[net-next-2.6.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/skbuff.h>
#include <linux/uio.h>
#include <linux/virtio_config.h>
#include <linux/virtio_ring.h>
#include <asm/atomic.h>

struct vhost_device;

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_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn,
		     unsigned long mask, struct vhost_dev *dev);
void 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);

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;

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

	struct iovec iov[UIO_MAXIOV];
	/* hdr is used to store the virtio header.
	 * Since each iovec has >= 1 byte length, we never need more than
	 * header length entries to store the header. */
	struct iovec hdr[sizeof(struct virtio_net_hdr_mrg_rxbuf)];
	struct iovec *indirect;
	size_t vhost_hlen;
	size_t sock_hlen;
	struct vring_used_elem *heads;
	/* We use a kind of RCU to access private pointer.
	 * All readers access it from worker, which makes it possible to
	 * flush the vhost_work instead of synchronize_rcu. Therefore readers do
	 * not need to call rcu_read_lock/rcu_read_unlock: the beginning of
	 * vhost_work execution acts instead of rcu_read_lock() and the end of
	 * vhost_work execution acts instead of rcu_read_lock().
	 * Writers use virtqueue mutex. */
	void __rcu *private_data;
	/* Log write descriptors */
	void __user *log_base;
	struct vhost_log *log;
};

struct vhost_dev {
	/* Readers use RCU to access memory table pointer
	 * log base pointer and features.
	 * Writers use mutex below.*/
	struct vhost_memory __rcu *memory;
	struct mm_struct *mm;
	struct mutex mutex;
	unsigned acked_features;
	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;
};

long vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue *vqs, int nvqs);
long vhost_dev_check_owner(struct vhost_dev *);
long vhost_dev_reset_owner(struct vhost_dev *);
void vhost_dev_cleanup(struct vhost_dev *);
long vhost_dev_ioctl(struct vhost_dev *, unsigned int ioctl, unsigned long arg);
int vhost_vq_access_ok(struct vhost_virtqueue *vq);
int vhost_log_access_ok(struct vhost_dev *);

int vhost_get_vq_desc(struct vhost_dev *, 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_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_virtqueue *);
bool vhost_enable_notify(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 = (1 << VIRTIO_F_NOTIFY_ON_EMPTY) |
			 (1 << VIRTIO_RING_F_INDIRECT_DESC) |
			 (1 << VHOST_F_LOG_ALL) |
			 (1 << VHOST_NET_F_VIRTIO_NET_HDR) |
			 (1 << VIRTIO_NET_F_MRG_RXBUF),
};

static inline int vhost_has_feature(struct vhost_dev *dev, int bit)
{
	unsigned acked_features;

	acked_features =
		rcu_dereference_index_check(dev->acked_features,
					    lockdep_is_held(&dev->mutex));
	return acked_features & (1 << bit);
}

