[thirdparty/linux.git] / drivers / vhost / vhost.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _VHOST_H
#define _VHOST_H

#include <linux/eventfd.h>
#include <linux/vhost.h>
#include <linux/mm.h>
#include <linux/mutex.h>
#include <linux/poll.h>
#include <linux/file.h>
#include <linux/uio.h>
#include <linux/virtio_config.h>
#include <linux/virtio_ring.h>
#include <linux/atomic.h>
#include <linux/vhost_iotlb.h>

struct vhost_work;
typedef void (*vhost_work_fn_t)(struct vhost_work *work);

#define VHOST_WORK_QUEUED 1
struct vhost_work {
	struct llist_node	  node;
	vhost_work_fn_t		  fn;
	unsigned long		  flags;
};

/* Poll a file (eventfd or socket) */
/* Note: there's nothing vhost specific about this structure. */
struct vhost_poll {
	poll_table                table;
	wait_queue_head_t        *wqh;
	wait_queue_entry_t              wait;
	struct vhost_work	  work;
	__poll_t		  mask;
	struct vhost_dev	 *dev;
};

void vhost_work_init(struct vhost_work *work, vhost_work_fn_t fn);
void vhost_work_queue(struct vhost_dev *dev, struct vhost_work *work);
bool vhost_has_work(struct vhost_dev *dev);

void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn,
		     __poll_t mask, struct vhost_dev *dev);
int vhost_poll_start(struct vhost_poll *poll, struct file *file);
void vhost_poll_stop(struct vhost_poll *poll);
void vhost_poll_flush(struct vhost_poll *poll);
void vhost_poll_queue(struct vhost_poll *poll);
void vhost_work_flush(struct vhost_dev *dev, struct vhost_work *work);
long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp);

struct vhost_log {
	u64 addr;
	u64 len;
};

enum vhost_uaddr_type {
	VHOST_ADDR_DESC = 0,
	VHOST_ADDR_AVAIL = 1,
	VHOST_ADDR_USED = 2,
	VHOST_NUM_ADDRS = 3,
};

/* The virtqueue structure describes a queue attached to a device. */
struct vhost_virtqueue {
	struct vhost_dev *dev;

	/* The actual ring of buffers. */
	struct mutex mutex;
	unsigned int num;
	struct vring_desc __user *desc;
	struct vring_avail __user *avail;
	struct vring_used __user *used;
	const struct vhost_iotlb_map *meta_iotlb[VHOST_NUM_ADDRS];
	struct file *kick;
	struct eventfd_ctx *call_ctx;
	struct eventfd_ctx *error_ctx;
	struct eventfd_ctx *log_ctx;

	struct vhost_poll poll;

	/* The routine to call when the Guest pings us, or timeout. */
	vhost_work_fn_t handle_kick;

	/* Last available index we saw. */
	u16 last_avail_idx;

	/* Caches available index value from user. */
	u16 avail_idx;

	/* Last index we used. */
	u16 last_used_idx;

	/* Used flags */
	u16 used_flags;

	/* Last used index value we have signalled on */
	u16 signalled_used;

	/* Last used index value we have signalled on */
	bool signalled_used_valid;

	/* Log writes to used structure. */
	bool log_used;
	u64 log_addr;

	struct iovec iov[UIO_MAXIOV];
	struct iovec iotlb_iov[64];
	struct iovec *indirect;
	struct vring_used_elem *heads;
	/* Protected by virtqueue mutex. */
	struct vhost_iotlb *umem;
	struct vhost_iotlb *iotlb;
	void *private_data;
	u64 acked_features;
	u64 acked_backend_features;
	/* Log write descriptors */
	void __user *log_base;
	struct vhost_log *log;

