From patchwork Wed Feb 24 13:27:23 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paolo Bonzini X-Patchwork-Id: 62794 Delivered-To: patch@linaro.org Received: by 10.112.43.199 with SMTP id y7csp2403750lbl; Wed, 24 Feb 2016 05:28:53 -0800 (PST) X-Received: by 10.140.194.205 with SMTP id p196mr19561624qha.30.1456320533895; Wed, 24 Feb 2016 05:28:53 -0800 (PST) Return-Path: Received: from lists.gnu.org (lists.gnu.org. [2001:4830:134:3::11]) by mx.google.com with ESMTPS id f17si2791913qhc.19.2016.02.24.05.28.53 for (version=TLS1 cipher=AES128-SHA bits=128/128); Wed, 24 Feb 2016 05:28:53 -0800 (PST) Received-SPF: pass (google.com: domain of qemu-devel-bounces+patch=linaro.org@nongnu.org designates 2001:4830:134:3::11 as permitted sender) client-ip=2001:4830:134:3::11; Authentication-Results: mx.google.com; spf=pass (google.com: domain of qemu-devel-bounces+patch=linaro.org@nongnu.org designates 2001:4830:134:3::11 as permitted sender) smtp.mailfrom=qemu-devel-bounces+patch=linaro.org@nongnu.org Received: from localhost ([::1]:35820 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aYZUr-0005r5-B7 for patch@linaro.org; Wed, 24 Feb 2016 08:28:53 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43966) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aYZTp-0004hz-MI for qemu-devel@nongnu.org; Wed, 24 Feb 2016 08:27:50 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aYZTn-0005g5-GU for qemu-devel@nongnu.org; Wed, 24 Feb 2016 08:27:49 -0500 Received: from mx1.redhat.com ([209.132.183.28]:36534) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aYZTn-0005fu-96 for qemu-devel@nongnu.org; Wed, 24 Feb 2016 08:27:47 -0500 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (Postfix) with ESMTPS id DCBA0821C3; Wed, 24 Feb 2016 13:27:46 +0000 (UTC) Received: from donizetti.redhat.com (ovpn-112-42.ams2.redhat.com [10.36.112.42]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u1ODRhZp009553; Wed, 24 Feb 2016 08:27:45 -0500 From: Paolo Bonzini To: qemu-devel@nongnu.org Date: Wed, 24 Feb 2016 14:27:23 +0100 Message-Id: <1456320461-26756-2-git-send-email-pbonzini@redhat.com> In-Reply-To: <1456320461-26756-1-git-send-email-pbonzini@redhat.com> References: <1456320461-26756-1-git-send-email-pbonzini@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.23 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 209.132.183.28 Cc: Peter Maydell Subject: [Qemu-devel] [PULL 01/19] qemu-options.hx: Improve documentation of chardev multiplexing mode 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+patch=linaro.org@nongnu.org Sender: qemu-devel-bounces+patch=linaro.org@nongnu.org From: Peter Maydell The current documentation of chardev mux=on is rather brief and opaque; expand it to hopefully be a bit more helpful. Signed-off-by: Peter Maydell Message-Id: <1455643738-6068-1-git-send-email-peter.maydell@linaro.org> Signed-off-by: Paolo Bonzini --- qemu-doc.texi | 30 ++++++++++++++++++++---------- qemu-options.hx | 45 +++++++++++++++++++++++++++++++++++++++++++-- 2 files changed, 63 insertions(+), 12 deletions(-) -- 2.5.0 diff --git a/qemu-doc.texi b/qemu-doc.texi index c324da8..bc9dd13 100644 --- a/qemu-doc.texi +++ b/qemu-doc.texi @@ -158,7 +158,8 @@ TODO (no longer available) * pcsys_introduction:: Introduction * pcsys_quickstart:: Quick Start * sec_invocation:: Invocation -* pcsys_keys:: Keys +* pcsys_keys:: Keys in the graphical frontends +* mux_keys:: Keys in the character backend multiplexer * pcsys_monitor:: QEMU Monitor * disk_images:: Disk Images * pcsys_network:: Network emulation @@ -272,7 +273,7 @@ targets do not need a disk image. @c man end @node pcsys_keys -@section Keys +@section Keys in the graphical frontends @c man begin OPTIONS @@ -322,15 +323,23 @@ Toggle mouse and keyboard grab. In the virtual consoles, you can use @key{Ctrl-Up}, @key{Ctrl-Down}, @key{Ctrl-PageUp} and @key{Ctrl-PageDown} to move in the back log. -@kindex Ctrl-a h -During emulation, if you are using the @option{-nographic} option, use -@key{Ctrl-a h} to get terminal commands: +@c man end + +@node mux_keys +@section Keys in the character backend multiplexer + +@c man begin OPTIONS + +During emulation, if you are using a character backend multiplexer +(which is the default if you are using @option{-nographic}) then +several commands are available via an escape sequence. These +key sequences all start with an escape character, which is @key{Ctrl-a} +by default, but can be changed with @option{-echr}. The list below assumes +you're using the default. @table @key @item Ctrl-a h @kindex Ctrl-a h -@item Ctrl-a ? -@kindex Ctrl-a ? Print this help @item Ctrl-a x @kindex Ctrl-a x @@ -346,10 +355,11 @@ Toggle console timestamps Send break (magic sysrq in Linux) @item Ctrl-a c @kindex Ctrl-a c -Switch between console and monitor +Rotate between the frontends connected to the multiplexer (usually +this switches between the monitor and the console) @item Ctrl-a Ctrl-a -@kindex Ctrl-a a -Send Ctrl-a +@kindex Ctrl-a Ctrl-a +Send the escape character to the frontend @end table @c man end diff --git a/qemu-options.hx b/qemu-options.hx index 2f0465e..7e6762e 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -2162,8 +2162,49 @@ All devices must have an id, which can be any string up to 127 characters long. It is used to uniquely identify this device in other command line directives. A character device may be used in multiplexing mode by multiple front-ends. -The key sequence of @key{Control-a} and @key{c} will rotate the input focus -between attached front-ends. Specify @option{mux=on} to enable this mode. +Specify @option{mux=on} to enable this mode. +A multiplexer is a "1:N" device, and here the "1" end is your specified chardev +backend, and the "N" end is the various parts of QEMU that can talk to a chardev. +If you create a chardev with @option{id=myid} and @option{mux=on}, QEMU will +create a multiplexer with your specified ID, and you can then configure multiple +front ends to use that chardev ID for their input/output. Up to four different +front ends can be connected to a single multiplexed chardev. (Without +multiplexing enabled, a chardev can only be used by a single front end.) +For instance you could use this to allow a single stdio chardev to be used by +two serial ports and the QEMU monitor: + +@example +-chardev stdio,mux=on,id=char0 \ +-mon chardev=char0,mode=readline,default \ +-serial chardev:char0 \ +-serial chardev:char0 +@end example + +You can have more than one multiplexer in a system configuration; for instance +you could have a TCP port multiplexed between UART 0 and UART 1, and stdio +multiplexed between the QEMU monitor and a parallel port: + +@example +-chardev stdio,mux=on,id=char0 \ +-mon chardev=char0,mode=readline,default \ +-parallel chardev:char0 \ +-chardev tcp,...,mux=on,id=char1 \ +-serial chardev:char1 \ +-serial chardev:char1 +@end example + +When you're using a multiplexed character device, some escape sequences are +interpreted in the input. @xref{mux_keys, Keys in the character backend +multiplexer}. + +Note that some other command line options may implicitly create multiplexed +character backends; for instance @option{-serial mon:stdio} creates a +multiplexed stdio backend connected to the serial port and the QEMU monitor, +and @option{-nographic} also multiplexes the console and the monitor to +stdio. + +There is currently no support for multiplexing in the other direction +(where a single QEMU front end takes input and output from multiple chardevs). Every backend supports the @option{logfile} option, which supplies the path to a file to record all data transmitted via the backend. The @option{logappend}