On 18-Oct-18 5:41 PM, Alejandro Lucero wrote:
On Thu, Oct 18, 2018 at 5:26 PM Burakov, Anatoly
<[email protected] <mailto:[email protected]>> wrote:
On 27-Sep-18 1:30 PM, Alejandro Lucero wrote:
> Invoking rte_pci_read/write_config functions requires device with
> a intr_handle type for using VFIO or UIO driver related functions.
>
> Secondary processes rely on primary processes for device
initialization
> so they do not usually require using these functions. However,
some PMDs,
> like NFP PMD, require using these functions even for secondary
processes.
>
> Signed-off-by: Alejandro Lucero <[email protected]
<mailto:[email protected]>>
> ---
Hi Alejandro,
I’m curious of consequences of setting intr handle to a valid value
when
we don’t have an interrupt thread. Something may try to use it
(although
I couldn’t find any such usage).
The point is secondary processes do not deal with interrupts so I assume
setting the type does not change anything but it allows to use PCI
read/write functions by secondary processes.
PCI config read really uses intr handle type to discover userspace
driver type – this seems ever so slightly wrong, and looks like
something that should be part of rte_device somewhere, independent of
interrupt types. Do we have any other alternative to do the same thing
(i.e. know what userspace driver is used for a particular PCI device)?
I agree current way not being specially good.
Your comment has reminded me there is another way: just using the kdrv
field from the rte_pci_device struct. I have code using that field for
doing a different thing in the NFP PMD depending on the driver in use,
UIO or VFIO. So I think a better patch would be just to modify those pci
functions for using kdrv field instead.
Adding Ferruh in the thread for commenting on this potential change.
I definitely think the way you describe would be a better way to fix
this (i.e. use kdrv in PCI config functions rather than intr handle type).
--
Thanks,
Anatoly