	/* Ring endianness. Defaults to legacy native endianness.
	 * Set to true when starting a modern virtio device. */
	bool is_le;
#ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY
	/* Ring endianness requested by userspace for cross-endian support. */
	bool user_be;
#endif
	u32 busyloop_timeout;
};

struct vhost_msg_node {
  union {
	  struct vhost_msg msg;
	  struct vhost_msg_v2 msg_v2;
  };
  struct vhost_virtqueue *vq;
  struct list_head node;
};

struct vhost_dev {
	struct mm_struct *mm;
	struct mutex mutex;
	struct vhost_virtqueue **vqs;
	int nvqs;
	struct eventfd_ctx *log_ctx;
	struct llist_head work_list;
	struct task_struct *worker;
	struct vhost_iotlb *umem;
	struct vhost_iotlb *iotlb;
	spinlock_t iotlb_lock;
	struct list_head read_list;
	struct list_head pending_list;
	wait_queue_head_t wait;
	int iov_limit;
	int weight;
	int byte_weight;
	u64 kcov_handle;
	int (*msg_handler)(struct vhost_dev *dev,
			   struct vhost_iotlb_msg *msg);
};

bool vhost_exceeds_weight(struct vhost_virtqueue *vq, int pkts, int total_len);
void vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue **vqs,
		    int nvqs, int iov_limit, int weight, int byte_weight,
		    int (*msg_handler)(struct vhost_dev *dev,
				       struct vhost_iotlb_msg *msg));
long vhost_dev_set_owner(struct vhost_dev *dev);
bool vhost_dev_has_owner(struct vhost_dev *dev);
long vhost_dev_check_owner(struct vhost_dev *);
struct vhost_iotlb *vhost_dev_reset_owner_prepare(void);
void vhost_dev_reset_owner(struct vhost_dev *dev, struct vhost_iotlb *iotlb);
void vhost_dev_cleanup(struct vhost_dev *);
void vhost_dev_stop(struct vhost_dev *);
long vhost_dev_ioctl(struct vhost_dev *, unsigned int ioctl, void __user *argp);
long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp);
bool vhost_vq_access_ok(struct vhost_virtqueue *vq);
bool vhost_log_access_ok(struct vhost_dev *);

int vhost_get_vq_desc(struct vhost_virtqueue *,
		      struct iovec iov[], unsigned int iov_count,
		      unsigned int *out_num, unsigned int *in_num,
		      struct vhost_log *log, unsigned int *log_num);
void vhost_discard_vq_desc(struct vhost_virtqueue *, int n);

int vhost_vq_init_access(struct vhost_virtqueue *);
int vhost_add_used(struct vhost_virtqueue *, unsigned int head, int len);
int vhost_add_used_n(struct vhost_virtqueue *, struct vring_used_elem *heads,
		     unsigned count);
void vhost_add_used_and_signal(struct vhost_dev *, struct vhost_virtqueue *,
			       unsigned int id, int len);
void vhost_add_used_and_signal_n(struct vhost_dev *, struct vhost_virtqueue *,
			       struct vring_used_elem *heads, unsigned count);
void vhost_signal(struct vhost_dev *, struct vhost_virtqueue *);
void vhost_disable_notify(struct vhost_dev *, struct vhost_virtqueue *);
bool vhost_vq_avail_empty(struct vhost_dev *, struct vhost_virtqueue *);
bool vhost_enable_notify(struct vhost_dev *, struct vhost_virtqueue *);

int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log,
		    unsigned int log_num, u64 len,
		    struct iovec *iov, int count);
int vq_meta_prefetch(struct vhost_virtqueue *vq);

struct vhost_msg_node *vhost_new_msg(struct vhost_virtqueue *vq, int type);
void vhost_enqueue_msg(struct vhost_dev *dev,
		       struct list_head *head,
		       struct vhost_msg_node *node);
struct vhost_msg_node *vhost_dequeue_msg(struct vhost_dev *dev,
					 struct list_head *head);
__poll_t vhost_chr_poll(struct file *file, struct vhost_dev *dev,
			    poll_table *wait);
ssize_t vhost_chr_read_iter(struct vhost_dev *dev, struct iov_iter *to,
			    int noblock);
ssize_t vhost_chr_write_iter(struct vhost_dev *dev,
			     struct iov_iter *from);
int vhost_init_device_iotlb(struct vhost_dev *d, bool enabled);

void vhost_iotlb_map_free(struct vhost_iotlb *iotlb,
			  struct vhost_iotlb_map *map);

