Re: [Qemu-devel] [PATCH for-2.7] char: fix waiting for TLS and telnet connection

["Marc-André Lureau" <mlureau@redhat.com>]

Hi

----- Original Message -----
> On Tue, Aug 16, 2016 at 12:33:32PM +0400, Marc-André Lureau wrote:
> > Since commit d7a04fd7d5008, tcp_chr_wait_connected() was introduced,
> > so vhost-user could wait until a backend started successfully. In
> > vhost-user case, the chr socket must be plain unix, and the chr+vhost
> > setup happens synchronously during qemu startup.
> > 
> > However, with TLS and telnet socket, initial socket setup happens
> > asynchronously, and s->connected is not set after the socket is
> > accepted. In order for tcp_chr_wait_connected() to not keep accepting
> > new connections and proceed with the last accepted socket, it can
> > check for s->ioc instead.
> > 
> > Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> > ---
> >  qemu-char.c | 4 +++-
> >  1 file changed, 3 insertions(+), 1 deletion(-)
> > 
> > diff --git a/qemu-char.c b/qemu-char.c
> > index 8a0ab05..5f82ebb 100644
> > --- a/qemu-char.c
> > +++ b/qemu-char.c
> > @@ -3176,7 +3176,9 @@ static int tcp_chr_wait_connected(CharDriverState
> > *chr, Error **errp)
> >      TCPCharDriver *s = chr->opaque;
> >      QIOChannelSocket *sioc;
> >  
> > -    while (!s->connected) {
> > +    /* It can't wait on s->connected, since it is set asynchronously
> > +     * in TLS and telnet cases, only wait for an accepted socket */
> > +    while (!s->ioc) {
> >          if (s->is_listen) {
> >              fprintf(stderr, "QEMU waiting for connection on: %s\n",
> >                      chr->filename);
> 
> Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
> 
> This is a definite must fix for 2.7.0.
> 
> Also shows we really badly need unit tests for the chardev stuff :-)

That was my thought too :)