xref: /openbmc/qemu/include/hw/virtio/vhost.h (revision f4152040)
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 /* Generic structures common for any vhost based device. */
12 
13 struct vhost_inflight {
14     int fd;
15     void *addr;
16     uint64_t size;
17     uint64_t offset;
18     uint16_t queue_size;
19 };
20 
21 struct vhost_virtqueue {
22     int kick;
23     int call;
24     void *desc;
25     void *avail;
26     void *used;
27     int num;
28     unsigned long long desc_phys;
29     unsigned desc_size;
30     unsigned long long avail_phys;
31     unsigned avail_size;
32     unsigned long long used_phys;
33     unsigned used_size;
34     EventNotifier masked_notifier;
35     EventNotifier error_notifier;
36     EventNotifier masked_config_notifier;
37     struct vhost_dev *dev;
38 };
39 
40 typedef unsigned long vhost_log_chunk_t;
41 #define VHOST_LOG_PAGE 0x1000
42 #define VHOST_LOG_BITS (8 * sizeof(vhost_log_chunk_t))
43 #define VHOST_LOG_CHUNK (VHOST_LOG_PAGE * VHOST_LOG_BITS)
44 #define VHOST_INVALID_FEATURE_BIT   (0xff)
45 #define VHOST_QUEUE_NUM_CONFIG_INR 0
46 
47 struct vhost_log {
48     unsigned long long size;
49     int refcnt;
50     int fd;
51     vhost_log_chunk_t *log;
52 };
53 
54 struct vhost_dev;
55 struct vhost_iommu {
56     struct vhost_dev *hdev;
57     MemoryRegion *mr;
58     hwaddr iommu_offset;
59     IOMMUNotifier n;
60     QLIST_ENTRY(vhost_iommu) iommu_next;
61 };
62 
63 typedef struct VhostDevConfigOps {
64     /* Vhost device config space changed callback
65      */
66     int (*vhost_dev_config_notifier)(struct vhost_dev *dev);
67 } VhostDevConfigOps;
68 
69 struct vhost_memory;
70 
71 /**
72  * struct vhost_dev - common vhost_dev structure
73  * @vhost_ops: backend specific ops
74  * @config_ops: ops for config changes (see @vhost_dev_set_config_notifier)
75  */
76 struct vhost_dev {
77     VirtIODevice *vdev;
78     MemoryListener memory_listener;
79     MemoryListener iommu_listener;
80     struct vhost_memory *mem;
81     int n_mem_sections;
82     MemoryRegionSection *mem_sections;
83     int n_tmp_sections;
84     MemoryRegionSection *tmp_sections;
85     struct vhost_virtqueue *vqs;
86     unsigned int nvqs;
87     /* the first virtqueue which would be used by this vhost dev */
88     int vq_index;
89     /* one past the last vq index for the virtio device (not vhost) */
90     int vq_index_end;
91     /* if non-zero, minimum required value for max_queues */
92     int num_queues;
93     /**
94      * vhost feature handling requires matching the feature set
95      * offered by a backend which may be a subset of the total
96      * features eventually offered to the guest.
97      *
98      * @features: available features provided by the backend
99      * @acked_features: final negotiated features with front-end driver
100      *
101      * @backend_features: this is used in a couple of places to either
102      * store VHOST_USER_F_PROTOCOL_FEATURES to apply to
103      * VHOST_USER_SET_FEATURES or VHOST_NET_F_VIRTIO_NET_HDR. Its
104      * future use should be discouraged and the variable retired as
105      * its easy to confuse with the VirtIO backend_features.
106      */
107     uint64_t features;
108     uint64_t acked_features;
109     uint64_t backend_features;
110 
111     /**
112      * @protocol_features: is the vhost-user only feature set by
113      * VHOST_USER_SET_PROTOCOL_FEATURES. Protocol features are only
114      * negotiated if VHOST_USER_F_PROTOCOL_FEATURES has been offered
115      * by the backend (see @features).
