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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>
21#include "vfio.h"
22
23struct kvm_vfio_group {
24 struct list_head node;
25 struct vfio_group *vfio_group;
26};
27
28struct kvm_vfio {
29 struct list_head group_list;
30 struct mutex lock;
31 bool noncoherent;
32};
33
34static struct vfio_group *kvm_vfio_group_get_external_user(struct file *filep)
35{
36 struct vfio_group *vfio_group;
37 struct vfio_group *(*fn)(struct file *);
38
39 fn = symbol_get(vfio_group_get_external_user);
40 if (!fn)
41 return ERR_PTR(-EINVAL);
42
43 vfio_group = fn(filep);
44
45 symbol_put(vfio_group_get_external_user);
46
47 return vfio_group;
48}
49
50static void kvm_vfio_group_put_external_user(struct vfio_group *vfio_group)
51{
52 void (*fn)(struct vfio_group *);
53
54 fn = symbol_get(vfio_group_put_external_user);
55 if (!fn)
56 return;
57
58 fn(vfio_group);
59
60 symbol_put(vfio_group_put_external_user);
61}
62
63static bool kvm_vfio_group_is_coherent(struct vfio_group *vfio_group)
64{
65 long (*fn)(struct vfio_group *, unsigned long);
66 long ret;
67
68 fn = symbol_get(vfio_external_check_extension);
69 if (!fn)
70 return false;
71
72 ret = fn(vfio_group, VFIO_DMA_CC_IOMMU);
73
74 symbol_put(vfio_external_check_extension);
75
76 return ret > 0;
77}
78
79
80
81
82
83
84
85
86static void kvm_vfio_update_coherency(struct kvm_device *dev)
87{
88 struct kvm_vfio *kv = dev->private;
89 bool noncoherent = false;
90 struct kvm_vfio_group *kvg;
91
92 mutex_lock(&kv->lock);
93
94 list_for_each_entry(kvg, &kv->group_list, node) {
95 if (!kvm_vfio_group_is_coherent(kvg->vfio_group)) {
96 noncoherent = true;
97 break;
98 }
99 }
100
101 if (noncoherent != kv->noncoherent) {
102 kv->noncoherent = noncoherent;
103
104 if (kv->noncoherent)
105 kvm_arch_register_noncoherent_dma(dev->kvm);
106 else
107 kvm_arch_unregister_noncoherent_dma(dev->kvm);
108 }
109
110 mutex_unlock(&kv->lock);
111}
112
113static int kvm_vfio_set_group(struct kvm_device *dev, long attr, u64 arg)
114{
115 struct kvm_vfio *kv = dev->private;
116 struct vfio_group *vfio_group;
117 struct kvm_vfio_group *kvg;
118 int32_t __user *argp = (int32_t __user *)(unsigned long)arg;
119 struct fd f;
120 int32_t fd;
121 int ret;
122
123 switch (attr) {
124 case KVM_DEV_VFIO_GROUP_ADD:
125 if (get_user(fd, argp))
126 return -EFAULT;
127
128 f = fdget(fd);
129 if (!f.file)
130 return -EBADF;
131
132 vfio_group = kvm_vfio_group_get_external_user(f.file);
133 fdput(f);
134
135 if (IS_ERR(vfio_group))
136 return PTR_ERR(vfio_group);
137
138 mutex_lock(&kv->lock);
139
140 list_for_each_entry(kvg, &kv->group_list, node) {
141 if (kvg->vfio_group == vfio_group) {
142 mutex_unlock(&kv->lock);
143 kvm_vfio_group_put_external_user(vfio_group);
144 return -EEXIST;
145 }
146 }
147
148 kvg = kzalloc(sizeof(*kvg), GFP_KERNEL);
149 if (!kvg) {
150 mutex_unlock(&kv->lock);
151 kvm_vfio_group_put_external_user(vfio_group);
152 return -ENOMEM;
153 }
