Re: [dpdk-dev] [PATCH v3 3/8] vhost: make some vDPA callbacks mandatory

["Xia, Chenbo" <chenbo.xia@intel.com>]

> -----Original Message-----
> From: Adrian Moreno <amorenoz@redhat.com>
> Sent: Monday, July 6, 2020 7:25 PM
> To: dev@dpdk.org; Xia, Chenbo <chenbo.xia@intel.com>; Ye, Xiaolong
> <xiaolong.ye@intel.com>; shahafs@mellanox.com; matan@mellanox.com;
> maxime.coquelin@redhat.com; Wang, Xiao W <xiao.w.wang@intel.com>;
> viacheslavo@mellanox.com
> Cc: jasowang@redhat.com; lulu@redhat.com
> Subject: [PATCH v3 3/8] vhost: make some vDPA callbacks mandatory
> 
> From: Maxime Coquelin <maxime.coquelin@redhat.com>
> 
> Some of the vDPA callbacks have to be implemented for vDPA to work properly.
> 
> This patch marks them as mandatory in the API doc and simplify code calling
> these ops with removing unnecessary checks that are now done at registration
> time.
> 
> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
> ---
>  lib/librte_vhost/rte_vdpa_dev.h | 14 ++++++++------
>  lib/librte_vhost/socket.c       |  6 +++---
>  lib/librte_vhost/vdpa.c         | 10 ++++++++++
>  lib/librte_vhost/vhost.c        |  2 +-
>  lib/librte_vhost/vhost_user.c   |  6 ++----
>  5 files changed, 24 insertions(+), 14 deletions(-)
> 
> diff --git a/lib/librte_vhost/rte_vdpa_dev.h b/lib/librte_vhost/rte_vdpa_dev.h
> index 65557cb05..89444c2ea 100644
> --- a/lib/librte_vhost/rte_vdpa_dev.h
> +++ b/lib/librte_vhost/rte_vdpa_dev.h
> @@ -15,24 +15,26 @@
>   * vdpa device operations
>   */
>  struct rte_vdpa_dev_ops {
> -	/** Get capabilities of this device */
> +	/** Get capabilities of this device (Mandatory) */
>  	int (*get_queue_num)(struct rte_vdpa_device *dev, uint32_t
> *queue_num);
> 
> -	/** Get supported features of this device */
> +	/** Get supported features of this device (Mandatory) */
>  	int (*get_features)(struct rte_vdpa_device *dev, uint64_t *features);
> 
> -	/** Get supported protocol features of this device */
> +	/** Get supported protocol features of this device (Mandatory) */
>  	int (*get_protocol_features)(struct rte_vdpa_device *dev,
>  			uint64_t *protocol_features);
> 
> -	/** Driver configure/close the device */
> +	/** Driver configure the device (Mandatory) */
>  	int (*dev_conf)(int vid);
> +
> +	/** Driver close the device (Mandatory) */
>  	int (*dev_close)(int vid);
> 
> -	/** Enable/disable this vring */
> +	/** Enable/disable this vring (Mandatory) */
>  	int (*set_vring_state)(int vid, int vring, int state);
> 
> -	/** Set features when changed */
> +	/** Set features when changed (Mandatory) */
>  	int (*set_features)(int vid);
> 
>  	/** Destination operations when migration done */ diff --git
> a/lib/librte_vhost/socket.c b/lib/librte_vhost/socket.c index
> 49267cebf..047d9395d 100644
> --- a/lib/librte_vhost/socket.c
> +++ b/lib/librte_vhost/socket.c
> @@ -701,7 +701,7 @@ rte_vhost_driver_get_features(const char *path,
