virtio.h

  1/* SPDX-License-Identifier: GPL-2.0 */
  2#ifndef _LINUX_VIRTIO_H
  3#define _LINUX_VIRTIO_H
  4/* Everything a virtio driver needs to work with any particular virtio
  5 * implementation. */
  6#include <linux/types.h>
  7#include <linux/scatterlist.h>
  8#include <linux/spinlock.h>
  9#include <linux/device.h>
 10#include <linux/mod_devicetable.h>
 11#include <linux/gfp.h>
 12#include <linux/dma-mapping.h>
 13#include <linux/completion.h>
 14#include <linux/virtio_features.h>
 15
 16struct module;
 17
 18/**
 19 * struct virtqueue - a queue to register buffers for sending or receiving.
 20 * @list: the chain of virtqueues for this device
 21 * @callback: the function to call when buffers are consumed (can be NULL).
 22 * @name: the name of this virtqueue (mainly for debugging)
 23 * @vdev: the virtio device this queue was created for.
 24 * @priv: a pointer for the virtqueue implementation to use.
 25 * @index: the zero-based ordinal number for this queue.
 26 * @num_free: number of elements we expect to be able to fit.
 27 * @num_max: the maximum number of elements supported by the device.
 28 * @reset: vq is in reset state or not.
 29 *
 30 * A note on @num_free: with indirect buffers, each buffer needs one
 31 * element in the queue, otherwise a buffer will need one element per
 32 * sg element.
 33 */
 34struct virtqueue {
 35	struct list_head list;
 36	void (*callback)(struct virtqueue *vq);
 37	const char *name;
 38	struct virtio_device *vdev;
 39	unsigned int index;
 40	unsigned int num_free;
 41	unsigned int num_max;
 42	bool reset;
 43	void *priv;
 44};
 45
 46struct vduse_iova_domain;
 47
 48union virtio_map {
 49	/* Device that performs DMA */
 50	struct device *dma_dev;
 51	/* VDUSE specific mapping data */
 52	struct vduse_iova_domain *iova_domain;
 53};
 54
 55int virtqueue_add_outbuf(struct virtqueue *vq,
 56			 struct scatterlist sg[], unsigned int num,
 57			 void *data,
 58			 gfp_t gfp);
 59
 60int virtqueue_add_inbuf(struct virtqueue *vq,
 61			struct scatterlist sg[], unsigned int num,
 62			void *data,
 63			gfp_t gfp);
 64
 65int virtqueue_add_inbuf_ctx(struct virtqueue *vq,
 66			    struct scatterlist sg[], unsigned int num,
 67			    void *data,
 68			    void *ctx,
 69			    gfp_t gfp);
 70
 71int virtqueue_add_inbuf_premapped(struct virtqueue *vq,
 72				  struct scatterlist *sg, unsigned int num,
 73				  void *data,
 74				  void *ctx,
 75				  gfp_t gfp);
 76
 77int virtqueue_add_outbuf_premapped(struct virtqueue *vq,
 78				   struct scatterlist *sg, unsigned int num,
 79				   void *data,
 80				   gfp_t gfp);
 81
 82int virtqueue_add_sgs(struct virtqueue *vq,
 83		      struct scatterlist *sgs[],
 84		      unsigned int out_sgs,
 85		      unsigned int in_sgs,
 86		      void *data,
 87		      gfp_t gfp);
 88
 89struct device *virtqueue_dma_dev(struct virtqueue *vq);
 90
 91bool virtqueue_kick(struct virtqueue *vq);
 92
 93bool virtqueue_kick_prepare(struct virtqueue *vq);
 94
 95bool virtqueue_notify(struct virtqueue *vq);
 96
 97void *virtqueue_get_buf(struct virtqueue *vq, unsigned int *len);
 98
 99void *virtqueue_get_buf_ctx(struct virtqueue *vq, unsigned int *len,
100			    void **ctx);
101
102void virtqueue_disable_cb(struct virtqueue *vq);
103
104bool virtqueue_enable_cb(struct virtqueue *vq);
105
106unsigned virtqueue_enable_cb_prepare(struct virtqueue *vq);
107
108bool virtqueue_poll(struct virtqueue *vq, unsigned);
109
110bool virtqueue_enable_cb_delayed(struct virtqueue *vq);
111
112void *virtqueue_detach_unused_buf(struct virtqueue *vq);
113
114unsigned int virtqueue_get_vring_size(const struct virtqueue *vq);
115
116bool virtqueue_is_broken(const struct virtqueue *vq);
117
118const struct vring *virtqueue_get_vring(const struct virtqueue *vq);
119dma_addr_t virtqueue_get_desc_addr(const struct virtqueue *vq);
120dma_addr_t virtqueue_get_avail_addr(const struct virtqueue *vq);
121dma_addr_t virtqueue_get_used_addr(const struct virtqueue *vq);
122
123int virtqueue_resize(struct virtqueue *vq, u32 num,
124		     void (*recycle)(struct virtqueue *vq, void *buf),
125		     void (*recycle_done)(struct virtqueue *vq));
126int virtqueue_reset(struct virtqueue *vq,
127		    void (*recycle)(struct virtqueue *vq, void *buf),
128		    void (*recycle_done)(struct virtqueue *vq));
129
130struct virtio_admin_cmd {
131	__le16 opcode;
132	__le16 group_type;
133	__le64 group_member_id;
134	struct scatterlist *data_sg;
135	struct scatterlist *result_sg;
136	struct completion completion;
137	u32 result_sg_size;
138	int ret;
139};
140
141/**
142 * struct virtio_device - representation of a device using virtio
143 * @index: unique position on the virtio bus
144 * @failed: saved value for VIRTIO_CONFIG_S_FAILED bit (for restore)
145 * @config_core_enabled: configuration change reporting enabled by core
146 * @config_driver_disabled: configuration change reporting disabled by
147 *                          a driver
148 * @config_change_pending: configuration change reported while disabled
149 * @config_lock: protects configuration change reporting
150 * @vqs_list_lock: protects @vqs.