#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>
	9	#include <linux/file.h>
	10	#include <linux/skbuff.h>
	11	#include <linux/uio.h>
	12	#include <linux/virtio_config.h>
	13	#include <linux/virtio_ring.h>
c23f3445	14	#include <asm/atomic.h>
3a4d5c94 MT	15
	16	struct vhost_device;
	17
c23f3445 TH	18	struct vhost_work;
	19	typedef void (vhost_work_fn_t)(struct vhost_work work);
	20
	21	struct vhost_work {
	22	struct list_head node;
	23	vhost_work_fn_t fn;
	24	wait_queue_head_t done;
	25	int flushing;
	26	unsigned queue_seq;
	27	unsigned done_seq;
	28	};
	29
3a4d5c94 MT	30	/* Poll a file (eventfd or socket) */
	31	/* Note: there's nothing vhost specific about this structure. */
	32	struct vhost_poll {
	33	poll_table table;
	34	wait_queue_head_t *wqh;
	35	wait_queue_t wait;
c23f3445	36	struct vhost_work work;
3a4d5c94	37	unsigned long mask;
c23f3445	38	struct vhost_dev *dev;
3a4d5c94 MT	39	};
3a4d5c94 MT	40
c23f3445 TH	41	void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn,
c23f3445 TH	42	unsigned long mask, struct vhost_dev *dev);
3a4d5c94 MT	43	void vhost_poll_start(struct vhost_poll poll, struct file file);
	44	void vhost_poll_stop(struct vhost_poll *poll);
	45	void vhost_poll_flush(struct vhost_poll *poll);
	46	void vhost_poll_queue(struct vhost_poll *poll);
	47
	48	struct vhost_log {
	49	u64 addr;
	50	u64 len;
	51	};
	52
	53	/* The virtqueue structure describes a queue attached to a device. */
	54	struct vhost_virtqueue {
	55	struct vhost_dev *dev;
	56
	57	/* The actual ring of buffers. */
	58	struct mutex mutex;
	59	unsigned int num;
	60	struct vring_desc __user *desc;
	61	struct vring_avail __user *avail;
	62	struct vring_used __user *used;
	63	struct file *kick;
	64	struct file *call;
	65	struct file *error;
	66	struct eventfd_ctx *call_ctx;
	67	struct eventfd_ctx *error_ctx;
	68	struct eventfd_ctx *log_ctx;
	69
	70	struct vhost_poll poll;
	71
	72	/* The routine to call when the Guest pings us, or timeout. */
c23f3445	73	vhost_work_fn_t handle_kick;
3a4d5c94 MT	74
	75	/* Last available index we saw. */
	76	u16 last_avail_idx;
	77
	78	/* Caches available index value from user. */
	79	u16 avail_idx;
	80
	81	/* Last index we used. */
	82	u16 last_used_idx;
	83
	84	/* Used flags */
	85	u16 used_flags;
	86
	87	/* Log writes to used structure. */
	88	bool log_used;
	89	u64 log_addr;
	90
e0e9b406 JW	91	struct iovec iov[UIO_MAXIOV];
	92	/* hdr is used to store the virtio header.
	93	* Since each iovec has >= 1 byte length, we never need more than
	94	* header length entries to store the header. */
	95	struct iovec hdr[sizeof(struct virtio_net_hdr_mrg_rxbuf)];
	96	struct iovec *indirect;
8dd014ad DS	97	size_t vhost_hlen;
8dd014ad DS	98	size_t sock_hlen;
e0e9b406	99	struct vring_used_elem *heads;
3a4d5c94	100	/* We use a kind of RCU to access private pointer.
c23f3445 TH	101	* All readers access it from worker, which makes it possible to
c23f3445 TH	102	* flush the vhost_work instead of synchronize_rcu. Therefore readers do
3a4d5c94	103	* not need to call rcu_read_lock/rcu_read_unlock: the beginning of
c23f3445 TH	104	* vhost_work execution acts instead of rcu_read_lock() and the end of
c23f3445 TH	105	* vhost_work execution acts instead of rcu_read_lock().
3a4d5c94	106	* Writers use virtqueue mutex. */
28457ee6	107	void __rcu *private_data;
3a4d5c94 MT	108	/* Log write descriptors */
3a4d5c94 MT	109	void __user *log_base;
e0e9b406	110	struct vhost_log *log;
3a4d5c94 MT	111	};
	112
	113	struct vhost_dev {
	114	/* Readers use RCU to access memory table pointer
	115	* log base pointer and features.
	116	* Writers use mutex below.*/
28457ee6	117	struct vhost_memory __rcu *memory;
3a4d5c94 MT	118	struct mm_struct *mm;
	119	struct mutex mutex;
	120	unsigned acked_features;
	121	struct vhost_virtqueue *vqs;
	122	int nvqs;
	123	struct file *log_file;
	124	struct eventfd_ctx *log_ctx;
c23f3445 TH	125	spinlock_t work_lock;
	126	struct list_head work_list;
	127	struct task_struct *worker;
3a4d5c94 MT	128	};
	129
	130	long vhost_dev_init(struct vhost_dev , struct vhost_virtqueue vqs, int nvqs);
	131	long vhost_dev_check_owner(struct vhost_dev *);
	132	long vhost_dev_reset_owner(struct vhost_dev *);
	133	void vhost_dev_cleanup(struct vhost_dev *);
	134	long vhost_dev_ioctl(struct vhost_dev *, unsigned int ioctl, unsigned long arg);
	135	int vhost_vq_access_ok(struct vhost_virtqueue *vq);
	136	int vhost_log_access_ok(struct vhost_dev *);
	137
d5675bd2 MT	138	int vhost_get_vq_desc(struct vhost_dev , struct vhost_virtqueue ,
	139	struct iovec iov[], unsigned int iov_count,
	140	unsigned int out_num, unsigned int in_num,
	141	struct vhost_log log, unsigned int log_num);
8dd014ad	142	void vhost_discard_vq_desc(struct vhost_virtqueue *, int n);
3a4d5c94 MT	143
3a4d5c94 MT	144	int vhost_add_used(struct vhost_virtqueue *, unsigned int head, int len);
8dd014ad DS	145	int vhost_add_used_n(struct vhost_virtqueue , struct vring_used_elem heads,
8dd014ad DS	146	unsigned count);
3a4d5c94	147	void vhost_add_used_and_signal(struct vhost_dev , struct vhost_virtqueue ,
8dd014ad DS	148	unsigned int id, int len);
	149	void vhost_add_used_and_signal_n(struct vhost_dev , struct vhost_virtqueue ,
	150	struct vring_used_elem *heads, unsigned count);
	151	void vhost_signal(struct vhost_dev , struct vhost_virtqueue );
3a4d5c94 MT	152	void vhost_disable_notify(struct vhost_virtqueue *);
	153	bool vhost_enable_notify(struct vhost_virtqueue *);
	154
	155	int vhost_log_write(struct vhost_virtqueue vq, struct vhost_log log,
	156	unsigned int log_num, u64 len);
	157
3a4d5c94 MT	158	#define vq_err(vq, fmt, ...) do { \
	159	pr_debug(pr_fmt(fmt), ##__VA_ARGS__); \
	160	if ((vq)->error_ctx) \
	161	eventfd_signal((vq)->error_ctx, 1);\
	162	} while (0)
	163
	164	enum {
	165	VHOST_FEATURES = (1 << VIRTIO_F_NOTIFY_ON_EMPTY) \|
	166	(1 << VIRTIO_RING_F_INDIRECT_DESC) \|
	167	(1 << VHOST_F_LOG_ALL) \|
8dd014ad DS	168	(1 << VHOST_NET_F_VIRTIO_NET_HDR) \|
8dd014ad DS	169	(1 << VIRTIO_NET_F_MRG_RXBUF),
3a4d5c94 MT	170	};
	171
	172	static inline int vhost_has_feature(struct vhost_dev *dev, int bit)
	173	{
28457ee6 AB	174	unsigned acked_features;
	175
	176	acked_features =
	177	rcu_dereference_index_check(dev->acked_features,
	178	lockdep_is_held(&dev->mutex));
3a4d5c94 MT	179	return acked_features & (1 << bit);
	180	}
	181
	182	#endif