From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?iso-8859-1?Q?Ga=EBtan?= Rivet Subject: Re: [PATCH v7 13/15] eal: add hotplug add/remove functions Date: Fri, 30 Jun 2017 18:13:51 +0200 Message-ID: <20170630161351.GO13355@bidouze.vm.6wind.com> References: <20170630092017.GA18672@bricha3-MOBL3.ger.corp.intel.com> <1838805.2PTbaQPJV0@xps> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Cc: Jan Blunck , Bruce Richardson , dev@dpdk.org, Shreyansh Jain To: Thomas Monjalon Return-path: Received: from mail-wm0-f47.google.com (mail-wm0-f47.google.com [74.125.82.47]) by dpdk.org (Postfix) with ESMTP id 2E00916E for ; Fri, 30 Jun 2017 18:14:00 +0200 (CEST) Received: by mail-wm0-f47.google.com with SMTP id b184so50921457wme.1 for ; Fri, 30 Jun 2017 09:14:00 -0700 (PDT) Content-Disposition: inline In-Reply-To: <1838805.2PTbaQPJV0@xps> List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On Fri, Jun 30, 2017 at 06:03:17PM +0200, Thomas Monjalon wrote: > 30/06/2017 17:44, Jan Blunck: > > On Fri, Jun 30, 2017 at 11:20 AM, Bruce Richardson > > wrote: > > > On Fri, Jun 30, 2017 at 11:11:42AM +0200, Gaėtan Rivet wrote: > > >> On Fri, Jun 30, 2017 at 11:06:03AM +0200, Thomas Monjalon wrote: > > >> > 29/06/2017 20:22, Jan Blunck: > > >> > > /** > > >> > > + * Hotplug add a given device to a specific bus. > > >> > > + * > > >> > > + * @param busname > > >> > > + * The bus name the device is added to. > > >> > > + * @param devname > > >> > > + * The device name. Based on this device name, eal will identify a driver > > >> > > + * capable of handling it and pass it to the driver probing function. > > >> > > + * @param devargs > > >> > > + * Device arguments to be passed to the driver. > > >> > > + * @return > > >> > > + * 0 on success, negative on error. > > >> > > + */ > > >> > > +int rte_eal_hotplug_add(const char *busname, const char *devname, > > >> > > + const char *devargs); > > >> > > > >> > After the hotplug, we may need to get the rte_device. > > >> > Should we add a struct **rte_device as parameter, > > >> > or should we add a helper function to get the rte_device > > >> > from busname and devname? > > >> > > >> Also possible: return a struct *rte_device and set rte_errno on error. > > >> > > > +1 for this option. > > > > Given that the caller of this is usually something that injects events > > from the system I wonder what it is going to do with a rte_device > > reference. Additionally to what the caller knows anyway (name, > > numa_node, devargs) it can check if a driver got assigned. Sure the > > caller could upcast conditionally based on the busname ... > > > > At this point I guess the control plane would anyway want to get > > access to a high-level object, e.g. the rte_ethdev. I believe it is > > better to decouple this through callbacks that can get registered with > > individual buses. > > I think Gaetan has an example of use of rte_device after plugging > with the failsafe PMD (managing slaves). > Anyway, it can be discussed later with a real example of use if needed. > We have a couple of weeks before freezing the API. The rte_device should be accessible from the rte_eth_dev anyway so it does not make much difference. As long as a handle on the device is available. It is of course possible to add yet another callback to search the device just plugged, but I don't see a reason here not to do it in one pass. -- Gaëtan Rivet 6WIND