1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (c) 2023, NVIDIA CORPORATION & AFFILIATES. All rights reserved
4 */
5
6 #include <linux/device.h>
7 #include <linux/module.h>
8 #include <linux/mutex.h>
9 #include <linux/pci.h>
10 #include <linux/pm_runtime.h>
11 #include <linux/types.h>
12 #include <linux/uaccess.h>
13 #include <linux/vfio.h>
14 #include <linux/vfio_pci_core.h>
15 #include <linux/virtio_pci.h>
16 #include <linux/virtio_net.h>
17 #include <linux/virtio_pci_admin.h>
18
19 #include "common.h"
20
21 static int
virtiovf_issue_legacy_rw_cmd(struct virtiovf_pci_core_device * virtvdev,loff_t pos,char __user * buf,size_t count,bool read)22 virtiovf_issue_legacy_rw_cmd(struct virtiovf_pci_core_device *virtvdev,
23 loff_t pos, char __user *buf,
24 size_t count, bool read)
25 {
26 bool msix_enabled =
27 (virtvdev->core_device.irq_type == VFIO_PCI_MSIX_IRQ_INDEX);
28 struct pci_dev *pdev = virtvdev->core_device.pdev;
29 u8 *bar0_buf = virtvdev->bar0_virtual_buf;
30 bool common;
31 u8 offset;
32 int ret;
33
34 common = pos < VIRTIO_PCI_CONFIG_OFF(msix_enabled);
35 /* offset within the relevant configuration area */
36 offset = common ? pos : pos - VIRTIO_PCI_CONFIG_OFF(msix_enabled);
37 mutex_lock(&virtvdev->bar_mutex);
38 if (read) {
39 if (common)
40 ret = virtio_pci_admin_legacy_common_io_read(pdev, offset,
41 count, bar0_buf + pos);
42 else
43 ret = virtio_pci_admin_legacy_device_io_read(pdev, offset,
44 count, bar0_buf + pos);
45 if (ret)
46 goto out;
47 if (copy_to_user(buf, bar0_buf + pos, count))
48 ret = -EFAULT;
49 } else {
50 if (copy_from_user(bar0_buf + pos, buf, count)) {
51 ret = -EFAULT;
52 goto out;
53 }
54
55 if (common)
56 ret = virtio_pci_admin_legacy_common_io_write(pdev, offset,
57 count, bar0_buf + pos);
58 else
59 ret = virtio_pci_admin_legacy_device_io_write(pdev, offset,
60 count, bar0_buf + pos);
61 }
62 out:
63 mutex_unlock(&virtvdev->bar_mutex);
64 return ret;
65 }
66
67 static int
virtiovf_pci_bar0_rw(struct virtiovf_pci_core_device * virtvdev,loff_t pos,char __user * buf,size_t count,bool read)68 virtiovf_pci_bar0_rw(struct virtiovf_pci_core_device *virtvdev,
69 loff_t pos, char __user *buf,
70 size_t count, bool read)
71 {
72 struct vfio_pci_core_device *core_device = &virtvdev->core_device;
73 struct pci_dev *pdev = core_device->pdev;
74 u16 queue_notify;
75 int ret;
76
77 if (!(le16_to_cpu(virtvdev->pci_cmd) & PCI_COMMAND_IO))
78 return -EIO;
79
80 if (pos + count > virtvdev->bar0_virtual_buf_size)
81 return -EINVAL;
82
83 ret = pm_runtime_resume_and_get(&pdev->dev);
84 if (ret) {
85 pci_info_ratelimited(pdev, "runtime resume failed %d\n", ret);
86 return -EIO;
87 }
88
89 switch (pos) {
90 case VIRTIO_PCI_QUEUE_NOTIFY:
91 if (count != sizeof(queue_notify)) {
92 ret = -EINVAL;
93 goto end;
94 }
95 if (read) {
96 ret = vfio_pci_core_ioread16(core_device, true, &queue_notify,
97 virtvdev->notify_addr);
98 if (ret)
99 goto end;
