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OpenCloudOS-Kernel/samples/vfio-mdev/mbochs.c

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// SPDX-License-Identifier: GPL-2.0
/*
* Mediated virtual PCI display host device driver
*
* Emulate enough of qemu stdvga to make bochs-drm.ko happy. That is
* basically the vram memory bar and the bochs dispi interface vbe
* registers in the mmio register bar. Specifically it does *not*
* include any legacy vga stuff. Device looks a lot like "qemu -device
* secondary-vga".
*
* (c) Gerd Hoffmann <kraxel@redhat.com>
*
* based on mtty driver which is:
* Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved.
* Author: Neo Jia <cjia@nvidia.com>
* Kirti Wankhede <kwankhede@nvidia.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/cdev.h>
#include <linux/vfio.h>
#include <linux/iommu.h>
#include <linux/sysfs.h>
#include <linux/mdev.h>
#include <linux/pci.h>
#include <linux/dma-buf.h>
#include <linux/highmem.h>
#include <drm/drm_fourcc.h>
#include <drm/drm_rect.h>
#include <drm/drm_modeset_lock.h>
#include <drm/drm_property.h>
#include <drm/drm_plane.h>
#define VBE_DISPI_INDEX_ID 0x0
#define VBE_DISPI_INDEX_XRES 0x1
#define VBE_DISPI_INDEX_YRES 0x2
#define VBE_DISPI_INDEX_BPP 0x3
#define VBE_DISPI_INDEX_ENABLE 0x4
#define VBE_DISPI_INDEX_BANK 0x5
#define VBE_DISPI_INDEX_VIRT_WIDTH 0x6
#define VBE_DISPI_INDEX_VIRT_HEIGHT 0x7
#define VBE_DISPI_INDEX_X_OFFSET 0x8
#define VBE_DISPI_INDEX_Y_OFFSET 0x9
#define VBE_DISPI_INDEX_VIDEO_MEMORY_64K 0xa
#define VBE_DISPI_INDEX_COUNT 0xb
#define VBE_DISPI_ID0 0xB0C0
#define VBE_DISPI_ID1 0xB0C1
#define VBE_DISPI_ID2 0xB0C2
#define VBE_DISPI_ID3 0xB0C3
#define VBE_DISPI_ID4 0xB0C4
#define VBE_DISPI_ID5 0xB0C5
#define VBE_DISPI_DISABLED 0x00
#define VBE_DISPI_ENABLED 0x01
#define VBE_DISPI_GETCAPS 0x02
#define VBE_DISPI_8BIT_DAC 0x20
#define VBE_DISPI_LFB_ENABLED 0x40
#define VBE_DISPI_NOCLEARMEM 0x80
#define MBOCHS_NAME "mbochs"
#define MBOCHS_CLASS_NAME "mbochs"
#define MBOCHS_EDID_REGION_INDEX VFIO_PCI_NUM_REGIONS
#define MBOCHS_NUM_REGIONS (MBOCHS_EDID_REGION_INDEX+1)
#define MBOCHS_CONFIG_SPACE_SIZE 0xff
#define MBOCHS_MMIO_BAR_OFFSET PAGE_SIZE
#define MBOCHS_MMIO_BAR_SIZE PAGE_SIZE
#define MBOCHS_EDID_OFFSET (MBOCHS_MMIO_BAR_OFFSET + \
MBOCHS_MMIO_BAR_SIZE)
#define MBOCHS_EDID_SIZE PAGE_SIZE
#define MBOCHS_MEMORY_BAR_OFFSET (MBOCHS_EDID_OFFSET + \
MBOCHS_EDID_SIZE)
#define MBOCHS_EDID_BLOB_OFFSET (MBOCHS_EDID_SIZE/2)
#define STORE_LE16(addr, val) (*(u16 *)addr = val)
#define STORE_LE32(addr, val) (*(u32 *)addr = val)
MODULE_LICENSE("GPL v2");
static int max_mbytes = 256;
module_param_named(count, max_mbytes, int, 0444);
MODULE_PARM_DESC(mem, "megabytes available to " MBOCHS_NAME " devices");
#define MBOCHS_TYPE_1 "small"
#define MBOCHS_TYPE_2 "medium"
#define MBOCHS_TYPE_3 "large"
static struct mbochs_type {
struct mdev_type type;
u32 mbytes;
u32 max_x;
u32 max_y;
} mbochs_types[] = {
{
.type.sysfs_name = MBOCHS_TYPE_1,
.type.pretty_name = MBOCHS_CLASS_NAME "-" MBOCHS_TYPE_1,
.mbytes = 4,
.max_x = 800,
.max_y = 600,
}, {
.type.sysfs_name = MBOCHS_TYPE_2,
.type.pretty_name = MBOCHS_CLASS_NAME "-" MBOCHS_TYPE_2,
.mbytes = 16,
.max_x = 1920,
.max_y = 1440,
}, {
.type.sysfs_name = MBOCHS_TYPE_3,
.type.pretty_name = MBOCHS_CLASS_NAME "-" MBOCHS_TYPE_3,
.mbytes = 64,
.max_x = 0,
.max_y = 0,
},
};
static struct mdev_type *mbochs_mdev_types[] = {
&mbochs_types[0].type,
&mbochs_types[1].type,
&mbochs_types[2].type,
};
static dev_t mbochs_devt;
static struct class *mbochs_class;
static struct cdev mbochs_cdev;
static struct device mbochs_dev;
static struct mdev_parent mbochs_parent;
static atomic_t mbochs_avail_mbytes;
static const struct vfio_device_ops mbochs_dev_ops;
struct vfio_region_info_ext {
struct vfio_region_info base;
struct vfio_region_info_cap_type type;
};
struct mbochs_mode {
u32 drm_format;
u32 bytepp;
u32 width;
u32 height;
u32 stride;
u32 __pad;
u64 offset;
u64 size;
};
struct mbochs_dmabuf {
struct mbochs_mode mode;
u32 id;
struct page **pages;
pgoff_t pagecount;
struct dma_buf *buf;
struct mdev_state *mdev_state;
struct list_head next;
bool unlinked;
};
/* State of each mdev device */
struct mdev_state {
struct vfio_device vdev;
u8 *vconfig;
u64 bar_mask[3];
u32 memory_bar_mask;
