[linux-2.6-block.git] / drivers / vhost / vhost.h

#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>

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

struct vhost_work {
	struct list_head	  node;
	vhost_work_fn_t		  fn;
	wait_queue_head_t	  done;
	int			  flushing;
	unsigned		  queue_seq;
	unsigned		  done_seq;
};

/* 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_t              wait;
	struct vhost_work	  work;
	unsigned long		  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,
		     unsigned long 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, int ioctl, void __user *argp);

struct vhost_log {
	u64 addr;
	u64 len;
};

/* 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;
	struct file *kick;
	struct file *call;
	struct file *error;
	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 *indirect;
	struct vring_used_elem *heads;
	/* Protected by virtqueue mutex. */
	struct vhost_memory *memory;
	void *private_data;
	u64 acked_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_dev {
	struct vhost_memory *memory;
	struct mm_struct *mm;
	struct mutex mutex;
	struct vhost_virtqueue **vqs;
	int nvqs;
	struct file *log_file;
	struct eventfd_ctx *log_ctx;
	spinlock_t work_lock;
	struct list_head work_list;
	struct task_struct *worker;
};

void vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue **vqs, int nvqs);
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_memory *vhost_dev_reset_owner_prepare(void);
void vhost_dev_reset_owner(struct vhost_dev *, struct vhost_memory *);
void vhost_dev_cleanup(struct vhost_dev *, bool locked);
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, int ioctl, void __user *argp);
int vhost_vq_access_ok(struct vhost_virtqueue *vq);
int 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);

#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)
};

