On Wed, 31 Jul 2024 at 14:35, Ferruh Yigit <ferruh.yi...@amd.com> wrote:
> On 7/30/2024 6:36 AM, Prashant Upadhyaya wrote: > > > > > > > > On Mon, 29 Jul 2024 at 23:13, Dmitry Kozlyuk <dmitry.kozl...@gmail.com > > <mailto:dmitry.kozl...@gmail.com>> wrote: > > > > 2024-07-29 22:18 (UTC+0530), Prashant Upadhyaya: > > > Hi, > > > > > > I have 4 ethernet interfaces available as PCI devices. > > > The PCI addresses are known. > > > When I start my DPDK application, it starts up properly and > > assigns the > > > port numbers to them as 0, 1, 2, 3 expectedly. > > > > > > However, is there a way I can force that a particular PCI address > > should be > > > identified as port 0 by DPDK, another one as port 1 and so forth ? > > > Does passing the arguments like -a <address1> -a <address2> to > > rte_eal_init > > > ensure that, or is there any other way, or is there no way ? > > > > > > I am on 24.03 > > > > > > Regards > > > -Prashant > > > > Hi, > > > > Why do you need specific port numbers assigned to devices? > > > > If you're going to use devices for different purposes, > > you'd better have an application-level configuration > > to specify PCI addresses to use for each purpose. > > Iterate devices to match the address and find the port number. > > > > It is also possible to disable automatic probing with "-a 0:0.0", > > then to use rte_dev_probe() + rte_dev_event_callback_register() > > to add devices and to get their port numbers. > > However, this API, strictly speaking, does not guarantee > > that the numbers will be assigned sequentially. > > One advantage of using hot-plug is that you can build devargs > > from within the application (or from configuration). > > > > Refer to "rte_dev.h" in any case. > > Multiple "-a" don't work the way you've described. > > > > > > > > Thanks Dmitry. Ok, so if I have the port number with me, and I know it > > corresponds to a PCI device, how do I find out the PCI address of this > > device corresponding to this port number. I believe I can > > do rte_eth_dev_info_get to get the struct rte_eth_dev_info and from > > there the rte_device, but what after that ? I saw some references > > to RTE_DEV_TO_PCI but that macro isn't available for compilation after > > DPDK is installed as it is an internal header file and thus not a macro > > for application usage and wouldn't compile at application level. > > > > > > Hi Prashant, > > For PCI bus, most of the times ethdev device name is PCI ID, so you can > use 'rte_eth_dev_get_name_by_port(port_id, name)' API to get PCI ID for > port. > > But there are cases this is not true, like single PCI ID creates > multiple ethdev etc... for this case, PCI ID can be get from device name: > rte_eth_dev_info_get(port_id, *dev_info) > name = rte_dev_name(dev_info->device) > > > Thanks Ferruh, this was helpful. Regards -Prashant