#define vq_err(vq, fmt, ...) do {                                  \
		pr_debug(pr_fmt(fmt), ##__VA_ARGS__);       \
		if ((vq)->error_ctx)                               \
				eventfd_signal((vq)->error_ctx, 1);\
	} while (0)

enum {
	VHOST_FEATURES = (1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) |
			 (1ULL << VIRTIO_RING_F_INDIRECT_DESC) |
			 (1ULL << VIRTIO_RING_F_EVENT_IDX) |
			 (1ULL << VHOST_F_LOG_ALL) |
			 (1ULL << VIRTIO_F_ANY_LAYOUT) |
			 (1ULL << VIRTIO_F_VERSION_1)
};

/**
 * vhost_vq_set_backend - Set backend.
 *
 * @vq            Virtqueue.
 * @private_data  The private data.
 *
 * Context: Need to call with vq->mutex acquired.
 */
static inline void vhost_vq_set_backend(struct vhost_virtqueue *vq,
					void *private_data)
{
	vq->private_data = private_data;
}

/**
 * vhost_vq_get_backend - Get backend.
 *
 * @vq            Virtqueue.
 *
 * Context: Need to call with vq->mutex acquired.
 * Return: Private data previously set with vhost_vq_set_backend.
 */
static inline void *vhost_vq_get_backend(struct vhost_virtqueue *vq)
{
	return vq->private_data;
}

static inline bool vhost_has_feature(struct vhost_virtqueue *vq, int bit)
{
	return vq->acked_features & (1ULL << bit);
}

static inline bool vhost_backend_has_feature(struct vhost_virtqueue *vq, int bit)
{
	return vq->acked_backend_features & (1ULL << bit);
}

#ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY
static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq)
{
	return vq->is_le;
}
#else
static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq)
{
	return virtio_legacy_is_little_endian() || vq->is_le;
}
#endif

/* Memory accessors */
static inline u16 vhost16_to_cpu(struct vhost_virtqueue *vq, __virtio16 val)
{
	return __virtio16_to_cpu(vhost_is_little_endian(vq), val);
}

static inline __virtio16 cpu_to_vhost16(struct vhost_virtqueue *vq, u16 val)
{
	return __cpu_to_virtio16(vhost_is_little_endian(vq), val);
}

static inline u32 vhost32_to_cpu(struct vhost_virtqueue *vq, __virtio32 val)
{
	return __virtio32_to_cpu(vhost_is_little_endian(vq), val);
}

static inline __virtio32 cpu_to_vhost32(struct vhost_virtqueue *vq, u32 val)
{
	return __cpu_to_virtio32(vhost_is_little_endian(vq), val);
}

static inline u64 vhost64_to_cpu(struct vhost_virtqueue *vq, __virtio64 val)
{
	return __virtio64_to_cpu(vhost_is_little_endian(vq), val);
}

