Commit | Line | Data |
---|---|---|
ec53500f AW |
1 | /* |
2 | * VFIO-KVM bridge pseudo device | |
3 | * | |
4 | * Copyright (C) 2013 Red Hat, Inc. All rights reserved. | |
5 | * Author: Alex Williamson <alex.williamson@redhat.com> | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License version 2 as | |
9 | * published by the Free Software Foundation. | |
10 | */ | |
11 | ||
12 | #include <linux/errno.h> | |
13 | #include <linux/file.h> | |
14 | #include <linux/kvm_host.h> | |
15 | #include <linux/list.h> | |
16 | #include <linux/module.h> | |
17 | #include <linux/mutex.h> | |
18 | #include <linux/slab.h> | |
19 | #include <linux/uaccess.h> | |
20 | #include <linux/vfio.h> | |
3c3c29fd | 21 | #include "vfio.h" |
ec53500f | 22 | |
121f80ba AK |
23 | #ifdef CONFIG_SPAPR_TCE_IOMMU |
24 | #include <asm/kvm_ppc.h> | |
25 | #endif | |
26 | ||
ec53500f AW |
27 | struct kvm_vfio_group { |
28 | struct list_head node; | |
29 | struct vfio_group *vfio_group; | |
30 | }; | |
31 | ||
32 | struct kvm_vfio { | |
33 | struct list_head group_list; | |
34 | struct mutex lock; | |
e0f0bbc5 | 35 | bool noncoherent; |
ec53500f AW |
36 | }; |
37 | ||
38 | static struct vfio_group *kvm_vfio_group_get_external_user(struct file *filep) | |
39 | { | |
40 | struct vfio_group *vfio_group; | |
41 | struct vfio_group *(*fn)(struct file *); | |
42 | ||
43 | fn = symbol_get(vfio_group_get_external_user); | |
44 | if (!fn) | |
45 | return ERR_PTR(-EINVAL); | |
46 | ||
47 | vfio_group = fn(filep); | |
48 | ||
49 | symbol_put(vfio_group_get_external_user); | |
50 | ||
51 | return vfio_group; | |
52 | } | |
53 | ||
5d6dee80 AW |
54 | static bool kvm_vfio_external_group_match_file(struct vfio_group *group, |
55 | struct file *filep) | |
56 | { | |
57 | bool ret, (*fn)(struct vfio_group *, struct file *); | |
58 | ||
59 | fn = symbol_get(vfio_external_group_match_file); | |
60 | if (!fn) | |
61 | return false; | |
62 | ||
63 | ret = fn(group, filep); | |
64 | ||
65 | symbol_put(vfio_external_group_match_file); | |
66 | ||
67 | return ret; | |
68 | } | |
69 | ||
ec53500f AW |
70 | static void kvm_vfio_group_put_external_user(struct vfio_group *vfio_group) |
71 | { | |
72 | void (*fn)(struct vfio_group *); | |
73 | ||
74 | fn = symbol_get(vfio_group_put_external_user); | |
75 | if (!fn) | |
76 | return; | |
77 | ||
78 | fn(vfio_group); | |
79 | ||
80 | symbol_put(vfio_group_put_external_user); | |
81 | } | |
82 | ||
2fc1bec1 JS |
83 | static void kvm_vfio_group_set_kvm(struct vfio_group *group, struct kvm *kvm) |
84 | { | |
85 | void (*fn)(struct vfio_group *, struct kvm *); | |
86 | ||
87 | fn = symbol_get(vfio_group_set_kvm); | |
88 | if (!fn) | |
89 | return; | |
90 | ||
91 | fn(group, kvm); | |
92 | ||
93 | symbol_put(vfio_group_set_kvm); | |
94 | } | |
95 | ||
9d830d47 AW |
96 | static bool kvm_vfio_group_is_coherent(struct vfio_group *vfio_group) |
97 | { | |
98 | long (*fn)(struct vfio_group *, unsigned long); | |
99 | long ret; | |
100 | ||
101 | fn = symbol_get(vfio_external_check_extension); | |
102 | if (!fn) | |
103 | return false; | |
104 | ||
105 | ret = fn(vfio_group, VFIO_DMA_CC_IOMMU); | |
106 | ||
107 | symbol_put(vfio_external_check_extension); | |
108 | ||
109 | return ret > 0; | |
110 | } | |
111 | ||
121f80ba AK |
112 | #ifdef CONFIG_SPAPR_TCE_IOMMU |