100 if (copy_to_user(buf, &queue_notify,
101 sizeof(queue_notify))) {
102 ret = -EFAULT;
103 goto end;
104 }
105 } else {
106 if (copy_from_user(&queue_notify, buf, count)) {
107 ret = -EFAULT;
108 goto end;
109 }
110 ret = vfio_pci_core_iowrite16(core_device, true, queue_notify,
111 virtvdev->notify_addr);
112 }
113 break;
114 default:
115 ret = virtiovf_issue_legacy_rw_cmd(virtvdev, pos, buf, count,
116 read);
117 }
118
119 end:
120 pm_runtime_put(&pdev->dev);
121 return ret ? ret : count;
122 }
123
virtiovf_pci_read_config(struct vfio_device * core_vdev,char __user * buf,size_t count,loff_t * ppos)124 static ssize_t virtiovf_pci_read_config(struct vfio_device *core_vdev,
125 char __user *buf, size_t count,
126 loff_t *ppos)
127 {
128 struct virtiovf_pci_core_device *virtvdev = container_of(
129 core_vdev, struct virtiovf_pci_core_device, core_device.vdev);
130 loff_t pos = *ppos & VFIO_PCI_OFFSET_MASK;
131 size_t register_offset;
132 loff_t copy_offset;
133 size_t copy_count;
134 __le32 val32;
135 __le16 val16;
136 u8 val8;
137 int ret;
138
139 ret = vfio_pci_core_read(core_vdev, buf, count, ppos);
140 if (ret < 0)
141 return ret;
142
143 if (vfio_pci_core_range_intersect_range(pos, count, PCI_DEVICE_ID,
144 sizeof(val16), ©_offset,
145 ©_count, ®ister_offset)) {
146 val16 = cpu_to_le16(VIRTIO_TRANS_ID_NET);
147 if (copy_to_user(buf + copy_offset, (void *)&val16 + register_offset, copy_count))
148 return -EFAULT;
149 }
150
151 if ((le16_to_cpu(virtvdev->pci_cmd) & PCI_COMMAND_IO) &&
152 vfio_pci_core_range_intersect_range(pos, count, PCI_COMMAND,
153 sizeof(val16), ©_offset,
154 ©_count, ®ister_offset)) {
155 if (copy_from_user((void *)&val16 + register_offset, buf + copy_offset,
156 copy_count))
157 return -EFAULT;
158 val16 |= cpu_to_le16(PCI_COMMAND_IO);
159 if (copy_to_user(buf + copy_offset, (void *)&val16 + register_offset,
160 copy_count))
161 return -EFAULT;
162 }
163
164 if (vfio_pci_core_range_intersect_range(pos, count, PCI_REVISION_ID,
165 sizeof(val8), ©_offset,
166 ©_count, ®ister_offset)) {
167 /* Transional needs to have revision 0 */
168 val8 = 0;
169 if (copy_to_user(buf + copy_offset, &val8, copy_count))
170 return -EFAULT;
171 }
172
173 if (vfio_pci_core_range_intersect_range(pos, count, PCI_BASE_ADDRESS_0,
174 sizeof(val32), ©_offset,
175 ©_count, ®ister_offset)) {
176 u32 bar_mask = ~(virtvdev->bar0_virtual_buf_size - 1);
177 u32 pci_base_addr_0 = le32_to_cpu(virtvdev->pci_base_addr_0);
178
179 val32 = cpu_to_le32((pci_base_addr_0 & bar_mask) | PCI_BASE_ADDRESS_SPACE_IO);
180 if (copy_to_user(buf + copy_offset, (void *)&val32 + register_offset, copy_count))
181 return -EFAULT;
182 }
183
184 if (vfio_pci_core_range_intersect_range(pos, count, PCI_SUBSYSTEM_ID,
185 sizeof(val16), ©_offset,
186 ©_count, ®ister_offset)) {
187 /*
188 * Transitional devices use the PCI subsystem device id as
189 * virtio device id, same as legacy driver always did.
