From a9b1315f86d9323587b340bd3bf83b9d66a55563 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Thu, 25 Feb 2021 11:47:52 +0100 Subject: [PATCH] chardev: add nodelay option The "delay" option was introduced as a way to enable Nagle's algorithm with ",nodelay". Since the short form for boolean options has now been deprecated, introduce a more properly named "nodelay" option. The "delay" option remains as an undocumented option. "delay" and "nodelay" are mutually exclusive. Because the check is done at consumption time, the code also rejects them if one of the two is specified via -set. Based-on: <20210226080526.651705-1-pbonzini@redhat.com> Signed-off-by: Paolo Bonzini --- chardev/char-socket.c | 13 +++++++++++-- chardev/char.c | 3 +++ gdbstub.c | 2 +- qemu-options.hx | 14 +++++++------- 4 files changed, 22 insertions(+), 10 deletions(-) diff --git a/chardev/char-socket.c b/chardev/char-socket.c index 06a37c0cc8..c8bced76b7 100644 --- a/chardev/char-socket.c +++ b/chardev/char-socket.c @@ -1472,8 +1472,17 @@ static void qemu_chr_parse_socket(QemuOpts *opts, ChardevBackend *backend, sock = backend->u.socket.data = g_new0(ChardevSocket, 1); qemu_chr_parse_common(opts, qapi_ChardevSocket_base(sock)); - sock->has_nodelay = qemu_opt_get(opts, "delay"); - sock->nodelay = !qemu_opt_get_bool(opts, "delay", true); + if (qemu_opt_get(opts, "delay") && qemu_opt_get(opts, "nodelay")) { + error_setg(errp, "'delay' and 'nodelay' are mutually exclusive"); + return; + } + sock->has_nodelay = + qemu_opt_get(opts, "delay") || + qemu_opt_get(opts, "nodelay"); + sock->nodelay = + !qemu_opt_get_bool(opts, "delay", true) || + qemu_opt_get_bool(opts, "nodelay", false); + /* * We have different default to QMP for 'server', hence * we can't just check for existence of 'server' diff --git a/chardev/char.c b/chardev/char.c index 288efebd12..97cafd6849 100644 --- a/chardev/char.c +++ b/chardev/char.c @@ -867,6 +867,9 @@ QemuOptsList qemu_chardev_opts = { },{ .name = "delay", .type = QEMU_OPT_BOOL, + },{ + .name = "nodelay", + .type = QEMU_OPT_BOOL, },{ .name = "reconnect", .type = QEMU_OPT_NUMBER, diff --git a/gdbstub.c b/gdbstub.c index 3ee40479b6..16d7c8f534 100644 --- a/gdbstub.c +++ b/gdbstub.c @@ -3505,7 +3505,7 @@ int gdbserver_start(const char *device) if (strstart(device, "tcp:", NULL)) { /* enforce required TCP attributes */ snprintf(gdbstub_device_name, sizeof(gdbstub_device_name), - "%s,wait=off,delay=off,server=on", device); + "%s,wait=off,nodelay=on,server=on", device); device = gdbstub_device_name; } #ifndef _WIN32 diff --git a/qemu-options.hx b/qemu-options.hx index 252db9357c..90801286c6 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -3033,7 +3033,7 @@ DEFHEADING(Character device options:) DEF("chardev", HAS_ARG, QEMU_OPTION_chardev, "-chardev help\n" "-chardev null,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" - "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4=on|off][,ipv6=on|off][,delay=on|off][,reconnect=seconds]\n" + "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4=on|off][,ipv6=on|off][,nodelay=on|off][,reconnect=seconds]\n" " [,server=on|off][,wait=on|off][,telnet=on|off][,websocket=on|off][,reconnect=seconds][,mux=on|off]\n" " [,logfile=PATH][,logappend=on|off][,tls-creds=ID][,tls-authz=ID] (tcp)\n" "-chardev socket,id=id,path=path[,server=on|off][,wait=on|off][,telnet=on|off][,websocket=on|off][,reconnect=seconds]\n" @@ -3184,7 +3184,7 @@ The available backends are: TCP and unix socket options are given below: - ``TCP options: port=port[,host=host][,to=to][,ipv4=on|off][,ipv6=on|off][,delay=on|off]`` + ``TCP options: port=port[,host=host][,to=to][,ipv4=on|off][,ipv6=on|off][,nodelay=on|off]`` ``host`` for a listening socket specifies the local address to be bound. For a connecting socket species the remote host to connect to. ``host`` is optional for listening sockets. If not @@ -3204,7 +3204,7 @@ The available backends are: or IPv6 must be used. If neither is specified the socket may use either protocol. - ``delay=on|off`` disables the Nagle algorithm. + ``nodelay=on|off`` disables the Nagle algorithm. ``unix options: path=path[,abstract=on|off][,tight=on|off]`` ``path`` specifies the local path of the unix socket. ``path`` @@ -3593,13 +3593,13 @@ SRST ``telnet options:`` localhost 5555 - ``tcp:[host]:port[,server=on|off][,wait=on|off][,delay=on|off][,reconnect=seconds]`` + ``tcp:[host]:port[,server=on|off][,wait=on|off][,nodelay=on|off][,reconnect=seconds]`` The TCP Net Console has two modes of operation. It can send the serial I/O to a location or wait for a connection from a location. By default the TCP Net Console is sent to host at the port. If you use the ``server=on`` option QEMU will wait for a client socket application to connect to the port before continuing, - unless the ``wait=on|off`` option was specified. The ``delay=on|off`` + unless the ``wait=on|off`` option was specified. The ``nodelay=on|off`` option disables the Nagle buffering algorithm. The ``reconnect=on`` option only applies if ``server=no`` is set, if the connection goes down it will attempt to reconnect at the given interval. If host @@ -3616,7 +3616,7 @@ SRST ``Example to not wait and listen on ip 192.168.0.100 port 4444`` -serial tcp:192.168.0.100:4444,server=on,wait=off - ``telnet:host:port[,server=on|off][,wait=on|off][,delay=on|off]`` + ``telnet:host:port[,server=on|off][,wait=on|off][,nodelay=on|off]`` The telnet protocol is used instead of raw tcp sockets. The options work the same as if you had specified ``-serial tcp``. The difference is that the port acts like a telnet server or @@ -3626,7 +3626,7 @@ SRST you do it with Control-] and then type "send break" followed by pressing the enter key. - ``websocket:host:port,server=on[,wait=on|off][,delay=on|off]`` + ``websocket:host:port,server=on[,wait=on|off][,nodelay=on|off]`` The WebSocket protocol is used instead of raw tcp socket. The port acts as a WebSocket server. Client mode is not supported.