RE: [PATCH v7 07/18] vhost: add API to get vDPA device type

["Pei, Andy" <andy.pei@intel.com>]

Hi Chenbo,

Thanks for your reply.
My reply is inline.

> -----Original Message-----
> From: Xia, Chenbo <chenbo.xia@intel.com>
> Sent: Thursday, May 12, 2022 9:14 PM
> To: Pei, Andy <andy.pei@intel.com>; dev@dpdk.org
> Cc: maxime.coquelin@redhat.com; Cao, Gang <gang.cao@intel.com>; Liu,
> Changpeng <changpeng.liu@intel.com>
> Subject: RE: [PATCH v7 07/18] vhost: add API to get vDPA device type
> 
> > -----Original Message-----
> > From: Pei, Andy <andy.pei@intel.com>
> > Sent: Wednesday, April 27, 2022 4:30 PM
> > To: dev@dpdk.org
> > Cc: Xia, Chenbo <chenbo.xia@intel.com>; maxime.coquelin@redhat.com;
> > Cao, Gang <gang.cao@intel.com>; Liu, Changpeng
> > <changpeng.liu@intel.com>
> > Subject: [PATCH v7 07/18] vhost: add API to get vDPA device type
> >
> > Vhost backend of different devices have different features.
> > Add a API to get vDPA device type, net device or blk device currently,
> > so users can set different features for different kinds of devices.
> >
> > Signed-off-by: Andy Pei <andy.pei@intel.com>
> > ---
> >  lib/vhost/rte_vhost.h   | 17 +++++++++++++++++
> >  lib/vhost/socket.c      | 39 +++++++++++++++++++++++++++++++++++++++
> >  lib/vhost/vdpa_driver.h |  3 +++
> >  lib/vhost/version.map   |  2 ++
> >  4 files changed, 61 insertions(+)
> >
> > diff --git a/lib/vhost/rte_vhost.h b/lib/vhost/rte_vhost.h index
> > c733f85..c977a24 100644
> > --- a/lib/vhost/rte_vhost.h
> > +++ b/lib/vhost/rte_vhost.h
> > @@ -117,6 +117,9 @@
> >
> >  #define RTE_MAX_VHOST_DEVICE	1024
> >
> > +#define VDPA_DEVICE_TYPE_NET 0
> > +#define VDPA_DEVICE_TYPE_BLK 1
> > +
> >  struct rte_vdpa_device;
> >
> >  /**
> > @@ -486,6 +489,20 @@ struct rte_vdpa_device *
> > rte_vhost_driver_get_vdpa_device(const char *path);
> >
> >  /**
> > + * Get the device type of the vdpa device.
> > + *
> > + * @param path
> > + *  The vhost-user socket file path
> > + * @param type
> > + *  the device type of the vdpa device
> > + * @return
> > + *  0 on success, -1 on failure
> > + */
> > +__rte_experimental
> > +int
> > +rte_vhost_driver_get_vdpa_dev_type(const char *path, uint32_t *type);
> > +
> > +/**
> >   * Set the feature bits the vhost-user driver supports.
> >   *
> >   * @param path
> > diff --git a/lib/vhost/socket.c b/lib/vhost/socket.c index
> > b304339..7da90e8 100644
> > --- a/lib/vhost/socket.c
> > +++ b/lib/vhost/socket.c
> > @@ -619,6 +619,45 @@ struct rte_vdpa_device *  }
> >
> >  int
> > +rte_vhost_driver_get_vdpa_dev_type(const char *path, uint32_t *type)
> > +{
> > +	struct vhost_user_socket *vsocket;
> > +	struct rte_vdpa_device *vdpa_dev;
> > +	uint32_t vdpa_type = 0;
> > +	int ret = 0;
> > +
> > +	pthread_mutex_lock(&vhost_user.mutex);
> > +	vsocket = find_vhost_user_socket(path);
> > +	if (!vsocket) {
> > +		VHOST_LOG_CONFIG(ERR,
> > +				 "(%s) socket file is not registered yet.\n",
> > +				 path);
> > +		ret = -1;
> > +		goto unlock_exit;
> > +	}
> > +
> > +	vdpa_dev = vsocket->vdpa_dev;
> > +	if (!vdpa_dev) {
> > +		ret = -1;
> > +		goto unlock_exit;
> > +	}
> > +
> > +	if (vdpa_dev->ops->get_dev_type(vdpa_dev, &vdpa_type) < 0) {
> > +		VHOST_LOG_CONFIG(ERR,
> > +			"(%s) failed to get vdpa dev type for socket file.\n",
> > +			path);
> > +		ret = -1;
> > +		goto unlock_exit;
> > +	}
> 
> If vendor's vdpa driver does not implement this callback, should return type
> NET.
> Another way to do may be make every vdpa driver implement the callback,
> but since other vendors only have one type. I prefer the first way.
> 
Yes, I agree with you. I will send a new version to fix this.
> > +
> > +	*type = vdpa_type;
> > +
> > +unlock_exit:
> > +	pthread_mutex_unlock(&vhost_user.mutex);
> > +	return ret;
> > +}
> > +
> > +int
> >  rte_vhost_driver_disable_features(const char *path, uint64_t
> > features)  {
> >  	struct vhost_user_socket *vsocket;
> > diff --git a/lib/vhost/vdpa_driver.h b/lib/vhost/vdpa_driver.h index
> > e59a834..9cbd7cd 100644
> > --- a/lib/vhost/vdpa_driver.h
> > +++ b/lib/vhost/vdpa_driver.h
> > @@ -78,6 +78,9 @@ struct rte_vdpa_dev_ops {
> >  	/** Set the device configuration space */
> >  	int (*set_config)(int vid, uint8_t *config, uint32_t offset,
> >  		      uint32_t size, uint32_t flags);
> > +
> > +	/** get device type: net device, blk device... */
> > +	int (*get_dev_type)(struct rte_vdpa_device *dev, uint32_t *type);
> >  };
> >
> >  /**
> > diff --git a/lib/vhost/version.map b/lib/vhost/version.map index
> > 0a66c58..fe4e8de 100644
> > --- a/lib/vhost/version.map
> > +++ b/lib/vhost/version.map
> > @@ -87,6 +87,8 @@ EXPERIMENTAL {
> >
> >  	# added in 22.03
> >  	rte_vhost_async_dma_configure;
> > +
> > +	rte_vhost_driver_get_vdpa_dev_type;
> 
> Missed '# added in 22.07' tag, but when you do v8, this may not be a
> problem as other patches may add this tag with new API introduced.
> 
> And introducing new API will need update of release note.
> Please refer to http://git.dpdk.org/next/dpdk-next-
> virtio/commit/?id=868883e899af386abcc298ea80ec7f6a18d8a8e7
> as an example.
> 
> Thanks,
> Chenbo
> 
Sure. I will refer to this.
> >  };
> >
> >  INTERNAL {
> > --
> > 1.8.3.1
>