1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Virtio PCI driver - modern (virtio 1.0) device support
4 *
5 * This module allows virtio devices to be used over a virtual PCI device.
6 * This can be used with QEMU based VMMs like KVM or Xen.
7 *
8 * Copyright IBM Corp. 2007
9 * Copyright Red Hat, Inc. 2014
10 *
11 * Authors:
12 * Anthony Liguori <aliguori@us.ibm.com>
13 * Rusty Russell <rusty@rustcorp.com.au>
14 * Michael S. Tsirkin <mst@redhat.com>
15 */
16
17 #include <linux/delay.h>
18 #define VIRTIO_PCI_NO_LEGACY
19 #define VIRTIO_RING_NO_LEGACY
20 #include "virtio_pci_common.h"
21
vp_get_features(struct virtio_device * vdev)22 static u64 vp_get_features(struct virtio_device *vdev)
23 {
24 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
25
26 return vp_modern_get_features(&vp_dev->mdev);
27 }
28
vp_transport_features(struct virtio_device * vdev,u64 features)29 static void vp_transport_features(struct virtio_device *vdev, u64 features)
30 {
31 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
32 struct pci_dev *pci_dev = vp_dev->pci_dev;
33
34 if ((features & BIT_ULL(VIRTIO_F_SR_IOV)) &&
35 pci_find_ext_capability(pci_dev, PCI_EXT_CAP_ID_SRIOV))
36 __virtio_set_bit(vdev, VIRTIO_F_SR_IOV);
37 }
38
39 /* virtio config->finalize_features() implementation */
vp_finalize_features(struct virtio_device * vdev)40 static int vp_finalize_features(struct virtio_device *vdev)
41 {
42 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
43 u64 features = vdev->features;
44
45 /* Give virtio_ring a chance to accept features. */
46 vring_transport_features(vdev);
47
48 /* Give virtio_pci a chance to accept features. */
49 vp_transport_features(vdev, features);
50
51 if (!__virtio_test_bit(vdev, VIRTIO_F_VERSION_1)) {
52 dev_err(&vdev->dev, "virtio: device uses modern interface "
53 "but does not have VIRTIO_F_VERSION_1\n");
54 return -EINVAL;
55 }
56
57 vp_modern_set_features(&vp_dev->mdev, vdev->features);
58
59 return 0;
60 }
61
62 /* virtio config->get() implementation */
vp_get(struct virtio_device * vdev,unsigned int offset,void * buf,unsigned int len)63 static void vp_get(struct virtio_device *vdev, unsigned int offset,
64 void *buf, unsigned int len)
65 {
66 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
67 struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
68 void __iomem *device = mdev->device;
69 u8 b;
70 __le16 w;
71 __le32 l;
72
73 BUG_ON(offset + len > mdev->device_len);
74
75 switch (len) {
76 case 1:
77 b = ioread8(device + offset);
78 memcpy(buf, &b, sizeof b);
79 break;
80 case 2:
81 w = cpu_to_le16(ioread16(device + offset));
82 memcpy(buf, &w, sizeof w);
83 break;
84 case 4:
85 l = cpu_to_le32(ioread32(device + offset));
86 memcpy(buf, &l, sizeof l);
87 break;
88 case 8:
89 l = cpu_to_le32(ioread32(device + offset));
90 memcpy(buf, &l, sizeof l);
91 l = cpu_to_le32(ioread32(device + offset + sizeof l));
92 memcpy(buf + sizeof l, &l, sizeof l);
93 break;
94 default:
95 BUG();
96 }
97 }
98
99 /* the config->set() implementation. it's symmetric to the config->get()
100 * implementation */
vp_set(struct virtio_device * vdev,unsigned int offset,const void * buf,unsigned int len)101 static void vp_set(struct virtio_device *vdev, unsigned int offset,
102 const void *buf, unsigned int len)
103 {
104 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
105 struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
106 void __iomem *device = mdev->device;
107 u8 b;
108 __le16 w;
109 __le32 l;
