[Qemu-devel] [PATCH 0/3] Migration cancel with dead network

[Dr. David Alan Gilbert (git)]

From: "Dr. David Alan Gilbert" <address@hidden>

If the remote host, or networking dies during a migration, the socket can be
waiting for a long timeout, and migration_cancel can't complete the cancel
for a long time (and you can't start a new one to somewhere else).
(Where 'long' is the TCP timeout, that's ~15 mins)

This patch set uses the shutdown(2) syscall to unblock any write/sends that
are in progress to let the migrate_cancel happen quickly.

  1/3: socket shutdown  - An updated patch from my postcopy world to
                          add a shut_down method on QEMUFile - only
                          for 'socket' (where the syscall is supported).

  2/3: Handle bi-directional communication for fd migration
                        - A patch from Cristian Klein to use the socket
                          QEMUFile for FDs that are passed in, if the FDs
                          are sockets; this is needed so that libvirt
                          migrations can take advantage of the other patches.
                          Again this patch (and its naming) come from the
                          postcopy world.

  3/3: migration_cancel: shutdown migration socket
                        - A new patch that uses the shutdown in 
migrate_fd_cancel


Note this does not fix the timeout if you try to migrate to an already dead 
host;
the connect timeout is typically a much shorter 2 minutes anyway.

Dave

Cristian Klein (1):
  Handle bi-directional communication for fd migration

Dr. David Alan Gilbert (2):
  socket shutdown
  migration_cancel: shutdown migration socket

 include/migration/qemu-file.h | 10 ++++++++++
 include/qemu/sockets.h        |  7 +++++++
 migration/fd.c                | 24 ++++++++++++++++++++++--
 migration/migration.c         | 12 ++++++++++++
 migration/qemu-file-unix.c    | 23 +++++++++++++++++++----
 migration/qemu-file.c         | 12 ++++++++++++
 6 files changed, 82 insertions(+), 6 deletions(-)

-- 
2.1.0