xref: /openbmc/qemu/include/hw/virtio/vhost.h (revision 701bff24)
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     struct vhost_dev *dev;
37 };
38 
39 typedef unsigned long vhost_log_chunk_t;
40 #define VHOST_LOG_PAGE 0x1000
41 #define VHOST_LOG_BITS (8 * sizeof(vhost_log_chunk_t))
42 #define VHOST_LOG_CHUNK (VHOST_LOG_PAGE * VHOST_LOG_BITS)
43 #define VHOST_INVALID_FEATURE_BIT   (0xff)
44 
45 struct vhost_log {
46     unsigned long long size;
47     int refcnt;
48     int fd;
49     vhost_log_chunk_t *log;
50 };
51 
52 struct vhost_dev;
53 struct vhost_iommu {
54     struct vhost_dev *hdev;
55     MemoryRegion *mr;
56     hwaddr iommu_offset;
57     IOMMUNotifier n;
58     QLIST_ENTRY(vhost_iommu) iommu_next;
59 };
60 
61 typedef struct VhostDevConfigOps {
62     /* Vhost device config space changed callback
63      */
64     int (*vhost_dev_config_notifier)(struct vhost_dev *dev);
65 } VhostDevConfigOps;
66 
67 struct vhost_memory;
68 
69 /**
70  * struct vhost_dev - common vhost_dev structure
71  * @vhost_ops: backend specific ops
72  * @config_ops: ops for config changes (see @vhost_dev_set_config_notifier)
73  */
74 struct vhost_dev {
75     VirtIODevice *vdev;
76     MemoryListener memory_listener;
77     MemoryListener iommu_listener;
78     struct vhost_memory *mem;
79     int n_mem_sections;
80     MemoryRegionSection *mem_sections;
81     int n_tmp_sections;
82     MemoryRegionSection *tmp_sections;
83     struct vhost_virtqueue *vqs;
84     unsigned int nvqs;
85     /* the first virtqueue which would be used by this vhost dev */
86     int vq_index;
87     /* one past the last vq index for the virtio device (not vhost) */
88     int vq_index_end;
89     /* if non-zero, minimum required value for max_queues */
90     int num_queues;
91     uint64_t features;
92     /** @acked_features: final set of negotiated features */
93     uint64_t acked_features;
94     /** @backend_features: backend specific feature bits */
95     uint64_t backend_features;
96     /** @protocol_features: final negotiated protocol features */
97     uint64_t protocol_features;
98     uint64_t max_queues;
99     uint64_t backend_cap;
100     /* @started: is the vhost device started? */
101     bool started;
102     bool log_enabled;
103     uint64_t log_size;
104     Error *migration_blocker;
105     const VhostOps *vhost_ops;
106     void *opaque;
107     struct vhost_log *log;
108     QLIST_ENTRY(vhost_dev) entry;
109     QLIST_HEAD(, vhost_iommu) iommu_list;
110     IOMMUNotifier n;
111     const VhostDevConfigOps *config_ops;
112 };
113 
114 extern const VhostOps kernel_ops;
115 extern const VhostOps user_ops;
116 extern const VhostOps vdpa_ops;
117 
118 struct vhost_net {
119     struct vhost_dev dev;
120     struct vhost_virtqueue vqs[2];
121     int backend;
122     NetClientState *nc;
123 };
124 
125 /**
126  * vhost_dev_init() - initialise the vhost interface
127  * @hdev: the common vhost_dev structure
128  * @opaque: opaque ptr passed to backend (vhost/vhost-user/vdpa)
129  * @backend_type: type of backend
130  * @busyloop_timeout: timeout for polling virtqueue
131  * @errp: error handle
132  *
133  * The initialisation of the vhost device will trigger the
134  * initialisation of the backend and potentially capability
135  * negotiation of backend interface. Configuration of the VirtIO
136  * itself won't happen until the interface is started.
137  *
138  * Return: 0 on success, non-zero on error while setting errp.
139  */
140 int vhost_dev_init(struct vhost_dev *hdev, void *opaque,
141                    VhostBackendType backend_type,
142                    uint32_t busyloop_timeout, Error **errp);
143 
144 /**
145  * vhost_dev_cleanup() - tear down and cleanup vhost interface
146  * @hdev: the common vhost_dev structure
147  */
148 void vhost_dev_cleanup(struct vhost_dev *hdev);
149 
150 /**
151  * vhost_dev_enable_notifiers() - enable event notifiers
152  * @hdev: common vhost_dev structure
153  * @vdev: the VirtIODevice structure
154  *
155  * Enable notifications directly to the vhost device rather than being
156  * triggered by QEMU itself. Notifications should be enabled before
157  * the vhost device is started via @vhost_dev_start.
158  *
159  * Return: 0 on success, < 0 on error.
160  */
161 int vhost_dev_enable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev);
162 
163 /**
164  * vhost_dev_disable_notifiers - disable event notifications
165  * @hdev: common vhost_dev structure
166  * @vdev: the VirtIODevice structure
167  *
168  * Disable direct notifications to vhost device.
