1 // SPDX-License-Identifier: GPL-2.0
3 * Mediated virtual PCI display host device driver
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
11 * (c) Gerd Hoffmann <kraxel@redhat.com>
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>
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.
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>
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
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
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
70 #define MBOCHS_NAME "mbochs"
71 #define MBOCHS_CLASS_NAME "mbochs"
73 #define MBOCHS_EDID_REGION_INDEX VFIO_PCI_NUM_REGIONS
74 #define MBOCHS_NUM_REGIONS (MBOCHS_EDID_REGION_INDEX+1)
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 + \
81 #define MBOCHS_EDID_SIZE PAGE_SIZE
82 #define MBOCHS_MEMORY_BAR_OFFSET (MBOCHS_EDID_OFFSET + \
85 #define MBOCHS_EDID_BLOB_OFFSET (MBOCHS_EDID_SIZE/2)
87 #define STORE_LE16(addr, val) (*(u16 *)addr = val)
88 #define STORE_LE32(addr, val) (*(u32 *)addr = val)
91 MODULE_LICENSE("GPL v2");
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");
98 #define MBOCHS_TYPE_1 "small"
99 #define MBOCHS_TYPE_2 "medium"
100 #define MBOCHS_TYPE_3 "large"
102 static struct mbochs_type {
103 struct mdev_type type;
109 .type.sysfs_name = MBOCHS_TYPE_1,
110 .type.pretty_name = MBOCHS_CLASS_NAME "-" MBOCHS_TYPE_1,
115 .type.sysfs_name = MBOCHS_TYPE_2,
116 .type.pretty_name = MBOCHS_CLASS_NAME "-" MBOCHS_TYPE_2,
121 .type.sysfs_name = MBOCHS_TYPE_3,
122 .type.pretty_name = MBOCHS_CLASS_NAME "-" MBOCHS_TYPE_3,
129 static struct mdev_type *mbochs_mdev_types[] = {
130 &mbochs_types[0].type,
131 &mbochs_types[1].type,
132 &mbochs_types[2].type,
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;
143 struct vfio_region_info_ext {
144 struct vfio_region_info base;
145 struct vfio_region_info_cap_type type;
159 struct mbochs_dmabuf {
160 struct mbochs_mode mode;
165 struct mdev_state *mdev_state;
166 struct list_head next;
170 /* State of each mdev device */
172 struct vfio_device vdev;
176 struct mutex ops_lock;
177 struct mdev_device *mdev;
179 const struct mbochs_type *type;
180 u16 vbe[VBE_DISPI_INDEX_COUNT];
184 struct vfio_region_gfx_edid edid_regs;
187 struct list_head dmabufs;
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",
206 static const char *vbe_name(u32 index)
208 if (index < ARRAY_SIZE(vbe_name_list))
209 return vbe_name_list[index];
213 static struct page *__mbochs_get_page(struct mdev_state *mdev_state,
215 static struct page *mbochs_get_page(struct mdev_state *mdev_state,
218 static void mbochs_create_config_space(struct mdev_state *mdev_state)
220 STORE_LE16((u16 *) &mdev_state->vconfig[PCI_VENDOR_ID],
222 STORE_LE16((u16 *) &mdev_state->vconfig[PCI_DEVICE_ID],
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);
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;
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;
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;
247 static int mbochs_check_framebuffer(struct mdev_state *mdev_state,
248 struct mbochs_mode *mode)
250 struct device *dev = mdev_dev(mdev_state->mdev);
251 u16 *vbe = mdev_state->vbe;
254 WARN_ON(!mutex_is_locked(&mdev_state->ops_lock));
256 if (!(vbe[VBE_DISPI_INDEX_ENABLE] & VBE_DISPI_ENABLED))
259 memset(mode, 0, sizeof(*mode));
