On Fri, Nov 06, 2020 at 02:24:53PM +0800, Chuan Zheng wrote: > The qemu main loop could hang up forever when we enable TLS+Multifd. > The Src multifd_send_0 invokes tls handshake, it sends hello to sever > and wait response. > However, the Dst main qemu loop has been waiting recvmsg() for multifd_recv_1. > Both of Src and Dst main qemu loop are blocking and waiting for reponse which > results in hanging up forever. > > Src: (multifd_send_0) Dst: > (multifd_recv_1) > multifd_channel_connect > migration_channel_process_incoming > multifd_tls_channel_connect > migration_tls_channel_process_incoming > multifd_tls_channel_connect > qio_channel_tls_handshake_task > qio_channel_tls_handshake > gnutls_handshake > qio_channel_tls_handshake_task > ... > qcrypto_tls_session_handshake > ... > gnutls_handshake > ... > ... > ... > recvmsg (Blocking I/O waiting for response) > recvmsg (Blocking I/O waiting for response) > > Fix this by offloadinig handshake work to a background thread. > > Reported-by: Yan Jin <jinya...@huawei.com> > Suggested-by: Daniel P. Berrangé <berra...@redhat.com> > Signed-off-by: Chuan Zheng <zhengch...@huawei.com> > --- > migration/multifd.c | 23 +++++++++++++++++------ > 1 file changed, 17 insertions(+), 6 deletions(-)
Reviewed-by: Daniel P. Berrangé <berra...@redhat.com> Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|
