[xeon-phi-kernel-module] / host / vhost / vhost.h

/*
  This is the exact copy of linux-2.6.32-220.7.1.el6.x86_64/drivers/vhost/vhost.h
  except for this comment.
 */
#ifndef _VHOST_H
#define _VHOST_H

#include <linux/eventfd.h>
#ifdef RHEL_RELEASE_CODE
#include <linux/vhost.h>
#else
#include "./linux/vhost.h"
#endif
#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>

/* This is for zerocopy, used buffer len is set to 1 when lower device DMA
 * done */
#define VHOST_DMA_DONE_LEN	1
#define VHOST_DMA_CLEAR_LEN	0

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;
};

struct vhost_virtqueue;

struct vhost_ubuf_ref {
	struct kref kref;
	wait_queue_head_t wait;
	struct vhost_virtqueue *vq;
};

struct vhost_ubuf_ref *vhost_ubuf_alloc(struct vhost_virtqueue *, bool zcopy);
void vhost_ubuf_put(struct vhost_ubuf_ref *);
void vhost_ubuf_put_and_wait(struct vhost_ubuf_ref *);

/* 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];
	/* 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 *private_data;
	/* Log write descriptors */
	void __user *log_base;
	struct vhost_log *log;
	/* vhost zerocopy support fields below: */
	/* last used idx for outstanding DMA zerocopy buffers */
	int upend_idx;
	/* first used idx for DMA done zerocopy buffers */
	int done_idx;
	/* an array of userspace buffers info */
	struct ubuf_info *ubuf_info;
	/* Reference counting for outstanding ubufs.
	 * Protected by vq mutex. Writers must also take device mutex. */
	struct vhost_ubuf_ref *ubufs;
};

struct vhost_dev {
	/* Readers use RCU to access memory table pointer
	 * log base pointer and features.
	 * Writers use mutex below.*/
	struct vhost_memory *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_init_used(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_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);
void vhost_zerocopy_callback(void *arg);
int vhost_zerocopy_signal_used(struct vhost_virtqueue *vq);

#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)

#ifndef __rcu_dereference_index_check
#define __rcu_dereference_index_check(p, c) \
	({ \
	 typeof(p) _________p1 = READ_ONCE(p); \
	 RCU_LOCKDEP_WARN(c, \
		 "suspicious rcu_dereference_index_check()" \
		 " usage"); \
	 smp_read_barrier_depends(); \
	 (_________p1); \
	})
#endif

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 << VHOST_NET_F_VIRTIO_NET_HDR) |
			 (1ULL << VIRTIO_NET_F_MRG_RXBUF),
};

static inline int vhost_has_feature(struct vhost_dev *dev, int bit)
{
#ifdef RHEL_RELEASE_CODE
#if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,10,0))
	unsigned acked_features = rcu_dereference_index_check(dev->acked_features, rcu_read_lock_held());
#else
	unsigned acked_features = rcu_dereference(dev->acked_features);
#endif
#else
#if (LINUX_VERSION_CODE < KERNEL_VERSION(4,2,0))
	unsigned acked_features = rcu_dereference_index_check(dev->acked_features, rcu_read_lock_held());
#else
	unsigned acked_features = __rcu_dereference_index_check(dev->acked_features, rcu_read_lock_held());
#endif
#endif
	return acked_features & (1 << bit);
}

void vhost_enable_zcopy(int vq);

