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