260 switch (vbe[VBE_DISPI_INDEX_BPP]) {
262 mode->drm_format = DRM_FORMAT_XRGB8888;
266 dev_info_ratelimited(dev, "%s: bpp %d not supported\n",
267 __func__, vbe[VBE_DISPI_INDEX_BPP]);
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);
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);
286 if (mode->offset + mode->size > mdev_state->memsize) {
287 dev_info_ratelimited(dev, "%s: framebuffer memory overflow\n",
295 memset(mode, 0, sizeof(*mode));
299 static bool mbochs_modes_equal(struct mbochs_mode *mode1,
300 struct mbochs_mode *mode2)
302 return memcmp(mode1, mode2, sizeof(struct mbochs_mode)) == 0;
305 static void handle_pci_cfg_write(struct mdev_state *mdev_state, u16 offset,
306 char *buf, u32 count)
308 struct device *dev = mdev_dev(mdev_state->mdev);
309 int index = (offset - PCI_BASE_ADDRESS_0) / 0x04;
313 case PCI_BASE_ADDRESS_0:
314 case PCI_BASE_ADDRESS_2:
315 cfg_addr = *(u32 *)buf;
317 if (cfg_addr == 0xffffffff) {
318 cfg_addr = (cfg_addr & mdev_state->bar_mask[index]);
320 cfg_addr &= PCI_BASE_ADDRESS_MEM_MASK;
322 dev_info(dev, "BAR #%d @ 0x%x\n",
326 cfg_addr |= (mdev_state->vconfig[offset] &
327 ~PCI_BASE_ADDRESS_MEM_MASK);
328 STORE_LE32(&mdev_state->vconfig[offset], cfg_addr);
333 static void handle_mmio_write(struct mdev_state *mdev_state, u16 offset,
334 char *buf, u32 count)
336 struct device *dev = mdev_dev(mdev_state->mdev);
341 case 0x400 ... 0x41f: /* vga ioports remapped */
343 case 0x500 ... 0x515: /* bochs dispi interface */
346 index = (offset - 0x500) / 2;
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));
353 case 0x600 ... 0x607: /* qemu extended regs */
357 dev_dbg(dev, "%s: @0x%03x, count %d (unhandled)\n",
358 __func__, offset, count);
363 static void handle_mmio_read(struct mdev_state *mdev_state, u16 offset,
364 char *buf, u32 count)
366 struct device *dev = mdev_dev(mdev_state->mdev);
367 struct vfio_region_gfx_edid *edid;
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);
379 memcpy(buf, mdev_state->edid_blob + offset, count);
381 case 0x500 ... 0x515: /* bochs dispi interface */
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));
393 dev_dbg(dev, "%s: @0x%03x, count %d (unhandled)\n",
394 __func__, offset, count);
395 memset(buf, 0, count);
400 static void handle_edid_regs(struct mdev_state *mdev_state, u16 offset,
401 char *buf, u32 count, bool is_write)
403 char *regs = (void *)&mdev_state->edid_regs;
405 if (offset + count > sizeof(mdev_state->edid_regs))
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);
423 memcpy(buf, regs + offset, count);
427 static void handle_edid_blob(struct mdev_state *mdev_state, u16 offset,
428 char *buf, u32 count, bool is_write)
430 if (offset + count > mdev_state->edid_regs.edid_max_size)
433 memcpy(mdev_state->edid_blob + offset, buf, count);
435 memcpy(buf, mdev_state->edid_blob + offset, count);
438 static ssize_t mdev_access(struct mdev_state *mdev_state, char *buf,
439 size_t count, loff_t pos, bool is_write)
446 mutex_lock(&mdev_state->ops_lock);
448 if (pos < MBOCHS_CONFIG_SPACE_SIZE) {
450 handle_pci_cfg_write(mdev_state, pos, buf, count);
452 memcpy(buf, (mdev_state->vconfig + pos), count);
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;
459 handle_mmio_write(mdev_state, pos, buf, count);
461 handle_mmio_read(mdev_state, pos, buf, count);