151 * @dev: underlying device.
152 * @id: the device type identification (used to match it with a driver).
153 * @config: the configuration ops for this device.
154 * @vringh_config: configuration ops for host vrings.
155 * @vqs: the list of virtqueues for this device.
156 * @features: the 64 lower features supported by both driver and device.
157 * @features_array: the full features space supported by both driver and
158 *		    device.
159 * @priv: private pointer for the driver's use.
160 * @debugfs_dir: debugfs directory entry.
161 * @debugfs_filter_features: features to be filtered set by debugfs.
162 */
163struct virtio_device {
164	int index;
165	bool failed;
166	bool config_core_enabled;
167	bool config_driver_disabled;
168	bool config_change_pending;
169	spinlock_t config_lock;
170	spinlock_t vqs_list_lock;
171	struct device dev;
172	struct virtio_device_id id;
173	const struct virtio_config_ops *config;
174	const struct vringh_config_ops *vringh_config;
175	const struct virtio_map_ops *map;
176	struct list_head vqs;
177	VIRTIO_DECLARE_FEATURES(features);
178	void *priv;
179	union virtio_map vmap;
180#ifdef CONFIG_VIRTIO_DEBUG
181	struct dentry *debugfs_dir;
182	u64 debugfs_filter_features[VIRTIO_FEATURES_U64S];
183#endif
184};
185
186#define dev_to_virtio(_dev)	container_of_const(_dev, struct virtio_device, dev)
187
188void virtio_add_status(struct virtio_device *dev, unsigned int status);
189int register_virtio_device(struct virtio_device *dev);
190void unregister_virtio_device(struct virtio_device *dev);
191bool is_virtio_device(struct device *dev);
192
193void virtio_break_device(struct virtio_device *dev);
194void __virtio_unbreak_device(struct virtio_device *dev);
195
196void __virtqueue_break(struct virtqueue *_vq);
197void __virtqueue_unbreak(struct virtqueue *_vq);
198
199void virtio_config_changed(struct virtio_device *dev);
200
201void virtio_config_driver_disable(struct virtio_device *dev);
202void virtio_config_driver_enable(struct virtio_device *dev);
203
204#ifdef CONFIG_PM_SLEEP
205int virtio_device_freeze(struct virtio_device *dev);
206int virtio_device_restore(struct virtio_device *dev);
207#endif
208void virtio_reset_device(struct virtio_device *dev);
209int virtio_device_reset_prepare(struct virtio_device *dev);
210int virtio_device_reset_done(struct virtio_device *dev);
211
212size_t virtio_max_dma_size(const struct virtio_device *vdev);
213
214#define virtio_device_for_each_vq(vdev, vq) \
215	list_for_each_entry(vq, &(vdev)->vqs, list)
216
217/**
218 * struct virtio_driver - operations for a virtio I/O driver
219 * @driver: underlying device driver (populate name).
220 * @id_table: the ids serviced by this driver.
221 * @feature_table: an array of feature numbers supported by this driver.
222 * @feature_table_size: number of entries in the feature table array.
223 * @feature_table_legacy: same as feature_table but when working in legacy mode.
224 * @feature_table_size_legacy: number of entries in feature table legacy array.
225 * @validate: the function to call to validate features and config space.
226 *            Returns 0 or -errno.
227 * @probe: the function to call when a device is found.  Returns 0 or -errno.
228 * @scan: optional function to call after successful probe; intended
229 *    for virtio-scsi to invoke a scan.
230 * @remove: the function to call when a device is removed.
