[Qemu-devel] Re: [RFC][PATCH v1 08/12] qemu-char: add qmp_proxy chardev

[Anthony Liguori <aliguori@us.ibm.com>]

On 03/25/2011 02:47 PM, Michael Roth wrote:
> This allows qemu to be started with guest agent support via:
>
> qemu -chardev qmp_proxy,path=<optional>,id=qmp_proxy \
>        -device ...,chardev=qmp_proxy
>
> It is essentially a wrapper for -chardev socket, which takes the extra
> step of setting required defaults and initializing the qmp proxy by
> passing the path argument along.
>
> Not sure if this is the most elegant approach, but in terms of the
> command-line invocation it seems to be the most consistent way to do
> it.
>
> Signed-off-by: Michael Roth<mdroth@linux.vnet.ibm.com>
> ---
>   qemu-char.c |   46 ++++++++++++++++++++++++++++++++++++++++++++++
>   1 files changed, 46 insertions(+), 0 deletions(-)
>
> diff --git a/qemu-char.c b/qemu-char.c
> index d301925..6ff7698 100644
> --- a/qemu-char.c
> +++ b/qemu-char.c
> @@ -2275,6 +2275,51 @@ static CharDriverState *qemu_chr_open_socket(QemuOpts *opts)
>       return NULL;
>   }
>
> +#include "qmp-proxy-core.h"
> +
> +extern QmpProxy *qmp_proxy_default;
> +
> +static CharDriverState *qemu_chr_open_qmp_proxy(QemuOpts *opts)
> +{
> +    CharDriverState *chr;
> +    QmpProxy *p;
> +    const char *path;
> +
> +    /* revert to/enforce default socket chardev options for qmp proxy */
> +    path = qemu_opt_get(opts, "path");
> +    if (path == NULL) {
> +        path = QMP_PROXY_PATH_DEFAULT;
> +        qemu_opt_set_qerr(opts, "path", path);
> +    }
> +    /* required options for qmp proxy */
> +    qemu_opt_set_qerr(opts, "server", "on");
> +    qemu_opt_set_qerr(opts, "wait", "off");
> +    qemu_opt_set_qerr(opts, "telnet", "off");

Why are these options required?

Regards,

Anthony Liguori

> +
> +    chr = qemu_chr_open_socket(opts);
> +    if (chr == NULL) {
> +        goto err;
> +    }
> +
> +    /* initialize virtagent using the socket we just set up */
> +    if (qmp_proxy_default) {
> +        fprintf(stderr, "error, multiple qmp guest proxies are not allowed\n");
> +    }
> +    p = qmp_proxy_new(path);
> +    if (p == NULL) {
> +        fprintf(stderr, "error initializing qmp guest proxy\n");
> +        goto err;
> +    }
> +    qmp_proxy_default = p;
> +
> +    return chr;
> +err:
> +    if (chr) {
> +        qemu_free(chr);
> +    }
> +    return NULL;
> +}
> +
>   /***********************************************************/
>   /* Memory chardev */
>   typedef struct {
> @@ -2495,6 +2540,7 @@ static const struct {
>       || defined(__FreeBSD_kernel__)
>       { .name = "parport",   .open = qemu_chr_open_pp },
>   #endif
> +    { .name = "qmp_proxy", .open = qemu_chr_open_qmp_proxy },
>   };
>
>   CharDriverState *qemu_chr_open_opts(QemuOpts *opts,