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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
ec53500f AW |
2 | /* |
3 | * VFIO-KVM bridge pseudo device | |
4 | * | |
5 | * Copyright (C) 2013 Red Hat, Inc. All rights reserved. | |
6 | * Author: Alex Williamson <[email protected]> | |
ec53500f AW |
7 | */ |
8 | ||
9 | #include <linux/errno.h> | |
10 | #include <linux/file.h> | |
11 | #include <linux/kvm_host.h> | |
12 | #include <linux/list.h> | |
13 | #include <linux/module.h> | |
14 | #include <linux/mutex.h> | |
15 | #include <linux/slab.h> | |
16 | #include <linux/uaccess.h> | |
17 | #include <linux/vfio.h> | |
3c3c29fd | 18 | #include "vfio.h" |
ec53500f | 19 | |
121f80ba AK |
20 | #ifdef CONFIG_SPAPR_TCE_IOMMU |
21 | #include <asm/kvm_ppc.h> | |
22 | #endif | |
23 | ||
ec53500f AW |
24 | struct kvm_vfio_group { |
25 | struct list_head node; | |
26 | struct vfio_group *vfio_group; | |
27 | }; | |
28 | ||
29 | struct kvm_vfio { | |
30 | struct list_head group_list; | |
31 | struct mutex lock; | |
e0f0bbc5 | 32 | bool noncoherent; |
ec53500f AW |
33 | }; |
34 | ||
35 | static struct vfio_group *kvm_vfio_group_get_external_user(struct file *filep) | |
36 | { | |
37 | struct vfio_group *vfio_group; | |
38 | struct vfio_group *(*fn)(struct file *); | |
39 | ||
40 | fn = symbol_get(vfio_group_get_external_user); | |
41 | if (!fn) | |
42 | return ERR_PTR(-EINVAL); | |
43 | ||
44 | vfio_group = fn(filep); | |
45 | ||
46 | symbol_put(vfio_group_get_external_user); | |
47 | ||
48 | return vfio_group; | |
49 | } | |
50 | ||
5d6dee80 AW |
51 | static bool kvm_vfio_external_group_match_file(struct vfio_group *group, |
52 | struct file *filep) | |
53 | { | |
54 | bool ret, (*fn)(struct vfio_group *, struct file *); | |
55 | ||
56 | fn = symbol_get(vfio_external_group_match_file); | |
57 | if (!fn) | |
58 | return false; | |
59 | ||
60 | ret = fn(group, filep); | |
61 | ||
62 | symbol_put(vfio_external_group_match_file); | |
63 | ||
64 | return ret; | |
65 | } | |
66 | ||
ec53500f AW |
67 | static void kvm_vfio_group_put_external_user(struct vfio_group *vfio_group) |
68 | { | |
69 | void (*fn)(struct vfio_group *); | |
70 | ||
71 | fn = symbol_get(vfio_group_put_external_user); | |
72 | if (!fn) | |
73 | return; | |
74 | ||
75 | fn(vfio_group); | |
76 | ||
77 | symbol_put(vfio_group_put_external_user); | |
78 | } | |
79 | ||
2fc1bec1 JS |
80 | static void kvm_vfio_group_set_kvm(struct vfio_group *group, struct kvm *kvm) |
81 | { | |
82 | void (*fn)(struct vfio_group *, struct kvm *); | |
83 | ||
84 | fn = symbol_get(vfio_group_set_kvm); | |
85 | if (!fn) | |
86 | return; | |
87 | ||
88 | fn(group, kvm); | |
89 | ||
90 | symbol_put(vfio_group_set_kvm); | |
91 | } | |
92 | ||
9d830d47 AW |
93 | static bool kvm_vfio_group_is_coherent(struct vfio_group *vfio_group) |
94 | { | |
95 | long (*fn)(struct vfio_group *, unsigned long); | |
96 | long ret; | |
97 | ||
98 | fn = symbol_get(vfio_external_check_extension); | |
99 | if (!fn) | |
100 | return false; | |
101 | ||
102 | ret = fn(vfio_group, VFIO_DMA_CC_IOMMU); | |
103 | ||
104 | symbol_put(vfio_external_check_extension); | |
105 | ||
106 | return ret > 0; | |
107 | } | |
108 | ||
121f80ba AK |
109 | #ifdef CONFIG_SPAPR_TCE_IOMMU |
110 | static int kvm_vfio_external_user_iommu_id(struct vfio_group *vfio_group) | |