#endif
Commit	Line	Data
800f879a AT	1	/*
	2	This is the exact copy of linux-2.6.32-220.7.1.el6.x86_64/drivers/vhost/vhost.h
	3	except for this comment.
	4	*/
	5	#ifndef _VHOST_H
	6	#define _VHOST_H
	7
	8	#include <linux/eventfd.h>
	9	#ifdef RHEL_RELEASE_CODE
	10	#include <linux/vhost.h>
	11	#else
	12	#include "./linux/vhost.h"
	13	#endif
	14	#include <linux/mm.h>
	15	#include <linux/mutex.h>
	16	#include <linux/poll.h>
	17	#include <linux/file.h>
	18	#include <linux/skbuff.h>
	19	#include <linux/uio.h>
	20	#include <linux/virtio_config.h>
	21	#include <linux/virtio_ring.h>
	22	#include <asm/atomic.h>
	23
	24	/* This is for zerocopy, used buffer len is set to 1 when lower device DMA
	25	* done */
	26	#define VHOST_DMA_DONE_LEN 1
	27	#define VHOST_DMA_CLEAR_LEN 0
	28
	29	struct vhost_device;
	30
	31	struct vhost_work;
	32	typedef void (vhost_work_fn_t)(struct vhost_work work);
	33
	34	struct vhost_work {
	35	struct list_head node;
	36	vhost_work_fn_t fn;
	37	wait_queue_head_t done;
	38	int flushing;
	39	unsigned queue_seq;
	40	unsigned done_seq;
	41	};
	42
	43	/* Poll a file (eventfd or socket) */
	44	/* Note: there's nothing vhost specific about this structure. */
	45	struct vhost_poll {
	46	poll_table table;
	47	wait_queue_head_t *wqh;
	48	wait_queue_t wait;
	49	struct vhost_work work;
	50	unsigned long mask;
	51	struct vhost_dev *dev;
	52	};
	53
	54	void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn,
	55	unsigned long mask, struct vhost_dev *dev);
	56	void vhost_poll_start(struct vhost_poll poll, struct file file);
	57	void vhost_poll_stop(struct vhost_poll *poll);
	58	void vhost_poll_flush(struct vhost_poll *poll);
	59	void vhost_poll_queue(struct vhost_poll *poll);
	60
	61	struct vhost_log {
	62	u64 addr;
	63	u64 len;
	64	};
65
66	struct vhost_virtqueue;
67
68	struct vhost_ubuf_ref {
69	struct kref kref;
70	wait_queue_head_t wait;
71	struct vhost_virtqueue *vq;
72	};
73
74	struct vhost_ubuf_ref vhost_ubuf_alloc(struct vhost_virtqueue , bool zcopy);
75	void vhost_ubuf_put(struct vhost_ubuf_ref *);
76	void vhost_ubuf_put_and_wait(struct vhost_ubuf_ref *);
77
78	/* The virtqueue structure describes a queue attached to a device. */
79	struct vhost_virtqueue {
80	struct vhost_dev *dev;
81
82	/* The actual ring of buffers. */
83	struct mutex mutex;
84	unsigned int num;
85	struct vring_desc __user *desc;
86	struct vring_avail __user *avail;
87	struct vring_used __user *used;
88	struct file *kick;
89	struct file *call;
90	struct file *error;
91	struct eventfd_ctx *call_ctx;
92	struct eventfd_ctx *error_ctx;
93	struct eventfd_ctx *log_ctx;
94
95	struct vhost_poll poll;
96
97	/* The routine to call when the Guest pings us, or timeout. */
98	vhost_work_fn_t handle_kick;
99
100	/* Last available index we saw. */
101	u16 last_avail_idx;
102
103	/* Caches available index value from user. */
104	u16 avail_idx;
105
106	/* Last index we used. */
107	u16 last_used_idx;
108
109	/* Used flags */
110	u16 used_flags;
111
112	/* Last used index value we have signalled on */
113	u16 signalled_used;
114
115	/* Last used index value we have signalled on */
116	bool signalled_used_valid;
117
118	/* Log writes to used structure. */
119	bool log_used;
120	u64 log_addr;
121
122	struct iovec iov[UIO_MAXIOV];
123	/* hdr is used to store the virtio header.
124	* Since each iovec has >= 1 byte length, we never need more than
125	* header length entries to store the header. */
126	struct iovec hdr[sizeof(struct virtio_net_hdr_mrg_rxbuf)];
127	struct iovec *indirect;
128	size_t vhost_hlen;
129	size_t sock_hlen;
130	struct vring_used_elem *heads;
131	/* We use a kind of RCU to access private pointer.
132	* All readers access it from worker, which makes it possible to
133	* flush the vhost_work instead of synchronize_rcu. Therefore readers do
134	* not need to call rcu_read_lock/rcu_read_unlock: the beginning of
135	* vhost_work execution acts instead of rcu_read_lock() and the end of
136	* vhost_work execution acts instead of rcu_read_lock().
137	* Writers use virtqueue mutex. */
138	void *private_data;
139	/* Log write descriptors */
140	void __user *log_base;
141	struct vhost_log *log;
