On Fri, 2 Dec 2022 03:27:38 +0000 Rongwei Liu <rongw...@nvidia.com> wrote:
> > > > The state of the devices and the system is really unstable if this fails. > > There is > > no rollback here. > > > Assume application is calling rte_eth_process_set_primary(false); > Once failed, call all preceding successful ports as > rte_eth_process_set_primary(true); > What do you think? > > I think this should have a PMD capability flag so that application can check > > that device supports doing this. And it would have to be opt-in so that > > existing > > devices would always fail. > If device doesn't support it, it can set the ethdev callback to NULL or > return failure for all devices. > Then the devices' state will be consistent. Assume there are two DPDK ports. If the application tries to change roles and one of the devices does not support the change over, then that error is fatal. The first device has changed state already, and the second doesn't allow it. This needs to be a capability flag for the device, and would need an additional flag in the device documentation as well. I bet many devices do regular malloc or mmap in the primary process and that is not going to work with this change.
