From patchwork Wed Dec 18 14:15:19 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gal Hammer X-Patchwork-Id: 302900 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 1304B2C00B7 for ; Thu, 19 Dec 2013 01:16:13 +1100 (EST) Received: from localhost ([::1]:38954 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VtHv0-0003wv-4n for incoming@patchwork.ozlabs.org; Wed, 18 Dec 2013 09:16:10 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:44238) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VtHuf-0003wX-Ab for qemu-devel@nongnu.org; Wed, 18 Dec 2013 09:15:55 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VtHuZ-0008JF-AX for qemu-devel@nongnu.org; Wed, 18 Dec 2013 09:15:49 -0500 Received: from mx1.redhat.com ([209.132.183.28]:56302) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VtHuZ-0008J8-0F for qemu-devel@nongnu.org; Wed, 18 Dec 2013 09:15:43 -0500 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id rBIEFesJ019090 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Wed, 18 Dec 2013 09:15:41 -0500 Received: from wolverine.usersys.redhat.com.com (dhcp-4-160.tlv.redhat.com [10.35.4.160]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id rBIEFcmJ008910; Wed, 18 Dec 2013 09:15:39 -0500 From: Gal Hammer To: qemu-devel@nongnu.org Date: Wed, 18 Dec 2013 16:15:19 +0200 Message-Id: <1387376119-11654-1-git-send-email-ghammer@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.22 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 209.132.183.28 Cc: Amit Shah , Gal Hammer , Gerd Hoffmann , Anthony Liguori Subject: [Qemu-devel] [PATCH V5] char: restore read callback on a reattached (hotplug) chardev X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Fix a bug that was introduced in commit 386a5a1e. A removal of a device set the chr handlers to NULL. However when the device is plugged back, its read callback is not restored so data can't be transferred from the host to the guest (e.g. via the virtio-serial port). https://bugzilla.redhat.com/show_bug.cgi?id=1027181 Signed-off-by: Gal Hammer Reviewed-by: Amit Shah --- qemu-char.c | 21 +++++++++++++++++---- 1 file changed, 17 insertions(+), 4 deletions(-) V5: - remove_fd_in_watch in fd_chr_update_read_handler as well. - fix pty backend. V4: - Same as V3, but this time done right. V3: - fix a typo in comment. - move the revision history after the "signed-off-by" tag. V2: - do not call chr_update_read_handler on device removal. - add asserts to verify chr_update_read_handler is not called with an assigned fd_in_tag to prevent fd leaks. - update fd and udp backends' chr_update_read_handler function so it won't remove fd_in to prevent a double release. diff --git a/qemu-char.c b/qemu-char.c index 418dc69..019c178 100644 --- a/qemu-char.c +++ b/qemu-char.c @@ -213,7 +213,7 @@ void qemu_chr_add_handlers(CharDriverState *s, s->chr_read = fd_read; s->chr_event = fd_event; s->handler_opaque = opaque; - if (s->chr_update_read_handler) + if (fe_open && s->chr_update_read_handler) s->chr_update_read_handler(s); if (!s->explicit_fe_open) { @@ -870,7 +870,7 @@ static void fd_chr_update_read_handler(CharDriverState *chr) { FDCharDriver *s = chr->opaque; - remove_fd_in_watch(chr); + assert(!chr->fd_in_tag); if (s->fd_in) { chr->fd_in_tag = io_add_watch_poll(s->fd_in, fd_chr_read_poll, fd_chr_read, chr); @@ -1136,13 +1136,14 @@ static void pty_chr_state(CharDriverState *chr, int connected) if (!s->connected) { s->connected = 1; qemu_chr_be_generic_open(chr); + } + if (!chr->fd_in_tag) { chr->fd_in_tag = io_add_watch_poll(s->fd, pty_chr_read_poll, pty_chr_read, chr); } } } - static void pty_chr_close(struct CharDriverState *chr) { PtyCharDriver *s = chr->opaque; @@ -2228,7 +2229,7 @@ static void udp_chr_update_read_handler(CharDriverState *chr) { NetCharDriver *s = chr->opaque; - remove_fd_in_watch(chr); + assert(!chr->fd_in_tag); if (s->chan) { chr->fd_in_tag = io_add_watch_poll(s->chan, udp_chr_read_poll, udp_chr_read, chr); @@ -2510,6 +2511,17 @@ static void tcp_chr_connect(void *opaque) qemu_chr_be_generic_open(chr); } +static void tcp_chr_update_read_handler(CharDriverState *chr) +{ + TCPCharDriver *s = chr->opaque; + + assert(!chr->fd_in_tag); + if (s->chan) { + chr->fd_in_tag = io_add_watch_poll(s->chan, tcp_chr_read_poll, + tcp_chr_read, chr); + } +} + #define IACSET(x,a,b,c) x[0] = a; x[1] = b; x[2] = c; static void tcp_chr_telnet_init(int fd) { @@ -2665,6 +2677,7 @@ static CharDriverState *qemu_chr_open_socket_fd(int fd, bool do_nodelay, chr->get_msgfd = tcp_get_msgfd; chr->chr_add_client = tcp_chr_add_client; chr->chr_add_watch = tcp_chr_add_watch; + chr->chr_update_read_handler = tcp_chr_update_read_handler; /* be isn't opened until we get a connection */ chr->explicit_be_open = true;