struct mutex ops_lock;
struct mdev_device *mdev;
const struct mbochs_type *type;
u16 vbe[VBE_DISPI_INDEX_COUNT];
u64 memsize;
struct page **pages;
pgoff_t pagecount;
struct vfio_region_gfx_edid edid_regs;
u8 edid_blob[0x400];
struct list_head dmabufs;
u32 active_id;
u32 next_id;
};
static const char *vbe_name_list[VBE_DISPI_INDEX_COUNT] = {
[VBE_DISPI_INDEX_ID] = "id",
[VBE_DISPI_INDEX_XRES] = "xres",
[VBE_DISPI_INDEX_YRES] = "yres",
[VBE_DISPI_INDEX_BPP] = "bpp",
[VBE_DISPI_INDEX_ENABLE] = "enable",
[VBE_DISPI_INDEX_BANK] = "bank",
[VBE_DISPI_INDEX_VIRT_WIDTH] = "virt-width",
[VBE_DISPI_INDEX_VIRT_HEIGHT] = "virt-height",
[VBE_DISPI_INDEX_X_OFFSET] = "x-offset",
[VBE_DISPI_INDEX_Y_OFFSET] = "y-offset",
[VBE_DISPI_INDEX_VIDEO_MEMORY_64K] = "video-mem",
};
static const char *vbe_name(u32 index)
{
if (index < ARRAY_SIZE(vbe_name_list))
return vbe_name_list[index];
return "(invalid)";
}
static struct page *__mbochs_get_page(struct mdev_state *mdev_state,
pgoff_t pgoff);
static struct page *mbochs_get_page(struct mdev_state *mdev_state,
pgoff_t pgoff);
static void mbochs_create_config_space(struct mdev_state *mdev_state)
{
STORE_LE16((u16 *) &mdev_state->vconfig[PCI_VENDOR_ID],
0x1234);
STORE_LE16((u16 *) &mdev_state->vconfig[PCI_DEVICE_ID],
0x1111);
STORE_LE16((u16 *) &mdev_state->vconfig[PCI_SUBSYSTEM_VENDOR_ID],
PCI_SUBVENDOR_ID_REDHAT_QUMRANET);
STORE_LE16((u16 *) &mdev_state->vconfig[PCI_SUBSYSTEM_ID],
PCI_SUBDEVICE_ID_QEMU);
STORE_LE16((u16 *) &mdev_state->vconfig[PCI_COMMAND],
PCI_COMMAND_IO | PCI_COMMAND_MEMORY);
STORE_LE16((u16 *) &mdev_state->vconfig[PCI_CLASS_DEVICE],
PCI_CLASS_DISPLAY_OTHER);
mdev_state->vconfig[PCI_CLASS_REVISION] = 0x01;
STORE_LE32((u32 *) &mdev_state->vconfig[PCI_BASE_ADDRESS_0],
PCI_BASE_ADDRESS_SPACE_MEMORY |
PCI_BASE_ADDRESS_MEM_TYPE_32 |
PCI_BASE_ADDRESS_MEM_PREFETCH);
mdev_state->bar_mask[0] = ~(mdev_state->memsize) + 1;
STORE_LE32((u32 *) &mdev_state->vconfig[PCI_BASE_ADDRESS_2],
PCI_BASE_ADDRESS_SPACE_MEMORY |
PCI_BASE_ADDRESS_MEM_TYPE_32);
mdev_state->bar_mask[2] = ~(MBOCHS_MMIO_BAR_SIZE) + 1;
}
static int mbochs_check_framebuffer(struct mdev_state *mdev_state,
struct mbochs_mode *mode)
{
struct device *dev = mdev_dev(mdev_state->mdev);
u16 *vbe = mdev_state->vbe;
u32 virt_width;
WARN_ON(!mutex_is_locked(&mdev_state->ops_lock));
if (!(vbe[VBE_DISPI_INDEX_ENABLE] & VBE_DISPI_ENABLED))
goto nofb;
memset(mode, 0, sizeof(*mode));
switch (vbe[VBE_DISPI_INDEX_BPP]) {
case 32:
mode->drm_format = DRM_FORMAT_XRGB8888;
mode->bytepp = 4;
break;
default:
dev_info_ratelimited(dev, "%s: bpp %d not supported\n",
__func__, vbe[VBE_DISPI_INDEX_BPP]);
goto nofb;
}
mode->width = vbe[VBE_DISPI_INDEX_XRES];
mode->height = vbe[VBE_DISPI_INDEX_YRES];
virt_width = vbe[VBE_DISPI_INDEX_VIRT_WIDTH];
if (virt_width < mode->width)
virt_width = mode->width;
mode->stride = virt_width * mode->bytepp;
mode->size = (u64)mode->stride * mode->height;
mode->offset = ((u64)vbe[VBE_DISPI_INDEX_X_OFFSET] * mode->bytepp +
(u64)vbe[VBE_DISPI_INDEX_Y_OFFSET] * mode->stride);
if (mode->width < 64 || mode->height < 64) {
dev_info_ratelimited(dev, "%s: invalid resolution %dx%d\n",
__func__, mode->width, mode->height);
goto nofb;
}
if (mode->offset + mode->size > mdev_state->memsize) {
dev_info_ratelimited(dev, "%s: framebuffer memory overflow\n",
__func__);
goto nofb;
}
return 0;
nofb:
memset(mode, 0, sizeof(*mode));
return -EINVAL;
}
static bool mbochs_modes_equal(struct mbochs_mode *mode1,
struct mbochs_mode *mode2)
{
return memcmp(mode1, mode2, sizeof(struct mbochs_mode)) == 0;
}
static void handle_pci_cfg_write(struct mdev_state *mdev_state, u16 offset,
char *buf, u32 count)
{
struct device *dev = mdev_dev(mdev_state->mdev);
int index = (offset - PCI_BASE_ADDRESS_0) / 0x04;
u32 cfg_addr;
switch (offset) {
case PCI_BASE_ADDRESS_0:
case PCI_BASE_ADDRESS_2:
cfg_addr = *(u32 *)buf;
if (cfg_addr == 0xffffffff) {
cfg_addr = (cfg_addr & mdev_state->bar_mask[index]);
} else {
cfg_addr &= PCI_BASE_ADDRESS_MEM_MASK;
if (cfg_addr)
dev_info(dev, "BAR #%d @ 0x%x\n",
index, cfg_addr);
}
cfg_addr |= (mdev_state->vconfig[offset] &
~PCI_BASE_ADDRESS_MEM_MASK);
STORE_LE32(&mdev_state->vconfig[offset], cfg_addr);
break;
}
}
static void handle_mmio_write(struct mdev_state *mdev_state, u16 offset,
char *buf, u32 count)
