Re: kern/56857: ixg(4) doesn't work in legacy interrupt mode

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

On Thu, May 26, 2022 at 11:35:01AM +0000, bouyer%antioche.eu.org@localhost wrote:
>  [...]
> 
> 	cause igx(4) device to fail to receive packet (or to receive them
> 	with very high latency). Other devices, including nvme(4) and wm(4)
> 	works fine in legacy mode. This is a show stopper for Xen (see PR
> 	kern/55667).
> 	The device works fine with MSI-X. I coulnd't test with MSI as
> 	disabling only MSI-X cause the kernel to panic (probably unrelated to
> 	igx(4)), but experiments with Xen suggest that it fails too.

Restricting the Xen dom0 to a single CPU makes ixg work with MSI.
So maybe the issue is that too much queues are allocated when one interrupt
per queue is not available ?

-- 
Manuel Bouyer <bouyer%antioche.eu.org@localhost>
     NetBSD: 26 ans d'experience feront toujours la difference
--