116      */
117     uint64_t protocol_features;
118 
119     uint64_t max_queues;
120     uint64_t backend_cap;
121     /* @started: is the vhost device started? */
122     bool started;
123     bool log_enabled;
124     uint64_t log_size;
125     Error *migration_blocker;
126     const VhostOps *vhost_ops;
127     void *opaque;
128     struct vhost_log *log;
129     QLIST_ENTRY(vhost_dev) entry;
130     QLIST_HEAD(, vhost_iommu) iommu_list;
131     IOMMUNotifier n;
132     const VhostDevConfigOps *config_ops;
133 };
134 
135 extern const VhostOps kernel_ops;
136 extern const VhostOps user_ops;
137 extern const VhostOps vdpa_ops;
138 
139 struct vhost_net {
140     struct vhost_dev dev;
141     struct vhost_virtqueue vqs[2];
142     int backend;
143     NetClientState *nc;
144 };
145 
146 /**
147  * vhost_dev_init() - initialise the vhost interface
148  * @hdev: the common vhost_dev structure
149  * @opaque: opaque ptr passed to backend (vhost/vhost-user/vdpa)
150  * @backend_type: type of backend
151  * @busyloop_timeout: timeout for polling virtqueue
152  * @errp: error handle
153  *
154  * The initialisation of the vhost device will trigger the
155  * initialisation of the backend and potentially capability
156  * negotiation of backend interface. Configuration of the VirtIO
157  * itself won't happen until the interface is started.
158  *
159  * Return: 0 on success, non-zero on error while setting errp.
160  */
161 int vhost_dev_init(struct vhost_dev *hdev, void *opaque,
162                    VhostBackendType backend_type,
163                    uint32_t busyloop_timeout, Error **errp);
164 
165 /**
166  * vhost_dev_cleanup() - tear down and cleanup vhost interface
167  * @hdev: the common vhost_dev structure
168  */
169 void vhost_dev_cleanup(struct vhost_dev *hdev);
170 
171 /**
172  * vhost_dev_enable_notifiers() - enable event notifiers
173  * @hdev: common vhost_dev structure
174  * @vdev: the VirtIODevice structure
175  *
176  * Enable notifications directly to the vhost device rather than being
177  * triggered by QEMU itself. Notifications should be enabled before
178  * the vhost device is started via @vhost_dev_start.
179  *
180  * Return: 0 on success, < 0 on error.
181  */
182 int vhost_dev_enable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev);
183 
184 /**
185  * vhost_dev_disable_notifiers - disable event notifications
186  * @hdev: common vhost_dev structure
187  * @vdev: the VirtIODevice structure
188  *
189  * Disable direct notifications to vhost device.
190  */
191 void vhost_dev_disable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev);
192 bool vhost_config_pending(struct vhost_dev *hdev);
193 void vhost_config_mask(struct vhost_dev *hdev, VirtIODevice *vdev, bool mask);
194 
195 /**
196  * vhost_dev_is_started() - report status of vhost device
197  * @hdev: common vhost_dev structure
198  *
199  * Return the started status of the vhost device
200  */
201 static inline bool vhost_dev_is_started(struct vhost_dev *hdev)
202 {
203     return hdev->started;
204 }
205 
206 /**
207  * vhost_dev_start() - start the vhost device
208  * @hdev: common vhost_dev structure
209  * @vdev: the VirtIODevice structure
210  * @vrings: true to have vrings enabled in this call
211  *
212  * Starts the vhost device. From this point VirtIO feature negotiation
213  * can start and the device can start processing VirtIO transactions.
214  *
215  * Return: 0 on success, < 0 on error.
216  */
217 int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev, bool vrings);
218 
219 /**
220  * vhost_dev_stop() - stop the vhost device
221  * @hdev: common vhost_dev structure
222  * @vdev: the VirtIODevice structure
223  * @vrings: true to have vrings disabled in this call
224  *
225  * Stop the vhost device. After the device is stopped the notifiers
226  * can be disabled (@vhost_dev_disable_notifiers) and the device can
227  * be torn down (@vhost_dev_cleanup).
228  */
229 void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev, bool vrings);
230 
231 /**
232  * DOC: vhost device configuration handling
233  *
234  * The VirtIO device configuration space is used for rarely changing
235  * or initialisation time parameters. The configuration can be updated
236  * by either the guest driver or the device itself. If the device can
237  * change the configuration over time the vhost handler should
238  * register a @VhostDevConfigOps structure with
239  * @vhost_dev_set_config_notifier so the guest can be notified. Some
240  * devices register a handler anyway and will signal an error if an
241  * unexpected config change happens.