463 } else if (pos >= MBOCHS_EDID_OFFSET &&
464 pos + count <= (MBOCHS_EDID_OFFSET +
466 pos -= MBOCHS_EDID_OFFSET;
467 if (pos < MBOCHS_EDID_BLOB_OFFSET) {
468 handle_edid_regs(mdev_state, pos, buf, count, is_write);
470 pos -= MBOCHS_EDID_BLOB_OFFSET;
471 handle_edid_blob(mdev_state, pos, buf, count, is_write);
474 } else if (pos >= MBOCHS_MEMORY_BAR_OFFSET &&
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);
482 memcpy(map + poff, buf, count);
484 memcpy(buf, map + poff, count);
489 dev_dbg(mdev_state->vdev.dev, "%s: %s @0x%llx (unhandled)\n",
490 __func__, is_write ? "WR" : "RD", pos);
499 mutex_unlock(&mdev_state->ops_lock);
504 static int mbochs_reset(struct mdev_state *mdev_state)
506 u32 size64k = mdev_state->memsize / (64 * 1024);
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;
516 static int mbochs_init_dev(struct vfio_device *vdev)
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);
527 if (avail_mbytes < type->mbytes)
529 } while (!atomic_try_cmpxchg(&mbochs_avail_mbytes, &avail_mbytes,
530 avail_mbytes - type->mbytes));
532 mdev_state->vconfig = kzalloc(MBOCHS_CONFIG_SPACE_SIZE, GFP_KERNEL);
533 if (!mdev_state->vconfig)
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 *),
541 if (!mdev_state->pages)
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;
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);
557 dev_info(vdev->dev, "%s: %s, %d MB, %ld pages\n", __func__,
558 type->type.pretty_name, type->mbytes, mdev_state->pagecount);
562 kfree(mdev_state->vconfig);
564 atomic_add(type->mbytes, &mbochs_avail_mbytes);
568 static int mbochs_probe(struct mdev_device *mdev)
570 struct mdev_state *mdev_state;
573 mdev_state = vfio_alloc_device(mdev_state, vdev, &mdev->dev,
575 if (IS_ERR(mdev_state))
576 return PTR_ERR(mdev_state);
578 ret = vfio_register_emulated_iommu_dev(&mdev_state->vdev);
581 dev_set_drvdata(&mdev->dev, mdev_state);
585 vfio_put_device(&mdev_state->vdev);
589 static void mbochs_release_dev(struct vfio_device *vdev)
591 struct mdev_state *mdev_state =
592 container_of(vdev, struct mdev_state, vdev);
594 atomic_add(mdev_state->type->mbytes, &mbochs_avail_mbytes);
595 kfree(mdev_state->pages);
596 kfree(mdev_state->vconfig);
597 vfio_free_device(vdev);
600 static void mbochs_remove(struct mdev_device *mdev)
602 struct mdev_state *mdev_state = dev_get_drvdata(&mdev->dev);
604 vfio_unregister_group_dev(&mdev_state->vdev);
605 vfio_put_device(&mdev_state->vdev);
608 static ssize_t mbochs_read(struct vfio_device *vdev, char __user *buf,
609 size_t count, loff_t *ppos)
611 struct mdev_state *mdev_state =
612 container_of(vdev, struct mdev_state, vdev);
613 unsigned int done = 0;
619 if (count >= 4 && !(*ppos % 4)) {
622 ret = mdev_access(mdev_state, (char *)&val, sizeof(val),
627 if (copy_to_user(buf, &val, sizeof(val)))
631 } else if (count >= 2 && !(*ppos % 2)) {
634 ret = mdev_access(mdev_state, (char *)&val, sizeof(val),
639 if (copy_to_user(buf, &val, sizeof(val)))
646 ret = mdev_access(mdev_state, (char *)&val, sizeof(val),
651 if (copy_to_user(buf, &val, sizeof(val)))
669 static ssize_t mbochs_write(struct vfio_device *vdev, const char __user *buf,
670 size_t count, loff_t *ppos)
672 struct mdev_state *mdev_state =
673 container_of(vdev, struct mdev_state, vdev);
674 unsigned int done = 0;