111 | { | |
112 | int (*fn)(struct vfio_group *); | |
113 | int ret = -EINVAL; | |
114 | ||
115 | fn = symbol_get(vfio_external_user_iommu_id); | |
116 | if (!fn) | |
117 | return ret; | |
118 | ||
119 | ret = fn(vfio_group); | |
120 | ||
121 | symbol_put(vfio_external_user_iommu_id); | |
122 | ||
123 | return ret; | |
124 | } | |
125 | ||
126 | static struct iommu_group *kvm_vfio_group_get_iommu_group( | |
127 | struct vfio_group *group) | |
128 | { | |
129 | int group_id = kvm_vfio_external_user_iommu_id(group); | |
130 | ||
131 | if (group_id < 0) | |
132 | return NULL; | |
133 | ||
134 | return iommu_group_get_by_id(group_id); | |
135 | } | |
136 | ||
137 | static void kvm_spapr_tce_release_vfio_group(struct kvm *kvm, | |
138 | struct vfio_group *vfio_group) | |
139 | { | |
140 | struct iommu_group *grp = kvm_vfio_group_get_iommu_group(vfio_group); | |
141 | ||
142 | if (WARN_ON_ONCE(!grp)) | |
143 | return; | |
144 | ||
145 | kvm_spapr_tce_release_iommu_group(kvm, grp); | |
146 | iommu_group_put(grp); | |
147 | } | |
148 | #endif | |
149 | ||
e0f0bbc5 AW |
150 | /* |
151 | * Groups can use the same or different IOMMU domains. If the same then | |
152 | * adding a new group may change the coherency of groups we've previously | |
153 | * been told about. We don't want to care about any of that so we retest | |
154 | * each group and bail as soon as we find one that's noncoherent. This | |
155 | * means we only ever [un]register_noncoherent_dma once for the whole device. | |
156 | */ | |
157 | static void kvm_vfio_update_coherency(struct kvm_device *dev) | |
158 | { | |
159 | struct kvm_vfio *kv = dev->private; | |
160 | bool noncoherent = false; | |
161 | struct kvm_vfio_group *kvg; | |
162 | ||
163 | mutex_lock(&kv->lock); | |
164 | ||
165 | list_for_each_entry(kvg, &kv->group_list, node) { | |
9d830d47 AW |
166 | if (!kvm_vfio_group_is_coherent(kvg->vfio_group)) { |
167 | noncoherent = true; | |
168 | break; | |
169 | } | |
e0f0bbc5 AW |
170 | } |
171 | ||
172 | if (noncoherent != kv->noncoherent) { | |
173 | kv->noncoherent = noncoherent; | |
174 | ||
175 | if (kv->noncoherent) | |
176 | kvm_arch_register_noncoherent_dma(dev->kvm); | |
177 | else | |
178 | kvm_arch_unregister_noncoherent_dma(dev->kvm); | |
179 | } | |
180 | ||
181 | mutex_unlock(&kv->lock); | |
182 | } | |
183 | ||
ec53500f AW |
184 | static int kvm_vfio_set_group(struct kvm_device *dev, long attr, u64 arg) |
185 | { | |
186 | struct kvm_vfio *kv = dev->private; | |
187 | struct vfio_group *vfio_group; | |
188 | struct kvm_vfio_group *kvg; | |
e81d1ad3 | 189 | int32_t __user *argp = (int32_t __user *)(unsigned long)arg; |
ec53500f AW |
190 | struct fd f; |
191 | int32_t fd; | |
192 | int ret; | |
193 | ||
194 | switch (attr) { | |
195 | case KVM_DEV_VFIO_GROUP_ADD: | |
e81d1ad3 | 196 | if (get_user(fd, argp)) |
ec53500f AW |
197 | return -EFAULT; |
198 | ||
199 | f = fdget(fd); | |
200 | if (!f.file) | |
201 | return -EBADF; | |
202 | ||
203 | vfio_group = kvm_vfio_group_get_external_user(f.file); | |
204 | fdput(f); | |
205 | ||
206 | if (IS_ERR(vfio_group)) | |
207 | return PTR_ERR(vfio_group); | |
208 | ||
209 | mutex_lock(&kv->lock); | |
210 | ||
211 | list_for_each_entry(kvg, &kv->group_list, node) { | |
