xref: /openbmc/qemu/include/hw/virtio/vhost.h (revision e0c72452)
1 #ifndef VHOST_H
2 #define VHOST_H
3 
4 #include "hw/virtio/vhost-backend.h"
5 #include "hw/virtio/virtio.h"
6 #include "exec/memory.h"
7 
8 #define VHOST_F_DEVICE_IOTLB 63
9 #define VHOST_USER_F_PROTOCOL_FEATURES 30
10 
11 #define VU_REALIZE_CONN_RETRIES 3
12 
13 /* Generic structures common for any vhost based device. */
14 
15 struct vhost_inflight {
16     int fd;
17     void *addr;
18     uint64_t size;
19     uint64_t offset;
20     uint16_t queue_size;
21 };
22 
23 struct vhost_virtqueue {
24     int kick;
25     int call;
26     void *desc;
27     void *avail;
28     void *used;
29     int num;
30     unsigned long long desc_phys;
31     unsigned desc_size;
32     unsigned long long avail_phys;
33     unsigned avail_size;
34     unsigned long long used_phys;
35     unsigned used_size;
36     EventNotifier masked_notifier;
37     EventNotifier error_notifier;
38     EventNotifier masked_config_notifier;
39     struct vhost_dev *dev;
40 };
41 
42 typedef unsigned long vhost_log_chunk_t;
43 #define VHOST_LOG_PAGE 0x1000
44 #define VHOST_LOG_BITS (8 * sizeof(vhost_log_chunk_t))
45 #define VHOST_LOG_CHUNK (VHOST_LOG_PAGE * VHOST_LOG_BITS)
46 #define VHOST_INVALID_FEATURE_BIT   (0xff)
47 #define VHOST_QUEUE_NUM_CONFIG_INR 0
48 
49 struct vhost_log {
50     unsigned long long size;
51     int refcnt;
52     int fd;
53     vhost_log_chunk_t *log;
54 };
55 
56 struct vhost_dev;
57 struct vhost_iommu {
58     struct vhost_dev *hdev;
59     MemoryRegion *mr;
60     hwaddr iommu_offset;
61     IOMMUNotifier n;
62     QLIST_ENTRY(vhost_iommu) iommu_next;
63 };
64 
65 typedef struct VhostDevConfigOps {
66     /* Vhost device config space changed callback
67      */
68     int (*vhost_dev_config_notifier)(struct vhost_dev *dev);
69 } VhostDevConfigOps;
70 
71 struct vhost_memory;
72 
73 /**
74  * struct vhost_dev - common vhost_dev structure
75  * @vhost_ops: backend specific ops
76  * @config_ops: ops for config changes (see @vhost_dev_set_config_notifier)
77  */
78 struct vhost_dev {
79     VirtIODevice *vdev;
80     MemoryListener memory_listener;
81     MemoryListener iommu_listener;
82     struct vhost_memory *mem;
83     int n_mem_sections;
84     MemoryRegionSection *mem_sections;
85     int n_tmp_sections;
86     MemoryRegionSection *tmp_sections;
87     struct vhost_virtqueue *vqs;
88     unsigned int nvqs;
89     /* the first virtqueue which would be used by this vhost dev */
90     int vq_index;
91     /* one past the last vq index for the virtio device (not vhost) */
92     int vq_index_end;
93     /* if non-zero, minimum required value for max_queues */
94     int num_queues;
95     /**
96      * vhost feature handling requires matching the feature set
97      * offered by a backend which may be a subset of the total
98      * features eventually offered to the guest.
99      *
100      * @features: available features provided by the backend
101      * @acked_features: final negotiated features with front-end driver
102      *
103      * @backend_features: this is used in a couple of places to either
104      * store VHOST_USER_F_PROTOCOL_FEATURES to apply to
105      * VHOST_USER_SET_FEATURES or VHOST_NET_F_VIRTIO_NET_HDR. Its
106      * future use should be discouraged and the variable retired as
107      * its easy to confuse with the VirtIO backend_features.
108      */
109     uint64_t features;
110     uint64_t acked_features;
111     uint64_t backend_features;
112 
113     /**
114      * @protocol_features: is the vhost-user only feature set by
115      * VHOST_USER_SET_PROTOCOL_FEATURES. Protocol features are only
116      * negotiated if VHOST_USER_F_PROTOCOL_FEATURES has been offered
117      * by the backend (see @features).