{
struct device *dev = mdev_dev(mdev_state->mdev);
int index;
u16 reg16;
switch (offset) {
case 0x400 ... 0x41f: /* vga ioports remapped */
goto unhandled;
case 0x500 ... 0x515: /* bochs dispi interface */
if (count != 2)
goto unhandled;
index = (offset - 0x500) / 2;
reg16 = *(u16 *)buf;
if (index < ARRAY_SIZE(mdev_state->vbe))
mdev_state->vbe[index] = reg16;
dev_dbg(dev, "%s: vbe write %d = %d (%s)\n",
__func__, index, reg16, vbe_name(index));
break;
case 0x600 ... 0x607: /* qemu extended regs */
goto unhandled;
default:
unhandled:
dev_dbg(dev, "%s: @0x%03x, count %d (unhandled)\n",
__func__, offset, count);
break;
}
}
static void handle_mmio_read(struct mdev_state *mdev_state, u16 offset,
char *buf, u32 count)
{
struct device *dev = mdev_dev(mdev_state->mdev);
struct vfio_region_gfx_edid *edid;
u16 reg16 = 0;
int index;
switch (offset) {
case 0x000 ... 0x3ff: /* edid block */
edid = &mdev_state->edid_regs;
if (edid->link_state != VFIO_DEVICE_GFX_LINK_STATE_UP ||
offset >= edid->edid_size) {
memset(buf, 0, count);
break;
}
memcpy(buf, mdev_state->edid_blob + offset, count);
break;
case 0x500 ... 0x515: /* bochs dispi interface */
if (count != 2)
goto unhandled;
index = (offset - 0x500) / 2;
if (index < ARRAY_SIZE(mdev_state->vbe))
reg16 = mdev_state->vbe[index];
dev_dbg(dev, "%s: vbe read %d = %d (%s)\n",
__func__, index, reg16, vbe_name(index));
*(u16 *)buf = reg16;
break;
default:
unhandled:
dev_dbg(dev, "%s: @0x%03x, count %d (unhandled)\n",
__func__, offset, count);
memset(buf, 0, count);
break;
}
}
static void handle_edid_regs(struct mdev_state *mdev_state, u16 offset,
char *buf, u32 count, bool is_write)
{
char *regs = (void *)&mdev_state->edid_regs;
if (offset + count > sizeof(mdev_state->edid_regs))
return;
if (count != 4)
return;
if (offset % 4)
return;
if (is_write) {
switch (offset) {
case offsetof(struct vfio_region_gfx_edid, link_state):
case offsetof(struct vfio_region_gfx_edid, edid_size):
memcpy(regs + offset, buf, count);
break;
default:
/* read-only regs */
break;
}
} else {
memcpy(buf, regs + offset, count);
}
}
static void handle_edid_blob(struct mdev_state *mdev_state, u16 offset,
char *buf, u32 count, bool is_write)
{
if (offset + count > mdev_state->edid_regs.edid_max_size)
return;
if (is_write)
memcpy(mdev_state->edid_blob + offset, buf, count);
else
memcpy(buf, mdev_state->edid_blob + offset, count);
}
static ssize_t mdev_access(struct mdev_state *mdev_state, char *buf,
size_t count, loff_t pos, bool is_write)
{
struct page *pg;
loff_t poff;
char *map;
int ret = 0;
mutex_lock(&mdev_state->ops_lock);
if (pos < MBOCHS_CONFIG_SPACE_SIZE) {
if (is_write)
handle_pci_cfg_write(mdev_state, pos, buf, count);
else
memcpy(buf, (mdev_state->vconfig + pos), count);
} else if (pos >= MBOCHS_MMIO_BAR_OFFSET &&
pos + count <= (MBOCHS_MMIO_BAR_OFFSET +
MBOCHS_MMIO_BAR_SIZE)) {
pos -= MBOCHS_MMIO_BAR_OFFSET;
if (is_write)
handle_mmio_write(mdev_state, pos, buf, count);
else
handle_mmio_read(mdev_state, pos, buf, count);
} else if (pos >= MBOCHS_EDID_OFFSET &&
pos + count <= (MBOCHS_EDID_OFFSET +
MBOCHS_EDID_SIZE)) {
pos -= MBOCHS_EDID_OFFSET;
if (pos < MBOCHS_EDID_BLOB_OFFSET) {
handle_edid_regs(mdev_state, pos, buf, count, is_write);
} else {
pos -= MBOCHS_EDID_BLOB_OFFSET;
handle_edid_blob(mdev_state, pos, buf, count, is_write);
}
} else if (pos >= MBOCHS_MEMORY_BAR_OFFSET &&
pos + count <=
MBOCHS_MEMORY_BAR_OFFSET + mdev_state->memsize) {
pos -= MBOCHS_MMIO_BAR_OFFSET;
poff = pos & ~PAGE_MASK;
pg = __mbochs_get_page(mdev_state, pos >> PAGE_SHIFT);
map = kmap(pg);
if (is_write)
memcpy(map + poff, buf, count);
else
memcpy(buf, map + poff, count);
kunmap(pg);
put_page(pg);
} else {
dev_dbg(mdev_state->vdev.dev, "%s: %s @0x%llx (unhandled)\n",
__func__, is_write ? "WR" : "RD", pos);
ret = -1;
goto accessfailed;
}
ret = count;
accessfailed:
mutex_unlock(&mdev_state->ops_lock);
return ret;
}
static int mbochs_reset(struct mdev_state *mdev_state)
{
u32 size64k = mdev_state->memsize / (64 * 1024);
int i;
for (i = 0; i < ARRAY_SIZE(mdev_state->vbe); i++)
mdev_state->vbe[i] = 0;
mdev_state->vbe[VBE_DISPI_INDEX_ID] = VBE_DISPI_ID5;
mdev_state->vbe[VBE_DISPI_INDEX_VIDEO_MEMORY_64K] = size64k;
return 0;
}
static int mbochs_init_dev(struct vfio_device *vdev)
{