110
111 BUG_ON(offset + len > mdev->device_len);
112
113 switch (len) {
114 case 1:
115 memcpy(&b, buf, sizeof b);
116 iowrite8(b, device + offset);
117 break;
118 case 2:
119 memcpy(&w, buf, sizeof w);
120 iowrite16(le16_to_cpu(w), device + offset);
121 break;
122 case 4:
123 memcpy(&l, buf, sizeof l);
124 iowrite32(le32_to_cpu(l), device + offset);
125 break;
126 case 8:
127 memcpy(&l, buf, sizeof l);
128 iowrite32(le32_to_cpu(l), device + offset);
129 memcpy(&l, buf + sizeof l, sizeof l);
130 iowrite32(le32_to_cpu(l), device + offset + sizeof l);
131 break;
132 default:
133 BUG();
134 }
135 }
136
vp_generation(struct virtio_device * vdev)137 static u32 vp_generation(struct virtio_device *vdev)
138 {
139 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
140
141 return vp_modern_generation(&vp_dev->mdev);
142 }
143
144 /* config->{get,set}_status() implementations */
vp_get_status(struct virtio_device * vdev)145 static u8 vp_get_status(struct virtio_device *vdev)
146 {
147 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
148
149 return vp_modern_get_status(&vp_dev->mdev);
150 }
151
vp_set_status(struct virtio_device * vdev,u8 status)152 static void vp_set_status(struct virtio_device *vdev, u8 status)
153 {
154 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
155
156 /* We should never be setting status to 0. */
157 BUG_ON(status == 0);
158 vp_modern_set_status(&vp_dev->mdev, status);
159 }
160
vp_reset(struct virtio_device * vdev)161 static void vp_reset(struct virtio_device *vdev)
162 {
163 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
164 struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
165
166 /* 0 status means a reset. */
167 vp_modern_set_status(mdev, 0);
168 /* After writing 0 to device_status, the driver MUST wait for a read of
169 * device_status to return 0 before reinitializing the device.
170 * This will flush out the status write, and flush in device writes,
171 * including MSI-X interrupts, if any.
172 */
173 while (vp_modern_get_status(mdev))
174 msleep(1);
175 /* Flush pending VQ/configuration callbacks. */
176 vp_synchronize_vectors(vdev);
177 }
178
vp_config_vector(struct virtio_pci_device * vp_dev,u16 vector)179 static u16 vp_config_vector(struct virtio_pci_device *vp_dev, u16 vector)
180 {
181 return vp_modern_config_vector(&vp_dev->mdev, vector);
182 }
183
setup_vq(struct virtio_pci_device * vp_dev,struct virtio_pci_vq_info * info,unsigned int index,void (* callback)(struct virtqueue * vq),const char * name,bool ctx,u16 msix_vec)184 static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev,
185 struct virtio_pci_vq_info *info,
186 unsigned int index,
187 void (*callback)(struct virtqueue *vq),
188 const char *name,
189 bool ctx,
190 u16 msix_vec)
191 {
192
193 struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
194 struct virtqueue *vq;
195 u16 num;
196 int err;
197
198 if (index >= vp_modern_get_num_queues(mdev))
199 return ERR_PTR(-ENOENT);
200
201 /* Check if queue is either not available or already active. */
202 num = vp_modern_get_queue_size(mdev, index);
203 if (!num || vp_modern_get_queue_enable(mdev, index))
204 return ERR_PTR(-ENOENT);
205
206 if (num & (num - 1)) {
207 dev_warn(&vp_dev->pci_dev->dev, "bad queue size %u", num);
208 return ERR_PTR(-EINVAL);
209 }
210
211 info->msix_vector = msix_vec;
212
213 /* create the vring */
214 vq = vring_create_virtqueue(index, num,
215 SMP_CACHE_BYTES, &vp_dev->vdev,
216 true, true, ctx,
