vhost-net: mergeable buffers support

[~andy/linux] / drivers / vhost / vhost.h

diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
index 44591ba9b07a2a93d7caa9d9c3d05f1a797650d8..afd77295971ce3044117d0d6e5ea8f4e20f655fe 100644 (file)
--- a/drivers/vhost/vhost.h
+++ b/drivers/vhost/vhost.h
@@ -5,13 +5,13 @@
 #include <linux/vhost.h>
 #include <linux/mm.h>
 #include <linux/mutex.h>
-#include <linux/workqueue.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;
 
@@ -20,19 +20,31 @@ enum {
        VHOST_NET_MAX_SG = MAX_SKB_FRAGS + 2,
 };
 
+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 which will handle all actual work. */
-       struct work_struct        work;
+       struct vhost_work         work;
        unsigned long             mask;
+       struct vhost_dev         *dev;
 };
 
-void vhost_poll_init(struct vhost_poll *poll, work_func_t func,
-                    unsigned long mask);
+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);
@@ -63,7 +75,7 @@ struct vhost_virtqueue {
        struct vhost_poll poll;
 
        /* The routine to call when the Guest pings us, or timeout. */
-       work_func_t handle_kick;
+       vhost_work_fn_t handle_kick;
 
        /* Last available index we saw. */
        u16 last_avail_idx;
@@ -84,13 +96,15 @@ struct vhost_virtqueue {
        struct iovec indirect[VHOST_NET_MAX_SG];
        struct iovec iov[VHOST_NET_MAX_SG];
        struct iovec hdr[VHOST_NET_MAX_SG];
-       size_t hdr_size;
+       size_t vhost_hlen;
+       size_t sock_hlen;
+       struct vring_used_elem heads[VHOST_NET_MAX_SG];
        /* We use a kind of RCU to access private pointer.
-        * All readers access it from workqueue, which makes it possible to
-        * flush the workqueue instead of synchronize_rcu. Therefore readers do
+        * 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
-        * work item execution acts instead of rcu_read_lock() and the end of
-        * work item execution acts instead of rcu_read_lock().
+        * 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 */
@@ -110,6 +124,9 @@ struct vhost_dev {
        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);
@@ -120,25 +137,26 @@ 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 *);
 
-unsigned 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 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);
-void vhost_signal(struct vhost_dev *, struct vhost_virtqueue *);
+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 head, int len);
+                              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);
 
-int vhost_init(void);
-void vhost_cleanup(void);
-
 #define vq_err(vq, fmt, ...) do {                                  \
                pr_debug(pr_fmt(fmt), ##__VA_ARGS__);       \
                if ((vq)->error_ctx)                               \
@@ -149,7 +167,8 @@ 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 << VHOST_NET_F_VIRTIO_NET_HDR) |
+                        (1 << VIRTIO_NET_F_MRG_RXBUF),
 };
 
 static inline int vhost_has_feature(struct vhost_dev *dev, int bit)