142	/* vhost zerocopy support fields below: */
143	/* last used idx for outstanding DMA zerocopy buffers */
144	int upend_idx;
145	/* first used idx for DMA done zerocopy buffers */
146	int done_idx;
147	/* an array of userspace buffers info */
148	struct ubuf_info *ubuf_info;
149	/* Reference counting for outstanding ubufs.
150	* Protected by vq mutex. Writers must also take device mutex. */
151	struct vhost_ubuf_ref *ubufs;
152	};
153
154	struct vhost_dev {
155	/* Readers use RCU to access memory table pointer
156	* log base pointer and features.
157	* Writers use mutex below.*/
158	struct vhost_memory *memory;
159	struct mm_struct *mm;
160	struct mutex mutex;
161	unsigned acked_features;
162	struct vhost_virtqueue *vqs;
163	int nvqs;
164	struct file *log_file;
165	struct eventfd_ctx *log_ctx;
166	spinlock_t work_lock;
167	struct list_head work_list;
168	struct task_struct *worker;
169	};
170
171	long vhost_dev_init(struct vhost_dev , struct vhost_virtqueue vqs, int nvqs);
172	long vhost_dev_check_owner(struct vhost_dev *);
173	long vhost_dev_reset_owner(struct vhost_dev *);
174	void vhost_dev_cleanup(struct vhost_dev *);
175	long vhost_dev_ioctl(struct vhost_dev *, unsigned int ioctl, unsigned long arg);
176	int vhost_vq_access_ok(struct vhost_virtqueue *vq);
177	int vhost_log_access_ok(struct vhost_dev *);
178
179	int vhost_get_vq_desc(struct vhost_dev , struct vhost_virtqueue ,
180	struct iovec iov[], unsigned int iov_count,
181	unsigned int out_num, unsigned int in_num,
182	struct vhost_log log, unsigned int log_num);
183	void vhost_discard_vq_desc(struct vhost_virtqueue *, int n);
184
185	int vhost_init_used(struct vhost_virtqueue *);
186	int vhost_add_used(struct vhost_virtqueue *, unsigned int head, int len);
187	int vhost_add_used_n(struct vhost_virtqueue , struct vring_used_elem heads,
188	unsigned count);
189	void vhost_add_used_and_signal(struct vhost_dev , struct vhost_virtqueue ,
190	unsigned int id, int len);
191	void vhost_add_used_and_signal_n(struct vhost_dev , struct vhost_virtqueue ,
192	struct vring_used_elem *heads, unsigned count);
193	void vhost_signal(struct vhost_dev , struct vhost_virtqueue );
194	void vhost_disable_notify(struct vhost_dev , struct vhost_virtqueue );
195	bool vhost_enable_notify(struct vhost_dev , struct vhost_virtqueue );
196
197	int vhost_log_write(struct vhost_virtqueue vq, struct vhost_log log,
198	unsigned int log_num, u64 len);
199	void vhost_zerocopy_callback(void *arg);
200	int vhost_zerocopy_signal_used(struct vhost_virtqueue *vq);
201
202	#define vq_err(vq, fmt, ...) do { \
203	pr_debug(pr_fmt(fmt), ##__VA_ARGS__); \
204	if ((vq)->error_ctx) \
205	eventfd_signal((vq)->error_ctx, 1);\
206	} while (0)
207
208	#ifndef __rcu_dereference_index_check
800f879a AT	209	#define __rcu_dereference_index_check(p, c) \
800f879a AT	210	({ \
5f16ba5a	211	typeof(p) _________p1 = READ_ONCE(p); \
800f879a AT	212	RCU_LOCKDEP_WARN(c, \
	213	"suspicious rcu_dereference_index_check()" \
	214	" usage"); \
	215	smp_read_barrier_depends(); \
	216	(_________p1); \
	217	})
	218	#endif
800f879a AT	219
	220	enum {
	221	VHOST_FEATURES = (1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) \|
	222	(1ULL << VIRTIO_RING_F_INDIRECT_DESC) \|
	223	(1ULL << VIRTIO_RING_F_EVENT_IDX) \|
	224	(1ULL << VHOST_F_LOG_ALL) \|
	225	(1ULL << VHOST_NET_F_VIRTIO_NET_HDR) \|
	226	(1ULL << VIRTIO_NET_F_MRG_RXBUF),
	227	};
	228
	229	static inline int vhost_has_feature(struct vhost_dev *dev, int bit)
	230	{
	231	#ifdef RHEL_RELEASE_CODE
	232	#if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,10,0))
	233	unsigned acked_features = rcu_dereference_index_check(dev->acked_features, rcu_read_lock_held());
	234	#else
	235	unsigned acked_features = rcu_dereference(dev->acked_features);
	236	#endif
	237	#else
	238	#if (LINUX_VERSION_CODE < KERNEL_VERSION(4,2,0))
	239	unsigned acked_features = rcu_dereference_index_check(dev->acked_features, rcu_read_lock_held());
	240	#else
	241	unsigned acked_features = __rcu_dereference_index_check(dev->acked_features, rcu_read_lock_held());
	242	#endif
	243	#endif
	244	return acked_features & (1 << bit);
	245	}
	246
	247	void vhost_enable_zcopy(int vq);
	248
	249	#endif