Re: [dpdk-dev] [EXT] Re: [PATCH] bus/pci: restricted bus scanning to allowed devices

[Sunil Kumar Kori <skori@marvell.com>]

Hello Stephen,
Any suggestions ? 

Regards
Sunil Kumar Kori

>-----Original Message-----
>From: dev <dev-bounces@dpdk.org> On Behalf Of Sunil Kumar Kori
>Sent: Tuesday, December 17, 2019 4:30 PM
>To: Stephen Hemminger <stephen@networkplumber.org>
>Cc: dev@dpdk.org
>Subject: Re: [dpdk-dev] [EXT] Re: [PATCH] bus/pci: restricted bus scanning to
>allowed devices
>
>
>
>Regards
>Sunil Kumar Kori
>
>>-----Original Message-----
>>From: Stephen Hemminger <stephen@networkplumber.org>
>>Sent: Monday, December 16, 2019 9:43 PM
>>To: Sunil Kumar Kori <skori@marvell.com>
>>Cc: dev@dpdk.org
>>Subject: [EXT] Re: [dpdk-dev] [PATCH] bus/pci: restricted bus scanning
>>to allowed devices
>>
>>External Email
>>
>>----------------------------------------------------------------------
>>> 			/* Create dummy pci device to get devargs */
>>> +			dummy_dev.addr.domain =
>>matches[i].pc_sel.pc_domain;
>>> +			dummy_dev.addr.bus = matches[i].pc_sel.pc_bus;
>>> +			dummy_dev.addr.devid = matches[i].pc_sel.pc_dev;
>>> +			dummy_dev.addr.function =
>>matches[i].pc_sel.pc_func;
>>> +			dummy_dev.device.devargs =
>>> +
>>	pci_devargs_lookup(&dummy_dev);
>>> +
>>> +			/* Check that device should be ignored or not  */
>>> +			if (pci_ignore_device(&dummy_dev))
>>> +				continue;
>>
>>It seems that you are creating dummy_dev as an alternative to passing
>>just the PCI bus/device/function. Wouldn't be easier to just use BDF
>>instead. Dummy arguments on the stack can lead to more corner cases in
>>the future if device subsystem changes.
>Agreed and initially I have implemented using BDF only instead of using
>dummy device.
>But using that approach, I was not able to use existing APIs to get devargs and
>ignore device.
>I had to write almost same functions to solve the purpose. So just to avoid
>having replica of same code, I followed this approach. Please suggest.
>>
>>> +/**
>>> + * Get the devargs of a PCI device.
>>> + *
>>> + * @param pci_dev
>>> + *	PCI device to be validated
>>> + * @return
>>> + *	devargs on succes, NULL otherwise
>>> + */
>>> +struct rte_devargs *pci_devargs_lookup(struct rte_pci_device
>>> +*pci_dev);
>>
>>Must be marked experimental (or internal).
>>The pci_device should be marked const.
>Okay but If I go with BDF one then this change is not required anyway.
>>
>>
>>> +
>>> +/**
>>> + * Validate whether a pci device should be ignored or not.
>>> + *
>>> + * @param pci_dev
>>> + *	PCI device to be validated
>>> + * @return
>>> + *	1 if device is to be ignored, 0 otherwise
>>> + */
>>> +bool pci_ignore_device(const struct rte_pci_device *pci_dev);
>>
>>ditto
>ditto