[dpdk-dev] [PATCH v4 3/5] vhost: add apis for datapath configuration

Maxime Coquelin maxime.coquelin at redhat.com
Sat Mar 31 09:04:24 CEST 2018



On 03/10/2018 11:01 AM, Zhihong Wang wrote:
> This patch adds APIs for datapath configuration.
> 
> The did of the vhost-user socket can be set to identify the backend device,
> in this case each vhost-user socket can have only 1 connection. The did is
> set to -1 by default when the software datapath is used.
> 
> Signed-off-by: Zhihong Wang <zhihong.wang at intel.com>
> ---
> Changes in v4:
> 
>   1. Remove the "engine" concept in the lib.
> 
>   lib/librte_vhost/rte_vhost.h           | 35 +++++++++++++++++++++++++++++++++
>   lib/librte_vhost/rte_vhost_version.map |  3 +++
>   lib/librte_vhost/socket.c              | 36 ++++++++++++++++++++++++++++++++++
>   lib/librte_vhost/vhost.c               | 25 +++++++++++++++++++++++
>   lib/librte_vhost/vhost.h               |  9 +++++++++
>   5 files changed, 108 insertions(+)
> 
> diff --git a/lib/librte_vhost/rte_vhost.h b/lib/librte_vhost/rte_vhost.h
> index 671ea5053..d50f4c67d 100644
> --- a/lib/librte_vhost/rte_vhost.h
> +++ b/lib/librte_vhost/rte_vhost.h
> @@ -200,6 +200,30 @@ int rte_vhost_driver_register(const char *path, uint64_t flags);
>   int rte_vhost_driver_unregister(const char *path);
>   
>   /**
> + * Set the device id, enforce single connection per socket
> + *
> + * @param path
> + *  The vhost-user socket file path
> + * @param did
> + *  Device id
> + * @return
> + *  0 on success, -1 on failure
> + */
> +int __rte_experimental
> +rte_vhost_driver_set_vdpa_did(const char *path, int did);

IIUC, we call this to attach a VDPA device to a Vhost-user port?

What about having this named explicitly? Something like:

rte_vhost_driver_attach_vdpa_did(const char *path, int did)
rte_vhost_driver_detach_vdpa_did(const char *path)

The later would set to did -1

This is not mandatory though

> +
> +/**
> + * Get the device id
> + *
> + * @param path
> + *  The vhost-user socket file path
> + * @return
> + *  Device id, -1 on failure
> + */
> +int __rte_experimental
> +rte_vhost_driver_get_vdpa_did(const char *path);
> +
> +/**
>    * Set the feature bits the vhost-user driver supports.
>    *
>    * @param path
> @@ -464,6 +488,17 @@ int rte_vhost_vring_call(int vid, uint16_t vring_idx);
>    */
>   uint32_t rte_vhost_rx_queue_count(int vid, uint16_t qid);
>   
> +/**
> + * Get vdpa device id for vhost device.
> + *
> + * @param vid
> + *  vhost device ID
> + * @return
> + *  device id
> + */
> +int __rte_experimental
> +rte_vhost_get_vdpa_did(int vid);
> +
>   #ifdef __cplusplus
>   }
>   #endif
> diff --git a/lib/librte_vhost/rte_vhost_version.map b/lib/librte_vhost/rte_vhost_version.map
> index 7bcffb490..6e2d5364a 100644
> --- a/lib/librte_vhost/rte_vhost_version.map
> +++ b/lib/librte_vhost/rte_vhost_version.map
> @@ -64,4 +64,7 @@ EXPERIMENTAL {
>   	rte_vdpa_register_device;
>   	rte_vdpa_unregister_device;
>   	rte_vdpa_find_device_id;
> +	rte_vhost_driver_set_vdpa_did;
> +	rte_vhost_driver_get_vdpa_did;
> +	rte_vhost_get_vdpa_did;
>   } DPDK_18.02;
> diff --git a/lib/librte_vhost/socket.c b/lib/librte_vhost/socket.c
> index cfc31e179..3d58da94e 100644
> --- a/lib/librte_vhost/socket.c
> +++ b/lib/librte_vhost/socket.c
> @@ -52,6 +52,13 @@ struct vhost_user_socket {
>   	uint64_t supported_features;
>   	uint64_t features;
>   
> +	/*
> +	 * Device id to identify a specific backend device.
> +	 * It's set to -1 for the default software implementation.
> +	 * If valid, one socket can have 1 connection only.
> +	 */
> +	int did;
I would rename it to something like vdpa_did or even better,
vdpa_dev_id. At least prefix it with vdpa not to confuse the user.