static inline bool vhost_has_feature(struct vhost_virtqueue *vq, int bit)
{
	return vq->acked_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
3a4d5c94 MT	1	#ifndef _VHOST_H
	2	#define _VHOST_H
	3
	4	#include <linux/eventfd.h>
	5	#include <linux/vhost.h>
	6	#include <linux/mm.h>
	7	#include <linux/mutex.h>
3a4d5c94 MT	8	#include <linux/poll.h>
3a4d5c94 MT	9	#include <linux/file.h>
3a4d5c94 MT	10	#include <linux/uio.h>
	11	#include <linux/virtio_config.h>
	12	#include <linux/virtio_ring.h>
60063497	13	#include <linux/atomic.h>
3a4d5c94	14
c23f3445 TH	15	struct vhost_work;
	16	typedef void (vhost_work_fn_t)(struct vhost_work work);
	17
	18	struct vhost_work {
	19	struct list_head node;
	20	vhost_work_fn_t fn;
	21	wait_queue_head_t done;
	22	int flushing;
	23	unsigned queue_seq;
	24	unsigned done_seq;
	25	};
	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;
	32	wait_queue_t wait;
c23f3445	33	struct vhost_work work;
3a4d5c94	34	unsigned long 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 TH	42	void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn,
c23f3445 TH	43	unsigned long 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 AH	48	void vhost_work_flush(struct vhost_dev dev, struct vhost_work work);
6ac1afbf AH	49	long vhost_vring_ioctl(struct vhost_dev d, int ioctl, void __user argp);
3a4d5c94 MT	50
	51	struct vhost_log {
	52	u64 addr;
	53	u64 len;
	54	};
	55
	56	/* The virtqueue structure describes a queue attached to a device. */
	57	struct vhost_virtqueue {
	58	struct vhost_dev *dev;
	59
	60	/* The actual ring of buffers. */
	61	struct mutex mutex;
	62	unsigned int num;
	63	struct vring_desc __user *desc;
	64	struct vring_avail __user *avail;
	65	struct vring_used __user *used;
	66	struct file *kick;
	67	struct file *call;
	68	struct file *error;
	69	struct eventfd_ctx *call_ctx;
	70	struct eventfd_ctx *error_ctx;
	71	struct eventfd_ctx *log_ctx;
	72
	73	struct vhost_poll poll;
	74
	75	/* The routine to call when the Guest pings us, or timeout. */
c23f3445	76	vhost_work_fn_t handle_kick;
3a4d5c94 MT	77
	78	/* Last available index we saw. */
	79	u16 last_avail_idx;
	80
	81	/* Caches available index value from user. */
	82	u16 avail_idx;
	83
	84	/* Last index we used. */
	85	u16 last_used_idx;
	86
	87	/* Used flags */
	88	u16 used_flags;
	89
8ea8cf89 MT	90	/* Last used index value we have signalled on */
	91	u16 signalled_used;
	92
	93	/* Last used index value we have signalled on */
	94	bool signalled_used_valid;
	95
3a4d5c94 MT	96	/* Log writes to used structure. */
	97	bool log_used;
	98	u64 log_addr;
	99
e0e9b406	100	struct iovec iov[UIO_MAXIOV];
e0e9b406	101	struct iovec *indirect;
e0e9b406	102	struct vring_used_elem *heads;
22fa90c7	103	/* Protected by virtqueue mutex. */
47283bef	104	struct vhost_memory *memory;
22fa90c7	105	void *private_data;
bd82752a	106	u64 acked_features;
3a4d5c94 MT	107	/* Log write descriptors */
3a4d5c94 MT	108	void __user *log_base;
e0e9b406	109	struct vhost_log *log;
2751c988 GK	110
	111	/* Ring endianness. Defaults to legacy native endianness.
	112	* Set to true when starting a modern virtio device. */
	113	bool is_le;
	114	#ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY
	115	/* Ring endianness requested by userspace for cross-endian support. */
	116	bool user_be;
	117	#endif
03088137	118	u32 busyloop_timeout;
3a4d5c94 MT	119	};
	120
	121	struct vhost_dev {
47283bef	122	struct vhost_memory *memory;
3a4d5c94 MT	123	struct mm_struct *mm;
3a4d5c94 MT	124	struct mutex mutex;
3ab2e420	125	struct vhost_virtqueue **vqs;
3a4d5c94 MT	126	int nvqs;
	127	struct file *log_file;
	128	struct eventfd_ctx *log_ctx;
c23f3445 TH	129	spinlock_t work_lock;
	130	struct list_head work_list;
	131	struct task_struct *worker;
3a4d5c94 MT	132	};
3a4d5c94 MT	133
59566b6e	134	void vhost_dev_init(struct vhost_dev , struct vhost_virtqueue *vqs, int nvqs);
54db63c2	135	long vhost_dev_set_owner(struct vhost_dev *dev);
05c05351	136	bool vhost_dev_has_owner(struct vhost_dev *dev);
3a4d5c94	137	long vhost_dev_check_owner(struct vhost_dev *);
150b9e51 MT	138	struct vhost_memory *vhost_dev_reset_owner_prepare(void);
