf->next, &mdev_state->dmabufs);
958 
959 	mbochs_print_dmabuf(dmabuf, __func__);
960 	return dmabuf;
961 
962 err_free_pages:
963 	while (pg > 0)
964 		put_page(dmabuf->pages[--pg]);
965 	kfree(dmabuf->pages);
966 err_free_dmabuf:
967 	kfree(dmabuf);
968 	return NULL;
969 }
970 
971 static struct mbochs_dmabuf *
mbochs_dmabuf_find_by_mode(struct mdev_state * mdev_state,struct mbochs_mode * mode)972 mbochs_dmabuf_find_by_mode(struct mdev_state *mdev_state,
973 			   struct mbochs_mode *mode)
974 {
975 	struct mbochs_dmabuf *dmabuf;
976 
977 	WARN_ON(!mutex_is_locked(&mdev_state->ops_lock));
978 
979 	list_for_each_entry(dmabuf, &mdev_state->dmabufs, next)
980 		if (mbochs_modes_equal(&dmabuf->mode, mode))
981 			return dmabuf;
982 
983 	return NULL;
984 }
985 
986 static struct mbochs_dmabuf *
mbochs_dmabuf_find_by_id(struct mdev_state * mdev_state,u32 id)987 mbochs_dmabuf_find_by_id(struct mdev_state *mdev_state, u32 id)
988 {
989 	struct mbochs_dmabuf *dmabuf;
990 
991 	WARN_ON(!mutex_is_locked(&mdev_state->ops_lock));
992 
993 	list_for_each_entry(dmabuf, &mdev_state->dmabufs, next)
994 		if (dmabuf->id == id)
995 			return dmabuf;
996 
997 	return NULL;
998 }
999 
mbochs_dmabuf_export(struct mbochs_dmabuf * dmabuf)1000 static int mbochs_dmabuf_export(struct mbochs_dmabuf *dmabuf)
1001 {
1002 	struct mdev_state *mdev_state = dmabuf->mdev_state;
1003 	struct device *dev = mdev_state->vdev.dev;
1004 	DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
1005 	struct dma_buf *buf;
1006 
1007 	WARN_ON(!mutex_is_locked(&mdev_state->ops_lock));
1008 
1009 	if (!IS_ALIGNED(dmabuf->mode.offset, PAGE_SIZE)) {
1010 		dev_info_ratelimited(dev, "%s: framebuffer not page-aligned\n",
1011 				     __func__);
1012 		return -EINVAL;
1013 	}
1014 
1015 	exp_info.ops = &mbochs_dmabuf_ops;
1016 	exp_info.size = dmabuf->mode.size;
1017 	exp_info.priv = dmabuf;
1018 
1019 	buf = dma_buf_export(&exp_info);
1020 	if (IS_ERR(buf)) {
1021 		dev_info_ratelimited(dev, "%s: dma_buf_export failed: %ld\n",
1022 				     __func__, PTR_ERR(buf));
1023 		return PTR_ERR(buf);
1024 	}
1025 
1026 	dmabuf->buf = buf;
1027 	dev_dbg(dev, "%s: %d\n", __func__, dmabuf->id);
1028 	return 0;
1029 }
1030 
mbochs_ioctl_get_region_info(struct vfio_device * vdev,struct vfio_region_info * region_info,struct vfio_info_cap * caps)1031 static int mbochs_ioctl_get_region_info(struct vfio_device *vdev,
1032 					struct vfio_region_info *region_info,
1033 					struct vfio_info_cap *caps)
1034 {
1035 	struct mdev_state *mdev_state =
1036 		container_of(vdev, struct mdev_state, vdev);
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 		struct vfio_region_info_cap_type cap_type = {
1063 			.header.id = VFIO_REGION_INFO_CAP_TYPE,
1064 			.header.version = 1,
1065 			.type = VFIO_REGION_TYPE_GFX,
1066 			.subtype = VFIO_REGION_SUBTYPE_GFX_EDID,
1067 		};
1068 
1069 		region_info->offset = MBOCHS_EDID_OFFSET;
1070 		region_info->size = MBOCHS_EDID_SIZE;
1071 		region_info->flags = (VFIO_REGION_INFO_FLAG_READ |
1072 				      VFIO_REGION_INFO_FLAG_WRITE |
1073 				      VFIO_REGION_INFO_FLAG_CAPS);
1074 
1075 		return vfio_info_add_capability(caps, &cap_type.header,
1076 						sizeof(cap_type));
1077 	}
1078 	default:
1079 		region_info->size   = 0;
1080 		region_info->offset = 0;
1081 		region_info->flags  = 0;
1082 	}
1083 
1084 	return 0;
1085 }
1086 
mbochs_get_irq_info(struct vfio_irq_info * irq_info)1087 static int mbochs_get_irq_info(struct vfio_irq_info *irq_info)
1088 {
