[mirror_ubuntu-bionic-kernel.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);

#define VHOST_WORK_QUEUED 1
struct vhost_work {
	struct llist_node	  node;
	vhost_work_fn_t		  fn;
	wait_queue_head_t	  done;
	int			  flushing;
	unsigned		  queue_seq;
	unsigned		  done_seq;
	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_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;
};

#define START(node) ((node)->start)
#define LAST(node) ((node)->last)

struct vhost_umem_node {
	struct rb_node rb;
	struct list_head link;
	__u64 start;
	__u64 last;
	__u64 size;
	__u64 userspace_addr;
	__u64 flags_padding;
	__u64 __subtree_last;
};

struct vhost_umem {
	struct rb_root umem_tree;
	struct list_head umem_list;
};

/* 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_umem *umem;
	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 mm_struct *mm;
	struct mutex mutex;
	struct vhost_virtqueue **vqs;
	int nvqs;
	struct file *log_file;
	struct eventfd_ctx *log_ctx;
	struct llist_head work_list;
	struct task_struct *worker;
	struct vhost_umem *umem;
};

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_umem *vhost_dev_reset_owner_prepare(void);
void vhost_dev_reset_owner(struct vhost_dev *, struct vhost_umem *);
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
04b96e55	18	#define VHOST_WORK_QUEUED 1
c23f3445	19	struct vhost_work {
04b96e55	20	struct llist_node node;
c23f3445 TH	21	vhost_work_fn_t fn;
	22	wait_queue_head_t done;
	23	int flushing;
	24	unsigned queue_seq;
	25	unsigned done_seq;
04b96e55	26	unsigned long flags;
c23f3445 TH	27	};
c23f3445 TH	28
3a4d5c94 MT	29	/* Poll a file (eventfd or socket) */
	30	/* Note: there's nothing vhost specific about this structure. */
	31	struct vhost_poll {
	32	poll_table table;
	33	wait_queue_head_t *wqh;
	34	wait_queue_t wait;
c23f3445	35	struct vhost_work work;
3a4d5c94	36	unsigned long mask;
c23f3445	37	struct vhost_dev *dev;
3a4d5c94 MT	38	};
3a4d5c94 MT	39
163049ae SH	40	void vhost_work_init(struct vhost_work *work, vhost_work_fn_t fn);
163049ae SH	41	void vhost_work_queue(struct vhost_dev dev, struct vhost_work work);
526d3e7f	42	bool vhost_has_work(struct vhost_dev *dev);
163049ae	43
c23f3445 TH	44	void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn,
c23f3445 TH	45	unsigned long mask, struct vhost_dev *dev);
2b8b328b	46	int vhost_poll_start(struct vhost_poll poll, struct file file);
3a4d5c94 MT	47	void vhost_poll_stop(struct vhost_poll *poll);
	48	void vhost_poll_flush(struct vhost_poll *poll);
	49	void vhost_poll_queue(struct vhost_poll *poll);
6ac1afbf AH	50	void vhost_work_flush(struct vhost_dev dev, struct vhost_work work);
6ac1afbf AH	51	long vhost_vring_ioctl(struct vhost_dev d, int ioctl, void __user argp);
3a4d5c94 MT	52
	53	struct vhost_log {
	54	u64 addr;
	55	u64 len;
	56	};
	57
a9709d68 JW	58	#define START(node) ((node)->start)
	59	#define LAST(node) ((node)->last)
	60
	61	struct vhost_umem_node {
	62	struct rb_node rb;
	63	struct list_head link;
	64	__u64 start;
	65	__u64 last;
	66	__u64 size;
	67	__u64 userspace_addr;
	68	__u64 flags_padding;
	69	__u64 __subtree_last;
	70	};
	71
	72	struct vhost_umem {
	73	struct rb_root umem_tree;
	74	struct list_head umem_list;
	75	};
	76
3a4d5c94 MT	77	/* The virtqueue structure describes a queue attached to a device. */
	78	struct vhost_virtqueue {
	79	struct vhost_dev *dev;