212 | if (kvg->vfio_group == vfio_group) { | |
213 | mutex_unlock(&kv->lock); | |
214 | kvm_vfio_group_put_external_user(vfio_group); | |
215 | return -EEXIST; | |
216 | } | |
217 | } | |
218 | ||
b12ce36a | 219 | kvg = kzalloc(sizeof(*kvg), GFP_KERNEL_ACCOUNT); |
ec53500f AW |
220 | if (!kvg) { |
221 | mutex_unlock(&kv->lock); | |
222 | kvm_vfio_group_put_external_user(vfio_group); | |
223 | return -ENOMEM; | |
224 | } | |
225 | ||
226 | list_add_tail(&kvg->node, &kv->group_list); | |
227 | kvg->vfio_group = vfio_group; | |
228 | ||
5544eb9b PB |
229 | kvm_arch_start_assignment(dev->kvm); |
230 | ||
ec53500f AW |
231 | mutex_unlock(&kv->lock); |
232 | ||
2fc1bec1 JS |
233 | kvm_vfio_group_set_kvm(vfio_group, dev->kvm); |
234 | ||
e0f0bbc5 AW |
235 | kvm_vfio_update_coherency(dev); |
236 | ||
ec53500f AW |
237 | return 0; |
238 | ||
239 | case KVM_DEV_VFIO_GROUP_DEL: | |
e81d1ad3 | 240 | if (get_user(fd, argp)) |
ec53500f AW |
241 | return -EFAULT; |
242 | ||
243 | f = fdget(fd); | |
244 | if (!f.file) | |
245 | return -EBADF; | |
246 | ||
ec53500f AW |
247 | ret = -ENOENT; |
248 | ||
249 | mutex_lock(&kv->lock); | |
250 | ||
251 | list_for_each_entry(kvg, &kv->group_list, node) { | |
5d6dee80 AW |
252 | if (!kvm_vfio_external_group_match_file(kvg->vfio_group, |
253 | f.file)) | |
ec53500f AW |
254 | continue; |
255 | ||
256 | list_del(&kvg->node); | |
e323369b AW |
257 | kvm_arch_end_assignment(dev->kvm); |
258 | #ifdef CONFIG_SPAPR_TCE_IOMMU | |
259 | kvm_spapr_tce_release_vfio_group(dev->kvm, | |
260 | kvg->vfio_group); | |
261 | #endif | |
262 | kvm_vfio_group_set_kvm(kvg->vfio_group, NULL); | |
ec53500f AW |
263 | kvm_vfio_group_put_external_user(kvg->vfio_group); |
264 | kfree(kvg); | |
265 | ret = 0; | |
266 | break; | |
267 | } | |
268 | ||
269 | mutex_unlock(&kv->lock); | |
270 | ||
5d6dee80 | 271 | fdput(f); |
ec53500f | 272 | |
e0f0bbc5 AW |
273 | kvm_vfio_update_coherency(dev); |
274 | ||
ec53500f | 275 | return ret; |
121f80ba AK |
276 | |
277 | #ifdef CONFIG_SPAPR_TCE_IOMMU | |
278 | case KVM_DEV_VFIO_GROUP_SET_SPAPR_TCE: { | |
279 | struct kvm_vfio_spapr_tce param; | |
280 | struct kvm_vfio *kv = dev->private; | |
281 | struct vfio_group *vfio_group; | |
282 | struct kvm_vfio_group *kvg; | |
283 | struct fd f; | |
284 | struct iommu_group *grp; | |
285 | ||
286 | if (copy_from_user(¶m, (void __user *)arg, | |
287 | sizeof(struct kvm_vfio_spapr_tce))) | |
288 | return -EFAULT; | |
289 | ||
290 | f = fdget(param.groupfd); | |
291 | if (!f.file) | |
292 | return -EBADF; | |
293 | ||
294 | vfio_group = kvm_vfio_group_get_external_user(f.file); | |
295 | fdput(f); | |
296 | ||
297 | if (IS_ERR(vfio_group)) | |
298 | return PTR_ERR(vfio_group); | |
299 | ||
300 | grp = kvm_vfio_group_get_iommu_group(vfio_group); | |
301 | if (WARN_ON_ONCE(!grp)) { | |
302 | kvm_vfio_group_put_external_user(vfio_group); | |
303 | return -EIO; | |
304 | } | |
305 | ||
306 | ret = -ENOENT; | |
307 | ||
308 | mutex_lock(&kv->lock); | |
309 | ||
310 | list_for_each_entry(kvg, &kv->group_list, node) { | |
311 | if (kvg->vfio_group != vfio_group) | |
312 | continue; | |
313 | ||
314 | ret = kvm_spapr_tce_attach_iommu_group(dev->kvm, | |
315 | param.tablefd, grp); | |
316 | break; | |
317 | } | |
318 | ||
319 | mutex_unlock(&kv->lock); | |
320 | ||