190 */
191 val16 = cpu_to_le16(VIRTIO_ID_NET);
192 if (copy_to_user(buf + copy_offset, (void *)&val16 + register_offset,
193 copy_count))
194 return -EFAULT;
195 }
196
197 if (vfio_pci_core_range_intersect_range(pos, count, PCI_SUBSYSTEM_VENDOR_ID,
198 sizeof(val16), ©_offset,
199 ©_count, ®ister_offset)) {
200 val16 = cpu_to_le16(PCI_VENDOR_ID_REDHAT_QUMRANET);
201 if (copy_to_user(buf + copy_offset, (void *)&val16 + register_offset,
202 copy_count))
203 return -EFAULT;
204 }
205
206 return count;
207 }
208
virtiovf_pci_core_read(struct vfio_device * core_vdev,char __user * buf,size_t count,loff_t * ppos)209 ssize_t virtiovf_pci_core_read(struct vfio_device *core_vdev, char __user *buf,
210 size_t count, loff_t *ppos)
211 {
212 struct virtiovf_pci_core_device *virtvdev = container_of(
213 core_vdev, struct virtiovf_pci_core_device, core_device.vdev);
214 unsigned int index = VFIO_PCI_OFFSET_TO_INDEX(*ppos);
215 loff_t pos = *ppos & VFIO_PCI_OFFSET_MASK;
216
217 if (!count)
218 return 0;
219
220 if (index == VFIO_PCI_CONFIG_REGION_INDEX)
221 return virtiovf_pci_read_config(core_vdev, buf, count, ppos);
222
223 if (index == VFIO_PCI_BAR0_REGION_INDEX)
224 return virtiovf_pci_bar0_rw(virtvdev, pos, buf, count, true);
225
226 return vfio_pci_core_read(core_vdev, buf, count, ppos);
227 }
228
virtiovf_pci_write_config(struct vfio_device * core_vdev,const char __user * buf,size_t count,loff_t * ppos)229 static ssize_t virtiovf_pci_write_config(struct vfio_device *core_vdev,
230 const char __user *buf, size_t count,
231 loff_t *ppos)
232 {
233 struct virtiovf_pci_core_device *virtvdev = container_of(
234 core_vdev, struct virtiovf_pci_core_device, core_device.vdev);
235 loff_t pos = *ppos & VFIO_PCI_OFFSET_MASK;
236 size_t register_offset;
237 loff_t copy_offset;
238 size_t copy_count;
239
240 if (vfio_pci_core_range_intersect_range(pos, count, PCI_COMMAND,
241 sizeof(virtvdev->pci_cmd),
242 ©_offset, ©_count,
243 ®ister_offset)) {
244 if (copy_from_user((void *)&virtvdev->pci_cmd + register_offset,
245 buf + copy_offset,
246 copy_count))
247 return -EFAULT;
248 }
249
250 if (vfio_pci_core_range_intersect_range(pos, count, PCI_BASE_ADDRESS_0,
251 sizeof(virtvdev->pci_base_addr_0),
252 ©_offset, ©_count,
253 ®ister_offset)) {
254 if (copy_from_user((void *)&virtvdev->pci_base_addr_0 + register_offset,
255 buf + copy_offset,
256 copy_count))
257 return -EFAULT;
258 }
259
260 return vfio_pci_core_write(core_vdev, buf, count, ppos);
261 }
262
virtiovf_pci_core_write(struct vfio_device * core_vdev,const char __user * buf,size_t count,loff_t * ppos)263 ssize_t virtiovf_pci_core_write(struct vfio_device *core_vdev, const char __user *buf,
264 size_t count, loff_t *ppos)
265 {
266 struct virtiovf_pci_core_device *virtvdev = container_of(
267 core_vdev, struct virtiovf_pci_core_device, core_device.vdev);
268 unsigned int index = VFIO_PCI_OFFSET_TO_INDEX(*ppos);
269 loff_t pos = *ppos & VFIO_PCI_OFFSET_MASK;
270
271 if (!count)
272 return 0;
273
274 if (index == VFIO_PCI_CONFIG_REGION_INDEX)
275 return virtiovf_pci_write_config(core_vdev, buf, count, ppos);
276
277 if (index == VFIO_PCI_BAR0_REGION_INDEX)
278 return virtiovf_pci_bar0_rw(virtvdev, pos, (char __user *)buf, count, false);
279
280 return vfio_pci_core_write(core_vdev, buf, count, ppos);
281 }
282
virtiovf_pci_ioctl_get_region_info(struct vfio_device * core_vdev,struct vfio_region_info * info,struct vfio_info_cap * caps)283 int virtiovf_pci_ioctl_get_region_info(struct vfio_device *core_vdev,
284 struct vfio_region_info *info,
285 struct vfio_info_cap *caps)
286 {
287 struct virtiovf_pci_core_device *virtvdev = container_of(
288 core_vdev, struct virtiovf_pci_core_device, core_device.vdev);
289
290 if (info->index != VFIO_PCI_BAR0_REGION_INDEX)
291 return vfio_pci_ioctl_get_region_info(core_vdev, info, caps);
292
293 info->offset = VFIO_PCI_INDEX_TO_OFFSET(info->index);
294 info->size = virtvdev->bar0_virtual_buf_size;
295 info->flags = VFIO_REGION_INFO_FLAG_READ | VFIO_REGION_INFO_FLAG_WRITE;
296 return 0;
297 }
298
virtiovf_set_notify_addr(struct virtiovf_pci_core_device * virtvdev)299 static int virtiovf_set_notify_addr(struct virtiovf_pci_core_device *virtvdev)
300 {
301 struct vfio_pci_core_device *core_device = &virtvdev->core_device;
302 int ret;
303
304 /*
305 * Setup the BAR where the 'notify' exists to be used by vfio as well
306 * This will let us mmap it only once and use it when needed.
