Merge remote-tracking branch 'remotes/dgilbert/tags/pull-migration-20200828a' into...

Merge remote-tracking branch 'remotes/dgilbert/tags/pull-migration-20200828a' into staging

Migration and virtiofsd pull 2020-08-28

Migration:
   vsock support for migration
   minor fixes

virtiofsd:
   Disable remote posix locks by default - because we
     never supported blocking variants and this breaks things
   Some prep work for un/less priviliged modes

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
# gpg: Signature made Fri 28 Aug 2020 13:43:18 BST
# gpg:                using RSA key 45F5C71B4A0CB7FB977A9FA90516331EBC5BFDE7
# gpg: Good signature from "Dr. David Alan Gilbert (RH2) <dgilbert@redhat.com>" [full]
# Primary key fingerprint: 45F5 C71B 4A0C B7FB 977A  9FA9 0516 331E BC5B FDE7

* remotes/dgilbert/tags/pull-migration-20200828a:
  virtiofsd: probe unshare(CLONE_FS) and print an error
  virtiofsd: drop CAP_DAC_READ_SEARCH
  virtiofsd: Remove "norace" from cmdline help and docs
  virtiofsd: Disable remote posix locks by default
  migration: tls: fix memory leak in migration_tls_get_creds
  migration: improve error reporting of block driver state name
  migration: add vsock as data channel support
  migration: unify the framework of socket-type channel

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>