1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * VFIO PCI Intel Graphics support
4 *
5 * Copyright (C) 2016 Red Hat, Inc. All rights reserved.
6 * Author: Alex Williamson <alex.williamson@redhat.com>
7 *
8 * Register a device specific region through which to provide read-only
9 * access to the Intel IGD opregion. The register defining the opregion
10 * address is also virtualized to prevent user modification.
11 */
12
13 #include <linux/io.h>
14 #include <linux/pci.h>
15 #include <linux/uaccess.h>
16 #include <linux/vfio.h>
17
18 #include "vfio_pci_private.h"
19
20 #define OPREGION_SIGNATURE "IntelGraphicsMem"
21 #define OPREGION_SIZE (8 * 1024)
22 #define OPREGION_PCI_ADDR 0xfc
23
vfio_pci_igd_rw(struct vfio_pci_device * vdev,char __user * buf,size_t count,loff_t * ppos,bool iswrite)24 static size_t vfio_pci_igd_rw(struct vfio_pci_device *vdev, char __user *buf,
25 size_t count, loff_t *ppos, bool iswrite)
26 {
27 unsigned int i = VFIO_PCI_OFFSET_TO_INDEX(*ppos) - VFIO_PCI_NUM_REGIONS;
28 void *base = vdev->region[i].data;
29 loff_t pos = *ppos & VFIO_PCI_OFFSET_MASK;
30
31 if (pos >= vdev->region[i].size || iswrite)
32 return -EINVAL;
33
34 count = min(count, (size_t)(vdev->region[i].size - pos));
35
36 if (copy_to_user(buf, base + pos, count))
37 return -EFAULT;
38
39 *ppos += count;
40
41 return count;
42 }
43
vfio_pci_igd_release(struct vfio_pci_device * vdev,struct vfio_pci_region * region)44 static void vfio_pci_igd_release(struct vfio_pci_device *vdev,
45 struct vfio_pci_region *region)
46 {
47 memunmap(region->data);
48 }
49
50 static const struct vfio_pci_regops vfio_pci_igd_regops = {
51 .rw = vfio_pci_igd_rw,
52 .release = vfio_pci_igd_release,
53 };
54
vfio_pci_igd_opregion_init(struct vfio_pci_device * vdev)55 static int vfio_pci_igd_opregion_init(struct vfio_pci_device *vdev)
56 {
57 __le32 *dwordp = (__le32 *)(vdev->vconfig + OPREGION_PCI_ADDR);
58 u32 addr, size;
59 void *base;
60 int ret;
61
62 ret = pci_read_config_dword(vdev->pdev, OPREGION_PCI_ADDR, &addr);
63 if (ret)
64 return ret;
65
66 if (!addr || !(~addr))
67 return -ENODEV;
68
69 base = memremap(addr, OPREGION_SIZE, MEMREMAP_WB);
70 if (!base)
71 return -ENOMEM;
72
73 if (memcmp(base, OPREGION_SIGNATURE, 16)) {
74 memunmap(base);
75 return -EINVAL;
76 }
77
78 size = le32_to_cpu(*(__le32 *)(base + 16));
79 if (!size) {
80 memunmap(base);
81 return -EINVAL;
82 }
83
84 size *= 1024; /* In KB */
85
86 if (size != OPREGION_SIZE) {
87 memunmap(base);
88 base = memremap(addr, size, MEMREMAP_WB);
89 if (!base)
90 return -ENOMEM;
91 }
92
93 ret = vfio_pci_register_dev_region(vdev,
94 PCI_VENDOR_ID_INTEL | VFIO_REGION_TYPE_PCI_VENDOR_TYPE,
95 VFIO_REGION_SUBTYPE_INTEL_IGD_OPREGION,
96 &vfio_pci_igd_regops, size, VFIO_REGION_INFO_FLAG_READ, base);
97 if (ret) {
98 memunmap(base);
99 return ret;
100 }
101
102 /* Fill vconfig with the hw value and virtualize register */
103 *dwordp = cpu_to_le32(addr);
104 memset(vdev->pci_config_map + OPREGION_PCI_ADDR,
105 PCI_CAP_ID_INVALID_VIRT, 4);
106
107 return ret;
108 }
109
vfio_pci_igd_cfg_rw(struct vfio_pci_device * vdev,char __user * buf,size_t count,loff_t * ppos,bool iswrite)110 static size_t vfio_pci_igd_cfg_rw(struct vfio_pci_device *vdev,
111 char __user *buf, size_t count, loff_t *ppos,
112 bool iswrite)
113 {
114 unsigned int i = VFIO_PCI_OFFSET_TO_INDEX(*ppos) - VFIO_PCI_NUM_REGIONS;
115 struct pci_dev *pdev = vdev->region[i].data;
116 loff_t pos = *ppos & VFIO_PCI_OFFSET_MASK;
117 size_t size;
118 int ret;
119
120 if (pos >= vdev->region[i].size || iswrite)
121 return -EINVAL;
122
123 size = count = min(count, (size_t)(vdev->region[i].size - pos));