struct mdev_state *mdev_state =
container_of(vdev, struct mdev_state, vdev);
struct mdev_device *mdev = to_mdev_device(vdev->dev);
struct mbochs_type *type =
container_of(mdev->type, struct mbochs_type, type);
int avail_mbytes = atomic_read(&mbochs_avail_mbytes);
int ret = -ENOMEM;
do {
if (avail_mbytes < type->mbytes)
return -ENOSPC;
} while (!atomic_try_cmpxchg(&mbochs_avail_mbytes, &avail_mbytes,
avail_mbytes - type->mbytes));
mdev_state->vconfig = kzalloc(MBOCHS_CONFIG_SPACE_SIZE, GFP_KERNEL);
if (!mdev_state->vconfig)
goto err_avail;
mdev_state->memsize = type->mbytes * 1024 * 1024;
mdev_state->pagecount = mdev_state->memsize >> PAGE_SHIFT;
mdev_state->pages = kcalloc(mdev_state->pagecount,
sizeof(struct page *),
GFP_KERNEL);
if (!mdev_state->pages)
goto err_vconfig;
mutex_init(&mdev_state->ops_lock);
mdev_state->mdev = mdev;
INIT_LIST_HEAD(&mdev_state->dmabufs);
mdev_state->next_id = 1;
mdev_state->type = type;
mdev_state->edid_regs.max_xres = type->max_x;
mdev_state->edid_regs.max_yres = type->max_y;
mdev_state->edid_regs.edid_offset = MBOCHS_EDID_BLOB_OFFSET;
mdev_state->edid_regs.edid_max_size = sizeof(mdev_state->edid_blob);
mbochs_create_config_space(mdev_state);
mbochs_reset(mdev_state);
dev_info(vdev->dev, "%s: %s, %d MB, %ld pages\n", __func__,
type->type.pretty_name, type->mbytes, mdev_state->pagecount);
return 0;
err_vconfig:
kfree(mdev_state->vconfig);
err_avail:
atomic_add(type->mbytes, &mbochs_avail_mbytes);
return ret;
}
static int mbochs_probe(struct mdev_device *mdev)
{
struct mdev_state *mdev_state;
int ret = -ENOMEM;
mdev_state = vfio_alloc_device(mdev_state, vdev, &mdev->dev,
&mbochs_dev_ops);
if (IS_ERR(mdev_state))
return PTR_ERR(mdev_state);
ret = vfio_register_emulated_iommu_dev(&mdev_state->vdev);
if (ret)
goto err_put_vdev;
dev_set_drvdata(&mdev->dev, mdev_state);
return 0;
err_put_vdev:
vfio_put_device(&mdev_state->vdev);
return ret;
}
static void mbochs_release_dev(struct vfio_device *vdev)
{
struct mdev_state *mdev_state =
container_of(vdev, struct mdev_state, vdev);
atomic_add(mdev_state->type->mbytes, &mbochs_avail_mbytes);
kfree(mdev_state->pages);
kfree(mdev_state->vconfig);
}
static void mbochs_remove(struct mdev_device *mdev)
{
struct mdev_state *mdev_state = dev_get_drvdata(&mdev->dev);
vfio_unregister_group_dev(&mdev_state->vdev);
vfio_put_device(&mdev_state->vdev);
}
static ssize_t mbochs_read(struct vfio_device *vdev, char __user *buf,
size_t count, loff_t *ppos)
{
struct mdev_state *mdev_state =
container_of(vdev, struct mdev_state, vdev);
unsigned int done = 0;
int ret;
while (count) {
size_t filled;
if (count >= 4 && !(*ppos % 4)) {
u32 val;
ret = mdev_access(mdev_state, (char *)&val, sizeof(val),
*ppos, false);
if (ret <= 0)
goto read_err;
if (copy_to_user(buf, &val, sizeof(val)))
goto read_err;
filled = 4;
} else if (count >= 2 && !(*ppos % 2)) {
u16 val;
ret = mdev_access(mdev_state, (char *)&val, sizeof(val),
*ppos, false);
if (ret <= 0)
goto read_err;
if (copy_to_user(buf, &val, sizeof(val)))
goto read_err;
filled = 2;
} else {
u8 val;
ret = mdev_access(mdev_state, (char *)&val, sizeof(val),
*ppos, false);
if (ret <= 0)
goto read_err;
if (copy_to_user(buf, &val, sizeof(val)))
goto read_err;
filled = 1;
}
count -= filled;
done += filled;
*ppos += filled;
buf += filled;
}
return done;
read_err:
return -EFAULT;
}
static ssize_t mbochs_write(struct vfio_device *vdev, const char __user *buf,
size_t count, loff_t *ppos)
{
struct mdev_state *mdev_state =
container_of(vdev, struct mdev_state, vdev);
unsigned int done = 0;
int ret;
while (count) {
size_t filled;
if (count >= 4 && !(*ppos % 4)) {
u32 val;
if (copy_from_user(&val, buf, sizeof(val)))
goto write_err;
ret = mdev_access(mdev_state, (char *)&val, sizeof(val),
*ppos, true);
if (ret <= 0)
goto write_err;
filled = 4;
} else if (count >= 2 && !(*ppos % 2)) {
u16 val;
if (copy_from_user(&val, buf, sizeof(val)))
goto write_err;
ret = mdev_access(mdev_state, (char *)&val, sizeof(val),
*ppos, true);
if (ret <= 0)
goto write_err;
filled = 2;
} else {
u8 val;
if (copy_from_user(&val, buf, sizeof(val)))
goto write_err;
ret = mdev_access(mdev_state, (char *)&val, sizeof(val),
*ppos, true);
if (ret <= 0)
goto write_err;
filled = 1;
}
count -= filled;
done += filled;
*ppos += filled;
buf += filled;
}
return done;