118      */
119     uint64_t protocol_features;
120 
121     uint64_t max_queues;
122     uint64_t backend_cap;
123     /* @started: is the vhost device started? */
124     bool started;
125     bool log_enabled;
126     uint64_t log_size;
127     Error *migration_blocker;
128     const VhostOps *vhost_ops;
129     void *opaque;
130     struct vhost_log *log;
131     QLIST_ENTRY(vhost_dev) entry;
132     QLIST_HEAD(, vhost_iommu) iommu_list;
133     IOMMUNotifier n;
134     const VhostDevConfigOps *config_ops;
135 };
136 
137 extern const VhostOps kernel_ops;
138 extern const VhostOps user_ops;
139 extern const VhostOps vdpa_ops;
140 
141 struct vhost_net {
142     struct vhost_dev dev;
143     struct vhost_virtqueue vqs[2];
144     int backend;
145     NetClientState *nc;
146 };
147 
148 /**
149  * vhost_dev_init() - initialise the vhost interface
150  * @hdev: the common vhost_dev structure
151  * @opaque: opaque ptr passed to backend (vhost/vhost-user/vdpa)
152  * @backend_type: type of backend
153  * @busyloop_timeout: timeout for polling virtqueue
154  * @errp: error handle
155  *
156  * The initialisation of the vhost device will trigger the
157  * initialisation of the backend and potentially capability
158  * negotiation of backend interface. Configuration of the VirtIO
159  * itself won't happen until the interface is started.
160  *
161  * Return: 0 on success, non-zero on error while setting errp.
162  */
163 int vhost_dev_init(struct vhost_dev *hdev, void *opaque,
164                    VhostBackendType backend_type,
165                    uint32_t busyloop_timeout, Error **errp);
166 
167 /**
168  * vhost_dev_cleanup() - tear down and cleanup vhost interface
169  * @hdev: the common vhost_dev structure
170  */
171 void vhost_dev_cleanup(struct vhost_dev *hdev);
172 
173 /**
174  * vhost_dev_enable_notifiers() - enable event notifiers
175  * @hdev: common vhost_dev structure
176  * @vdev: the VirtIODevice structure
177  *
178  * Enable notifications directly to the vhost device rather than being
179  * triggered by QEMU itself. Notifications should be enabled before
180  * the vhost device is started via @vhost_dev_start.
181  *
182  * Return: 0 on success, < 0 on error.
183  */
184 int vhost_dev_enable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev);
185 
186 /**
187  * vhost_dev_disable_notifiers - disable event notifications
188  * @hdev: common vhost_dev structure
189  * @vdev: the VirtIODevice structure
190  *
191  * Disable direct notifications to vhost device.
192  */
193 void vhost_dev_disable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev);
194 bool vhost_config_pending(struct vhost_dev *hdev);
195 void vhost_config_mask(struct vhost_dev *hdev, VirtIODevice *vdev, bool mask);
196 
197 /**
198  * vhost_dev_is_started() - report status of vhost device
199  * @hdev: common vhost_dev structure
200  *
201  * Return the started status of the vhost device
202  */
203 static inline bool vhost_dev_is_started(struct vhost_dev *hdev)
204 {
205     return hdev->started;
206 }
207 
208 /**
209  * vhost_dev_start() - start the vhost device
210  * @hdev: common vhost_dev structure
211  * @vdev: the VirtIODevice structure
212  * @vrings: true to have vrings enabled in this call
213  *
214  * Starts the vhost device. From this point VirtIO feature negotiation
215  * can start and the device can start processing VirtIO transactions.
216  *
217  * Return: 0 on success, < 0 on error.
218  */
219 int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev, bool vrings);
220 
221 /**
222  * vhost_dev_stop() - stop the vhost device
223  * @hdev: common vhost_dev structure
224  * @vdev: the VirtIODevice structure
225  * @vrings: true to have vrings disabled in this call
226  *
227  * Stop the vhost device. After the device is stopped the notifiers
228  * can be disabled (@vhost_dev_disable_notifiers) and the device can
229  * be torn down (@vhost_dev_cleanup).
230  */
231 void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev, bool vrings);
232 
233 /**
234  * DOC: vhost device configuration handling
235  *
236  * The VirtIO device configuration space is used for rarely changing
237  * or initialisation time parameters. The configuration can be updated
238  * by either the guest driver or the device itself. If the device can
239  * change the configuration over time the vhost handler should
240  * register a @VhostDevConfigOps structure with
241  * @vhost_dev_set_config_notifier so the guest can be notified. Some
242  * devices register a handler anyway and will signal an error if an
243  * unexpected config change happens.