124
125 if ((pos & 1) && size) {
126 u8 val;
127
128 ret = pci_user_read_config_byte(pdev, pos, &val);
129 if (ret)
130 return pcibios_err_to_errno(ret);
131
132 if (copy_to_user(buf + count - size, &val, 1))
133 return -EFAULT;
134
135 pos++;
136 size--;
137 }
138
139 if ((pos & 3) && size > 2) {
140 u16 val;
141
142 ret = pci_user_read_config_word(pdev, pos, &val);
143 if (ret)
144 return pcibios_err_to_errno(ret);
145
146 val = cpu_to_le16(val);
147 if (copy_to_user(buf + count - size, &val, 2))
148 return -EFAULT;
149
150 pos += 2;
151 size -= 2;
152 }
153
154 while (size > 3) {
155 u32 val;
156
157 ret = pci_user_read_config_dword(pdev, pos, &val);
158 if (ret)
159 return pcibios_err_to_errno(ret);
160
161 val = cpu_to_le32(val);
162 if (copy_to_user(buf + count - size, &val, 4))
163 return -EFAULT;
164
165 pos += 4;
166 size -= 4;
167 }
168
169 while (size >= 2) {
170 u16 val;
171
172 ret = pci_user_read_config_word(pdev, pos, &val);
173 if (ret)
174 return pcibios_err_to_errno(ret);
175
176 val = cpu_to_le16(val);
177 if (copy_to_user(buf + count - size, &val, 2))
178 return -EFAULT;
179
180 pos += 2;
181 size -= 2;
182 }
183
184 while (size) {
185 u8 val;
186
187 ret = pci_user_read_config_byte(pdev, pos, &val);
188 if (ret)
189 return pcibios_err_to_errno(ret);
190
191 if (copy_to_user(buf + count - size, &val, 1))
192 return -EFAULT;
193
194 pos++;
195 size--;
196 }
197
198 *ppos += count;
199
200 return count;
201 }
202
vfio_pci_igd_cfg_release(struct vfio_pci_device * vdev,struct vfio_pci_region * region)203 static void vfio_pci_igd_cfg_release(struct vfio_pci_device *vdev,
204 struct vfio_pci_region *region)
205 {
206 struct pci_dev *pdev = region->data;
207
208 pci_dev_put(pdev);
209 }
210
211 static const struct vfio_pci_regops vfio_pci_igd_cfg_regops = {
212 .rw = vfio_pci_igd_cfg_rw,
213 .release = vfio_pci_igd_cfg_release,
214 };
215
vfio_pci_igd_cfg_init(struct vfio_pci_device * vdev)216 static int vfio_pci_igd_cfg_init(struct vfio_pci_device *vdev)
217 {
218 struct pci_dev *host_bridge, *lpc_bridge;
219 int ret;
220
221 host_bridge = pci_get_domain_bus_and_slot(0, 0, PCI_DEVFN(0, 0));
222 if (!host_bridge)
223 return -ENODEV;
224
225 if (host_bridge->vendor != PCI_VENDOR_ID_INTEL ||
226 host_bridge->class != (PCI_CLASS_BRIDGE_HOST << 8)) {
227 pci_dev_put(host_bridge);
228 return -EINVAL;
229 }
230
231 ret = vfio_pci_register_dev_region(vdev,
232 PCI_VENDOR_ID_INTEL | VFIO_REGION_TYPE_PCI_VENDOR_TYPE,
233 VFIO_REGION_SUBTYPE_INTEL_IGD_HOST_CFG,
234 &vfio_pci_igd_cfg_regops, host_bridge->cfg_size,
235 VFIO_REGION_INFO_FLAG_READ, host_bridge);
236 if (ret) {
237 pci_dev_put(host_bridge);
238 return ret;
239 }
240
241 lpc_bridge = pci_get_domain_bus_and_slot(0, 0, PCI_DEVFN(0x1f, 0));
242 if (!lpc_bridge)
243 return -ENODEV;
244
245 if (lpc_bridge->vendor != PCI_VENDOR_ID_INTEL ||
246 lpc_bridge->class != (PCI_CLASS_BRIDGE_ISA << 8)) {
247 pci_dev_put(lpc_bridge);
248 return -EINVAL;
249 }
250
251 ret = vfio_pci_register_dev_region(vdev,
252 PCI_VENDOR_ID_INTEL | VFIO_REGION_TYPE_PCI_VENDOR_TYPE,
253 VFIO_REGION_SUBTYPE_INTEL_IGD_LPC_CFG,
254 &vfio_pci_igd_cfg_regops, lpc_bridge->cfg_size,
255 VFIO_REGION_INFO_FLAG_READ, lpc_bridge);
256 if (ret) {
257 pci_dev_put(lpc_bridge);
258 return ret;
259 }
260
261 return 0;
262 }
263
vfio_pci_igd_init(struct vfio_pci_device * vdev)264 int vfio_pci_igd_init(struct vfio_pci_device *vdev)
265 {
266 int ret;
267
268 ret = vfio_pci_igd_opregion_init(vdev);
269 if (ret)
270 return ret;
271
272 ret = vfio_pci_igd_cfg_init(vdev);
273 if (ret)
274 return ret;
275
276 return 0;
277 }
278