1089 	irq_info->count = 0;
1090 	return 0;
1091 }
1092 
mbochs_get_device_info(struct vfio_device_info * dev_info)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 
mbochs_query_gfx_plane(struct mdev_state * mdev_state,struct vfio_device_gfx_plane_info * plane)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 
mbochs_get_gfx_dmabuf(struct mdev_state * mdev_state,u32 id)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 
mbochs_ioctl(struct vfio_device * vdev,unsigned int cmd,unsigned long arg)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;
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 
1219 	case VFIO_DEVICE_GET_IRQ_INFO:
1220 	{
1221 		struct vfio_irq_info info;
1222 
1223 		minsz = offsetofend(struct vfio_irq_info, count);
1224 
1225 		if (copy_from_user(&info, (void __user *)arg, minsz))
1226 			return -EFAULT;
1227 
1228 		if ((info.argsz < minsz) ||
1229 		    (info.index >= VFIO_PCI_NUM_IRQS))
1230 			return -EINVAL;
1231 
1232 		ret = mbochs_get_irq_info(&info);
1233 		if (ret)
1234 			return ret;
1235 
1236 		if (copy_to_user((void __user *)arg, &info, minsz))
1237 			return -EFAULT;
1238 
1239 		return 0;
1240 	}
1241 
1242 	case VFIO_DEVICE_QUERY_GFX_PLANE:
1243 	{
1244 		struct vfio_device_gfx_plane_info plane = {};
1245 
1246 		minsz = offsetofend(struct vfio_device_gfx_plane_info,
1247 				    region_index);
1248 
1249 		if (copy_from_user(&plane, (void __user *)arg, minsz))
1250 			return -EFAULT;
1251 
1252 		if (plane.argsz < minsz)
1253 			return -EINVAL;
1254 
1255 		ret = mbochs_query_gfx_plane(mdev_state, &plane);
1256 		if (ret)
1257 			return ret;
1258 
1259 		if (copy_to_user((void __user *)arg, &plane, minsz))
1260 			return -EFAULT;
1261 
1262 		return 0;
1263 	}
1264 
1265 	case VFIO_DEVICE_GET_GFX_DMABUF:
1266 	{
1267 		u32 dmabuf_id;
1268 
1269 		if (get_user(dmabuf_id, (__u32 __user *)arg))
1270 			return -EFAULT;
1271 
1272 		return mbochs_get_gfx_dmabuf(mdev_state, dmabuf_id);
1273 	}
1274 
1275 	case VFIO_DEVICE_SET_IRQS:
1276 		return -EINVAL;
1277 
1278 	case VFIO_DEVICE_RESET:
1279 		return mbochs_reset(mdev_state);
1280 	}
1281 	return -ENOTTY;
1282 }
1283 
mbochs_close_device(struct vfio_device * vdev)1284 static void mbochs_close_device(struct vfio_device *vdev)
1285 {
1286 	struct mdev_state *mdev_state =
1287 		container_of(vdev, struct mdev_state, vdev);
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 }
1305 
1306 static ssize_t
memory_show(struct device * dev,struct device_attribute * attr,char * buf)1307 memory_show(struct device *dev, struct device_attribute *attr,
1308 	    char *buf)
1309 {
1310 	struct mdev_state *mdev_state = dev_get_drvdata(dev);
1311 
1312 	return sprintf(buf, "%d MB\n", mdev_state->type->mbytes);
1313 }
1314 static DEVICE_ATTR_RO(memory);
1315 
1316 static struct attribute *mdev_dev_attrs[] = {
1317 	&dev_attr_memory.attr,
1318 	NULL,
1319 };
1320 
1321 static const struct attribute_group mdev_dev_group = {
1322 	.name  = "vendor",
1323 	.attrs = mdev_dev_attrs,
1324 };
1325 
1326 static const struct attribute_group *mdev_dev_groups[] = {
1327 	&mdev_dev_group,
1328 	NULL,
1329 };
1330 
mbochs_show_description(struct mdev_type * mtype,char * buf)1331 static ssize_t mbochs_show_description(struct mdev_type *mtype, char *buf)
1332 {
1333 	struct mbochs_type *type =
1334 		container_of(mtype, struct mbochs_type, type);
1335 
1336 	return sprintf(buf, "virtual display, %d MB video memory\n",
1337 		       type ? type->mbytes  : 0);
1338 }