write_err:
return -EFAULT;
}
static struct page *__mbochs_get_page(struct mdev_state *mdev_state,
pgoff_t pgoff)
{
WARN_ON(!mutex_is_locked(&mdev_state->ops_lock));
if (!mdev_state->pages[pgoff]) {
mdev_state->pages[pgoff] =
alloc_pages(GFP_HIGHUSER | __GFP_ZERO, 0);
if (!mdev_state->pages[pgoff])
return NULL;
}
get_page(mdev_state->pages[pgoff]);
return mdev_state->pages[pgoff];
}
static struct page *mbochs_get_page(struct mdev_state *mdev_state,
pgoff_t pgoff)
{
struct page *page;
if (WARN_ON(pgoff >= mdev_state->pagecount))
return NULL;
mutex_lock(&mdev_state->ops_lock);
page = __mbochs_get_page(mdev_state, pgoff);
mutex_unlock(&mdev_state->ops_lock);
return page;
}
static void mbochs_put_pages(struct mdev_state *mdev_state)
{
struct device *dev = mdev_dev(mdev_state->mdev);
int i, count = 0;
WARN_ON(!mutex_is_locked(&mdev_state->ops_lock));
for (i = 0; i < mdev_state->pagecount; i++) {
if (!mdev_state->pages[i])
continue;
put_page(mdev_state->pages[i]);
mdev_state->pages[i] = NULL;
count++;
}
dev_dbg(dev, "%s: %d pages released\n", __func__, count);
}
static vm_fault_t mbochs_region_vm_fault(struct vm_fault *vmf)
{
struct vm_area_struct *vma = vmf->vma;
struct mdev_state *mdev_state = vma->vm_private_data;
pgoff_t page_offset = (vmf->address - vma->vm_start) >> PAGE_SHIFT;
if (page_offset >= mdev_state->pagecount)
return VM_FAULT_SIGBUS;
vmf->page = mbochs_get_page(mdev_state, page_offset);
if (!vmf->page)
return VM_FAULT_SIGBUS;
return 0;
}
static const struct vm_operations_struct mbochs_region_vm_ops = {
.fault = mbochs_region_vm_fault,
};
static int mbochs_mmap(struct vfio_device *vdev, struct vm_area_struct *vma)
{
struct mdev_state *mdev_state =
container_of(vdev, struct mdev_state, vdev);
if (vma->vm_pgoff != MBOCHS_MEMORY_BAR_OFFSET >> PAGE_SHIFT)
return -EINVAL;
if (vma->vm_end < vma->vm_start)
return -EINVAL;
if (vma->vm_end - vma->vm_start > mdev_state->memsize)
return -EINVAL;
if ((vma->vm_flags & VM_SHARED) == 0)
return -EINVAL;
vma->vm_ops = &mbochs_region_vm_ops;
vma->vm_private_data = mdev_state;
return 0;
}
static vm_fault_t mbochs_dmabuf_vm_fault(struct vm_fault *vmf)
{
struct vm_area_struct *vma = vmf->vma;
struct mbochs_dmabuf *dmabuf = vma->vm_private_data;
if (WARN_ON(vmf->pgoff >= dmabuf->pagecount))
return VM_FAULT_SIGBUS;
vmf->page = dmabuf->pages[vmf->pgoff];
get_page(vmf->page);
return 0;
}
static const struct vm_operations_struct mbochs_dmabuf_vm_ops = {
.fault = mbochs_dmabuf_vm_fault,
};
static int mbochs_mmap_dmabuf(struct dma_buf *buf, struct vm_area_struct *vma)
{
struct mbochs_dmabuf *dmabuf = buf->priv;
struct device *dev = mdev_dev(dmabuf->mdev_state->mdev);
dev_dbg(dev, "%s: %d\n", __func__, dmabuf->id);
if ((vma->vm_flags & VM_SHARED) == 0)
return -EINVAL;
vma->vm_ops = &mbochs_dmabuf_vm_ops;
vma->vm_private_data = dmabuf;
return 0;
}
static void mbochs_print_dmabuf(struct mbochs_dmabuf *dmabuf,
const char *prefix)
{
struct device *dev = mdev_dev(dmabuf->mdev_state->mdev);
u32 fourcc = dmabuf->mode.drm_format;
dev_dbg(dev, "%s/%d: %c%c%c%c, %dx%d, stride %d, off 0x%llx, size 0x%llx, pages %ld\n",
prefix, dmabuf->id,
fourcc ? ((fourcc >> 0) & 0xff) : '-',
fourcc ? ((fourcc >> 8) & 0xff) : '-',
fourcc ? ((fourcc >> 16) & 0xff) : '-',
fourcc ? ((fourcc >> 24) & 0xff) : '-',
dmabuf->mode.width, dmabuf->mode.height, dmabuf->mode.stride,
dmabuf->mode.offset, dmabuf->mode.size, dmabuf->pagecount);
}
static struct sg_table *mbochs_map_dmabuf(struct dma_buf_attachment *at,
enum dma_data_direction direction)
{
struct mbochs_dmabuf *dmabuf = at->dmabuf->priv;
struct device *dev = mdev_dev(dmabuf->mdev_state->mdev);
struct sg_table *sg;
dev_dbg(dev, "%s: %d\n", __func__, dmabuf->id);
sg = kzalloc(sizeof(*sg), GFP_KERNEL);
if (!sg)
goto err1;
if (sg_alloc_table_from_pages(sg, dmabuf->pages, dmabuf->pagecount,
0, dmabuf->mode.size, GFP_KERNEL) < 0)
goto err2;
if (dma_map_sgtable(at->dev, sg, direction, 0))
goto err3;
return sg;
err3:
sg_free_table(sg);
err2:
kfree(sg);
err1:
return ERR_PTR(-ENOMEM);
}
static void mbochs_unmap_dmabuf(struct dma_buf_attachment *at,
struct sg_table *sg,
enum dma_data_direction direction)
{
struct mbochs_dmabuf *dmabuf = at->dmabuf->priv;
struct device *dev = mdev_dev(dmabuf->mdev_state->mdev);
dev_dbg(dev, "%s: %d\n", __func__, dmabuf->id);