113 | static int kvm_vfio_external_user_iommu_id(struct vfio_group *vfio_group) | |
114 | { | |
115 | int (*fn)(struct vfio_group *); | |
116 | int ret = -EINVAL; | |
117 | ||
118 | fn = symbol_get(vfio_external_user_iommu_id); | |
119 | if (!fn) | |
120 | return ret; | |
121 | ||
122 | ret = fn(vfio_group); | |
123 | ||
124 | symbol_put(vfio_external_user_iommu_id); | |
125 | ||
126 | return ret; | |
127 | } | |
128 | ||
129 | static struct iommu_group *kvm_vfio_group_get_iommu_group( | |
130 | struct vfio_group *group) | |
131 | { | |
132 | int group_id = kvm_vfio_external_user_iommu_id(group); | |
133 | ||
134 | if (group_id < 0) | |
135 | return NULL; | |
136 | ||
137 | return iommu_group_get_by_id(group_id); | |
138 | } | |
139 | ||
140 | static void kvm_spapr_tce_release_vfio_group(struct kvm *kvm, | |
141 | struct vfio_group *vfio_group) | |
142 | { | |
143 | struct iommu_group *grp = kvm_vfio_group_get_iommu_group(vfio_group); | |
144 | ||
145 | if (WARN_ON_ONCE(!grp)) | |
146 | return; | |
147 | ||
148 | kvm_spapr_tce_release_iommu_group(kvm, grp); | |
149 | iommu_group_put(grp); | |
150 | } | |
151 | #endif | |
152 | ||
e0f0bbc5 AW |
153 | /* |
154 | * Groups can use the same or different IOMMU domains. If the same then | |
155 | * adding a new group may change the coherency of groups we've previously | |
156 | * been told about. We don't want to care about any of that so we retest | |
157 | * each group and bail as soon as we find one that's noncoherent. This | |
158 | * means we only ever [un]register_noncoherent_dma once for the whole device. | |
159 | */ | |
160 | static void kvm_vfio_update_coherency(struct kvm_device *dev) | |
161 | { | |
162 | struct kvm_vfio *kv = dev->private; | |
163 | bool noncoherent = false; | |
164 | struct kvm_vfio_group *kvg; | |
165 | ||
166 | mutex_lock(&kv->lock); | |
167 | ||
168 | list_for_each_entry(kvg, &kv->group_list, node) { | |
9d830d47 AW |
169 | if (!kvm_vfio_group_is_coherent(kvg->vfio_group)) { |
170 | noncoherent = true; | |
171 | break; | |
172 | } | |
e0f0bbc5 AW |
173 | } |
174 | ||
175 | if (noncoherent != kv->noncoherent) { | |
176 | kv->noncoherent = noncoherent; | |
177 | ||
178 | if (kv->noncoherent) | |
179 | kvm_arch_register_noncoherent_dma(dev->kvm); | |
180 | else | |
181 | kvm_arch_unregister_noncoherent_dma(dev->kvm); | |
182 | } | |
183 | ||
184 | mutex_unlock(&kv->lock); | |
185 | } | |
186 | ||
ec53500f AW |
187 | static int kvm_vfio_set_group(struct kvm_device *dev, long attr, u64 arg) |
188 | { | |
189 | struct kvm_vfio *kv = dev->private; | |
190 | struct vfio_group *vfio_group; | |
191 | struct kvm_vfio_group *kvg; | |
e81d1ad3 | 192 | int32_t __user *argp = (int32_t __user *)(unsigned long)arg; |
ec53500f AW |
193 | struct fd f; |
194 | int32_t fd; | |
195 | int ret; | |
196 | ||
197 | switch (attr) { | |
198 | case KVM_DEV_VFIO_GROUP_ADD: | |
e81d1ad3 | 199 | if (get_user(fd, argp)) |
ec53500f AW |
200 | return -EFAULT; |
201 | ||
202 | f = fdget(fd); | |
203 | if (!f.file) | |
204 | return -EBADF; | |
205 | ||
206 | vfio_group = kvm_vfio_group_get_external_user(f.file); | |
207 | fdput(f); | |
208 | ||
209 | if (IS_ERR(vfio_group)) | |
210 | return PTR_ERR(vfio_group); | |
211 | ||
212 | mutex_lock(&kv->lock); | |
213 | ||
