On Fri, 3 Jul 2015, Roger Pau Monne wrote:
> HVM guests have always used the emulated serial console by default, but if
> the emulated serial pty cannot be fetched from xenstore try to use the PV
> console instead.
>
> Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
> Cc: Ian Jackson <ian.jackson@eu.citrix.com>
> Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
> Cc: Ian Campbell <ian.campbell@citrix.com>
> Cc: Wei Liu <wei.liu2@citrix.com>
> ---
>  tools/console/client/main.c | 11 ++++++++---
>  1 file changed, 8 insertions(+), 3 deletions(-)
>
> diff --git a/tools/console/client/main.c b/tools/console/client/main.c
> index f4c783b..c92553e 100644
> --- a/tools/console/client/main.c
> +++ b/tools/console/client/main.c
> @@ -279,7 +279,7 @@ int main(int argc, char **argv)
>  		{ 0 },
>
>  	};
> -	char *dom_path = NULL, *path = NULL;
> +	char *dom_path = NULL, *path = NULL, *test = NULL;
>  	int spty, xsfd;
>  	struct xs_handle *xs;
>  	char *end;
> @@ -357,9 +357,14 @@ int main(int argc, char **argv)
>  	path = malloc(strlen(dom_path) + strlen("/device/console/0/tty") + 5);
>  	if (path == NULL)
>  		err(ENOMEM, "malloc");
> -	if (type == CONSOLE_SERIAL)
> +	if (type == CONSOLE_SERIAL) {
>  		snprintf(path, strlen(dom_path) + strlen("/serial/0/tty") + 5, "%s/serial/%d/tty", dom_path, num);
> -	else {
> +		test = xs_read(xs, XBT_NULL, path, NULL);
> +		free(test);
> +		if (test == NULL)
> +			goto pv_console;

instead of using labels I would probably do:

        if (test == NULL)
            type = CONSOLE_PV;
    }
    if (type == CONSOLE_PV) {
        ...

> +	} else {
> +pv_console:
>  		if (num == 0)
>  			snprintf(path, strlen(dom_path) + strlen("/console/tty") + 1, "%s/console/tty", dom_path);
>  		else