From mboxrd@z Thu Jan  1 00:00:00 1970
From: "Burakov, Anatoly" <anatoly.burakov@intel.com>
Subject: Re: [PATCH v6 05/19] ethdev: support attach or detach
 share device from secondary
Date: Thu, 28 Jun 2018 10:23:41 +0100
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References: <20180607123849.14439-1-qi.z.zhang@intel.com>
 <20180628015247.42232-1-qi.z.zhang@intel.com>
 <20180628015247.42232-6-qi.z.zhang@intel.com>
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Cc: konstantin.ananyev@intel.com, dev@dpdk.org, bruce.richardson@intel.com,
 ferruh.yigit@intel.com, benjamin.h.shelton@intel.com,
 narender.vangati@intel.com
To: Qi Zhang <qi.z.zhang@intel.com>, thomas@monjalon.net
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On 28-Jun-18 2:52 AM, Qi Zhang wrote:
> This patch cover the multi-process hotplug case when a share device
> attach/detach request be issued from secondary process
> 
> device attach on secondary:
> a) seconary send sync request to primary.
> b) primary receive the request and attach the new device if failed
>     goto i).
> c) primary forward attach sync request to all secondary.
> d) secondary receive request and attach device and send reply.
> e) primary check the reply if all success go to j).
> f) primary send attach rollback sync request to all secondary.
> g) secondary receive the request and detach device and send reply.
> h) primary receive the reply and detach device as rollback action.
> i) send fail reply to secondary, goto k).
> j) send success reply to secondary.
> k) secondary process receive reply of step a) and return.
> 
> device detach on secondary:
> a) secondary send sync request to primary
> b) primary receive the request and perform pre-detach check, if device
>     is locked, goto j).
> c) primary send pre-detach sync request to all secondary.
> d) secondary perform pre-detach check and send reply.
> e) primary check the reply if any fail goto j).
> f) primary send detach sync request to all secondary
> g) secondary detach the device and send reply
> h) primary detach the device.
> i) send success reply to secondary, goto k).
> j) send fail reply to secondary.
> k) secondary process receive reply of step a) and return.
> 
> Signed-off-by: Qi Zhang <qi.z.zhang@intel.com>
> ---

<snip>

> +	const struct rte_mp_msg *msg = &bundle->msg;
> +	const struct eth_dev_mp_req *req =
> +		(const struct eth_dev_mp_req *)msg->param;
> +	struct eth_dev_mp_req tmp_req;
> +	uint16_t port_id;
> +	int ret = 0;
> +
> +	tmp_req = *req;
> +
> +	if (req->t == REQ_TYPE_ATTACH) {
> +		ret = do_eth_dev_attach(req->devargs, &port_id);
> +		if (!ret) {
> +			tmp_req.port_id = port_id;
> +			ret = eth_dev_request_to_secondary(&tmp_req);
> +		}
> +	} else if (req->t == REQ_TYPE_DETACH) {
> +		if (!rte_eth_dev_is_valid_port(req->port_id))
> +			ret = -EINVAL;
> +		if (!ret)
> +			ret = process_lock_callbacks(req->port_id);
> +		if (!ret) {
> +			tmp_req.t = REQ_TYPE_PRE_DETACH;
> +			ret = eth_dev_request_to_secondary(&tmp_req);
> +		}
> +		if (!ret) {
> +			if (!tmp_req.result) {
> +				tmp_req.t = REQ_TYPE_DETACH;
> +				ret = eth_dev_request_to_secondary(&tmp_req);
> +				if (!ret)
> +					ret = do_eth_dev_detach(req->port_id);
> +			} else {
> +				ret = tmp_req.result;
> +			}
> +		}

This seems like a good opportunity to use goto, rather than checking 
value of ret every step of the way.

> +	} else {
> +		ethdev_log(ERR, "unsupported secondary to primary request\n");
> +		ret = -ENOTSUP;
> +	}
> +
> +	ret = send_response_to_secondary(&tmp_req, ret, bundle->peer);
> +	if (ret)
> +		ethdev_log(ERR, "failed to send response to secondary\n");
> +
> +	free(bundle->peer);
> +	free(bundle);
> +}
> +
> +static int
> +handle_secondary_request(const struct rte_mp_msg *msg,
> +			const void *peer)
>   {
> -	RTE_SET_USED(msg);
> -	RTE_SET_USED(peer);
> -	return -ENOTSUP;
> +	struct mp_reply_bundle *bundle;
> +	const struct eth_dev_mp_req *req =
> +		(const struct eth_dev_mp_req *)msg->param;
> +	int ret = 0;
> +
> +	bundle = malloc(sizeof(*bundle));
> +	if (bundle == NULL) {
> +		ethdev_log(ERR, "not enough memory\n");
> +		return send_response_to_secondary(req, -ENOMEM, peer);
> +	}
> +
> +	bundle->msg = *msg;
> +	/**
> +	 * We need to send reply on interrupt thread, but peer can't be
> +	 * parsed directly, so this is a temporal hack, need to be fixed
> +	 * when it is ready.
> +	 */
> +	bundle->peer = strdup(peer);
> +
> +	ret = rte_eal_alarm_set(1, __handle_secondary_request, bundle);

Again, some comments explaining why this is being done on a separate 
thread would be great.

Otherwise,

Reviewed-by: Anatoly Burakov <anatoly.burakov@intel.com>

-- 
Thanks,
Anatoly