> uint64_t *features)
>  	}
> 
>  	vdpa_dev = vsocket->vdpa_dev;
> -	if (!vdpa_dev || !vdpa_dev->ops->get_features) {
> +	if (!vdpa_dev) {
>  		*features = vsocket->features;
>  		goto unlock_exit;
>  	}
> @@ -754,7 +754,7 @@ rte_vhost_driver_get_protocol_features(const char
> *path,
>  	}
> 
>  	vdpa_dev = vsocket->vdpa_dev;
> -	if (!vdpa_dev || !vdpa_dev->ops->get_protocol_features) {
> +	if (!vdpa_dev) {
>  		*protocol_features = vsocket->protocol_features;
>  		goto unlock_exit;
>  	}
> @@ -794,7 +794,7 @@ rte_vhost_driver_get_queue_num(const char *path,
> uint32_t *queue_num)
>  	}
> 
>  	vdpa_dev = vsocket->vdpa_dev;
> -	if (!vdpa_dev || !vdpa_dev->ops->get_queue_num) {
> +	if (!vdpa_dev) {
>  		*queue_num = VHOST_MAX_QUEUE_PAIRS;
>  		goto unlock_exit;
>  	}
> diff --git a/lib/librte_vhost/vdpa.c b/lib/librte_vhost/vdpa.c index
> ef21ca2a1..ae6fdd24e 100644
> --- a/lib/librte_vhost/vdpa.c
> +++ b/lib/librte_vhost/vdpa.c
> @@ -77,6 +77,16 @@ rte_vdpa_register_device(struct rte_device *rte_dev,
>  	if (ops == NULL)
>  		return NULL;
> 
> +	/* Check mandatory ops are implemented */
> +	if (!ops->get_queue_num || !ops->get_features ||
> +			!ops->get_protocol_features || !ops->dev_conf ||
> +			!ops->dev_close || !ops->set_vring_state ||
> +			!ops->set_features) {
> +		VHOST_LOG_CONFIG(ERR,
> +				"Some mandatory vDPA ops aren't
> implemented\n");
> +		return NULL;
> +	}
> +
>  	rte_spinlock_lock(&vdpa_device_list_lock);
>  	/* Check the device hasn't been register already */
>  	dev = __vdpa_find_device_by_name(rte_dev->name);
> diff --git a/lib/librte_vhost/vhost.c b/lib/librte_vhost/vhost.c index
> aa1424261..da461e843 100644
> --- a/lib/librte_vhost/vhost.c
> +++ b/lib/librte_vhost/vhost.c
> @@ -646,7 +646,7 @@ vhost_destroy_device_notify(struct virtio_net *dev)
> 
>  	if (dev->flags & VIRTIO_DEV_RUNNING) {
>  		vdpa_dev = dev->vdpa_dev;
> -		if (vdpa_dev && vdpa_dev->ops->dev_close)
> +		if (vdpa_dev)
>  			vdpa_dev->ops->dev_close(dev->vid);
>  		dev->flags &= ~VIRTIO_DEV_RUNNING;
>  		dev->notify_ops->destroy_device(dev->vid);
> diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c index
> ff8b1752b..6be5c771b 100644
> --- a/lib/librte_vhost/vhost_user.c
> +++ b/lib/librte_vhost/vhost_user.c
> @@ -398,7 +398,7 @@ vhost_user_set_features(struct virtio_net **pdev, struct
> VhostUserMsg *msg,
>  	}
> 
>  	vdpa_dev = dev->vdpa_dev;
> -	if (vdpa_dev && vdpa_dev->ops->set_features)
> +	if (vdpa_dev)
>  		vdpa_dev->ops->set_features(dev->vid);
> 
>  	return RTE_VHOST_MSG_RESULT_OK;
> @@ -2849,9 +2849,7 @@ vhost_user_msg_handler(int vid, int fd)
>  		goto out;
> 
>  	if (!(dev->flags & VIRTIO_DEV_VDPA_CONFIGURED)) {
> -		if (vdpa_dev->ops->dev_conf)
> -			vdpa_dev->ops->dev_conf(dev->vid);
> -
> +		vdpa_dev->ops->dev_conf(dev->vid);
>  		dev->flags |= VIRTIO_DEV_VDPA_CONFIGURED;
>  	}
> 
> --
> 2.26.2

Reviewed-by: Chenbo Xia <chenbo.xia@intel.com>