sjur.brandeland at stericsson.com
2013-Mar-08 10:08 UTC
[PATCHv2] virtio: Introduce vringh wrappers in virtio_config
From: Sjur Br?ndeland <sjur.brandeland at stericsson.com> 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 <ohad at wizery.com> Cc: Rusty Russell <rusty at rustcorp.com.au> Signed-off-by: Sjur Br?ndeland <sjur.brandeland at stericsson.com> --- Hi Rusty,>It's weird that you conflate the host and guest ring sides in rpmsg, but >that might make sense if they're really bound together.Weird or not, CAIF-virtio is design to use guest rings for TX traffic, and host rings for RX traffic. The motivation for this design is to allow zero-copy in the data-path on the remote-device/modem. Changes since v1: - Moved find_vrhs() and del_vrhs() to a separate struct vringh_config_ops. - Moved definition of struct vringh_config_ops into vringh.h - Added vringh_config field to struct virtio_device - Removed priv pointer field from struct vringh There are a number of different ways to do this, let me know if you want this changed in any way. Thanks, Sjur include/linux/virtio.h | 3 +++ include/linux/vringh.h | 29 +++++++++++++++++++++++++++++ 2 files changed, 32 insertions(+), 0 deletions(-) diff --git a/include/linux/virtio.h b/include/linux/virtio.h index 00ccc40..5b71fc1 100644 --- a/include/linux/virtio.h +++ b/include/linux/virtio.h @@ -8,6 +8,7 @@ #include <linux/device.h> #include <linux/mod_devicetable.h> #include <linux/gfp.h> +#include <linux/vringh.h> /** * 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; struct virtio_config_ops *config; + 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 ab41185..c7d9289 100644 --- a/include/linux/vringh.h +++ b/include/linux/vringh.h @@ -50,6 +50,28 @@ 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. */ @@ -182,4 +204,11 @@ 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 */ -- 1.7.5.4
Sjur Brændeland
2013-Mar-13 10:12 UTC
[PATCHv2] virtio: Introduce vringh wrappers in virtio_config
Hi Ohad, On Fri, Mar 8, 2013 at 11:08 AM, <sjur.brandeland at stericsson.com> wrote:> From: Sjur Br?ndeland <sjur.brandeland at stericsson.com> > > 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 <ohad at wizery.com> > Cc: Rusty Russell <rusty at rustcorp.com.au> > Signed-off-by: Sjur Br?ndeland <sjur.brandeland at stericsson.com>As you have been pushing for this wrapper, could you please add your Ack or Reviewed tag if you are happy with this patch? Thanks, Sjur
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