static inline __virtio64 cpu_to_vhost64(struct vhost_virtqueue *vq, u64 val)
{
	return __cpu_to_virtio64(vhost_is_little_endian(vq), val);
}
#endif
Commit	Line	Data
b2441318	1	/* SPDX-License-Identifier: GPL-2.0 */
3a4d5c94 MT	2	#ifndef _VHOST_H
	3	#define _VHOST_H
	4
	5	#include <linux/eventfd.h>
	6	#include <linux/vhost.h>
	7	#include <linux/mm.h>
	8	#include <linux/mutex.h>
3a4d5c94 MT	9	#include <linux/poll.h>
3a4d5c94 MT	10	#include <linux/file.h>
3a4d5c94 MT	11	#include <linux/uio.h>
	12	#include <linux/virtio_config.h>
	13	#include <linux/virtio_ring.h>
60063497	14	#include <linux/atomic.h>
0bbe3066	15	#include <linux/vhost_iotlb.h>
3a4d5c94	16
c23f3445 TH	17	struct vhost_work;
	18	typedef void (vhost_work_fn_t)(struct vhost_work work);
	19
04b96e55	20	#define VHOST_WORK_QUEUED 1
c23f3445	21	struct vhost_work {
04b96e55	22	struct llist_node node;
c23f3445	23	vhost_work_fn_t fn;
04b96e55	24	unsigned long flags;
c23f3445 TH	25	};
c23f3445 TH	26
3a4d5c94 MT	27	/* Poll a file (eventfd or socket) */
	28	/* Note: there's nothing vhost specific about this structure. */
	29	struct vhost_poll {
	30	poll_table table;
	31	wait_queue_head_t *wqh;
ac6424b9	32	wait_queue_entry_t wait;
c23f3445	33	struct vhost_work work;
58e3b602	34	__poll_t mask;
c23f3445	35	struct vhost_dev *dev;
3a4d5c94 MT	36	};
3a4d5c94 MT	37
163049ae SH	38	void vhost_work_init(struct vhost_work *work, vhost_work_fn_t fn);
163049ae SH	39	void vhost_work_queue(struct vhost_dev dev, struct vhost_work work);
526d3e7f	40	bool vhost_has_work(struct vhost_dev *dev);
163049ae	41
c23f3445	42	void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn,
58e3b602	43	__poll_t mask, struct vhost_dev *dev);
2b8b328b	44	int vhost_poll_start(struct vhost_poll poll, struct file file);
3a4d5c94 MT	45	void vhost_poll_stop(struct vhost_poll *poll);
	46	void vhost_poll_flush(struct vhost_poll *poll);
	47	void vhost_poll_queue(struct vhost_poll *poll);
6ac1afbf	48	void vhost_work_flush(struct vhost_dev dev, struct vhost_work work);
26b36604	49	long vhost_vring_ioctl(struct vhost_dev d, unsigned int ioctl, void __user argp);
3a4d5c94 MT	50
	51	struct vhost_log {
	52	u64 addr;
	53	u64 len;
	54	};
	55
f8894913 JW	56	enum vhost_uaddr_type {
	57	VHOST_ADDR_DESC = 0,
	58	VHOST_ADDR_AVAIL = 1,
	59	VHOST_ADDR_USED = 2,
	60	VHOST_NUM_ADDRS = 3,
	61	};
	62
3a4d5c94 MT	63	/* The virtqueue structure describes a queue attached to a device. */
	64	struct vhost_virtqueue {
	65	struct vhost_dev *dev;
	66
	67	/* The actual ring of buffers. */
	68	struct mutex mutex;
	69	unsigned int num;
	70	struct vring_desc __user *desc;
	71	struct vring_avail __user *avail;
	72	struct vring_used __user *used;
0bbe3066	73	const struct vhost_iotlb_map *meta_iotlb[VHOST_NUM_ADDRS];
3a4d5c94	74	struct file *kick;
3a4d5c94 MT	75	struct eventfd_ctx *call_ctx;
	76	struct eventfd_ctx *error_ctx;
	77	struct eventfd_ctx *log_ctx;
	78
	79	struct vhost_poll poll;
	80
	81	/* The routine to call when the Guest pings us, or timeout. */