307 */
308 ret = vfio_pci_core_setup_barmap(core_device,
309 virtvdev->notify_bar);
310 if (ret)
311 return ret;
312
313 virtvdev->notify_addr = core_device->barmap[virtvdev->notify_bar] +
314 virtvdev->notify_offset;
315 return 0;
316 }
317
virtiovf_open_legacy_io(struct virtiovf_pci_core_device * virtvdev)318 int virtiovf_open_legacy_io(struct virtiovf_pci_core_device *virtvdev)
319 {
320 if (!virtvdev->bar0_virtual_buf)
321 return 0;
322
323 /*
324 * Upon close_device() the vfio_pci_core_disable() is called
325 * and will close all the previous mmaps, so it seems that the
326 * valid life cycle for the 'notify' addr is per open/close.
327 */
328 return virtiovf_set_notify_addr(virtvdev);
329 }
330
virtiovf_get_device_config_size(unsigned short device)331 static int virtiovf_get_device_config_size(unsigned short device)
332 {
333 /* Network card */
334 return offsetofend(struct virtio_net_config, status);
335 }
336
virtiovf_read_notify_info(struct virtiovf_pci_core_device * virtvdev)337 static int virtiovf_read_notify_info(struct virtiovf_pci_core_device *virtvdev)
338 {
339 u64 offset;
340 int ret;
341 u8 bar;
342
343 ret = virtio_pci_admin_legacy_io_notify_info(virtvdev->core_device.pdev,
344 VIRTIO_ADMIN_CMD_NOTIFY_INFO_FLAGS_OWNER_MEM,
345 &bar, &offset);
346 if (ret)
347 return ret;
348
349 virtvdev->notify_bar = bar;
350 virtvdev->notify_offset = offset;
351 return 0;
352 }
353
virtiovf_bar0_exists(struct pci_dev * pdev)354 static bool virtiovf_bar0_exists(struct pci_dev *pdev)
355 {
356 struct resource *res = pdev->resource;
357
358 return res->flags;
359 }
360
virtiovf_support_legacy_io(struct pci_dev * pdev)361 bool virtiovf_support_legacy_io(struct pci_dev *pdev)
362 {
363 /* For now, the legacy IO functionality is supported only for virtio-net */
364 return pdev->device == 0x1041 && virtio_pci_admin_has_legacy_io(pdev) &&
365 !virtiovf_bar0_exists(pdev);
366 }
367
virtiovf_init_legacy_io(struct virtiovf_pci_core_device * virtvdev)368 int virtiovf_init_legacy_io(struct virtiovf_pci_core_device *virtvdev)
369 {
370 struct pci_dev *pdev = virtvdev->core_device.pdev;
371 int ret;
372
373 ret = virtiovf_read_notify_info(virtvdev);
374 if (ret)
375 return ret;
376
377 virtvdev->bar0_virtual_buf_size = VIRTIO_PCI_CONFIG_OFF(true) +
378 virtiovf_get_device_config_size(pdev->device);
379 BUILD_BUG_ON(!is_power_of_2(virtvdev->bar0_virtual_buf_size));
380 virtvdev->bar0_virtual_buf = kzalloc(virtvdev->bar0_virtual_buf_size,
381 GFP_KERNEL);
382 if (!virtvdev->bar0_virtual_buf)
383 return -ENOMEM;
384 mutex_init(&virtvdev->bar_mutex);
385 return 0;
386 }
387
virtiovf_release_legacy_io(struct virtiovf_pci_core_device * virtvdev)388 void virtiovf_release_legacy_io(struct virtiovf_pci_core_device *virtvdev)
389 {
390 kfree(virtvdev->bar0_virtual_buf);
391 }
392
virtiovf_legacy_io_reset_done(struct pci_dev * pdev)393 void virtiovf_legacy_io_reset_done(struct pci_dev *pdev)
394 {
395 struct virtiovf_pci_core_device *virtvdev = dev_get_drvdata(&pdev->dev);
396
397 virtvdev->pci_cmd = 0;
398 }
399