From 3beee86a4b9374e38dba36b44e81f1423a0d6b54 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Sjur=20Br=C3=A6ndeland?= Date: Wed, 20 Mar 2013 13:51:24 +1030 Subject: [PATCH] virtio: Introduce vringh wrappers in virtio_config MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Add wrappers for the host vrings to support loose coupling between the virtio device and driver. A new struct vringh_config_ops with the functions find_vrhs() and del_vrhs() is added to the virtio_device struct. This enables virtio drivers to manage virtio host rings without detailed knowledge of how the vrings are created and deleted. The function vringh_notify() is added so vringh clients can notify the other side that buffers are added to the used-ring. Cc: Ohad Ben-Cohen Signed-off-by: Sjur Brændeland Signed-off-by: Rusty Russell (constified vringh_config) --- include/linux/virtio.h | 3 +++ include/linux/vringh.h | 29 +++++++++++++++++++++++++++++ 2 files changed, 32 insertions(+) diff --git a/include/linux/virtio.h b/include/linux/virtio.h index ff6714e..5d5b3ab 100644 --- a/include/linux/virtio.h +++ b/include/linux/virtio.h @@ -8,6 +8,7 @@ #include #include #include +#include /** * virtqueue - a queue to register buffers for sending or receiving. @@ -70,6 +71,7 @@ static inline unsigned int virtqueue_get_queue_index(struct virtqueue *vq) * @dev: underlying device. * @id: the device type identification (used to match it with a driver). * @config: the configuration ops for this device. + * @vringh_config: configuration ops for host vrings. * @vqs: the list of virtqueues for this device. * @features: the features supported by both driver and device. * @priv: private pointer for the driver's use. @@ -79,6 +81,7 @@ struct virtio_device { struct device dev; struct virtio_device_id id; const struct virtio_config_ops *config; + const struct vringh_config_ops *vringh_config; struct list_head vqs; /* Note that this is a Linux set_bit-style bitmap. */ unsigned long features[1]; diff --git a/include/linux/vringh.h b/include/linux/vringh.h index b8f0866..749cde2 100644 --- a/include/linux/vringh.h +++ b/include/linux/vringh.h @@ -47,6 +47,28 @@ struct vringh { /* The vring (note: it may contain user pointers!) */ struct vring vring; + + /* The function to call to notify the guest about added buffers */ + void (*notify)(struct vringh *); +}; + +/** + * struct vringh_config_ops - ops for creating a host vring from a virtio driver + * @find_vrhs: find the host vrings and instantiate them + * vdev: the virtio_device + * nhvrs: the number of host vrings to find + * hvrs: on success, includes new host vrings + * callbacks: array of driver callbacks, for each host vring + * include a NULL entry for vqs that do not need a callback + * Returns 0 on success or error status + * @del_vrhs: free the host vrings found by find_vrhs(). + */ +struct virtio_device; +typedef void vrh_callback_t(struct virtio_device *, struct vringh *); +struct vringh_config_ops { + int (*find_vrhs)(struct virtio_device *vdev, unsigned nhvrs, + struct vringh *vrhs[], vrh_callback_t *callbacks[]); + void (*del_vrhs)(struct virtio_device *vdev); }; /* The memory the vring can access, and what offset to apply. */ @@ -193,4 +215,11 @@ void vringh_notify_disable_kern(struct vringh *vrh); int vringh_need_notify_kern(struct vringh *vrh); +/* Notify the guest about buffers added to the used ring */ +static inline void vringh_notify(struct vringh *vrh) +{ + if (vrh->notify) + vrh->notify(vrh); +} + #endif /* _LINUX_VRINGH_H */ -- 2.7.4