[1/1] doc: document chardev option 'append'

commit 31e38a22a0c5a25646f966f001e1f5513d5a186d
    Author: Olga Krishtal <okrishtal@virtuozzo.com>
    Date:   Fri Dec 4 09:42:04 2015 +0300

        qemu-char: append opt to stop truncation of serial file

has added the option to the runtime but does not added it to -help
output. This blocks libvirt from using it.

Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Dmitry Mishin <dim@virtuozzo.com>
CC: Eric Blake <eblake@redhat.com>
CC: Markus Armbruster <armbru@redhat.com>
CC: Paolo Bonzini <pbonzini@redhat.com>
---
 qemu-options.hx | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

On 22/12/15 12:43, "Denis V. Lunev" <den@openvz.org> wrote:

>    commit 31e38a22a0c5a25646f966f001e1f5513d5a186d
>    Author: Olga Krishtal <okrishtal@virtuozzo.com>
>    Date:   Fri Dec 4 09:42:04 2015 +0300
>
>        qemu-char: append opt to stop truncation of serial file
>
>has added the option to the runtime but does not added it to -help
>output. This blocks libvirt from using it.
>
>Signed-off-by: Denis V. Lunev <den@openvz.org>
>CC: Dmitry Mishin <dim@virtuozzo.com>
>CC: Eric Blake <eblake@redhat.com>
>CC: Markus Armbruster <armbru@redhat.com>
>CC: Paolo Bonzini <pbonzini@redhat.com>
>---
> qemu-options.hx | 7 +++++--
> 1 file changed, 5 insertions(+), 2 deletions(-)
>
>diff --git a/qemu-options.hx b/qemu-options.hx
>index 49afe6c..f706e4a 100644
>--- a/qemu-options.hx
>+++ b/qemu-options.hx
>@@ -2044,7 +2044,7 @@ DEF("chardev", HAS_ARG, QEMU_OPTION_chardev,
>     "-chardev 
>vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n"
>     "         [,mux=on|off]\n"
>     "-chardev ringbuf,id=id[,size=size]\n"
>-    "-chardev file,id=id,path=path[,mux=on|off]\n"
>+    "-chardev file,id=id,path=path[,mux=on|off][,append=on|off]\n"
>     "-chardev pipe,id=id,path=path[,mux=on|off]\n"
> #ifdef _WIN32
>     "-chardev console,id=id[,mux=on|off]\n"
>@@ -2199,7 +2199,7 @@ console with the given dimensions.
> Create a ring buffer with fixed size @option{size}.
> @var{size} must be a power of two, and defaults to @code{64K}).
> 
>-@item -chardev file ,id=@var{id} ,path=@var{path}
>+@item -chardev file ,id=@var{id} ,path=@var{path} [,append=@var{on|off}]
> 
> Log all traffic received from the guest to a file.
> 
>@@ -2207,6 +2207,9 @@ Log all traffic received from the guest to a file.
> created if it does not already exist, and overwritten if it does.
>@option{path}
> is required.
> 
>+@option{append} specifies that QEMU must truncate the file on open.
>+@option{append} is optional, default value is on.
According to code, default value is off.

>+
> @item -chardev pipe ,id=@var{id} ,path=@var{path}
> 
> Create a two-way connection to the guest. The behaviour differs slightly
>between
>-- 
>2.5.0
>