169  */
170 void vhost_dev_disable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev);
171 
172 /**
173  * vhost_dev_is_started() - report status of vhost device
174  * @hdev: common vhost_dev structure
175  *
176  * Return the started status of the vhost device
177  */
178 static inline bool vhost_dev_is_started(struct vhost_dev *hdev)
179 {
180     return hdev->started;
181 }
182 
183 /**
184  * vhost_dev_start() - start the vhost device
185  * @hdev: common vhost_dev structure
186  * @vdev: the VirtIODevice structure
187  *
188  * Starts the vhost device. From this point VirtIO feature negotiation
189  * can start and the device can start processing VirtIO transactions.
190  *
191  * Return: 0 on success, < 0 on error.
192  */
193 int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev);
194 
195 /**
196  * vhost_dev_stop() - stop the vhost device
197  * @hdev: common vhost_dev structure
198  * @vdev: the VirtIODevice structure
199  *
200  * Stop the vhost device. After the device is stopped the notifiers
201  * can be disabled (@vhost_dev_disable_notifiers) and the device can
202  * be torn down (@vhost_dev_cleanup).
203  */
204 void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev);
205 
206 /**
207  * DOC: vhost device configuration handling
208  *
209  * The VirtIO device configuration space is used for rarely changing
210  * or initialisation time parameters. The configuration can be updated
211  * by either the guest driver or the device itself. If the device can
212  * change the configuration over time the vhost handler should
213  * register a @VhostDevConfigOps structure with
214  * @vhost_dev_set_config_notifier so the guest can be notified. Some
215  * devices register a handler anyway and will signal an error if an
216  * unexpected config change happens.
217  */
218 
219 /**
220  * vhost_dev_get_config() - fetch device configuration
221  * @hdev: common vhost_dev_structure
222  * @config: pointer to device appropriate config structure
223  * @config_len: size of device appropriate config structure
224  *
225  * Return: 0 on success, < 0 on error while setting errp
226  */
227 int vhost_dev_get_config(struct vhost_dev *hdev, uint8_t *config,
228                          uint32_t config_len, Error **errp);
229 
230 /**
231  * vhost_dev_set_config() - set device configuration
232  * @hdev: common vhost_dev_structure
233  * @data: pointer to data to set
234  * @offset: offset into configuration space
235  * @size: length of set
236  * @flags: @VhostSetConfigType flags
237  *
238  * By use of @offset/@size a subset of the configuration space can be
239  * written to. The @flags are used to indicate if it is a normal
240  * transaction or related to migration.
241  *
242  * Return: 0 on success, non-zero on error
243  */
244 int vhost_dev_set_config(struct vhost_dev *dev, const uint8_t *data,
245                          uint32_t offset, uint32_t size, uint32_t flags);
246 
247 /**
248  * vhost_dev_set_config_notifier() - register VhostDevConfigOps
249  * @hdev: common vhost_dev_structure
250  * @ops: notifier ops
251  *
252  * If the device is expected to change configuration a notifier can be
253  * setup to handle the case.
254  */
255 void vhost_dev_set_config_notifier(struct vhost_dev *dev,
256                                    const VhostDevConfigOps *ops);
257 
258 
259 /* Test and clear masked event pending status.
260  * Should be called after unmask to avoid losing events.
261  */
262 bool vhost_virtqueue_pending(struct vhost_dev *hdev, int n);
263 
264 /* Mask/unmask events from this vq.
265  */
266 void vhost_virtqueue_mask(struct vhost_dev *hdev, VirtIODevice *vdev, int n,
267                           bool mask);
268 
269 /**
270  * vhost_get_features() - return a sanitised set of feature bits
271  * @hdev: common vhost_dev structure
272  * @feature_bits: pointer to terminated table of feature bits
273  * @features: original feature set
274  *
275  * This returns a set of features bits that is an intersection of what
276  * is supported by the vhost backend (hdev->features), the supported
277  * feature_bits and the requested feature set.
278  */
279 uint64_t vhost_get_features(struct vhost_dev *hdev, const int *feature_bits,
280                             uint64_t features);
281 
282 /**
283  * vhost_ack_features() - set vhost acked_features
284  * @hdev: common vhost_dev structure
285  * @feature_bits: pointer to terminated table of feature bits
286  * @features: requested feature set
287  *
288  * This sets the internal hdev->acked_features to the intersection of
289  * the backends advertised features and the supported feature_bits.
290  */
291 void vhost_ack_features(struct vhost_dev *hdev, const int *feature_bits,
292                         uint64_t features);
293 bool vhost_has_free_slot(void);
294 
295 int vhost_net_set_backend(struct vhost_dev *hdev,
296                           struct vhost_vring_file *file);
297 
298 int vhost_device_iotlb_miss(struct vhost_dev *dev, uint64_t iova, int write);
299 
300 void vhost_dev_reset_inflight(struct vhost_inflight *inflight);
301 void vhost_dev_free_inflight(struct vhost_inflight *inflight);
302 void vhost_dev_save_inflight(struct vhost_inflight *inflight, QEMUFile *f);
303 int vhost_dev_load_inflight(struct vhost_inflight *inflight, QEMUFile *f);
304 int vhost_dev_prepare_inflight(struct vhost_dev *hdev, VirtIODevice *vdev);
305 int vhost_dev_set_inflight(struct vhost_dev *dev,
306                            struct vhost_inflight *inflight);
307 int vhost_dev_get_inflight(struct vhost_dev *dev, uint16_t queue_size,
308                            struct vhost_inflight *inflight);
309 #endif
310