244  */
245 
246 /**
247  * vhost_dev_get_config() - fetch device configuration
248  * @hdev: common vhost_dev_structure
249  * @config: pointer to device appropriate config structure
250  * @config_len: size of device appropriate config structure
251  *
252  * Return: 0 on success, < 0 on error while setting errp
253  */
254 int vhost_dev_get_config(struct vhost_dev *hdev, uint8_t *config,
255                          uint32_t config_len, Error **errp);
256 
257 /**
258  * vhost_dev_set_config() - set device configuration
259  * @hdev: common vhost_dev_structure
260  * @data: pointer to data to set
261  * @offset: offset into configuration space
262  * @size: length of set
263  * @flags: @VhostSetConfigType flags
264  *
265  * By use of @offset/@size a subset of the configuration space can be
266  * written to. The @flags are used to indicate if it is a normal
267  * transaction or related to migration.
268  *
269  * Return: 0 on success, non-zero on error
270  */
271 int vhost_dev_set_config(struct vhost_dev *dev, const uint8_t *data,
272                          uint32_t offset, uint32_t size, uint32_t flags);
273 
274 /**
275  * vhost_dev_set_config_notifier() - register VhostDevConfigOps
276  * @hdev: common vhost_dev_structure
277  * @ops: notifier ops
278  *
279  * If the device is expected to change configuration a notifier can be
280  * setup to handle the case.
281  */
282 void vhost_dev_set_config_notifier(struct vhost_dev *dev,
283                                    const VhostDevConfigOps *ops);
284 
285 
286 /* Test and clear masked event pending status.
287  * Should be called after unmask to avoid losing events.
288  */
289 bool vhost_virtqueue_pending(struct vhost_dev *hdev, int n);
290 
291 /* Mask/unmask events from this vq.
292  */
293 void vhost_virtqueue_mask(struct vhost_dev *hdev, VirtIODevice *vdev, int n,
294                           bool mask);
295 
296 /**
297  * vhost_get_features() - return a sanitised set of feature bits
298  * @hdev: common vhost_dev structure
299  * @feature_bits: pointer to terminated table of feature bits
300  * @features: original feature set
301  *
302  * This returns a set of features bits that is an intersection of what
303  * is supported by the vhost backend (hdev->features), the supported
304  * feature_bits and the requested feature set.
305  */
306 uint64_t vhost_get_features(struct vhost_dev *hdev, const int *feature_bits,
307                             uint64_t features);
308 
309 /**
310  * vhost_ack_features() - set vhost acked_features
311  * @hdev: common vhost_dev structure
312  * @feature_bits: pointer to terminated table of feature bits
313  * @features: requested feature set
314  *
315  * This sets the internal hdev->acked_features to the intersection of
316  * the backends advertised features and the supported feature_bits.
317  */
318 void vhost_ack_features(struct vhost_dev *hdev, const int *feature_bits,
319                         uint64_t features);
320 unsigned int vhost_get_max_memslots(void);
321 unsigned int vhost_get_free_memslots(void);
322 
323 int vhost_net_set_backend(struct vhost_dev *hdev,
324                           struct vhost_vring_file *file);
325 
326 void vhost_toggle_device_iotlb(VirtIODevice *vdev);
327 int vhost_device_iotlb_miss(struct vhost_dev *dev, uint64_t iova, int write);
328 
329 int vhost_virtqueue_start(struct vhost_dev *dev, struct VirtIODevice *vdev,
330                           struct vhost_virtqueue *vq, unsigned idx);
331 void vhost_virtqueue_stop(struct vhost_dev *dev, struct VirtIODevice *vdev,
332                           struct vhost_virtqueue *vq, unsigned idx);
333 
334 void vhost_dev_reset_inflight(struct vhost_inflight *inflight);
335 void vhost_dev_free_inflight(struct vhost_inflight *inflight);
336 void vhost_dev_save_inflight(struct vhost_inflight *inflight, QEMUFile *f);
337 int vhost_dev_load_inflight(struct vhost_inflight *inflight, QEMUFile *f);
338 int vhost_dev_prepare_inflight(struct vhost_dev *hdev, VirtIODevice *vdev);
339 int vhost_dev_set_inflight(struct vhost_dev *dev,
340                            struct vhost_inflight *inflight);
341 int vhost_dev_get_inflight(struct vhost_dev *dev, uint16_t queue_size,
342                            struct vhost_inflight *inflight);
343 bool vhost_dev_has_iommu(struct vhost_dev *dev);
344 
345 #ifdef CONFIG_VHOST
346 int vhost_reset_device(struct vhost_dev *hdev);
347 #else
348 static inline int vhost_reset_device(struct vhost_dev *hdev)
349 {
350     return -ENOSYS;
351 }
352 #endif /* CONFIG_VHOST */
353 
354 #endif
355