This is the first step towards having fine-grained critical sections in
dataplane threads, which will resolve lock ordering problems between
address_space_* functions (which need the BQL when doing MMIO, even
after we complete RCU-based dispatch) and the AioContext.
Because AioContext does not use contention callbacks anymore, the
unit test has to be changed.
Previously applied as a0710f7995 and
then reverted.
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <1477565348-5458-19-git-send-email-pbonzini@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
This document explains how IOThreads and the main loop are related,
especially how to write code that can run in an IOThread. Currently
only virtio-blk-data-plane uses these techniques. The next obvious
target is virtio-scsi; there has also been work on virtio-net.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
