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

[Daniel P. Berrange]

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 <address@hidden>
> ---
>  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 <address@hidden>

This is a definite must fix for 2.7.0.

Also shows we really badly need unit tests for the chardev stuff :-)

Regards,
Daniel
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