c23f3445	82	vhost_work_fn_t handle_kick;
3a4d5c94 MT	83
	84	/* Last available index we saw. */
	85	u16 last_avail_idx;
	86
	87	/* Caches available index value from user. */
	88	u16 avail_idx;
	89
	90	/* Last index we used. */
	91	u16 last_used_idx;
	92
	93	/* Used flags */
	94	u16 used_flags;
	95
8ea8cf89 MT	96	/* Last used index value we have signalled on */
	97	u16 signalled_used;
	98
	99	/* Last used index value we have signalled on */
	100	bool signalled_used_valid;
	101
3a4d5c94 MT	102	/* Log writes to used structure. */
	103	bool log_used;
	104	u64 log_addr;
	105
e0e9b406	106	struct iovec iov[UIO_MAXIOV];
6b1e6cc7	107	struct iovec iotlb_iov[64];
e0e9b406	108	struct iovec *indirect;
e0e9b406	109	struct vring_used_elem *heads;
22fa90c7	110	/* Protected by virtqueue mutex. */
0bbe3066 JW	111	struct vhost_iotlb *umem;
0bbe3066 JW	112	struct vhost_iotlb *iotlb;
22fa90c7	113	void *private_data;
bd82752a	114	u64 acked_features;
429711ae	115	u64 acked_backend_features;
3a4d5c94 MT	116	/* Log write descriptors */
3a4d5c94 MT	117	void __user *log_base;
e0e9b406	118	struct vhost_log *log;
2751c988 GK	119
	120	/* Ring endianness. Defaults to legacy native endianness.
	121	* Set to true when starting a modern virtio device. */
	122	bool is_le;
	123	#ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY
	124	/* Ring endianness requested by userspace for cross-endian support. */
	125	bool user_be;
	126	#endif
03088137	127	u32 busyloop_timeout;
3a4d5c94 MT	128	};
3a4d5c94 MT	129
6b1e6cc7	130	struct vhost_msg_node {
429711ae JW	131	union {
	132	struct vhost_msg msg;
	133	struct vhost_msg_v2 msg_v2;
	134	};
6b1e6cc7 JW	135	struct vhost_virtqueue *vq;
	136	struct list_head node;
	137	};
	138
3a4d5c94	139	struct vhost_dev {
3a4d5c94 MT	140	struct mm_struct *mm;
3a4d5c94 MT	141	struct mutex mutex;
3ab2e420	142	struct vhost_virtqueue **vqs;
3a4d5c94	143	int nvqs;
3a4d5c94	144	struct eventfd_ctx *log_ctx;
04b96e55	145	struct llist_head work_list;
c23f3445	146	struct task_struct *worker;
0bbe3066 JW	147	struct vhost_iotlb *umem;
0bbe3066 JW	148	struct vhost_iotlb *iotlb;
6b1e6cc7 JW	149	spinlock_t iotlb_lock;
	150	struct list_head read_list;
	151	struct list_head pending_list;
	152	wait_queue_head_t wait;
b46a0bf7	153	int iov_limit;
e82b9b07 JW	154	int weight;
e82b9b07 JW	155	int byte_weight;
8f6a7f96	156	u64 kcov_handle;
792a4f2e JW	157	int (msg_handler)(struct vhost_dev dev,
792a4f2e JW	158	struct vhost_iotlb_msg *msg);
3a4d5c94 MT	159	};
3a4d5c94 MT	160
e82b9b07	161	bool vhost_exceeds_weight(struct vhost_virtqueue *vq, int pkts, int total_len);
b46a0bf7	162	void vhost_dev_init(struct vhost_dev , struct vhost_virtqueue *vqs,
792a4f2e JW	163	int nvqs, int iov_limit, int weight, int byte_weight,
	164	int (msg_handler)(struct vhost_dev dev,
	165	struct vhost_iotlb_msg *msg));
54db63c2	166	long vhost_dev_set_owner(struct vhost_dev *dev);
05c05351	167	bool vhost_dev_has_owner(struct vhost_dev *dev);
3a4d5c94	168	long vhost_dev_check_owner(struct vhost_dev *);
