iflib: Changes for ixlv(4) update

[erj]

Summary

• Add IFLIB_ADMIN_ALWAYS_RUN check to IOV task function so PF driver does not need to be up to handle VFLR events from VF

• Add public iflib_request_reset() function so ixlv(4) can request a full up/down cycle after a HW VF reset; this just sets the IFC_DO_RESET flag so init runs again when _task_fn_admin next runs

[erj]

I need to add the state lock to iflib_request_reset

[erj]

• iflib: Prevent kernel panic on detach in _task_fn_admin by checking if in detach
• iflib: Add STATE_LOCK() around flag setting in iflib_request_reset()

[erj]

• iflib: Free remaining interrupt resources on failure in iflib_device_register()
• iflib: Free RX queue TCP LRO memory on unload

[erj]

sys/net/iflib.c

258–259

Can I get feedback on whether it's ok to use an atomic flag like this?

264

Ditto

[mmacy]

I'm confused; this is just doing a normal store / load for the in detach - you need a lock to serialize reading it with other operations.

[erj]

• iflib: Destroy state lock at end of iflib_device_deregister()
• iflib: Move ifc_in_detach variable to flag in if_ctx_t's ifc_flags, and lock around it

[erj]

In D16428#360259, @mmacy wrote:

I'm confused; this is just doing a normal store / load for the in detach - you need a lock to serialize reading it with other operations.

Does moving the in_detach value to ifc_flags and making sure to use the STATE_LOCK() when accessing it work?

Though honestly, I wonder if this whole "IFLIB_ADMIN_ALWAYS_RUN" in _task_fn_admin is a bad idea. Maybe we need something like iflib_timer(), but one that doesn't get started/stopped when the driver goes up or down. But 12 is coming soon, and ixlv(4) currently depends on these changes.

[erj]

• Revert "iflib: Free RX queue TCP LRO memory on unload"