From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57239) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ciIMU-0003Ry-Nt for qemu-devel@nongnu.org; Mon, 27 Feb 2017 05:17:00 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ciIMP-0005RW-M1 for qemu-devel@nongnu.org; Mon, 27 Feb 2017 05:16:58 -0500 Received: from mx4-phx2.redhat.com ([209.132.183.25]:47615) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ciIMP-0005Qy-DX for qemu-devel@nongnu.org; Mon, 27 Feb 2017 05:16:53 -0500 Date: Mon, 27 Feb 2017 05:16:51 -0500 (EST) From: =?utf-8?Q?Marc-Andr=C3=A9?= Lureau Message-ID: <1800937540.12350937.1488190611084.JavaMail.zimbra@redhat.com> In-Reply-To: <20170227101013.GB2350@work-vm> References: <20170224202345.13311-1-marcandre.lureau@redhat.com> <20170227101013.GB2350@work-vm> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH] vhost-user: delay vhost_user_stop List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Dr. David Alan Gilbert" Cc: =?utf-8?Q?Marc-Andr=C3=A9?= Lureau , qemu-devel@nongnu.org, mst@redhat.com, pbonzini@redhat.com, den@openvz.org Hi ----- Original Message ----- > * Marc-Andr=C3=A9 Lureau (marcandre.lureau@redhat.com) wrote: > > Since commit b0a335e351103bf92f3f9d0bd5759311be8156ac, a socket write > > may trigger a disconnect events, calling vhost_user_stop() and clearing > > all the vhost_dev strutures holding data that vhost.c functions expect > > to remain valid. Delay the cleanup to keep the vhost_dev structure > > valid during the vhost.c functions. > >=20 > > Signed-off-by: Marc-Andr=C3=A9 Lureau >=20 > This does get me through a 'make check' succesfully. >=20 Yes, it's not optimal, but there is so much cleanup to deal with otherwise,= than I am inclined to go with this approach for now, and keep the FIXME fo= r 2.10 I'll update the patch to avoid the race on reconnect. > Dave >=20 > > --- > > net/vhost-user.c | 49 +++++++++++++++++++++++++++++++++++++++++++-----= - > > 1 file changed, 43 insertions(+), 6 deletions(-) > >=20 > > diff --git a/net/vhost-user.c b/net/vhost-user.c > > index 77b8110f8c..00573c8ac8 100644 > > --- a/net/vhost-user.c > > +++ b/net/vhost-user.c > > @@ -25,6 +25,7 @@ typedef struct VhostUserState { > > guint watch; > > uint64_t acked_features; > > bool started; > > + QEMUBH *chr_closed_bh; > > } VhostUserState; > > =20 > > VHostNetState *vhost_user_get_vhost_net(NetClientState *nc) > > @@ -190,9 +191,40 @@ static gboolean net_vhost_user_watch(GIOChannel *c= han, > > GIOCondition cond, > > =20 > > qemu_chr_fe_disconnect(&s->chr); > > =20 > > + s->watch =3D 0; > > return FALSE; > > } > > =20 > > +static void chr_closed_bh(void *opaque) > > +{ > > + const char *name =3D opaque; > > + NetClientState *ncs[MAX_QUEUE_NUM]; > > + VhostUserState *s; > > + Error *err =3D NULL; > > + int queues; > > + > > + queues =3D qemu_find_net_clients_except(name, ncs, > > + NET_CLIENT_DRIVER_NIC, > > + MAX_QUEUE_NUM); > > + assert(queues < MAX_QUEUE_NUM); > > + > > + s =3D DO_UPCAST(VhostUserState, nc, ncs[0]); > > + > > + qmp_set_link(name, false, &err); > > + vhost_user_stop(queues, ncs); > > + if (s->watch) { > > + g_source_remove(s->watch); > > + } > > + s->watch =3D 0; > > + > > + qemu_bh_delete(s->chr_closed_bh); > > + s->chr_closed_bh =3D NULL; > > + > > + if (err) { > > + error_report_err(err); > > + } > > +} > > + > > static void net_vhost_user_event(void *opaque, int event) > > { > > const char *name =3D opaque; > > @@ -212,20 +244,25 @@ static void net_vhost_user_event(void *opaque, in= t > > event) > > trace_vhost_user_event(chr->label, event); > > switch (event) { > > case CHR_EVENT_OPENED: > > - s->watch =3D qemu_chr_fe_add_watch(&s->chr, G_IO_HUP, > > - net_vhost_user_watch, s); > > if (vhost_user_start(queues, ncs, &s->chr) < 0) { > > qemu_chr_fe_disconnect(&s->chr); > > return; > > } > > + s->watch =3D qemu_chr_fe_add_watch(&s->chr, G_IO_HUP, > > + net_vhost_user_watch, s); > > qmp_set_link(name, true, &err); > > + s->chr_closed_bh =3D qemu_bh_new(chr_closed_bh, opaque); > > s->started =3D true; > > break; > > case CHR_EVENT_CLOSED: > > - qmp_set_link(name, false, &err); > > - vhost_user_stop(queues, ncs); > > - g_source_remove(s->watch); > > - s->watch =3D 0; > > + /* a close event may happen during a read/write, but vhost > > + * code assumes the vhost_dev remains setup, so delay the > > + * stop & clear to idle. > > + * FIXME: better handle failure in vhost code, remove bh > > + */ > > + if (s->chr_closed_bh) { > > + qemu_bh_schedule(s->chr_closed_bh); > > + } > > break; > > } > > =20 > > -- > > 2.12.0.rc2.3.gc93709801 > >=20 > -- > Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK >=20