[PATCH v2 0/3] migration: Fix disorder of channel creations

[Peter Xu <peterx@redhat.com>]

This patchset is rebased to Juan's latest pull request:
Based-on: <20230202160640.2300-1-quintela@redhat.com>

I can trigger disordered connections with preempt mode postcopy (1 out of a
few attemps), which can cause migration to hang during precopy phase, if
e.g. I set the NIC packet loss rate to 50%.

Patch 1 is IMHO a cleanup that I'd think good to have even without patch
2/3.  Patch 3 actually fixes the ordering issue.  For each of the patch,
please refer to the commit message and comments in-code.

Any comment welcomed, thanks.

Peter Xu (3):
  migration: Rework multi-channel checks on URI
  migration: Add a semaphore to count PONGs
  migration: Postpone postcopy preempt channel to be after main

 migration/migration.c    | 121 ++++++++++++++++++++++++++-------------
 migration/migration.h    |  15 ++++-
 migration/multifd.c      |  12 +---
 migration/postcopy-ram.c |  31 +++++-----
 migration/postcopy-ram.h |   4 +-
 migration/savevm.c       |   6 +-
 6 files changed, 117 insertions(+), 72 deletions(-)

-- 
2.37.3