On Wed, 25 Feb 2026 at 13:09, Bruce Richardson <[email protected]> wrote: > > On Wed, Feb 25, 2026 at 12:29:21PM +0100, David Marchand wrote: > > Some applications use port hotplug as their primary way for using DPDK > > resources. > > Having a systematic device probing is a problem when not all available > > resources will be used by the application, as such applications won't set > > an explicit allow list at startup. > > > > This is the case for OVS on systems with multiple mlx5 devices: > > one device can be used by the kernel while the other(s) are used by DPDK. > > In such a setup, the kernel used device may get reconfigured in > > unexpected ways and trigger issues like the one described by Kevin > > not so long ago in bugzilla 1873. > > > > Add an EAL option to disable device probing, allowing to select per bus. > > > > Note: the current implementation does not take combinations of the new > > option with -a/-b. > > > > Signed-off-by: David Marchand <[email protected]> > > --- > Wondering about this problem and fix options. Rather than a new flag for > no-probe, would an alternative flag to switch the default mode from > block-listing to allow-listing work? > > Right now, by default, EAL probes all buses and tries to take all > non-blocklisted devices. We could add a flag to switch that so that we > allow-list by default, which I think should have the same effect as this if > no -a flags are passed. We already have support for managing -a and -b flag > interactions, which should make interacting with the new flag easier.
I like the idea. The devil is in the details though and I'll have to look carefully at all bus probe() functions. I'll try to implement as a RFC v2. -- David Marchand