150b9e51 MT	139	void vhost_dev_reset_owner(struct vhost_dev , struct vhost_memory );
ea5d4046	140	void vhost_dev_cleanup(struct vhost_dev *, bool locked);
b211616d	141	void vhost_dev_stop(struct vhost_dev *);
935cdee7 MT	142	long vhost_dev_ioctl(struct vhost_dev , unsigned int ioctl, void __user argp);
935cdee7 MT	143	long vhost_vring_ioctl(struct vhost_dev d, int ioctl, void __user argp);
3a4d5c94 MT	144	int vhost_vq_access_ok(struct vhost_virtqueue *vq);
	145	int vhost_log_access_ok(struct vhost_dev *);
	146
47283bef	147	int vhost_get_vq_desc(struct vhost_virtqueue *,
d5675bd2 MT	148	struct iovec iov[], unsigned int iov_count,
	149	unsigned int out_num, unsigned int in_num,
	150	struct vhost_log log, unsigned int log_num);
8dd014ad	151	void vhost_discard_vq_desc(struct vhost_virtqueue *, int n);
3a4d5c94	152
80f7d030	153	int vhost_vq_init_access(struct vhost_virtqueue *);
3a4d5c94	154	int vhost_add_used(struct vhost_virtqueue *, unsigned int head, int len);
8dd014ad DS	155	int vhost_add_used_n(struct vhost_virtqueue , struct vring_used_elem heads,
8dd014ad DS	156	unsigned count);
3a4d5c94	157	void vhost_add_used_and_signal(struct vhost_dev , struct vhost_virtqueue ,
8dd014ad DS	158	unsigned int id, int len);
	159	void vhost_add_used_and_signal_n(struct vhost_dev , struct vhost_virtqueue ,
	160	struct vring_used_elem *heads, unsigned count);
	161	void vhost_signal(struct vhost_dev , struct vhost_virtqueue );
8ea8cf89	162	void vhost_disable_notify(struct vhost_dev , struct vhost_virtqueue );
d4a60603	163	bool vhost_vq_avail_empty(struct vhost_dev , struct vhost_virtqueue );
8ea8cf89	164	bool vhost_enable_notify(struct vhost_dev , struct vhost_virtqueue );
3a4d5c94 MT	165
	166	int vhost_log_write(struct vhost_virtqueue vq, struct vhost_log log,
	167	unsigned int log_num, u64 len);
	168
3a4d5c94 MT	169	#define vq_err(vq, fmt, ...) do { \
	170	pr_debug(pr_fmt(fmt), ##__VA_ARGS__); \
	171	if ((vq)->error_ctx) \
	172	eventfd_signal((vq)->error_ctx, 1);\
	173	} while (0)
	174
	175	enum {
8ea8cf89 MT	176	VHOST_FEATURES = (1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) \|
	177	(1ULL << VIRTIO_RING_F_INDIRECT_DESC) \|
	178	(1ULL << VIRTIO_RING_F_EVENT_IDX) \|
4e9fa50c MT	179	(1ULL << VHOST_F_LOG_ALL) \|
	180	(1ULL << VIRTIO_F_ANY_LAYOUT) \|
	181	(1ULL << VIRTIO_F_VERSION_1)
3a4d5c94 MT	182	};
3a4d5c94 MT	183
bd82752a	184	static inline bool vhost_has_feature(struct vhost_virtqueue *vq, int bit)
3a4d5c94	185	{
bd82752a	186	return vq->acked_features & (1ULL << bit);
3a4d5c94	187	}
e05fd12b	188
e407f39a	189	#ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY
ab27c07f GK	190	static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq)
ab27c07f GK	191	{
2751c988	192	return vq->is_le;
ab27c07f	193	}
e407f39a MT	194	#else
	195	static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq)
	196	{
	197	return virtio_legacy_is_little_endian() \|\| vq->is_le;
	198	}
	199	#endif
ab27c07f	200
e05fd12b MT	201	/* Memory accessors */
	202	static inline u16 vhost16_to_cpu(struct vhost_virtqueue *vq, __virtio16 val)
	203	{
ab27c07f	204	return __virtio16_to_cpu(vhost_is_little_endian(vq), val);
e05fd12b MT	205	}
	206
	207	static inline __virtio16 cpu_to_vhost16(struct vhost_virtqueue *vq, u16 val)
	208	{
ab27c07f	209	return __cpu_to_virtio16(vhost_is_little_endian(vq), val);
e05fd12b MT	210	}
	211
	212	static inline u32 vhost32_to_cpu(struct vhost_virtqueue *vq, __virtio32 val)
	213	{
ab27c07f	214	return __virtio32_to_cpu(vhost_is_little_endian(vq), val);
e05fd12b MT	215	}
	216
	217	static inline __virtio32 cpu_to_vhost32(struct vhost_virtqueue *vq, u32 val)
	218	{
ab27c07f	219	return __cpu_to_virtio32(vhost_is_little_endian(vq), val);
e05fd12b MT	220	}
	221
	222	static inline u64 vhost64_to_cpu(struct vhost_virtqueue *vq, __virtio64 val)
	223	{
ab27c07f	224	return __virtio64_to_cpu(vhost_is_little_endian(vq), val);
e05fd12b MT	225	}
	226
	227	static inline __virtio64 cpu_to_vhost64(struct vhost_virtqueue *vq, u64 val)
	228	{
ab27c07f	229	return __cpu_to_virtio64(vhost_is_little_endian(vq), val);
e05fd12b	230	}
3a4d5c94	231	#endif