680 if (count >= 4 && !(*ppos % 4)) {
683 if (copy_from_user(&val, buf, sizeof(val)))
686 ret = mdev_access(mdev_state, (char *)&val, sizeof(val),
692 } else if (count >= 2 && !(*ppos % 2)) {
695 if (copy_from_user(&val, buf, sizeof(val)))
698 ret = mdev_access(mdev_state, (char *)&val, sizeof(val),
707 if (copy_from_user(&val, buf, sizeof(val)))
710 ret = mdev_access(mdev_state, (char *)&val, sizeof(val),
728 static struct page *__mbochs_get_page(struct mdev_state *mdev_state,
731 WARN_ON(!mutex_is_locked(&mdev_state->ops_lock));
733 if (!mdev_state->pages[pgoff]) {
734 mdev_state->pages[pgoff] =
735 alloc_pages(GFP_HIGHUSER | __GFP_ZERO, 0);
736 if (!mdev_state->pages[pgoff])
740 get_page(mdev_state->pages[pgoff]);
741 return mdev_state->pages[pgoff];
744 static struct page *mbochs_get_page(struct mdev_state *mdev_state,
749 if (WARN_ON(pgoff >= mdev_state->pagecount))
752 mutex_lock(&mdev_state->ops_lock);
753 page = __mbochs_get_page(mdev_state, pgoff);
754 mutex_unlock(&mdev_state->ops_lock);
759 static void mbochs_put_pages(struct mdev_state *mdev_state)
761 struct device *dev = mdev_dev(mdev_state->mdev);
764 WARN_ON(!mutex_is_locked(&mdev_state->ops_lock));
766 for (i = 0; i < mdev_state->pagecount; i++) {
767 if (!mdev_state->pages[i])
769 put_page(mdev_state->pages[i]);
770 mdev_state->pages[i] = NULL;
773 dev_dbg(dev, "%s: %d pages released\n", __func__, count);
776 static vm_fault_t mbochs_region_vm_fault(struct vm_fault *vmf)
778 struct vm_area_struct *vma = vmf->vma;
779 struct mdev_state *mdev_state = vma->vm_private_data;
780 pgoff_t page_offset = (vmf->address - vma->vm_start) >> PAGE_SHIFT;
782 if (page_offset >= mdev_state->pagecount)
783 return VM_FAULT_SIGBUS;
785 vmf->page = mbochs_get_page(mdev_state, page_offset);
787 return VM_FAULT_SIGBUS;
792 static const struct vm_operations_struct mbochs_region_vm_ops = {
793 .fault = mbochs_region_vm_fault,
796 static int mbochs_mmap(struct vfio_device *vdev, struct vm_area_struct *vma)
798 struct mdev_state *mdev_state =
799 container_of(vdev, struct mdev_state, vdev);
801 if (vma->vm_pgoff != MBOCHS_MEMORY_BAR_OFFSET >> PAGE_SHIFT)
803 if (vma->vm_end < vma->vm_start)
805 if (vma->vm_end - vma->vm_start > mdev_state->memsize)
807 if ((vma->vm_flags & VM_SHARED) == 0)
810 vma->vm_ops = &mbochs_region_vm_ops;
811 vma->vm_private_data = mdev_state;
815 static vm_fault_t mbochs_dmabuf_vm_fault(struct vm_fault *vmf)
817 struct vm_area_struct *vma = vmf->vma;
818 struct mbochs_dmabuf *dmabuf = vma->vm_private_data;
820 if (WARN_ON(vmf->pgoff >= dmabuf->pagecount))
821 return VM_FAULT_SIGBUS;
823 vmf->page = dmabuf->pages[vmf->pgoff];
828 static const struct vm_operations_struct mbochs_dmabuf_vm_ops = {
829 .fault = mbochs_dmabuf_vm_fault,
832 static int mbochs_mmap_dmabuf(struct dma_buf *buf, struct vm_area_struct *vma)
834 struct mbochs_dmabuf *dmabuf = buf->priv;
835 struct device *dev = mdev_dev(dmabuf->mdev_state->mdev);
837 dev_dbg(dev, "%s: %d\n", __func__, dmabuf->id);
839 if ((vma->vm_flags & VM_SHARED) == 0)
842 vma->vm_ops = &mbochs_dmabuf_vm_ops;
843 vma->vm_private_data = dmabuf;
847 static void mbochs_print_dmabuf(struct mbochs_dmabuf *dmabuf,
850 struct device *dev = mdev_dev(dmabuf->mdev_state->mdev);
851 u32 fourcc = dmabuf->mode.drm_format;
853 dev_dbg(dev, "%s/%d: %c%c%c%c, %dx%d, stride %d, off 0x%llx, size 0x%llx, pages %ld\n",
