On Fri, Jun 24, 2016 at 03:51:09PM +0200, marcandre.lur...@redhat.com wrote:
> From: Marc-André Lureau <marcandre.lur...@redhat.com>
>
> The chardev waits for an initial connection before starting qemu,
> vhost-user wants the backend negotiation to be completed. vhost-user is
> started in the net_vhost_user_event callback, which is synchronously
> called after the socket is connected.
>
> Signed-off-by: Marc-André Lureau <marcandre.lur...@redhat.com>
> ---
> net/vhost-user.c | 12 +++++++++++-
> 1 file changed, 11 insertions(+), 1 deletion(-)
>
> diff --git a/net/vhost-user.c b/net/vhost-user.c
> index 95ed2d2..4badd9e 100644
> --- a/net/vhost-user.c
> +++ b/net/vhost-user.c
> @@ -24,6 +24,7 @@ typedef struct VhostUserState {
> VHostNetState *vhost_net;
> int watch;
> uint64_t acked_features;
> + bool started;
> } VhostUserState;
>
> typedef struct VhostUserChardevProps {
> @@ -211,6 +212,7 @@ static void net_vhost_user_event(void *opaque, int event)
> return;
> }
> qmp_set_link(name, true, &err);
> + s->started = true;
> break;
> case CHR_EVENT_CLOSED:
> qmp_set_link(name, false, &err);
> @@ -248,7 +250,15 @@ static int net_vhost_user_init(NetClientState *peer,
> const char *device,
> s->chr = chr;
> }
>
> - qemu_chr_add_handlers(chr, NULL, NULL, net_vhost_user_event, nc[0].name);
> + do {
> + Error *err = NULL;
> + if (qemu_chr_wait_connected(chr, &err) < 0) {
> + error_report_err(err);
> + return -1;
> + }
> + qemu_chr_add_handlers(chr, NULL, NULL,
> + net_vhost_user_event, nc[0].name);
> + } while (!s->started);
I haven't looked at your patchset carefully yet, but I did a quick test,
and showed that above code piece just breaks vhost-user: it's a dead loop
that vhost-user net will be initiated again and again.
The dead loop is due to, we check "s->started" corresponding to last nc,
while we set "s->started" corresponding to the first nc.
--yliu