217 vp_notify, callback, name);
218 if (!vq)
219 return ERR_PTR(-ENOMEM);
220
221 /* activate the queue */
222 vp_modern_set_queue_size(mdev, index, virtqueue_get_vring_size(vq));
223 vp_modern_queue_address(mdev, index, virtqueue_get_desc_addr(vq),
224 virtqueue_get_avail_addr(vq),
225 virtqueue_get_used_addr(vq));
226
227 vq->priv = (void __force *)vp_modern_map_vq_notify(mdev, index, NULL);
228 if (!vq->priv) {
229 err = -ENOMEM;
230 goto err_map_notify;
231 }
232
233 if (msix_vec != VIRTIO_MSI_NO_VECTOR) {
234 msix_vec = vp_modern_queue_vector(mdev, index, msix_vec);
235 if (msix_vec == VIRTIO_MSI_NO_VECTOR) {
236 err = -EBUSY;
237 goto err_assign_vector;
238 }
239 }
240
241 return vq;
242
243 err_assign_vector:
244 if (!mdev->notify_base)
245 pci_iounmap(mdev->pci_dev, (void __iomem __force *)vq->priv);
246 err_map_notify:
247 vring_del_virtqueue(vq);
248 return ERR_PTR(err);
249 }
250
vp_modern_find_vqs(struct virtio_device * vdev,unsigned int nvqs,struct virtqueue * vqs[],vq_callback_t * callbacks[],const char * const names[],const bool * ctx,struct irq_affinity * desc)251 static int vp_modern_find_vqs(struct virtio_device *vdev, unsigned int nvqs,
252 struct virtqueue *vqs[],
253 vq_callback_t *callbacks[],
254 const char * const names[], const bool *ctx,
255 struct irq_affinity *desc)
256 {
257 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
258 struct virtqueue *vq;
259 int rc = vp_find_vqs(vdev, nvqs, vqs, callbacks, names, ctx, desc);
260
261 if (rc)
262 return rc;
263
264 /* Select and activate all queues. Has to be done last: once we do
265 * this, there's no way to go back except reset.
266 */
267 list_for_each_entry(vq, &vdev->vqs, list)
268 vp_modern_set_queue_enable(&vp_dev->mdev, vq->index, true);
269
270 return 0;
271 }
272
del_vq(struct virtio_pci_vq_info * info)273 static void del_vq(struct virtio_pci_vq_info *info)
274 {
275 struct virtqueue *vq = info->vq;
276 struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
277 struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
278
279 if (vp_dev->msix_enabled)
280 vp_modern_queue_vector(mdev, vq->index,
281 VIRTIO_MSI_NO_VECTOR);
282
283 if (!mdev->notify_base)
284 pci_iounmap(mdev->pci_dev, (void __force __iomem *)vq->priv);
285
286 vring_del_virtqueue(vq);
287 }
288
virtio_pci_find_shm_cap(struct pci_dev * dev,u8 required_id,u8 * bar,u64 * offset,u64 * len)289 static int virtio_pci_find_shm_cap(struct pci_dev *dev, u8 required_id,
290 u8 *bar, u64 *offset, u64 *len)
291 {
292 int pos;
293
294 for (pos = pci_find_capability(dev, PCI_CAP_ID_VNDR); pos > 0;
295 pos = pci_find_next_capability(dev, pos, PCI_CAP_ID_VNDR)) {
296 u8 type, cap_len, id, res_bar;
297 u32 tmp32;
298 u64 res_offset, res_length;
299
300 pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap,
301 cfg_type), &type);
302 if (type != VIRTIO_PCI_CAP_SHARED_MEMORY_CFG)
303 continue;
304
305 pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap,
306 cap_len), &cap_len);
307 if (cap_len != sizeof(struct virtio_pci_cap64)) {
308 dev_err(&dev->dev, "%s: shm cap with bad size offset:"
309 " %d size: %d\n", __func__, pos, cap_len);
310 continue;
311 }
312
313 pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap,
314 id), &id);
315 if (id != required_id)
316 continue;
317
318 pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap,
319 bar), &res_bar);
320 if (res_bar >= PCI_STD_NUM_BARS)
321 continue;
322
323 /* Type and ID match, and the BAR value isn't reserved.
324 * Looks good.