855 fourcc ? ((fourcc >> 0) & 0xff) : '-',
856 fourcc ? ((fourcc >> 8) & 0xff) : '-',
857 fourcc ? ((fourcc >> 16) & 0xff) : '-',
858 fourcc ? ((fourcc >> 24) & 0xff) : '-',
859 dmabuf->mode.width, dmabuf->mode.height, dmabuf->mode.stride,
860 dmabuf->mode.offset, dmabuf->mode.size, dmabuf->pagecount);
863 static struct sg_table *mbochs_map_dmabuf(struct dma_buf_attachment *at,
864 enum dma_data_direction direction)
866 struct mbochs_dmabuf *dmabuf = at->dmabuf->priv;
867 struct device *dev = mdev_dev(dmabuf->mdev_state->mdev);
870 dev_dbg(dev, "%s: %d\n", __func__, dmabuf->id);
872 sg = kzalloc(sizeof(*sg), GFP_KERNEL);
875 if (sg_alloc_table_from_pages(sg, dmabuf->pages, dmabuf->pagecount,
876 0, dmabuf->mode.size, GFP_KERNEL) < 0)
878 if (dma_map_sgtable(at->dev, sg, direction, 0))
888 return ERR_PTR(-ENOMEM);
891 static void mbochs_unmap_dmabuf(struct dma_buf_attachment *at,
893 enum dma_data_direction direction)
895 struct mbochs_dmabuf *dmabuf = at->dmabuf->priv;
896 struct device *dev = mdev_dev(dmabuf->mdev_state->mdev);
898 dev_dbg(dev, "%s: %d\n", __func__, dmabuf->id);
900 dma_unmap_sgtable(at->dev, sg, direction, 0);
905 static void mbochs_release_dmabuf(struct dma_buf *buf)
907 struct mbochs_dmabuf *dmabuf = buf->priv;
908 struct mdev_state *mdev_state = dmabuf->mdev_state;
909 struct device *dev = mdev_dev(mdev_state->mdev);
912 dev_dbg(dev, "%s: %d\n", __func__, dmabuf->id);
914 for (pg = 0; pg < dmabuf->pagecount; pg++)
915 put_page(dmabuf->pages[pg]);
917 mutex_lock(&mdev_state->ops_lock);
919 if (dmabuf->unlinked)
921 mutex_unlock(&mdev_state->ops_lock);
924 static struct dma_buf_ops mbochs_dmabuf_ops = {
925 .map_dma_buf = mbochs_map_dmabuf,
926 .unmap_dma_buf = mbochs_unmap_dmabuf,
927 .release = mbochs_release_dmabuf,
928 .mmap = mbochs_mmap_dmabuf,
931 static struct mbochs_dmabuf *mbochs_dmabuf_alloc(struct mdev_state *mdev_state,
932 struct mbochs_mode *mode)
934 struct mbochs_dmabuf *dmabuf;
935 pgoff_t page_offset, pg;
937 WARN_ON(!mutex_is_locked(&mdev_state->ops_lock));
939 dmabuf = kzalloc(sizeof(struct mbochs_dmabuf), GFP_KERNEL);
943 dmabuf->mode = *mode;
944 dmabuf->id = mdev_state->next_id++;
945 dmabuf->pagecount = DIV_ROUND_UP(mode->size, PAGE_SIZE);
946 dmabuf->pages = kcalloc(dmabuf->pagecount, sizeof(struct page *),
949 goto err_free_dmabuf;
951 page_offset = dmabuf->mode.offset >> PAGE_SHIFT;
952 for (pg = 0; pg < dmabuf->pagecount; pg++) {
953 dmabuf->pages[pg] = __mbochs_get_page(mdev_state,
955 if (!dmabuf->pages[pg])
959 dmabuf->mdev_state = mdev_state;
960 list_add(&dmabuf->next, &mdev_state->dmabufs);
962 mbochs_print_dmabuf(dmabuf, __func__);
967 put_page(dmabuf->pages[--pg]);
968 kfree(dmabuf->pages);
974 static struct mbochs_dmabuf *
975 mbochs_dmabuf_find_by_mode(struct mdev_state *mdev_state,
976 struct mbochs_mode *mode)
978 struct mbochs_dmabuf *dmabuf;
980 WARN_ON(!mutex_is_locked(&mdev_state->ops_lock));
982 list_for_each_entry(dmabuf, &mdev_state->dmabufs, next)
983 if (mbochs_modes_equal(&dmabuf->mode, mode))
989 static struct mbochs_dmabuf *
990 mbochs_dmabuf_find_by_id(struct mdev_state *mdev_state, u32 id)
992 struct mbochs_dmabuf *dmabuf;
994 WARN_ON(!mutex_is_locked(&mdev_state->ops_lock));
996 list_for_each_entry(dmabuf, &mdev_state->dmabufs, next)
997 if (dmabuf->id == id)