154
155 list_add_tail(&kvg->node, &kv->group_list);
156 kvg->vfio_group = vfio_group;
157
158 kvm_arch_start_assignment(dev->kvm);
159
160 mutex_unlock(&kv->lock);
161
162 kvm_vfio_update_coherency(dev);
163
164 return 0;
165
166 case KVM_DEV_VFIO_GROUP_DEL:
167 if (get_user(fd, argp))
168 return -EFAULT;
169
170 f = fdget(fd);
171 if (!f.file)
172 return -EBADF;
173
174 vfio_group = kvm_vfio_group_get_external_user(f.file);
175 fdput(f);
176
177 if (IS_ERR(vfio_group))
178 return PTR_ERR(vfio_group);
179
180 ret = -ENOENT;
181
182 mutex_lock(&kv->lock);
183
184 list_for_each_entry(kvg, &kv->group_list, node) {
185 if (kvg->vfio_group != vfio_group)
186 continue;
187
188 list_del(&kvg->node);
189 kvm_vfio_group_put_external_user(kvg->vfio_group);
190 kfree(kvg);
191 ret = 0;
192 break;
193 }
194
195 kvm_arch_end_assignment(dev->kvm);
196
197 mutex_unlock(&kv->lock);
198
199 kvm_vfio_group_put_external_user(vfio_group);
200
201 kvm_vfio_update_coherency(dev);
202
203 return ret;
204 }
205
206 return -ENXIO;
207}
208
209static int kvm_vfio_set_attr(struct kvm_device *dev,
210 struct kvm_device_attr *attr)
211{
212 switch (attr->group) {
213 case KVM_DEV_VFIO_GROUP:
214 return kvm_vfio_set_group(dev, attr->attr, attr->addr);
215 }
216
217 return -ENXIO;
218}
219
220static int kvm_vfio_has_attr(struct kvm_device *dev,
221 struct kvm_device_attr *attr)
222{
223 switch (attr->group) {
224 case KVM_DEV_VFIO_GROUP:
225 switch (attr->attr) {
226 case KVM_DEV_VFIO_GROUP_ADD:
227 case KVM_DEV_VFIO_GROUP_DEL:
228 return 0;
229 }
230
231 break;
232 }
233
234 return -ENXIO;
235}
236
237static void kvm_vfio_destroy(struct kvm_device *dev)
238{
239 struct kvm_vfio *kv = dev->private;
240 struct kvm_vfio_group *kvg, *tmp;
241
242 list_for_each_entry_safe(kvg, tmp, &kv->group_list, node) {
243 kvm_vfio_group_put_external_user(kvg->vfio_group);
244 list_del(&kvg->node);
245 kfree(kvg);
246 kvm_arch_end_assignment(dev->kvm);
247 }
248
249 kvm_vfio_update_coherency(dev);
250
251 kfree(kv);
252 kfree(dev);
253}
254
255static int kvm_vfio_create(struct kvm_device *dev, u32 type);
256
257static struct kvm_device_ops kvm_vfio_ops = {
258 .name = "kvm-vfio",
259 .create = kvm_vfio_create,
260 .destroy = kvm_vfio_destroy,
261 .set_attr = kvm_vfio_set_attr,
262 .has_attr = kvm_vfio_has_attr,
263};
264
265static int kvm_vfio_create(struct kvm_device *dev, u32 type)
266{
267 struct kvm_device *tmp;
268 struct kvm_vfio *kv;
269
270
271 list_for_each_entry(tmp, &dev->kvm->devices, vm_node)
272 if (tmp->ops == &kvm_vfio_ops)
273 return -EBUSY;
274
275 kv = kzalloc(sizeof(*kv), GFP_KERNEL);
276 if (!kv)
277 return -ENOMEM;
278
279 INIT_LIST_HEAD(&kv->group_list);
280 mutex_init(&kv->lock);
281
282 dev->private = kv;
283
284 return 0;
285}
286
287int kvm_vfio_ops_init(void)
288{
289 return kvm_register_device_ops(&kvm_vfio_ops, KVM_DEV_TYPE_VFIO);
290}
291
292void kvm_vfio_ops_exit(void)
293{
294 kvm_unregister_device_ops(KVM_DEV_TYPE_VFIO);
295}
296