dma_unmap_sgtable(at->dev, sg, direction, 0);
sg_free_table(sg);
kfree(sg);
}
static void mbochs_release_dmabuf(struct dma_buf *buf)
{
struct mbochs_dmabuf *dmabuf = buf->priv;
struct mdev_state *mdev_state = dmabuf->mdev_state;
struct device *dev = mdev_dev(mdev_state->mdev);
pgoff_t pg;
dev_dbg(dev, "%s: %d\n", __func__, dmabuf->id);
for (pg = 0; pg < dmabuf->pagecount; pg++)
put_page(dmabuf->pages[pg]);
mutex_lock(&mdev_state->ops_lock);
dmabuf->buf = NULL;
if (dmabuf->unlinked)
kfree(dmabuf);
mutex_unlock(&mdev_state->ops_lock);
}
static struct dma_buf_ops mbochs_dmabuf_ops = {
.map_dma_buf = mbochs_map_dmabuf,
.unmap_dma_buf = mbochs_unmap_dmabuf,
.release = mbochs_release_dmabuf,
.mmap = mbochs_mmap_dmabuf,
};
static struct mbochs_dmabuf *mbochs_dmabuf_alloc(struct mdev_state *mdev_state,
struct mbochs_mode *mode)
{
struct mbochs_dmabuf *dmabuf;
pgoff_t page_offset, pg;
WARN_ON(!mutex_is_locked(&mdev_state->ops_lock));
dmabuf = kzalloc(sizeof(struct mbochs_dmabuf), GFP_KERNEL);
if (!dmabuf)
return NULL;
dmabuf->mode = *mode;
dmabuf->id = mdev_state->next_id++;
dmabuf->pagecount = DIV_ROUND_UP(mode->size, PAGE_SIZE);
dmabuf->pages = kcalloc(dmabuf->pagecount, sizeof(struct page *),
GFP_KERNEL);
if (!dmabuf->pages)
goto err_free_dmabuf;
page_offset = dmabuf->mode.offset >> PAGE_SHIFT;
for (pg = 0; pg < dmabuf->pagecount; pg++) {
dmabuf->pages[pg] = __mbochs_get_page(mdev_state,
page_offset + pg);
if (!dmabuf->pages[pg])
goto err_free_pages;
}
dmabuf->mdev_state = mdev_state;
list_add(&dmabuf->next, &mdev_state->dmabufs);
mbochs_print_dmabuf(dmabuf, __func__);
return dmabuf;
err_free_pages:
while (pg > 0)
put_page(dmabuf->pages[--pg]);
kfree(dmabuf->pages);
err_free_dmabuf:
kfree(dmabuf);
return NULL;
}
static struct mbochs_dmabuf *
mbochs_dmabuf_find_by_mode(struct mdev_state *mdev_state,
struct mbochs_mode *mode)
{
struct mbochs_dmabuf *dmabuf;
WARN_ON(!mutex_is_locked(&mdev_state->ops_lock));
list_for_each_entry(dmabuf, &mdev_state->dmabufs, next)
if (mbochs_modes_equal(&dmabuf->mode, mode))
return dmabuf;
return NULL;
}
static struct mbochs_dmabuf *
mbochs_dmabuf_find_by_id(struct mdev_state *mdev_state, u32 id)
{
struct mbochs_dmabuf *dmabuf;
WARN_ON(!mutex_is_locked(&mdev_state->ops_lock));
list_for_each_entry(dmabuf, &mdev_state->dmabufs, next)
if (dmabuf->id == id)
return dmabuf;
return NULL;
}
static int mbochs_dmabuf_export(struct mbochs_dmabuf *dmabuf)
{
struct mdev_state *mdev_state = dmabuf->mdev_state;
struct device *dev = mdev_state->vdev.dev;
DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
struct dma_buf *buf;
WARN_ON(!mutex_is_locked(&mdev_state->ops_lock));
if (!IS_ALIGNED(dmabuf->mode.offset, PAGE_SIZE)) {
dev_info_ratelimited(dev, "%s: framebuffer not page-aligned\n",
__func__);
return -EINVAL;
}
exp_info.ops = &mbochs_dmabuf_ops;
exp_info.size = dmabuf->mode.size;
exp_info.priv = dmabuf;
buf = dma_buf_export(&exp_info);
if (IS_ERR(buf)) {
dev_info_ratelimited(dev, "%s: dma_buf_export failed: %ld\n",
__func__, PTR_ERR(buf));
return PTR_ERR(buf);
}
dmabuf->buf = buf;
dev_dbg(dev, "%s: %d\n", __func__, dmabuf->id);
return 0;
}
static int mbochs_get_region_info(struct mdev_state *mdev_state,
struct vfio_region_info_ext *ext)
{
struct vfio_region_info *region_info = &ext->base;
if (region_info->index >= MBOCHS_NUM_REGIONS)
return -EINVAL;
switch (region_info->index) {
case VFIO_PCI_CONFIG_REGION_INDEX:
region_info->offset = 0;
region_info->size = MBOCHS_CONFIG_SPACE_SIZE;
region_info->flags = (VFIO_REGION_INFO_FLAG_READ |
VFIO_REGION_INFO_FLAG_WRITE);
break;
case VFIO_PCI_BAR0_REGION_INDEX:
region_info->offset = MBOCHS_MEMORY_BAR_OFFSET;
region_info->size = mdev_state->memsize;
region_info->flags = (VFIO_REGION_INFO_FLAG_READ |
VFIO_REGION_INFO_FLAG_WRITE |
VFIO_REGION_INFO_FLAG_MMAP);
break;
case VFIO_PCI_BAR2_REGION_INDEX:
region_info->offset = MBOCHS_MMIO_BAR_OFFSET;
region_info->size = MBOCHS_MMIO_BAR_SIZE;
region_info->flags = (VFIO_REGION_INFO_FLAG_READ |
VFIO_REGION_INFO_FLAG_WRITE);
break;
case MBOCHS_EDID_REGION_INDEX:
ext->base.argsz = sizeof(*ext);
ext->base.offset = MBOCHS_EDID_OFFSET;
ext->base.size = MBOCHS_EDID_SIZE;
ext->base.flags = (VFIO_REGION_INFO_FLAG_READ |
VFIO_REGION_INFO_FLAG_WRITE |
VFIO_REGION_INFO_FLAG_CAPS);