1339 
mbochs_get_available(struct mdev_type * mtype)1340 static unsigned int mbochs_get_available(struct mdev_type *mtype)
1341 {
1342 	struct mbochs_type *type =
1343 		container_of(mtype, struct mbochs_type, type);
1344 
1345 	return atomic_read(&mbochs_avail_mbytes) / type->mbytes;
1346 }
1347 
1348 static const struct vfio_device_ops mbochs_dev_ops = {
1349 	.close_device = mbochs_close_device,
1350 	.init = mbochs_init_dev,
1351 	.release = mbochs_release_dev,
1352 	.read = mbochs_read,
1353 	.write = mbochs_write,
1354 	.ioctl = mbochs_ioctl,
1355 	.get_region_info_caps = mbochs_ioctl_get_region_info,
1356 	.mmap = mbochs_mmap,
1357 	.bind_iommufd	= vfio_iommufd_emulated_bind,
1358 	.unbind_iommufd	= vfio_iommufd_emulated_unbind,
1359 	.attach_ioas	= vfio_iommufd_emulated_attach_ioas,
1360 	.detach_ioas	= vfio_iommufd_emulated_detach_ioas,
1361 };
1362 
1363 static struct mdev_driver mbochs_driver = {
1364 	.device_api = VFIO_DEVICE_API_PCI_STRING,
1365 	.driver = {
1366 		.name = "mbochs",
1367 		.owner = THIS_MODULE,
1368 		.mod_name = KBUILD_MODNAME,
1369 		.dev_groups = mdev_dev_groups,
1370 	},
1371 	.probe = mbochs_probe,
1372 	.remove	= mbochs_remove,
1373 	.get_available = mbochs_get_available,
1374 	.show_description = mbochs_show_description,
1375 };
1376 
1377 static const struct file_operations vd_fops = {
1378 	.owner		= THIS_MODULE,
1379 };
1380 
mbochs_device_release(struct device * dev)1381 static void mbochs_device_release(struct device *dev)
1382 {
1383 	/* nothing */
1384 }
1385 
mbochs_dev_init(void)1386 static int __init mbochs_dev_init(void)
1387 {
1388 	int ret = 0;
1389 
1390 	atomic_set(&mbochs_avail_mbytes, max_mbytes);
1391 
1392 	ret = alloc_chrdev_region(&mbochs_devt, 0, MINORMASK + 1, MBOCHS_NAME);
1393 	if (ret < 0) {
1394 		pr_err("Error: failed to register mbochs_dev, err: %d\n", ret);
1395 		return ret;
1396 	}
1397 	cdev_init(&mbochs_cdev, &vd_fops);
1398 	cdev_add(&mbochs_cdev, mbochs_devt, MINORMASK + 1);
1399 	pr_info("%s: major %d\n", __func__, MAJOR(mbochs_devt));
1400 
1401 	ret = mdev_register_driver(&mbochs_driver);
1402 	if (ret)
1403 		goto err_cdev;
1404 
1405 	ret = class_register(&mbochs_class);
1406 	if (ret)
1407 		goto err_driver;
1408 	mbochs_dev.class = &mbochs_class;
1409 	mbochs_dev.release = mbochs_device_release;
1410 	dev_set_name(&mbochs_dev, "%s", MBOCHS_NAME);
1411 
1412 	ret = device_register(&mbochs_dev);
1413 	if (ret)
1414 		goto err_put;
1415 
1416 	ret = mdev_register_parent(&mbochs_parent, &mbochs_dev, &mbochs_driver,
1417 				   mbochs_mdev_types,
1418 				   ARRAY_SIZE(mbochs_mdev_types));
1419 	if (ret)
1420 		goto err_device;
1421 
1422 	return 0;
1423 
1424 err_device:
1425 	device_del(&mbochs_dev);
1426 err_put:
1427 	put_device(&mbochs_dev);
1428 	class_unregister(&mbochs_class);
1429 err_driver:
1430 	mdev_unregister_driver(&mbochs_driver);
1431 err_cdev:
1432 	cdev_del(&mbochs_cdev);
1433 	unregister_chrdev_region(mbochs_devt, MINORMASK + 1);
1434 	return ret;
1435 }
1436 
mbochs_dev_exit(void)1437 static void __exit mbochs_dev_exit(void)
1438 {
1439 	mbochs_dev.bus = NULL;
1440 	mdev_unregister_parent(&mbochs_parent);
1441 
1442 	device_unregister(&mbochs_dev);
1443 	mdev_unregister_driver(&mbochs_driver);
1444 	cdev_del(&mbochs_cdev);
1445 	unregister_chrdev_region(mbochs_devt, MINORMASK + 1);
1446 	class_unregister(&mbochs_class);
1447 }
1448 
1449 MODULE_IMPORT_NS("DMA_BUF");
1450 module_init(mbochs_dev_init)
1451 module_exit(mbochs_dev_exit)
1452