1003 static int mbochs_dmabuf_export(struct mbochs_dmabuf *dmabuf)
1005 struct mdev_state *mdev_state = dmabuf->mdev_state;
1006 struct device *dev = mdev_state->vdev.dev;
1007 DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
1008 struct dma_buf *buf;
1010 WARN_ON(!mutex_is_locked(&mdev_state->ops_lock));
1012 if (!IS_ALIGNED(dmabuf->mode.offset, PAGE_SIZE)) {
1013 dev_info_ratelimited(dev, "%s: framebuffer not page-aligned\n",
1018 exp_info.ops = &mbochs_dmabuf_ops;
1019 exp_info.size = dmabuf->mode.size;
1020 exp_info.priv = dmabuf;
1022 buf = dma_buf_export(&exp_info);
1024 dev_info_ratelimited(dev, "%s: dma_buf_export failed: %ld\n",
1025 __func__, PTR_ERR(buf));
1026 return PTR_ERR(buf);
1030 dev_dbg(dev, "%s: %d\n", __func__, dmabuf->id);
1034 static int mbochs_get_region_info(struct mdev_state *mdev_state,
1035 struct vfio_region_info_ext *ext)
1037 struct vfio_region_info *region_info = &ext->base;
1039 if (region_info->index >= MBOCHS_NUM_REGIONS)
1042 switch (region_info->index) {
1043 case VFIO_PCI_CONFIG_REGION_INDEX:
1044 region_info->offset = 0;
1045 region_info->size = MBOCHS_CONFIG_SPACE_SIZE;
1046 region_info->flags = (VFIO_REGION_INFO_FLAG_READ |
1047 VFIO_REGION_INFO_FLAG_WRITE);
1049 case VFIO_PCI_BAR0_REGION_INDEX:
1050 region_info->offset = MBOCHS_MEMORY_BAR_OFFSET;
1051 region_info->size = mdev_state->memsize;
1052 region_info->flags = (VFIO_REGION_INFO_FLAG_READ |
1053 VFIO_REGION_INFO_FLAG_WRITE |
1054 VFIO_REGION_INFO_FLAG_MMAP);
1056 case VFIO_PCI_BAR2_REGION_INDEX:
1057 region_info->offset = MBOCHS_MMIO_BAR_OFFSET;
1058 region_info->size = MBOCHS_MMIO_BAR_SIZE;
1059 region_info->flags = (VFIO_REGION_INFO_FLAG_READ |
1060 VFIO_REGION_INFO_FLAG_WRITE);
1062 case MBOCHS_EDID_REGION_INDEX:
1063 ext->base.argsz = sizeof(*ext);
1064 ext->base.offset = MBOCHS_EDID_OFFSET;
1065 ext->base.size = MBOCHS_EDID_SIZE;
1066 ext->base.flags = (VFIO_REGION_INFO_FLAG_READ |
1067 VFIO_REGION_INFO_FLAG_WRITE |
1068 VFIO_REGION_INFO_FLAG_CAPS);
1069 ext->base.cap_offset = offsetof(typeof(*ext), type);
1070 ext->type.header.id = VFIO_REGION_INFO_CAP_TYPE;
1071 ext->type.header.version = 1;
1072 ext->type.header.next = 0;
1073 ext->type.type = VFIO_REGION_TYPE_GFX;
1074 ext->type.subtype = VFIO_REGION_SUBTYPE_GFX_EDID;
1077 region_info->size = 0;
1078 region_info->offset = 0;
1079 region_info->flags = 0;
1085 static int mbochs_get_irq_info(struct vfio_irq_info *irq_info)
1087 irq_info->count = 0;
1091 static int mbochs_get_device_info(struct vfio_device_info *dev_info)
1093 dev_info->flags = VFIO_DEVICE_FLAGS_PCI;
1094 dev_info->num_regions = MBOCHS_NUM_REGIONS;
1095 dev_info->num_irqs = VFIO_PCI_NUM_IRQS;
1099 static int mbochs_query_gfx_plane(struct mdev_state *mdev_state,
1100 struct vfio_device_gfx_plane_info *plane)
1102 struct mbochs_dmabuf *dmabuf;
1103 struct mbochs_mode mode;
1106 if (plane->flags & VFIO_GFX_PLANE_TYPE_PROBE) {
1107 if (plane->flags == (VFIO_GFX_PLANE_TYPE_PROBE |
1108 VFIO_GFX_PLANE_TYPE_DMABUF))
1113 if (plane->flags != VFIO_GFX_PLANE_TYPE_DMABUF)
1116 plane->drm_format_mod = 0;
1122 mutex_lock(&mdev_state->ops_lock);
1125 if (plane->drm_plane_type == DRM_PLANE_TYPE_PRIMARY)
1126 ret = mbochs_check_framebuffer(mdev_state, &mode);
1128 plane->drm_format = 0;
1133 plane->dmabuf_id = 0;