	80
	81	/* The actual ring of buffers. */
	82	struct mutex mutex;
	83	unsigned int num;
	84	struct vring_desc __user *desc;
	85	struct vring_avail __user *avail;
	86	struct vring_used __user *used;
	87	struct file *kick;
	88	struct file *call;
	89	struct file *error;
	90	struct eventfd_ctx *call_ctx;
	91	struct eventfd_ctx *error_ctx;
	92	struct eventfd_ctx *log_ctx;
	93
	94	struct vhost_poll poll;
	95
	96	/* The routine to call when the Guest pings us, or timeout. */
c23f3445	97	vhost_work_fn_t handle_kick;
3a4d5c94 MT	98
	99	/* Last available index we saw. */
	100	u16 last_avail_idx;
	101
	102	/* Caches available index value from user. */
	103	u16 avail_idx;
	104
	105	/* Last index we used. */
	106	u16 last_used_idx;
	107
	108	/* Used flags */
	109	u16 used_flags;
	110
8ea8cf89 MT	111	/* Last used index value we have signalled on */
	112	u16 signalled_used;
	113
	114	/* Last used index value we have signalled on */
	115	bool signalled_used_valid;
	116
3a4d5c94 MT	117	/* Log writes to used structure. */
	118	bool log_used;
	119	u64 log_addr;
	120
e0e9b406	121	struct iovec iov[UIO_MAXIOV];
e0e9b406	122	struct iovec *indirect;
e0e9b406	123	struct vring_used_elem *heads;
22fa90c7	124	/* Protected by virtqueue mutex. */
a9709d68	125	struct vhost_umem *umem;
22fa90c7	126	void *private_data;
bd82752a	127	u64 acked_features;
3a4d5c94 MT	128	/* Log write descriptors */
3a4d5c94 MT	129	void __user *log_base;
e0e9b406	130	struct vhost_log *log;
2751c988 GK	131
	132	/* Ring endianness. Defaults to legacy native endianness.
	133	* Set to true when starting a modern virtio device. */
	134	bool is_le;
	135	#ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY
	136	/* Ring endianness requested by userspace for cross-endian support. */
	137	bool user_be;
	138	#endif
03088137	139	u32 busyloop_timeout;
3a4d5c94 MT	140	};
	141
	142	struct vhost_dev {
3a4d5c94 MT	143	struct mm_struct *mm;
3a4d5c94 MT	144	struct mutex mutex;
3ab2e420	145	struct vhost_virtqueue **vqs;
3a4d5c94 MT	146	int nvqs;
	147	struct file *log_file;
	148	struct eventfd_ctx *log_ctx;
04b96e55	149	struct llist_head work_list;
c23f3445	150	struct task_struct *worker;
a9709d68	151	struct vhost_umem *umem;
3a4d5c94 MT	152	};
3a4d5c94 MT	153
59566b6e	154	void vhost_dev_init(struct vhost_dev , struct vhost_virtqueue *vqs, int nvqs);
54db63c2	155	long vhost_dev_set_owner(struct vhost_dev *dev);
05c05351	156	bool vhost_dev_has_owner(struct vhost_dev *dev);
3a4d5c94	157	long vhost_dev_check_owner(struct vhost_dev *);
a9709d68 JW	158	struct vhost_umem *vhost_dev_reset_owner_prepare(void);
a9709d68 JW	159	void vhost_dev_reset_owner(struct vhost_dev , struct vhost_umem );
ea5d4046	160	void vhost_dev_cleanup(struct vhost_dev *, bool locked);
b211616d	161	void vhost_dev_stop(struct vhost_dev *);
935cdee7 MT	162	long vhost_dev_ioctl(struct vhost_dev , unsigned int ioctl, void __user argp);
935cdee7 MT	163	long vhost_vring_ioctl(struct vhost_dev d, int ioctl, void __user argp);
3a4d5c94 MT	164	int vhost_vq_access_ok(struct vhost_virtqueue *vq);
	165	int vhost_log_access_ok(struct vhost_dev *);
	166
47283bef	167	int vhost_get_vq_desc(struct vhost_virtqueue *,
d5675bd2 MT	168	struct iovec iov[], unsigned int iov_count,
	169	unsigned int out_num, unsigned int in_num,
	170	struct vhost_log log, unsigned int log_num);