231 * @config_changed: optional function to call when the device configuration
232 *    changes; may be called in interrupt context.
233 * @freeze: optional function to call during suspend/hibernation.
234 * @restore: optional function to call on resume.
235 * @reset_prepare: optional function to call when a transport specific reset
236 *    occurs.
237 * @reset_done: optional function to call after transport specific reset
238 *    operation has finished.
239 * @shutdown: synchronize with the device on shutdown. If provided, replaces
240 *    the virtio core implementation.
241 */
242struct virtio_driver {
243	struct device_driver driver;
244	const struct virtio_device_id *id_table;
245	const unsigned int *feature_table;
246	unsigned int feature_table_size;
247	const unsigned int *feature_table_legacy;
248	unsigned int feature_table_size_legacy;
249	int (*validate)(struct virtio_device *dev);
250	int (*probe)(struct virtio_device *dev);
251	void (*scan)(struct virtio_device *dev);
252	void (*remove)(struct virtio_device *dev);
253	void (*config_changed)(struct virtio_device *dev);
254	int (*freeze)(struct virtio_device *dev);
255	int (*restore)(struct virtio_device *dev);
256	int (*reset_prepare)(struct virtio_device *dev);
257	int (*reset_done)(struct virtio_device *dev);
258	void (*shutdown)(struct virtio_device *dev);
259};
260
261#define drv_to_virtio(__drv)	container_of_const(__drv, struct virtio_driver, driver)
262
263/* use a macro to avoid include chaining to get THIS_MODULE */
264#define register_virtio_driver(drv) \
265	__register_virtio_driver(drv, THIS_MODULE)
266int __register_virtio_driver(struct virtio_driver *drv, struct module *owner);
267void unregister_virtio_driver(struct virtio_driver *drv);
268
269/* module_virtio_driver() - Helper macro for drivers that don't do
270 * anything special in module init/exit.  This eliminates a lot of
271 * boilerplate.  Each module may only use this macro once, and
272 * calling it replaces module_init() and module_exit()
273 */
274#define module_virtio_driver(__virtio_driver) \
275	module_driver(__virtio_driver, register_virtio_driver, \
276			unregister_virtio_driver)
277
278
279void *virtqueue_map_alloc_coherent(struct virtio_device *vdev,
280				   union virtio_map mapping_token,
281				   size_t size, dma_addr_t *dma_handle,
282				   gfp_t gfp);
283
284void virtqueue_map_free_coherent(struct virtio_device *vdev,
285				 union virtio_map mapping_token,
286				 size_t size, void *vaddr,
287				 dma_addr_t dma_handle);
288
289dma_addr_t virtqueue_map_page_attrs(const struct virtqueue *_vq,
290				    struct page *page,
291				    unsigned long offset,
292				    size_t size,
293				    enum dma_data_direction dir,
294				    unsigned long attrs);
295
296void virtqueue_unmap_page_attrs(const struct virtqueue *_vq,
297				dma_addr_t dma_handle,
298				size_t size, enum dma_data_direction dir,
299				unsigned long attrs);
300
301dma_addr_t virtqueue_map_single_attrs(const struct virtqueue *_vq, void *ptr, size_t size,
302					  enum dma_data_direction dir, unsigned long attrs);
303void virtqueue_unmap_single_attrs(const struct virtqueue *_vq, dma_addr_t addr,
304				      size_t size, enum dma_data_direction dir,
305				      unsigned long attrs);
306int virtqueue_map_mapping_error(const struct virtqueue *_vq, dma_addr_t addr);
307
308bool virtqueue_map_need_sync(const struct virtqueue *_vq, dma_addr_t addr);
309void virtqueue_map_sync_single_range_for_cpu(const struct virtqueue *_vq, dma_addr_t addr,
310					     unsigned long offset, size_t size,
311					     enum dma_data_direction dir);
312void virtqueue_map_sync_single_range_for_device(const struct virtqueue *_vq, dma_addr_t addr,
313						unsigned long offset, size_t size,
314						enum dma_data_direction dir);
315
316#ifdef CONFIG_VIRTIO_DEBUG
317void virtio_debug_device_init(struct virtio_device *dev);
318void virtio_debug_device_exit(struct virtio_device *dev);
319void virtio_debug_device_filter_features(struct virtio_device *dev);
320void virtio_debug_init(void);
321void virtio_debug_exit(void);
322#else
323static inline void virtio_debug_device_init(struct virtio_device *dev)
324{
325}
326
327static inline void virtio_debug_device_exit(struct virtio_device *dev)
328{
329}
330
331static inline void virtio_debug_device_filter_features(struct virtio_device *dev)
332{
333}
334
335static inline void virtio_debug_init(void)
336{
337}
338
339static inline void virtio_debug_exit(void)
340{
341}
342#endif
343
344#endif /* _LINUX_VIRTIO_H */