0bbe3066 JW	169	struct vhost_iotlb *vhost_dev_reset_owner_prepare(void);
0bbe3066 JW	170	void vhost_dev_reset_owner(struct vhost_dev dev, struct vhost_iotlb iotlb);
f6f93f75	171	void vhost_dev_cleanup(struct vhost_dev *);
b211616d	172	void vhost_dev_stop(struct vhost_dev *);
935cdee7	173	long vhost_dev_ioctl(struct vhost_dev , unsigned int ioctl, void __user argp);
26b36604	174	long vhost_vring_ioctl(struct vhost_dev d, unsigned int ioctl, void __user argp);
ddd3d408 SH	175	bool vhost_vq_access_ok(struct vhost_virtqueue *vq);
ddd3d408 SH	176	bool vhost_log_access_ok(struct vhost_dev *);
3a4d5c94	177
47283bef	178	int vhost_get_vq_desc(struct vhost_virtqueue *,
d5675bd2 MT	179	struct iovec iov[], unsigned int iov_count,
	180	unsigned int out_num, unsigned int in_num,
	181	struct vhost_log log, unsigned int log_num);
8dd014ad	182	void vhost_discard_vq_desc(struct vhost_virtqueue *, int n);
3a4d5c94	183
80f7d030	184	int vhost_vq_init_access(struct vhost_virtqueue *);
3a4d5c94	185	int vhost_add_used(struct vhost_virtqueue *, unsigned int head, int len);
8dd014ad DS	186	int vhost_add_used_n(struct vhost_virtqueue , struct vring_used_elem heads,
8dd014ad DS	187	unsigned count);
3a4d5c94	188	void vhost_add_used_and_signal(struct vhost_dev , struct vhost_virtqueue ,
8dd014ad DS	189	unsigned int id, int len);
	190	void vhost_add_used_and_signal_n(struct vhost_dev , struct vhost_virtqueue ,
	191	struct vring_used_elem *heads, unsigned count);
	192	void vhost_signal(struct vhost_dev , struct vhost_virtqueue );
8ea8cf89	193	void vhost_disable_notify(struct vhost_dev , struct vhost_virtqueue );
d4a60603	194	bool vhost_vq_avail_empty(struct vhost_dev , struct vhost_virtqueue );
8ea8cf89	195	bool vhost_enable_notify(struct vhost_dev , struct vhost_virtqueue );
3a4d5c94 MT	196
3a4d5c94 MT	197	int vhost_log_write(struct vhost_virtqueue vq, struct vhost_log log,
cc5e7107 JW	198	unsigned int log_num, u64 len,
cc5e7107 JW	199	struct iovec *iov, int count);
9b5e830b	200	int vq_meta_prefetch(struct vhost_virtqueue *vq);
6b1e6cc7 JW	201
	202	struct vhost_msg_node vhost_new_msg(struct vhost_virtqueue vq, int type);
	203	void vhost_enqueue_msg(struct vhost_dev *dev,
	204	struct list_head *head,
	205	struct vhost_msg_node *node);
	206	struct vhost_msg_node vhost_dequeue_msg(struct vhost_dev dev,
	207	struct list_head *head);
afc9a42b	208	__poll_t vhost_chr_poll(struct file file, struct vhost_dev dev,
6b1e6cc7 JW	209	poll_table *wait);
	210	ssize_t vhost_chr_read_iter(struct vhost_dev dev, struct iov_iter to,
	211	int noblock);
	212	ssize_t vhost_chr_write_iter(struct vhost_dev *dev,
	213	struct iov_iter *from);
	214	int vhost_init_device_iotlb(struct vhost_dev *d, bool enabled);
3a4d5c94	215
0bbe3066 JW	216	void vhost_iotlb_map_free(struct vhost_iotlb *iotlb,
	217	struct vhost_iotlb_map *map);
	218
3a4d5c94 MT	219	#define vq_err(vq, fmt, ...) do { \
	220	pr_debug(pr_fmt(fmt), ##__VA_ARGS__); \
	221	if ((vq)->error_ctx) \
	222	eventfd_signal((vq)->error_ctx, 1);\