1137 dmabuf = mbochs_dmabuf_find_by_mode(mdev_state, &mode);
1139 mbochs_dmabuf_alloc(mdev_state, &mode);
1141 mutex_unlock(&mdev_state->ops_lock);
1145 plane->drm_format = dmabuf->mode.drm_format;
1146 plane->width = dmabuf->mode.width;
1147 plane->height = dmabuf->mode.height;
1148 plane->stride = dmabuf->mode.stride;
1149 plane->size = dmabuf->mode.size;
1150 plane->dmabuf_id = dmabuf->id;
1153 if (plane->drm_plane_type == DRM_PLANE_TYPE_PRIMARY &&
1154 mdev_state->active_id != plane->dmabuf_id) {
1155 dev_dbg(mdev_state->vdev.dev, "%s: primary: %d => %d\n",
1156 __func__, mdev_state->active_id, plane->dmabuf_id);
1157 mdev_state->active_id = plane->dmabuf_id;
1159 mutex_unlock(&mdev_state->ops_lock);
1163 static int mbochs_get_gfx_dmabuf(struct mdev_state *mdev_state, u32 id)
1165 struct mbochs_dmabuf *dmabuf;
1167 mutex_lock(&mdev_state->ops_lock);
1169 dmabuf = mbochs_dmabuf_find_by_id(mdev_state, id);
1171 mutex_unlock(&mdev_state->ops_lock);
1176 mbochs_dmabuf_export(dmabuf);
1178 mutex_unlock(&mdev_state->ops_lock);
1183 return dma_buf_fd(dmabuf->buf, 0);
1186 static long mbochs_ioctl(struct vfio_device *vdev, unsigned int cmd,
1189 struct mdev_state *mdev_state =
1190 container_of(vdev, struct mdev_state, vdev);
1192 unsigned long minsz, outsz;
1195 case VFIO_DEVICE_GET_INFO:
1197 struct vfio_device_info info;
1199 minsz = offsetofend(struct vfio_device_info, num_irqs);
1201 if (copy_from_user(&info, (void __user *)arg, minsz))
1204 if (info.argsz < minsz)
1207 ret = mbochs_get_device_info(&info);
1211 if (copy_to_user((void __user *)arg, &info, minsz))
1216 case VFIO_DEVICE_GET_REGION_INFO:
1218 struct vfio_region_info_ext info;
1220 minsz = offsetofend(typeof(info), base.offset);
1222 if (copy_from_user(&info, (void __user *)arg, minsz))
1225 outsz = info.base.argsz;
1228 if (outsz > sizeof(info))
1231 ret = mbochs_get_region_info(mdev_state, &info);
1235 if (copy_to_user((void __user *)arg, &info, outsz))
1241 case VFIO_DEVICE_GET_IRQ_INFO:
1243 struct vfio_irq_info info;
1245 minsz = offsetofend(struct vfio_irq_info, count);
1247 if (copy_from_user(&info, (void __user *)arg, minsz))
1250 if ((info.argsz < minsz) ||
1251 (info.index >= VFIO_PCI_NUM_IRQS))
1254 ret = mbochs_get_irq_info(&info);
1258 if (copy_to_user((void __user *)arg, &info, minsz))
1264 case VFIO_DEVICE_QUERY_GFX_PLANE:
1266 struct vfio_device_gfx_plane_info plane;
1268 minsz = offsetofend(struct vfio_device_gfx_plane_info,
1271 if (copy_from_user(&plane, (void __user *)arg, minsz))
1274 if (plane.argsz < minsz)
1277 ret = mbochs_query_gfx_plane(mdev_state, &plane);
1281 if (copy_to_user((void __user *)arg, &plane, minsz))
1287 case VFIO_DEVICE_GET_GFX_DMABUF:
1291 if (get_user(dmabuf_id, (__u32 __user *)arg))
1294 return mbochs_get_gfx_dmabuf(mdev_state, dmabuf_id);
1297 case VFIO_DEVICE_SET_IRQS:
1300 case VFIO_DEVICE_RESET:
1301 return mbochs_reset(mdev_state);
1306 static void mbochs_close_device(struct vfio_device *vdev)
1308 struct mdev_state *mdev_state =
1309 container_of(vdev, struct mdev_state, vdev);
1310 struct mbochs_dmabuf *dmabuf, *tmp;
1312 mutex_lock(&mdev_state->ops_lock);
1314 list_for_each_entry_safe(dmabuf, tmp, &mdev_state->dmabufs, next) {
1315 list_del(&dmabuf->next);
1317 /* free in mbochs_release_dmabuf() */
1318 dmabuf->unlinked = true;
1323 mbochs_put_pages(mdev_state);