321 | iommu_group_put(grp); | |
322 | kvm_vfio_group_put_external_user(vfio_group); | |
323 | ||
324 | return ret; | |
325 | } | |
326 | #endif /* CONFIG_SPAPR_TCE_IOMMU */ | |
ec53500f AW |
327 | } |
328 | ||
329 | return -ENXIO; | |
330 | } | |
331 | ||
332 | static int kvm_vfio_set_attr(struct kvm_device *dev, | |
333 | struct kvm_device_attr *attr) | |
334 | { | |
335 | switch (attr->group) { | |
336 | case KVM_DEV_VFIO_GROUP: | |
337 | return kvm_vfio_set_group(dev, attr->attr, attr->addr); | |
338 | } | |
339 | ||
340 | return -ENXIO; | |
341 | } | |
342 | ||
343 | static int kvm_vfio_has_attr(struct kvm_device *dev, | |
344 | struct kvm_device_attr *attr) | |
345 | { | |
346 | switch (attr->group) { | |
347 | case KVM_DEV_VFIO_GROUP: | |
348 | switch (attr->attr) { | |
349 | case KVM_DEV_VFIO_GROUP_ADD: | |
350 | case KVM_DEV_VFIO_GROUP_DEL: | |
121f80ba AK |
351 | #ifdef CONFIG_SPAPR_TCE_IOMMU |
352 | case KVM_DEV_VFIO_GROUP_SET_SPAPR_TCE: | |
353 | #endif | |
ec53500f AW |
354 | return 0; |
355 | } | |
356 | ||
357 | break; | |
358 | } | |
359 | ||
360 | return -ENXIO; | |
361 | } | |
362 | ||
363 | static void kvm_vfio_destroy(struct kvm_device *dev) | |
364 | { | |
365 | struct kvm_vfio *kv = dev->private; | |
366 | struct kvm_vfio_group *kvg, *tmp; | |
367 | ||
368 | list_for_each_entry_safe(kvg, tmp, &kv->group_list, node) { | |
121f80ba AK |
369 | #ifdef CONFIG_SPAPR_TCE_IOMMU |
370 | kvm_spapr_tce_release_vfio_group(dev->kvm, kvg->vfio_group); | |
371 | #endif | |
2fc1bec1 | 372 | kvm_vfio_group_set_kvm(kvg->vfio_group, NULL); |
ec53500f AW |
373 | kvm_vfio_group_put_external_user(kvg->vfio_group); |
374 | list_del(&kvg->node); | |
375 | kfree(kvg); | |
5544eb9b | 376 | kvm_arch_end_assignment(dev->kvm); |
ec53500f AW |
377 | } |
378 | ||
e0f0bbc5 AW |
379 | kvm_vfio_update_coherency(dev); |
380 | ||
ec53500f AW |
381 | kfree(kv); |
382 | kfree(dev); /* alloc by kvm_ioctl_create_device, free by .destroy */ | |
383 | } | |
384 | ||
80ce1639 WD |
385 | static int kvm_vfio_create(struct kvm_device *dev, u32 type); |
386 | ||
387 | static struct kvm_device_ops kvm_vfio_ops = { | |
388 | .name = "kvm-vfio", | |
389 | .create = kvm_vfio_create, | |
390 | .destroy = kvm_vfio_destroy, | |
391 | .set_attr = kvm_vfio_set_attr, | |
392 | .has_attr = kvm_vfio_has_attr, | |
393 | }; | |
394 | ||
ec53500f AW |
395 | static int kvm_vfio_create(struct kvm_device *dev, u32 type) |
396 | { | |
397 | struct kvm_device *tmp; | |
398 | struct kvm_vfio *kv; | |
399 | ||
400 | /* Only one VFIO "device" per VM */ | |
401 | list_for_each_entry(tmp, &dev->kvm->devices, vm_node) | |
402 | if (tmp->ops == &kvm_vfio_ops) | |
403 | return -EBUSY; | |
404 | ||
b12ce36a | 405 | kv = kzalloc(sizeof(*kv), GFP_KERNEL_ACCOUNT); |
ec53500f AW |
406 | if (!kv) |
407 | return -ENOMEM; | |
408 | ||
409 | INIT_LIST_HEAD(&kv->group_list); | |
410 | mutex_init(&kv->lock); | |
411 | ||
412 | dev->private = kv; | |
413 | ||
414 | return 0; | |
415 | } | |
416 | ||
3c3c29fd | 417 | int kvm_vfio_ops_init(void) |
80ce1639 WD |
418 | { |
419 | return kvm_register_device_ops(&kvm_vfio_ops, KVM_DEV_TYPE_VFIO); | |
420 | } | |
571ee1b6 WL |
421 | |
422 | void kvm_vfio_ops_exit(void) | |
423 | { | |
424 | kvm_unregister_device_ops(KVM_DEV_TYPE_VFIO); | |
425 | } |