8dd014ad	171	void vhost_discard_vq_desc(struct vhost_virtqueue *, int n);
3a4d5c94	172
80f7d030	173	int vhost_vq_init_access(struct vhost_virtqueue *);
3a4d5c94	174	int vhost_add_used(struct vhost_virtqueue *, unsigned int head, int len);
8dd014ad DS	175	int vhost_add_used_n(struct vhost_virtqueue , struct vring_used_elem heads,
8dd014ad DS	176	unsigned count);
3a4d5c94	177	void vhost_add_used_and_signal(struct vhost_dev , struct vhost_virtqueue ,
8dd014ad DS	178	unsigned int id, int len);
	179	void vhost_add_used_and_signal_n(struct vhost_dev , struct vhost_virtqueue ,
	180	struct vring_used_elem *heads, unsigned count);
	181	void vhost_signal(struct vhost_dev , struct vhost_virtqueue );
8ea8cf89	182	void vhost_disable_notify(struct vhost_dev , struct vhost_virtqueue );
d4a60603	183	bool vhost_vq_avail_empty(struct vhost_dev , struct vhost_virtqueue );
8ea8cf89	184	bool vhost_enable_notify(struct vhost_dev , struct vhost_virtqueue );
3a4d5c94 MT	185
	186	int vhost_log_write(struct vhost_virtqueue vq, struct vhost_log log,
	187	unsigned int log_num, u64 len);
	188
3a4d5c94 MT	189	#define vq_err(vq, fmt, ...) do { \
	190	pr_debug(pr_fmt(fmt), ##__VA_ARGS__); \
	191	if ((vq)->error_ctx) \
	192	eventfd_signal((vq)->error_ctx, 1);\
	193	} while (0)
	194
	195	enum {
8ea8cf89 MT	196	VHOST_FEATURES = (1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) \|
	197	(1ULL << VIRTIO_RING_F_INDIRECT_DESC) \|
	198	(1ULL << VIRTIO_RING_F_EVENT_IDX) \|
4e9fa50c MT	199	(1ULL << VHOST_F_LOG_ALL) \|
	200	(1ULL << VIRTIO_F_ANY_LAYOUT) \|
	201	(1ULL << VIRTIO_F_VERSION_1)
3a4d5c94 MT	202	};
3a4d5c94 MT	203
bd82752a	204	static inline bool vhost_has_feature(struct vhost_virtqueue *vq, int bit)
3a4d5c94	205	{
bd82752a	206	return vq->acked_features & (1ULL << bit);
3a4d5c94	207	}
e05fd12b	208
e407f39a	209	#ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY
ab27c07f GK	210	static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq)
ab27c07f GK	211	{
2751c988	212	return vq->is_le;
ab27c07f	213	}
e407f39a MT	214	#else
	215	static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq)
	216	{
	217	return virtio_legacy_is_little_endian() \|\| vq->is_le;
	218	}
	219	#endif
ab27c07f	220
e05fd12b MT	221	/* Memory accessors */
	222	static inline u16 vhost16_to_cpu(struct vhost_virtqueue *vq, __virtio16 val)
	223	{
ab27c07f	224	return __virtio16_to_cpu(vhost_is_little_endian(vq), val);
e05fd12b MT	225	}
	226
	227	static inline __virtio16 cpu_to_vhost16(struct vhost_virtqueue *vq, u16 val)
	228	{
ab27c07f	229	return __cpu_to_virtio16(vhost_is_little_endian(vq), val);
e05fd12b MT	230	}
	231
	232	static inline u32 vhost32_to_cpu(struct vhost_virtqueue *vq, __virtio32 val)
	233	{
ab27c07f	234	return __virtio32_to_cpu(vhost_is_little_endian(vq), val);
e05fd12b MT	235	}
	236
	237	static inline __virtio32 cpu_to_vhost32(struct vhost_virtqueue *vq, u32 val)
	238	{
ab27c07f	239	return __cpu_to_virtio32(vhost_is_little_endian(vq), val);
e05fd12b MT	240	}
	241
	242	static inline u64 vhost64_to_cpu(struct vhost_virtqueue *vq, __virtio64 val)
	243	{
ab27c07f	244	return __virtio64_to_cpu(vhost_is_little_endian(vq), val);
e05fd12b MT	245	}
	246
	247	static inline __virtio64 cpu_to_vhost64(struct vhost_virtqueue *vq, u64 val)
	248	{
ab27c07f	249	return __cpu_to_virtio64(vhost_is_little_endian(vq), val);
e05fd12b	250	}
3a4d5c94	251	#endif