1325 mutex_unlock(&mdev_state->ops_lock);
1329 memory_show(struct device *dev, struct device_attribute *attr,
1332 struct mdev_state *mdev_state = dev_get_drvdata(dev);
1334 return sprintf(buf, "%d MB\n", mdev_state->type->mbytes);
1336 static DEVICE_ATTR_RO(memory);
1338 static struct attribute *mdev_dev_attrs[] = {
1339 &dev_attr_memory.attr,
1343 static const struct attribute_group mdev_dev_group = {
1345 .attrs = mdev_dev_attrs,
1348 static const struct attribute_group *mdev_dev_groups[] = {
1353 static ssize_t mbochs_show_description(struct mdev_type *mtype, char *buf)
1355 struct mbochs_type *type =
1356 container_of(mtype, struct mbochs_type, type);
1358 return sprintf(buf, "virtual display, %d MB video memory\n",
1359 type ? type->mbytes : 0);
1362 static unsigned int mbochs_get_available(struct mdev_type *mtype)
1364 struct mbochs_type *type =
1365 container_of(mtype, struct mbochs_type, type);
1367 return atomic_read(&mbochs_avail_mbytes) / type->mbytes;
1370 static const struct vfio_device_ops mbochs_dev_ops = {
1371 .close_device = mbochs_close_device,
1372 .init = mbochs_init_dev,
1373 .release = mbochs_release_dev,
1374 .read = mbochs_read,
1375 .write = mbochs_write,
1376 .ioctl = mbochs_ioctl,
1377 .mmap = mbochs_mmap,
1380 static struct mdev_driver mbochs_driver = {
1381 .device_api = VFIO_DEVICE_API_PCI_STRING,
1384 .owner = THIS_MODULE,
1385 .mod_name = KBUILD_MODNAME,
1386 .dev_groups = mdev_dev_groups,
1388 .probe = mbochs_probe,
1389 .remove = mbochs_remove,
1390 .get_available = mbochs_get_available,
1391 .show_description = mbochs_show_description,
1394 static const struct file_operations vd_fops = {
1395 .owner = THIS_MODULE,
1398 static void mbochs_device_release(struct device *dev)
1403 static int __init mbochs_dev_init(void)
1407 atomic_set(&mbochs_avail_mbytes, max_mbytes);
1409 ret = alloc_chrdev_region(&mbochs_devt, 0, MINORMASK + 1, MBOCHS_NAME);
1411 pr_err("Error: failed to register mbochs_dev, err: %d\n", ret);
1414 cdev_init(&mbochs_cdev, &vd_fops);
1415 cdev_add(&mbochs_cdev, mbochs_devt, MINORMASK + 1);
1416 pr_info("%s: major %d\n", __func__, MAJOR(mbochs_devt));
1418 ret = mdev_register_driver(&mbochs_driver);
1422 mbochs_class = class_create(THIS_MODULE, MBOCHS_CLASS_NAME);
1423 if (IS_ERR(mbochs_class)) {
1424 pr_err("Error: failed to register mbochs_dev class\n");
1425 ret = PTR_ERR(mbochs_class);
1428 mbochs_dev.class = mbochs_class;
1429 mbochs_dev.release = mbochs_device_release;
1430 dev_set_name(&mbochs_dev, "%s", MBOCHS_NAME);
1432 ret = device_register(&mbochs_dev);
1436 ret = mdev_register_parent(&mbochs_parent, &mbochs_dev, &mbochs_driver,
1438 ARRAY_SIZE(mbochs_mdev_types));
1445 device_unregister(&mbochs_dev);
1447 class_destroy(mbochs_class);
1449 mdev_unregister_driver(&mbochs_driver);
1451 cdev_del(&mbochs_cdev);
1452 unregister_chrdev_region(mbochs_devt, MINORMASK + 1);
1456 static void __exit mbochs_dev_exit(void)
1458 mbochs_dev.bus = NULL;
1459 mdev_unregister_parent(&mbochs_parent);
1461 device_unregister(&mbochs_dev);
1462 mdev_unregister_driver(&mbochs_driver);
1463 cdev_del(&mbochs_cdev);
1464 unregister_chrdev_region(mbochs_devt, MINORMASK + 1);
1465 class_destroy(mbochs_class);
1466 mbochs_class = NULL;
1469 MODULE_IMPORT_NS(DMA_BUF);
1470 module_init(mbochs_dev_init)
1471 module_exit(mbochs_dev_exit)