	223	} while (0)
	224
	225	enum {
8ea8cf89 MT	226	VHOST_FEATURES = (1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) \|
	227	(1ULL << VIRTIO_RING_F_INDIRECT_DESC) \|
	228	(1ULL << VIRTIO_RING_F_EVENT_IDX) \|
4e9fa50c MT	229	(1ULL << VHOST_F_LOG_ALL) \|
	230	(1ULL << VIRTIO_F_ANY_LAYOUT) \|
	231	(1ULL << VIRTIO_F_VERSION_1)
3a4d5c94 MT	232	};
3a4d5c94 MT	233
247643f8 EP	234	/**
	235	* vhost_vq_set_backend - Set backend.
	236	*
	237	* @vq Virtqueue.
	238	* @private_data The private data.
	239	*
	240	* Context: Need to call with vq->mutex acquired.
	241	*/
	242	static inline void vhost_vq_set_backend(struct vhost_virtqueue *vq,
	243	void *private_data)
	244	{
	245	vq->private_data = private_data;
	246	}
	247
	248	/**
	249	* vhost_vq_get_backend - Get backend.
	250	*
	251	* @vq Virtqueue.
	252	*
	253	* Context: Need to call with vq->mutex acquired.
	254	* Return: Private data previously set with vhost_vq_set_backend.
	255	*/
	256	static inline void vhost_vq_get_backend(struct vhost_virtqueue vq)
	257	{
	258	return vq->private_data;
	259	}
	260
bd82752a	261	static inline bool vhost_has_feature(struct vhost_virtqueue *vq, int bit)
3a4d5c94	262	{
bd82752a	263	return vq->acked_features & (1ULL << bit);
3a4d5c94	264	}
e05fd12b	265
429711ae JW	266	static inline bool vhost_backend_has_feature(struct vhost_virtqueue *vq, int bit)
	267	{
	268	return vq->acked_backend_features & (1ULL << bit);
	269	}
	270
e407f39a	271	#ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY
ab27c07f GK	272	static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq)
ab27c07f GK	273	{
2751c988	274	return vq->is_le;
ab27c07f	275	}
e407f39a MT	276	#else
	277	static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq)
	278	{
	279	return virtio_legacy_is_little_endian() \|\| vq->is_le;
	280	}
	281	#endif
ab27c07f	282
e05fd12b MT	283	/* Memory accessors */
	284	static inline u16 vhost16_to_cpu(struct vhost_virtqueue *vq, __virtio16 val)
	285	{
ab27c07f	286	return __virtio16_to_cpu(vhost_is_little_endian(vq), val);
e05fd12b MT	287	}
	288
	289	static inline __virtio16 cpu_to_vhost16(struct vhost_virtqueue *vq, u16 val)
	290	{
ab27c07f	291	return __cpu_to_virtio16(vhost_is_little_endian(vq), val);
e05fd12b MT	292	}
	293
	294	static inline u32 vhost32_to_cpu(struct vhost_virtqueue *vq, __virtio32 val)
	295	{
ab27c07f	296	return __virtio32_to_cpu(vhost_is_little_endian(vq), val);
e05fd12b MT	297	}
	298
	299	static inline __virtio32 cpu_to_vhost32(struct vhost_virtqueue *vq, u32 val)
	300	{
ab27c07f	301	return __cpu_to_virtio32(vhost_is_little_endian(vq), val);
e05fd12b MT	302	}
	303
	304	static inline u64 vhost64_to_cpu(struct vhost_virtqueue *vq, __virtio64 val)
	305	{
ab27c07f	306	return __virtio64_to_cpu(vhost_is_little_endian(vq), val);
e05fd12b MT	307	}
	308
	309	static inline __virtio64 cpu_to_vhost64(struct vhost_virtqueue *vq, u64 val)
	310	{
ab27c07f	311	return __cpu_to_virtio64(vhost_is_little_endian(vq), val);
e05fd12b	312	}
3a4d5c94	313	#endif