242  */
243 
244 /**
245  * vhost_dev_get_config() - fetch device configuration
246  * @hdev: common vhost_dev_structure
247  * @config: pointer to device appropriate config structure
248  * @config_len: size of device appropriate config structure
249  *
250  * Return: 0 on success, < 0 on error while setting errp
251  */
252 int vhost_dev_get_config(struct vhost_dev *hdev, uint8_t *config,
253                          uint32_t config_len, Error **errp);
254 
255 /**
256  * vhost_dev_set_config() - set device configuration
257  * @hdev: common vhost_dev_structure
258  * @data: pointer to data to set
259  * @offset: offset into configuration space
260  * @size: length of set
261  * @flags: @VhostSetConfigType flags
262  *
263  * By use of @offset/@size a subset of the configuration space can be
264  * written to. The @flags are used to indicate if it is a normal
265  * transaction or related to migration.
266  *
267  * Return: 0 on success, non-zero on error
268  */
269 int vhost_dev_set_config(struct vhost_dev *dev, const uint8_t *data,
270                          uint32_t offset, uint32_t size, uint32_t flags);
271 
272 /**
273  * vhost_dev_set_config_notifier() - register VhostDevConfigOps
274  * @hdev: common vhost_dev_structure
275  * @ops: notifier ops
276  *
277  * If the device is expected to change configuration a notifier can be
278  * setup to handle the case.
279  */
280 void vhost_dev_set_config_notifier(struct vhost_dev *dev,
281                                    const VhostDevConfigOps *ops);
282 
283 
284 /* Test and clear masked event pending status.
285  * Should be called after unmask to avoid losing events.
286  */
287 bool vhost_virtqueue_pending(struct vhost_dev *hdev, int n);
288 
289 /* Mask/unmask events from this vq.
290  */
291 void vhost_virtqueue_mask(struct vhost_dev *hdev, VirtIODevice *vdev, int n,
292                           bool mask);
293 
294 /**
295  * vhost_get_features() - return a sanitised set of feature bits
296  * @hdev: common vhost_dev structure
297  * @feature_bits: pointer to terminated table of feature bits
298  * @features: original feature set
299  *
300  * This returns a set of features bits that is an intersection of what
301  * is supported by the vhost backend (hdev->features), the supported
302  * feature_bits and the requested feature set.
303  */
304 uint64_t vhost_get_features(struct vhost_dev *hdev, const int *feature_bits,
305                             uint64_t features);
306 
307 /**
308  * vhost_ack_features() - set vhost acked_features
309  * @hdev: common vhost_dev structure
310  * @feature_bits: pointer to terminated table of feature bits
311  * @features: requested feature set
312  *
313  * This sets the internal hdev->acked_features to the intersection of
314  * the backends advertised features and the supported feature_bits.
315  */
316 void vhost_ack_features(struct vhost_dev *hdev, const int *feature_bits,
317                         uint64_t features);
318 bool vhost_has_free_slot(void);
319 
320 int vhost_net_set_backend(struct vhost_dev *hdev,
321                           struct vhost_vring_file *file);
322 
323 int vhost_device_iotlb_miss(struct vhost_dev *dev, uint64_t iova, int write);
324 
325 int vhost_virtqueue_start(struct vhost_dev *dev, struct VirtIODevice *vdev,
326                           struct vhost_virtqueue *vq, unsigned idx);
327 void vhost_virtqueue_stop(struct vhost_dev *dev, struct VirtIODevice *vdev,
328                           struct vhost_virtqueue *vq, unsigned idx);
329 
330 void vhost_dev_reset_inflight(struct vhost_inflight *inflight);
331 void vhost_dev_free_inflight(struct vhost_inflight *inflight);
332 void vhost_dev_save_inflight(struct vhost_inflight *inflight, QEMUFile *f);
333 int vhost_dev_load_inflight(struct vhost_inflight *inflight, QEMUFile *f);
334 int vhost_dev_prepare_inflight(struct vhost_dev *hdev, VirtIODevice *vdev);
335 int vhost_dev_set_inflight(struct vhost_dev *dev,
336                            struct vhost_inflight *inflight);
337 int vhost_dev_get_inflight(struct vhost_dev *dev, uint16_t queue_size,
338                            struct vhost_inflight *inflight);
339 bool vhost_dev_has_iommu(struct vhost_dev *dev);
340 #endif
341