Merge remote-tracking branch 'remotes/dgilbert-gitlab/tags/pull-virtiofs-20210916...

Merge remote-tracking branch 'remotes/dgilbert-gitlab/tags/pull-virtiofs-20210916' into staging

virtiofsd pull 2021-08-16

Two minor fixes; one for performance, the other seccomp
on s390x.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
# gpg: Signature made Thu 16 Sep 2021 14:51:38 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-gitlab/tags/pull-virtiofs-20210916:
  virtiofsd: Reverse req_list before processing it
  tools/virtiofsd: Add fstatfs64 syscall to the seccomp allowlist

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