[dpdk-dev] [PATCH v2] net/bonding: support bifurcated driver in eal cli using --vdev

[gowrishankar muthukrishnan]

Hi Thomas,
I will rework on my patch with these suggestions and send new version.
Thanks Declan and Gaëtan. Thank you Thomas too reminding me.

Regards,
Gowrishankar

On Tuesday 05 September 2017 02:43 PM, Thomas Monjalon wrote:
> Ping - any news?
>
> 31/07/2017 16:34, Gaëtan Rivet:
>> Hi Gowrishankar, Declan,
>>
>> On Mon, Jul 10, 2017 at 12:02:24PM +0530, gowrishankar muthukrishnan wrote:
>>> On Friday 07 July 2017 09:08 PM, Declan Doherty wrote:
>>>> On 04/07/2017 12:57 PM, Gowrishankar wrote:
>>>>> From: Gowrishankar Muthukrishnan <gowrishankar.m at linux.vnet.ibm.com>
>>>>>
>>>>> At present, creating bonding devices using --vdev is broken for PMD like
>>>>> mlx5 as it is neither UIO nor VFIO based and hence PMD driver is unknown
>>>>> to find_port_id_by_pci_addr(), as below.
>>>>>
>>>>> testpmd <EAL args> --vdev 'net_bonding0,mode=1,slave=<PCI>,socket_id=0'
>>>>>
>>>>> PMD: bond_ethdev_parse_slave_port_kvarg(150) - Invalid slave port value
>>>>> (<PCI ID>) specified
>>>>> EAL: Failed to parse slave ports for bonded device net_bonding0
>>>>>
>>>>> This patch fixes parsing PCI ID from bonding device params by verifying
>>>>> it in RTE PCI bus, rather than checking dev->kdrv.
>>>>>
>>>>> Changes:
>>>>>   v2 - revisit fix by iterating rte_pci_bus
>>>>>
>>>>> Signed-off-by: Gowrishankar Muthukrishnan
>>>>> <gowrishankar.m at linux.vnet.ibm.com>
>>>>> ---
>>>> ...
>>>> Hey Gowrishankar,
>>>>
>>>> I was having a look at this patch and there is the following checkpatch
>>>> error.
>>>>
>>>> _coding style issues_
>>>>
>>>>
>>>> WARNING:AVOID_EXTERNS: externs should be avoided in .c files
>>>> #48: FILE: drivers/net/bonding/rte_eth_bond_args.c:43:
>>>> +extern struct rte_pci_bus rte_pci_bus;
>>>>
>>> Hi Declan,
>>> Thank you for your review.
>>> Yes, but I also saw some references like above in older code.
>>>
>>>> Looking at bit closer at the issue I think there is a simpler solution,
>>>> the bonding driver really shouldn't be parsing the PCI bus directly, and
>>>> since PCI devices use the PCI DBF as their name we can simply replace the
>>>> all the scanning code with a simple call to rte_eth_dev_get_port_by_name
>>>> API.
>>>>
>> I agree that it would be better to be able to use the ether API for
>> this.
>>
>> The issue is that PCI devices are inconsistent regarding their names. The
>> possibility is given to the user to employ the simplified BDF format for
>> PCI device name, instead of the DomBDF format.
>>
>> Unfortunately, the default device name for a PCI device is in the DomBDF
>> format. This means that the name won't match if the device was probed by
>> using the PCI blacklist mode (the default PCI mode).
>>
>> The matching must be refined.
>>
>>> But you are removing an option to mention ports by PCI addresses right  (as
>>> I see parse_port_id() completely removed in your patch) ?.
>>> IMO, we just need to check if given eth pci id (incase we mention ports ib
>>> PCI ID) is one of what EAL scanned in PCI. Also, slaves should not be from
>>> any blacklisted PCI ids (as we test with -b or -w).
>>>
>> Declan is right about the iteration of PCI devices. The device list for
>> the PCI bus is private, the extern declaration to the rte_pci_bus is the
>> telltale sign that there is something wrong in the approach here.
>>
>> In order to respect the new rte_bus logic, I think what you want to
>> achieve can be done by using the rte_bus->find_device with the correct
>> device comparison function.
>>
>> static int
>> pci_addr_cmp(const struct rte_device *dev, const void *_pci_addr)
>> {
>>      struct rte_pci_device *pdev;
>>      char *addr = _pci_addr;
>>      struct rte_pci_addr paddr;
>>      static struct rte_bus *pci_bus = NULL;
>>
>>      if (pci_bus == NULL)
>>          pci_bus = rte_bus_find_by_name("pci");
>>
>>      if (pci_bus->parse(addr, &paddr) != 0) {
>>          /* Invalid PCI addr given as input. */
>>          return -1;
>>      }
>>      pdev = RTE_DEV_TO_PCI(dev);
>>      return rte_eal_compare_pci_addr(&pdev->addr, &paddr);
>> }
>>
>> Then verify that you are able to get a device by using it as follows:
>>
>> {
>>      struct rte_bus *pci_bus;
>>      struct rte_device *dev;
>>
>>      pci_bus = rte_bus_find_by_name("pci");
>>      if (pci_bus == NULL) {
>>          RTE_LOG(ERR, PMD, "Unable to find PCI bus\n");
>>          return -1;
>>      }
>>      dev = pci_bus->find_device(NULL, pci_addr_cmp, devname);
>>      if (dev == NULL) {
>>          RTE_LOG(ERR, PMD, "Unable to find the device %s to enslave.\n",
>>                  devname);
>>          return -EINVAL;
>>      }
>> }
>>
>> I hope it's clear enough. You can find examples of use for this API in
>> lib/librte_eal/common/eal_common_dev.c
>>
>> It's a quick implementation to outline the possible direction, I
>> haven't compiled it. It should be refined.
>>
>> For example, the PCI address validation should not be happening in the
>> comparison function, the pci_bus could be matched once instead of twice,
>> etc...
>>
>> But the logic should work.
>>
>> Best regards,
>>
>
>