Re: [PATCH net 2/4] ice: Stop processing VF messages during teardown

On Mon, 2021-08-09 at 15:58 -0700, Jakub Kicinski wrote:

On Mon,  9 Aug 2021 10:14:00 -0700 Tony Nguyen wrote:

quoted

When VFs are setup and torn down in quick succession, it is
possible
that a VF is torn down by the PF while the VF's virtchnl requests
are
still in the PF's mailbox ring. Processing the VF's virtchnl
request
when the VF itself doesn't exist results in undefined behavior. Fix
this by adding a check to stop processing virtchnl requests when VF
teardown is in progress.

What is "undefined behavior" in this context? Please improve the
commit
message. It should describe misbehavior visible to the user, failing
that what will happen from kernel/device perspective. Or state that
it's
just a "fix" to align with some internal driver <> firmware spec...

Three different call traces were reported, and that's the reason I
chose to say "undefined behavior" which I suppose isn't very helpful.
Will update the commit message to include more details.

Ani