> +
>   	struct vhost_device_ops const *notify_ops;
>   };
>   
> @@ -545,6 +552,35 @@ find_vhost_user_socket(const char *path)
>   }
>   
>   int
> +rte_vhost_driver_set_vdpa_did(const char *path, int did)
> +{
> +	struct vhost_user_socket *vsocket;
> +
> +	pthread_mutex_lock(&vhost_user.mutex);
> +	vsocket = find_vhost_user_socket(path);
> +	if (vsocket)
> +		vsocket->did = did;

I guess it is possible to know whether the did exists
at that time. Maybe we could check this?

> +	pthread_mutex_unlock(&vhost_user.mutex);
> +
> +	return vsocket ? 0 : -1;
> +}
> +
> +int
> +rte_vhost_driver_get_vdpa_did(const char *path)
> +{
> +	struct vhost_user_socket *vsocket;
> +	int did = -1;
> +
> +	pthread_mutex_lock(&vhost_user.mutex);
> +	vsocket = find_vhost_user_socket(path);
> +	if (vsocket)
> +		did = vsocket->did;
> +	pthread_mutex_unlock(&vhost_user.mutex);
> +
> +	return did;
> +}
> +
> +int
>   rte_vhost_driver_disable_features(const char *path, uint64_t features)
>   {
>   	struct vhost_user_socket *vsocket;
> diff --git a/lib/librte_vhost/vhost.c b/lib/librte_vhost/vhost.c
> index f6f12a03b..1740cc1ab 100644
> --- a/lib/librte_vhost/vhost.c
> +++ b/lib/librte_vhost/vhost.c
> @@ -283,6 +283,7 @@ vhost_new_device(void)
>   	dev->vid = i;
>   	dev->flags = VIRTIO_DEV_BUILTIN_VIRTIO_NET;
>   	dev->slave_req_fd = -1;
> +	dev->did = -1;
>   
>   	return i;
>   }
> @@ -311,6 +312,20 @@ vhost_destroy_device(int vid)
>   }
>   
>   void
> +vhost_set_vdpa_did(int vid, int did)
> +{
> +	struct virtio_net *dev = get_device(vid);
> +
> +	if (did < 0)
> +		return;
> +
> +	if (dev == NULL)
> +		return;
> +
> +	dev->did = did;
> +}
> +
> +void
>   vhost_set_ifname(int vid, const char *if_name, unsigned int if_len)
>   {
>   	struct virtio_net *dev;
> @@ -614,3 +629,13 @@ rte_vhost_rx_queue_count(int vid, uint16_t qid)
>   
>   	return *((volatile uint16_t *)&vq->avail->idx) - vq->last_avail_idx;
>   }
> +
> +int rte_vhost_get_vdpa_did(int vid)
> +{
> +	struct virtio_net *dev = get_device(vid);
> +
> +	if (dev == NULL)
> +		return -1;
> +
> +	return dev->did;
> +}
> diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h
> index 2e28e4026..2970c1eab 100644
> --- a/lib/librte_vhost/vhost.h
> +++ b/lib/librte_vhost/vhost.h
> @@ -19,6 +19,7 @@
>   #include <rte_rwlock.h>
>   
>   #include "rte_vhost.h"
> +#include "rte_vdpa.h"
>   
>   /* Used to indicate that the device is running on a data core */
>   #define VIRTIO_DEV_RUNNING 1
> @@ -239,6 +240,12 @@ struct virtio_net {
>   	struct guest_page       *guest_pages;
>   
>   	int			slave_req_fd;
> +
> +	/*
> +	 * Device id to identify a specific backend device.
> +	 * It's set to -1 for the default software implementation.
> +	 */
> +	int			did;

Same as for struct vhost_user_socket, it would be less confusing to
prefix it with vdpa.

>   } __rte_cache_aligned;
>   
>   
> @@ -365,6 +372,8 @@ void free_vq(struct vhost_virtqueue *vq);
>   
>   int alloc_vring_queue(struct virtio_net *dev, uint32_t vring_idx);
>   
> +void vhost_set_vdpa_did(int vid, int did);
> +
>   void vhost_set_ifname(int, const char *if_name, unsigned int if_len);
>   void vhost_enable_dequeue_zero_copy(int vid);
>   void vhost_set_builtin_virtio_net(int vid, bool enable);
> 


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