On Wed, Aug 5, 2020 at 1:51 PM Moshe Shemesh <mo...@mellanox.com> wrote: > > > On 8/5/2020 9:55 AM, Vasundhara Volam wrote: > > On Wed, Aug 5, 2020 at 12:02 PM Moshe Shemesh <mo...@mellanox.com> wrote: > >> > >> On 8/4/2020 1:13 PM, Vasundhara Volam wrote: > >>> On Mon, Aug 3, 2020 at 7:23 PM Moshe Shemesh <mo...@mellanox.com> wrote: > >>>> On 8/3/2020 3:47 PM, Vasundhara Volam wrote: > >>>>> On Mon, Aug 3, 2020 at 5:47 PM Moshe Shemesh <mo...@mellanox.com> wrote: > >>>>>> On 8/3/2020 1:24 PM, Vasundhara Volam wrote: > >>>>>>> On Tue, Jul 28, 2020 at 10:13 PM Jacob Keller > >>>>>>> <jacob.e.kel...@intel.com> wrote: > >>>>>>>> On 7/27/2020 10:25 PM, Vasundhara Volam wrote: > >>>>>>>>> On Mon, Jul 27, 2020 at 4:36 PM Moshe Shemesh <mo...@mellanox.com> > >>>>>>>>> wrote: > >>>>>>>>>> Introduce new option on devlink reload API to enable the user to > >>>>>>>>>> select the > >>>>>>>>>> reload level required. Complete support for all levels in mlx5. > >>>>>>>>>> The following reload levels are supported: > >>>>>>>>>> driver: Driver entities re-instantiation only. > >>>>>>>>>> fw_reset: Firmware reset and driver entities > >>>>>>>>>> re-instantiation. > >>>>>>>>> The Name is a little confusing. I think it should be renamed to > >>>>>>>>> fw_live_reset (in which both firmware and driver entities are > >>>>>>>>> re-instantiated). For only fw_reset, the driver should not undergo > >>>>>>>>> reset (it requires a driver reload for firmware to undergo reset). > >>>>>>>>> > >>>>>>>> So, I think the differentiation here is that "live_patch" doesn't > >>>>>>>> reset > >>>>>>>> anything. > >>>>>>> This seems similar to flashing the firmware and does not reset > >>>>>>> anything. > >>>>>> The live patch is activating fw change without reset. > >>>>>> > >>>>>> It is not suitable for any fw change but fw gaps which don't require > >>>>>> reset. > >>>>>> > >>>>>> I can query the fw to check if the pending image change is suitable or > >>>>>> require fw reset. > >>>>> Okay. > >>>>>>>>>> fw_live_patch: Firmware live patching only. > >>>>>>>>> This level is not clear. Is this similar to flashing?? > >>>>>>>>> > >>>>>>>>> Also I have a basic query. The reload command is split into > >>>>>>>>> reload_up/reload_down handlers (Please correct me if this behaviour > >>>>>>>>> is > >>>>>>>>> changed with this patchset). What if the vendor specific driver does > >>>>>>>>> not support up/down and needs only a single handler to fire a > >>>>>>>>> firmware > >>>>>>>>> reset or firmware live reset command? > >>>>>>>> In the "reload_down" handler, they would trigger the appropriate > >>>>>>>> reset, > >>>>>>>> and quiesce anything that needs to be done. Then on reload up, it > >>>>>>>> would > >>>>>>>> restore and bring up anything quiesced in the first stage. > >>>>>>> Yes, I got the "reload_down" and "reload_up". Similar to the device > >>>>>>> "remove" and "re-probe" respectively. > >>>>>>> > >>>>>>> But our requirement is a similar "ethtool reset" command, where > >>>>>>> ethtool calls a single callback in driver and driver just sends a > >>>>>>> firmware command for doing the reset. Once firmware receives the > >>>>>>> command, it will initiate the reset of driver and firmware entities > >>>>>>> asynchronously. > >>>>>> It is similar to mlx5 case here for fw_reset. The driver triggers the > >>>>>> fw > >>>>>> command to reset and all PFs drivers gets events to handle and do > >>>>>> re-initialization. To fit it to the devlink reload_down and reload_up, > >>>>>> I wait for the event handler to complete and it stops at driver unload > >>>>>> to have the driver up by devlink reload_up. See patch 8 in this > >>>>>> patchset. > >>>>>> > >>>>> Yes, I see reload_down is triggering the reset. In our driver, after > >>>>> triggering the reset through a firmware command, reset is done in > >>>>> another context as the driver initiates the reset only after receiving > >>>>> an ASYNC event from the firmware. > >>>> Same here. > >>>> > >>>>> Probably, we have to use reload_down() to send firmware command to > >>>>> trigger reset and do nothing in reload_up. > >>>> I had that in previous version, but its wrong to use devlink reload this > >>>> way, so I added wait with timeout for the event handling to complete > >>>> before unload_down function ends. See mlx5_fw_wait_fw_reset_done(). Also > >>>> the event handler stops before load back to have that done by devlink > >>>> reload_up. > >>> But "devlink dev reload" will be invoked by the user only on a single > >>> dev handler and all function drivers will be re-instantiated upon the > >>> ASYNC event. reload_down and reload_up are invoked only the function > >>> which the user invoked. > >>> > >>> Take an example of a 2-port (PF0 and PF1) adapter on a single host and > >>> with some VFs loaded on the device. User invokes "devlink dev reload" > >>> on PF0, ASYNC event is received on 2 PFs and VFs for reset. All the > >>> function drivers will be re-instantiated including PF0. > >>> > >>> If we wait for some time in reload_down() of PF0 and then call load in > >>> reload_up(), this code will be different from other function drivers. > >> > >> I see your point here, but the user run devlink reload command on one > >> PF, in this case of fw-reset it will influence other PFs, but that's a > >> result of the fw-reset, the user if asked for params change or namespace > >> change that was for this PF. > > Right, if any driver is implementing only fw-reset have to leave > > reload_up as an empty function. > > > No, its not only up the driver. The netns option is implemented by > devlink and its running between reload_down and reload_up. What I mean is, driver will provide a reload_up handler but it will not do anything and simply return 0. > > >>>>> And returning from reload > >>>>> does not mean that reset is complete as it is done in another context > >>>>> and the driver notifies the health reporter once the reset is > >>>>> complete. devlink framework may have to allow drivers to implement > >>>>> reload_down only to look more clean or call reload_up only if the > >>>>> driver notifies the devlink once reset is completed from another > >>>>> context. Please suggest.
