RE: [Patch v6 01/18] net/mana: add basic driver, build environment and doc

[Long Li <longli@microsoft.com>]

> Subject: Re: [Patch v6 01/18] net/mana: add basic driver, build environment and
> doc
> 
> On 2022/8/31 6:51, longli@linuxonhyperv.com wrote:
> > From: Long Li <longli@microsoft.com>
> >
> > MANA is a PCI device. It uses IB verbs to access hardware through the
> > kernel RDMA layer. This patch introduces build environment and basic
> > device probe functions.
> >
> > Signed-off-by: Long Li <longli@microsoft.com>
> 
> ...
> 
> > +static int mana_mp_primary_handle(const struct rte_mp_msg *mp_msg,
> > +				  const void *peer)
> > +{
> > +	struct rte_eth_dev *dev;
> > +	const struct mana_mp_param *param =
> > +		(const struct mana_mp_param *)mp_msg->param;
> > +	struct rte_mp_msg mp_res = { 0 };
> > +	struct mana_mp_param *res = (struct mana_mp_param
> *)mp_res.param;
> > +	int ret;
> > +	struct mana_priv *priv;
> > +
> > +	if (!rte_eth_dev_is_valid_port(param->port_id)) {
> > +		DRV_LOG(ERR, "MP handle port ID %u invalid", param->port_id);
> > +		return -ENODEV;
> > +	}
> > +
> > +	dev = &rte_eth_devices[param->port_id];
> > +	priv = dev->data->dev_private;
> > +
> > +	mp_init_msg(&mp_res, param->type, param->port_id);
> > +
> > +	switch (param->type) {
> > +	case MANA_MP_REQ_VERBS_CMD_FD:
> > +		mp_res.num_fds = 1;
> > +		mp_res.fds[0] = priv->ib_ctx->cmd_fd;
> 
> The cmd_fd is system level handler?
> 
> If it's process private handler, it should not used directly in another process.

According to rte_mp_xxx semantics, the file handle is duplicated to another process. It's not directly used. It's required for secondary process to map to the same doorbell pages.

> 
> > +		res->result = 0;
> > +		ret = rte_mp_reply(&mp_res, peer);
> > +		break;
> > +
> > +	default:
> > +		DRV_LOG(ERR, "Port %u unknown primary MP type %u",
> > +			param->port_id, param->type);
> > +		ret = -EINVAL;
> > +	}
> > +
> > +	return ret;
> > +}
> > +