ext->base.cap_offset = offsetof(typeof(*ext), type);
ext->type.header.id = VFIO_REGION_INFO_CAP_TYPE;
ext->type.header.version = 1;
ext->type.header.next = 0;
ext->type.type = VFIO_REGION_TYPE_GFX;
ext->type.subtype = VFIO_REGION_SUBTYPE_GFX_EDID;
break;
default:
region_info->size = 0;
region_info->offset = 0;
region_info->flags = 0;
}
return 0;
}
static int mbochs_get_irq_info(struct vfio_irq_info *irq_info)
{
irq_info->count = 0;
return 0;
}
static int mbochs_get_device_info(struct vfio_device_info *dev_info)
{
dev_info->flags = VFIO_DEVICE_FLAGS_PCI;
dev_info->num_regions = MBOCHS_NUM_REGIONS;
dev_info->num_irqs = VFIO_PCI_NUM_IRQS;
return 0;
}
static int mbochs_query_gfx_plane(struct mdev_state *mdev_state,
struct vfio_device_gfx_plane_info *plane)
{
struct mbochs_dmabuf *dmabuf;
struct mbochs_mode mode;
int ret;
if (plane->flags & VFIO_GFX_PLANE_TYPE_PROBE) {
if (plane->flags == (VFIO_GFX_PLANE_TYPE_PROBE |
VFIO_GFX_PLANE_TYPE_DMABUF))
return 0;
return -EINVAL;
}
if (plane->flags != VFIO_GFX_PLANE_TYPE_DMABUF)
return -EINVAL;
plane->drm_format_mod = 0;
plane->x_pos = 0;
plane->y_pos = 0;
plane->x_hot = 0;
plane->y_hot = 0;
mutex_lock(&mdev_state->ops_lock);
ret = -EINVAL;
if (plane->drm_plane_type == DRM_PLANE_TYPE_PRIMARY)
ret = mbochs_check_framebuffer(mdev_state, &mode);
if (ret < 0) {
plane->drm_format = 0;
plane->width = 0;
plane->height = 0;
plane->stride = 0;
plane->size = 0;
plane->dmabuf_id = 0;
goto done;
}
dmabuf = mbochs_dmabuf_find_by_mode(mdev_state, &mode);
if (!dmabuf)
mbochs_dmabuf_alloc(mdev_state, &mode);
if (!dmabuf) {
mutex_unlock(&mdev_state->ops_lock);
return -ENOMEM;
}
plane->drm_format = dmabuf->mode.drm_format;
plane->width = dmabuf->mode.width;
plane->height = dmabuf->mode.height;
plane->stride = dmabuf->mode.stride;
plane->size = dmabuf->mode.size;
plane->dmabuf_id = dmabuf->id;
done:
if (plane->drm_plane_type == DRM_PLANE_TYPE_PRIMARY &&
mdev_state->active_id != plane->dmabuf_id) {
dev_dbg(mdev_state->vdev.dev, "%s: primary: %d => %d\n",
__func__, mdev_state->active_id, plane->dmabuf_id);
mdev_state->active_id = plane->dmabuf_id;
}
mutex_unlock(&mdev_state->ops_lock);
return 0;
}
static int mbochs_get_gfx_dmabuf(struct mdev_state *mdev_state, u32 id)
{
struct mbochs_dmabuf *dmabuf;
mutex_lock(&mdev_state->ops_lock);
dmabuf = mbochs_dmabuf_find_by_id(mdev_state, id);
if (!dmabuf) {
mutex_unlock(&mdev_state->ops_lock);
return -ENOENT;
}
if (!dmabuf->buf)
mbochs_dmabuf_export(dmabuf);
mutex_unlock(&mdev_state->ops_lock);
if (!dmabuf->buf)
return -EINVAL;
return dma_buf_fd(dmabuf->buf, 0);
}
static long mbochs_ioctl(struct vfio_device *vdev, unsigned int cmd,
unsigned long arg)
{
struct mdev_state *mdev_state =
container_of(vdev, struct mdev_state, vdev);
int ret = 0;
unsigned long minsz, outsz;
switch (cmd) {
case VFIO_DEVICE_GET_INFO:
{
struct vfio_device_info info;
minsz = offsetofend(struct vfio_device_info, num_irqs);
if (copy_from_user(&info, (void __user *)arg, minsz))
return -EFAULT;
if (info.argsz < minsz)
return -EINVAL;
ret = mbochs_get_device_info(&info);
if (ret)
return ret;
if (copy_to_user((void __user *)arg, &info, minsz))
return -EFAULT;
return 0;
}
case VFIO_DEVICE_GET_REGION_INFO:
{
struct vfio_region_info_ext info;
minsz = offsetofend(typeof(info), base.offset);
if (copy_from_user(&info, (void __user *)arg, minsz))
return -EFAULT;
outsz = info.base.argsz;
if (outsz < minsz)
return -EINVAL;
if (outsz > sizeof(info))
return -EINVAL;
ret = mbochs_get_region_info(mdev_state, &info);
if (ret)
return ret;
if (copy_to_user((void __user *)arg, &info, outsz))
return -EFAULT;
return 0;
}
case VFIO_DEVICE_GET_IRQ_INFO:
{
struct vfio_irq_info info;
minsz = offsetofend(struct vfio_irq_info, count);
if (copy_from_user(&info, (void __user *)arg, minsz))
return -EFAULT;
if ((info.argsz < minsz) ||
(info.index >= VFIO_PCI_NUM_IRQS))
return -EINVAL;
ret = mbochs_get_irq_info(&info);
if (ret)
return ret;
if (copy_to_user((void __user *)arg, &info, minsz))
return -EFAULT;
return 0;
}
case VFIO_DEVICE_QUERY_GFX_PLANE:
{
struct vfio_device_gfx_plane_info plane;
minsz = offsetofend(struct vfio_device_gfx_plane_info,
region_index);
if (copy_from_user(&plane, (void __user *)arg, minsz))
return -EFAULT;
if (plane.argsz < minsz)
return -EINVAL;