214 | list_for_each_entry(kvg, &kv->group_list, node) { | |
215 | if (kvg->vfio_group == vfio_group) { | |
216 | mutex_unlock(&kv->lock); | |
217 | kvm_vfio_group_put_external_user(vfio_group); | |
218 | return -EEXIST; | |
219 | } | |
220 | } | |
221 | ||
222 | kvg = kzalloc(sizeof(*kvg), GFP_KERNEL); | |
223 | if (!kvg) { | |
224 | mutex_unlock(&kv->lock); | |
225 | kvm_vfio_group_put_external_user(vfio_group); | |
226 | return -ENOMEM; | |
227 | } | |
228 | ||
229 | list_add_tail(&kvg->node, &kv->group_list); | |
230 | kvg->vfio_group = vfio_group; | |
231 | ||
5544eb9b PB |
232 | kvm_arch_start_assignment(dev->kvm); |
233 | ||
ec53500f AW |
234 | mutex_unlock(&kv->lock); |
235 | ||
2fc1bec1 JS |
236 | kvm_vfio_group_set_kvm(vfio_group, dev->kvm); |
237 | ||
e0f0bbc5 AW |
238 | kvm_vfio_update_coherency(dev); |
239 | ||
ec53500f AW |
240 | return 0; |
241 | ||
242 | case KVM_DEV_VFIO_GROUP_DEL: | |
e81d1ad3 | 243 | if (get_user(fd, argp)) |
ec53500f AW |
244 | return -EFAULT; |
245 | ||
246 | f = fdget(fd); | |
247 | if (!f.file) | |
248 | return -EBADF; | |
249 | ||
ec53500f AW |
250 | ret = -ENOENT; |
251 | ||
252 | mutex_lock(&kv->lock); | |
253 | ||
254 | list_for_each_entry(kvg, &kv->group_list, node) { | |
5d6dee80 AW |
255 | if (!kvm_vfio_external_group_match_file(kvg->vfio_group, |
256 | f.file)) | |
ec53500f AW |
257 | continue; |
258 | ||
259 | list_del(&kvg->node); | |
e323369b AW |
260 | kvm_arch_end_assignment(dev->kvm); |
261 | #ifdef CONFIG_SPAPR_TCE_IOMMU | |
262 | kvm_spapr_tce_release_vfio_group(dev->kvm, | |
263 | kvg->vfio_group); | |
264 | #endif | |
265 | kvm_vfio_group_set_kvm(kvg->vfio_group, NULL); | |
ec53500f AW |
266 | kvm_vfio_group_put_external_user(kvg->vfio_group); |
267 | kfree(kvg); | |
268 | ret = 0; | |
269 | break; | |
270 | } | |
271 | ||
272 | mutex_unlock(&kv->lock); | |
273 | ||
5d6dee80 | 274 | fdput(f); |
ec53500f | 275 | |
e0f0bbc5 AW |
276 | kvm_vfio_update_coherency(dev); |
277 | ||
ec53500f | 278 | return ret; |
121f80ba AK |
279 | |
280 | #ifdef CONFIG_SPAPR_TCE_IOMMU | |
281 | case KVM_DEV_VFIO_GROUP_SET_SPAPR_TCE: { | |
282 | struct kvm_vfio_spapr_tce param; | |
283 | struct kvm_vfio *kv = dev->private; | |
284 | struct vfio_group *vfio_group; | |
285 | struct kvm_vfio_group *kvg; | |
286 | struct fd f; | |
287 | struct iommu_group *grp; | |
288 | ||
289 | if (copy_from_user(¶m, (void __user *)arg, | |
290 | sizeof(struct kvm_vfio_spapr_tce))) | |
291 | return -EFAULT; | |
292 | ||
293 | f = fdget(param.groupfd); | |
294 | if (!f.file) | |
295 | return -EBADF; | |
296 | ||
297 | vfio_group = kvm_vfio_group_get_external_user(f.file); | |
298 | fdput(f); | |
299 | ||
300 | if (IS_ERR(vfio_group)) | |
301 | return PTR_ERR(vfio_group); | |
302 | ||
303 | grp = kvm_vfio_group_get_iommu_group(vfio_group); | |
304 | if (WARN_ON_ONCE(!grp)) { | |
305 | kvm_vfio_group_put_external_user(vfio_group); | |
306 | return -EIO; | |
307 | } | |
308 | ||
309 | ret = -ENOENT; | |
310 | ||
311 | mutex_lock(&kv->lock); | |
312 | ||
313 | list_for_each_entry(kvg, &kv->group_list, node) { | |
314 | if (kvg->vfio_group != vfio_group) | |
315 | continue; | |
316 | ||
317 | ret = kvm_spapr_tce_attach_iommu_group(dev->kvm, | |
318 | param.tablefd, grp); | |
319 | break; | |
320 | } | |
321 | ||
