Re: [PATCH] bus/pci: don't open uio device in secondary process

[Konrad Sztyber <konrad.sztyber@intel.com>]

On 10/7/24 19:49, Stephen Hemminger wrote:
> On Wed, 28 Aug 2024 12:40:02 +0200
> Konrad Sztyber <konrad.sztyber@intel.com> wrote:
> 
>> The uio_pci_generic driver clears the bus master bit when the device
>> file is closed.  So, when the secondary process terminates after probing
>> a device, that device becomes unusable in the primary process.
>>
>> To avoid that, the device file is now opened only in the primary
>> process.  The commit that introduced this regression, 847d78fb95
>> ("bus/pci: fix FD in secondary process"), only mentioned enabling access
>> to config space from secondary process, which still works, as it doesn't
>> rely on the device file.
>>
>> Fixes: 847d78fb95 ("bus/pci: fix FD in secondary process")
>>
>> Signed-off-by: Konrad Sztyber <konrad.sztyber@intel.com>
> 
> Wouldn't this break use of interrupts in the secondary process?

Yes, it will. But I don't think we can support interrupts in the 
secondary process *and*, at the same time, keep the device usable in the 
primary process when secondary terminates. Maybe we could pass the fd 
via SCM_RIGHTS? But I don't know if that results in the same struct file 
being used by both processes.

> The patch does need the minor fix of the comment style.
> So resubmit

I already did, see: 
https://inbox.dpdk.org/dev/20240829085724.270041-1-konrad.sztyber@intel.com