Re: [PATCH] chardev: enable distinct input for -chardev file

["Daniel P. Berrangé" <berrange@redhat.com>]

On Fri, May 01, 2020 at 01:25:59PM -0400, Alexander Bulekov wrote:
> char-file already supports distinct paths for input/output but it was
> only possible to specify a distinct input through QMP. With this change,
> we can also specify a distinct input with the -chardev file argument:
>     qemu -chardev file,id=char1,path=/out/file,in=/in/file
> 
> Signed-off-by: Alexander Bulekov <alxndr@bu.edu>
> ---
>  chardev/char-file.c | 5 +++++
>  chardev/char.c      | 3 +++
>  qemu-options.hx     | 7 +++++--
>  3 files changed, 13 insertions(+), 2 deletions(-)
> 
> The naming here is awkward, with path= really turning into "out" when
> in= is specified, though i'm not sure about what is a good solution.
> 
> diff --git a/chardev/char-file.c b/chardev/char-file.c
> index 2fd80707e5..cc742cc234 100644
> --- a/chardev/char-file.c
> +++ b/chardev/char-file.c
> @@ -100,6 +100,7 @@ static void qemu_chr_parse_file_out(QemuOpts *opts, ChardevBackend *backend,
>                                      Error **errp)
>  {
>      const char *path = qemu_opt_get(opts, "path");
> +    const char *in = qemu_opt_get(opts, "in");
>      ChardevFile *file;
>  
>      backend->type = CHARDEV_BACKEND_KIND_FILE;
> @@ -110,6 +111,10 @@ static void qemu_chr_parse_file_out(QemuOpts *opts, ChardevBackend *backend,
>      file = backend->u.file.data = g_new0(ChardevFile, 1);
>      qemu_chr_parse_common(opts, qapi_ChardevFile_base(file));
>      file->out = g_strdup(path);
> +    if (in) {
> +        file->has_in = true;
> +        file->in = g_strdup(qemu_opt_get(opts, "in"));
> +    }
>  
>      file->has_append = true;
>      file->append = qemu_opt_get_bool(opts, "append", false);
> diff --git a/chardev/char.c b/chardev/char.c
> index e77564060d..797574f205 100644
> --- a/chardev/char.c
> +++ b/chardev/char.c
> @@ -849,6 +849,9 @@ QemuOptsList qemu_chardev_opts = {
>          },{
>              .name = "path",
>              .type = QEMU_OPT_STRING,
> +        },{
> +            .name = "in",
> +            .type = QEMU_OPT_STRING,
>          },{
>              .name = "host",
>              .type = QEMU_OPT_STRING,
> diff --git a/qemu-options.hx b/qemu-options.hx
> index 292d4e7c0c..bbb091872f 100644
> --- a/qemu-options.hx
> +++ b/qemu-options.hx
> @@ -2938,7 +2938,7 @@ DEF("chardev", HAS_ARG, QEMU_OPTION_chardev,
>      "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n"
>      "         [,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
>      "-chardev ringbuf,id=id[,size=size][,logfile=PATH][,logappend=on|off]\n"
> -    "-chardev file,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
> +    "-chardev file,id=id,path=path[,in=PATH][,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
>      "-chardev pipe,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
>  #ifdef _WIN32
>      "-chardev console,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
> @@ -3137,13 +3137,16 @@ The available backends are:
>      Create a ring buffer with fixed size ``size``. size must be a power
>      of two and defaults to ``64K``.
>  
> -``-chardev file,id=id,path=path``
> +``-chardev file,id=id,path=path,in=in``
>      Log all traffic received from the guest to a file.
>  
>      ``path`` specifies the path of the file to be opened. This file will
>      be created if it does not already exist, and overwritten if it does.
>      ``path`` is required.
>  
> +    ``in`` specifies a separate file as the input to the chardev. If
> +    ``in`` is omitted, ``path`` is used for both input and output

I'd suggest "pathin" rather than just "in"


Regards,
Daniel
-- 
|: https://berrange.com      -o-    https://www.flickr.com/photos/dberrange :|
|: https://libvirt.org         -o-            https://fstop138.berrange.com :|
|: https://entangle-photo.org    -o-    https://www.instagram.com/dberrange :|