322 | mutex_unlock(&kv->lock); | |
323 | ||
324 | iommu_group_put(grp); | |
325 | kvm_vfio_group_put_external_user(vfio_group); | |
326 | ||
327 | return ret; | |
328 | } | |
329 | #endif /* CONFIG_SPAPR_TCE_IOMMU */ | |
ec53500f AW |
330 | } |
331 | ||
332 | return -ENXIO; | |
333 | } | |
334 | ||
335 | static int kvm_vfio_set_attr(struct kvm_device *dev, | |
336 | struct kvm_device_attr *attr) | |
337 | { | |
338 | switch (attr->group) { | |
339 | case KVM_DEV_VFIO_GROUP: | |
340 | return kvm_vfio_set_group(dev, attr->attr, attr->addr); | |
341 | } | |
342 | ||
343 | return -ENXIO; | |
344 | } | |
345 | ||
346 | static int kvm_vfio_has_attr(struct kvm_device *dev, | |
347 | struct kvm_device_attr *attr) | |
348 | { | |
349 | switch (attr->group) { | |
350 | case KVM_DEV_VFIO_GROUP: | |
351 | switch (attr->attr) { | |
352 | case KVM_DEV_VFIO_GROUP_ADD: | |
353 | case KVM_DEV_VFIO_GROUP_DEL: | |
121f80ba AK |
354 | #ifdef CONFIG_SPAPR_TCE_IOMMU |
355 | case KVM_DEV_VFIO_GROUP_SET_SPAPR_TCE: | |
356 | #endif | |
ec53500f AW |
357 | return 0; |
358 | } | |
359 | ||
360 | break; | |
361 | } | |
362 | ||
363 | return -ENXIO; | |
364 | } | |
365 | ||
366 | static void kvm_vfio_destroy(struct kvm_device *dev) | |
367 | { | |
368 | struct kvm_vfio *kv = dev->private; | |
369 | struct kvm_vfio_group *kvg, *tmp; | |
370 | ||
371 | list_for_each_entry_safe(kvg, tmp, &kv->group_list, node) { | |
121f80ba AK |
372 | #ifdef CONFIG_SPAPR_TCE_IOMMU |
373 | kvm_spapr_tce_release_vfio_group(dev->kvm, kvg->vfio_group); | |
374 | #endif | |
2fc1bec1 | 375 | kvm_vfio_group_set_kvm(kvg->vfio_group, NULL); |
ec53500f AW |
376 | kvm_vfio_group_put_external_user(kvg->vfio_group); |
377 | list_del(&kvg->node); | |
378 | kfree(kvg); | |
5544eb9b | 379 | kvm_arch_end_assignment(dev->kvm); |
ec53500f AW |
380 | } |
381 | ||
e0f0bbc5 AW |
382 | kvm_vfio_update_coherency(dev); |
383 | ||
ec53500f AW |
384 | kfree(kv); |
385 | kfree(dev); /* alloc by kvm_ioctl_create_device, free by .destroy */ | |
386 | } | |
387 | ||
80ce1639 WD |
388 | static int kvm_vfio_create(struct kvm_device *dev, u32 type); |
389 | ||
390 | static struct kvm_device_ops kvm_vfio_ops = { | |
391 | .name = "kvm-vfio", | |
392 | .create = kvm_vfio_create, | |
393 | .destroy = kvm_vfio_destroy, | |
394 | .set_attr = kvm_vfio_set_attr, | |
395 | .has_attr = kvm_vfio_has_attr, | |
396 | }; | |
397 | ||
ec53500f AW |
398 | static int kvm_vfio_create(struct kvm_device *dev, u32 type) |
399 | { | |
400 | struct kvm_device *tmp; | |
401 | struct kvm_vfio *kv; | |
402 | ||
403 | /* Only one VFIO "device" per VM */ | |
404 | list_for_each_entry(tmp, &dev->kvm->devices, vm_node) | |
405 | if (tmp->ops == &kvm_vfio_ops) | |
406 | return -EBUSY; | |
407 | ||
408 | kv = kzalloc(sizeof(*kv), GFP_KERNEL); | |
409 | if (!kv) | |
410 | return -ENOMEM; | |
411 | ||
412 | INIT_LIST_HEAD(&kv->group_list); | |
413 | mutex_init(&kv->lock); | |
414 | ||
415 | dev->private = kv; | |
416 | ||
417 | return 0; | |
418 | } | |
419 | ||
3c3c29fd | 420 | int kvm_vfio_ops_init(void) |
80ce1639 WD |
421 | { |
422 | return kvm_register_device_ops(&kvm_vfio_ops, KVM_DEV_TYPE_VFIO); | |
423 | } | |
571ee1b6 WL |
424 | |
425 | void kvm_vfio_ops_exit(void) | |
426 | { | |
427 | kvm_unregister_device_ops(KVM_DEV_TYPE_VFIO); | |
428 | } |