325 */
326
327 /* Read the lower 32bit of length and offset */
328 pci_read_config_dword(dev, pos + offsetof(struct virtio_pci_cap,
329 offset), &tmp32);
330 res_offset = tmp32;
331 pci_read_config_dword(dev, pos + offsetof(struct virtio_pci_cap,
332 length), &tmp32);
333 res_length = tmp32;
334
335 /* and now the top half */
336 pci_read_config_dword(dev,
337 pos + offsetof(struct virtio_pci_cap64,
338 offset_hi), &tmp32);
339 res_offset |= ((u64)tmp32) << 32;
340 pci_read_config_dword(dev,
341 pos + offsetof(struct virtio_pci_cap64,
342 length_hi), &tmp32);
343 res_length |= ((u64)tmp32) << 32;
344
345 *bar = res_bar;
346 *offset = res_offset;
347 *len = res_length;
348
349 return pos;
350 }
351 return 0;
352 }
353
vp_get_shm_region(struct virtio_device * vdev,struct virtio_shm_region * region,u8 id)354 static bool vp_get_shm_region(struct virtio_device *vdev,
355 struct virtio_shm_region *region, u8 id)
356 {
357 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
358 struct pci_dev *pci_dev = vp_dev->pci_dev;
359 u8 bar;
360 u64 offset, len;
361 phys_addr_t phys_addr;
362 size_t bar_len;
363
364 if (!virtio_pci_find_shm_cap(pci_dev, id, &bar, &offset, &len))
365 return false;
366
367 phys_addr = pci_resource_start(pci_dev, bar);
368 bar_len = pci_resource_len(pci_dev, bar);
369
370 if ((offset + len) < offset) {
371 dev_err(&pci_dev->dev, "%s: cap offset+len overflow detected\n",
372 __func__);
373 return false;
374 }
375
376 if (offset + len > bar_len) {
377 dev_err(&pci_dev->dev, "%s: bar shorter than cap offset+len\n",
378 __func__);
379 return false;
380 }
381
382 region->len = len;
383 region->addr = (u64) phys_addr + offset;
384
385 return true;
386 }
387
388 static const struct virtio_config_ops virtio_pci_config_nodev_ops = {
389 .get = NULL,
390 .set = NULL,
391 .generation = vp_generation,
392 .get_status = vp_get_status,
393 .set_status = vp_set_status,
394 .reset = vp_reset,
395 .find_vqs = vp_modern_find_vqs,
396 .del_vqs = vp_del_vqs,
397 .synchronize_cbs = vp_synchronize_vectors,
398 .get_features = vp_get_features,
399 .finalize_features = vp_finalize_features,
400 .bus_name = vp_bus_name,
401 .set_vq_affinity = vp_set_vq_affinity,
402 .get_vq_affinity = vp_get_vq_affinity,
403 .get_shm_region = vp_get_shm_region,
404 };
405
406 static const struct virtio_config_ops virtio_pci_config_ops = {
407 .get = vp_get,
408 .set = vp_set,
409 .generation = vp_generation,
410 .get_status = vp_get_status,
411 .set_status = vp_set_status,
412 .reset = vp_reset,
413 .find_vqs = vp_modern_find_vqs,
414 .del_vqs = vp_del_vqs,
415 .synchronize_cbs = vp_synchronize_vectors,
416 .get_features = vp_get_features,
417 .finalize_features = vp_finalize_features,
418 .bus_name = vp_bus_name,
419 .set_vq_affinity = vp_set_vq_affinity,
420 .get_vq_affinity = vp_get_vq_affinity,
421 .get_shm_region = vp_get_shm_region,
422 };
423
424 /* the PCI probing function */
virtio_pci_modern_probe(struct virtio_pci_device * vp_dev)425 int virtio_pci_modern_probe(struct virtio_pci_device *vp_dev)
426 {
427 struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
428 struct pci_dev *pci_dev = vp_dev->pci_dev;
429 int err;
430
431 mdev->pci_dev = pci_dev;
432
433 err = vp_modern_probe(mdev);
434 if (err)
435 return err;
436
437 if (mdev->device)
438 vp_dev->vdev.config = &virtio_pci_config_ops;
439 else
440 vp_dev->vdev.config = &virtio_pci_config_nodev_ops;
441
442 vp_dev->config_vector = vp_config_vector;
443 vp_dev->setup_vq = setup_vq;
444 vp_dev->del_vq = del_vq;
445 vp_dev->isr = mdev->isr;
446 vp_dev->vdev.id = mdev->id;
447
448 return 0;
449 }
450
virtio_pci_modern_remove(struct virtio_pci_device * vp_dev)451 void virtio_pci_modern_remove(struct virtio_pci_device *vp_dev)
452 {
453 struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
454
455 vp_modern_remove(mdev);
456 }
457