ret = mbochs_query_gfx_plane(mdev_state, &plane);
if (ret)
return ret;
if (copy_to_user((void __user *)arg, &plane, minsz))
return -EFAULT;
return 0;
}
case VFIO_DEVICE_GET_GFX_DMABUF:
{
u32 dmabuf_id;
if (get_user(dmabuf_id, (__u32 __user *)arg))
return -EFAULT;
return mbochs_get_gfx_dmabuf(mdev_state, dmabuf_id);
}
case VFIO_DEVICE_SET_IRQS:
return -EINVAL;
case VFIO_DEVICE_RESET:
return mbochs_reset(mdev_state);
}
return -ENOTTY;
}
static void mbochs_close_device(struct vfio_device *vdev)
{
struct mdev_state *mdev_state =
container_of(vdev, struct mdev_state, vdev);
struct mbochs_dmabuf *dmabuf, *tmp;
mutex_lock(&mdev_state->ops_lock);
list_for_each_entry_safe(dmabuf, tmp, &mdev_state->dmabufs, next) {
list_del(&dmabuf->next);
if (dmabuf->buf) {
/* free in mbochs_release_dmabuf() */
dmabuf->unlinked = true;
} else {
kfree(dmabuf);
}
}
mbochs_put_pages(mdev_state);
mutex_unlock(&mdev_state->ops_lock);
}
static ssize_t
memory_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct mdev_state *mdev_state = dev_get_drvdata(dev);
return sprintf(buf, "%d MB\n", mdev_state->type->mbytes);
}
static DEVICE_ATTR_RO(memory);
static struct attribute *mdev_dev_attrs[] = {
&dev_attr_memory.attr,
NULL,
};
static const struct attribute_group mdev_dev_group = {
.name = "vendor",
.attrs = mdev_dev_attrs,
};
static const struct attribute_group *mdev_dev_groups[] = {
&mdev_dev_group,
NULL,
};
static ssize_t mbochs_show_description(struct mdev_type *mtype, char *buf)
{
struct mbochs_type *type =
container_of(mtype, struct mbochs_type, type);
return sprintf(buf, "virtual display, %d MB video memory\n",
type ? type->mbytes : 0);
}
static unsigned int mbochs_get_available(struct mdev_type *mtype)
{
struct mbochs_type *type =
container_of(mtype, struct mbochs_type, type);
return atomic_read(&mbochs_avail_mbytes) / type->mbytes;
}
static const struct vfio_device_ops mbochs_dev_ops = {
.close_device = mbochs_close_device,
.init = mbochs_init_dev,
.release = mbochs_release_dev,
.read = mbochs_read,
.write = mbochs_write,
.ioctl = mbochs_ioctl,
.mmap = mbochs_mmap,
};
static struct mdev_driver mbochs_driver = {
.device_api = VFIO_DEVICE_API_PCI_STRING,
.driver = {
.name = "mbochs",
.owner = THIS_MODULE,
.mod_name = KBUILD_MODNAME,
.dev_groups = mdev_dev_groups,
},
.probe = mbochs_probe,
.remove = mbochs_remove,
.get_available = mbochs_get_available,
.show_description = mbochs_show_description,
};
static const struct file_operations vd_fops = {
.owner = THIS_MODULE,
};
static void mbochs_device_release(struct device *dev)
{
/* nothing */
}
static int __init mbochs_dev_init(void)
{
int ret = 0;
atomic_set(&mbochs_avail_mbytes, max_mbytes);
ret = alloc_chrdev_region(&mbochs_devt, 0, MINORMASK + 1, MBOCHS_NAME);
if (ret < 0) {
pr_err("Error: failed to register mbochs_dev, err: %d\n", ret);
return ret;
}
cdev_init(&mbochs_cdev, &vd_fops);
cdev_add(&mbochs_cdev, mbochs_devt, MINORMASK + 1);
pr_info("%s: major %d\n", __func__, MAJOR(mbochs_devt));
ret = mdev_register_driver(&mbochs_driver);
if (ret)
goto err_cdev;
mbochs_class = class_create(THIS_MODULE, MBOCHS_CLASS_NAME);
if (IS_ERR(mbochs_class)) {
pr_err("Error: failed to register mbochs_dev class\n");
ret = PTR_ERR(mbochs_class);
goto err_driver;
}
mbochs_dev.class = mbochs_class;
mbochs_dev.release = mbochs_device_release;
dev_set_name(&mbochs_dev, "%s", MBOCHS_NAME);
ret = device_register(&mbochs_dev);
if (ret)
goto err_put;
ret = mdev_register_parent(&mbochs_parent, &mbochs_dev, &mbochs_driver,
mbochs_mdev_types,
ARRAY_SIZE(mbochs_mdev_types));
if (ret)
goto err_device;
return 0;
err_device:
device_del(&mbochs_dev);
err_put:
put_device(&mbochs_dev);
class_destroy(mbochs_class);
err_driver:
mdev_unregister_driver(&mbochs_driver);
err_cdev:
cdev_del(&mbochs_cdev);
unregister_chrdev_region(mbochs_devt, MINORMASK + 1);
return ret;
}
static void __exit mbochs_dev_exit(void)
{
mbochs_dev.bus = NULL;
mdev_unregister_parent(&mbochs_parent);
device_unregister(&mbochs_dev);
mdev_unregister_driver(&mbochs_driver);
cdev_del(&mbochs_cdev);
unregister_chrdev_region(mbochs_devt, MINORMASK + 1);
class_destroy(mbochs_class);
mbochs_class = NULL;
}
MODULE_IMPORT_NS(DMA_BUF);
module_init(mbochs_dev_init)
module_exit(mbochs_dev_exit)
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