Re: [Qemu-devel] [PATCH] Add optional dump of default config file paths..

[Anthony Liguori <anthony@codemonkey.ws>]

On 06/09/2010 03:05 AM, john cooper wrote:
> This patch adds the ability to determine the build-configured
> runtime "config file" paths from the command line.  After
> support for cpu model definitions were added to the default
> runtime "target-" config file, testing of this feature has
> tripped over an unintentionally mis-installed config file
> enough to indicate some help is needed resolving such issues.
>
> As no general "verbose" flag is currently available, specifying
> "-readconfig ?" on the command line will maintain the default
> (config file) disposition but additionally emit diagnostic info.
> This mode is optional, otherwise the existing startup behavior
> is identical.
>    

I assume this is something requested by libvirt?  I'd prefer we support 
this via Daniel's capabilities patchset instead of adding yet another 
hidden help output and having libvirt parse that output.

Regards,

Anthony Liguori

> Signed-off-by: john cooper<john.cooper@redhat.com>
> ---
>
> diff --git a/qemu-config.c b/qemu-config.c
> index 5a4e61b..a490603 100644
> --- a/qemu-config.c
> +++ b/qemu-config.c
> @@ -518,21 +518,29 @@ out:
>       return res;
>   }
>
> -int qemu_read_config_file(const char *filename)
> +/* attempt to open and parse config file, report problems if vflag
> + */
> +int qemu_read_config_file(const char *filename, int vflag)
>   {
>       FILE *f = fopen(filename, "r");
> -    int ret;
> +    int rv = 0;
>
>       if (f == NULL) {
> -        return -errno;
> +        rv = -errno;
>       }
> -
> -    ret = qemu_config_parse(f, vm_config_groups, filename);
> -    fclose(f);
> -
> -    if (ret == 0) {
> -        return 0;
> -    } else {
> -        return -EINVAL;
> +    else if (qemu_config_parse(f, vm_config_groups, filename) != 0) {
> +        rv = -EINVAL;
> +    }
> +    else if (vflag) {
> +        fprintf(stderr, "read config file %s\n", filename);
>       }
> +    if (f) {
> +        fclose(f);
> +    }
> +    if (rv&&  vflag) {
> +        fprintf(stderr, "can't read config file %s: %s\n",
> +                filename, strerror(-rv));
> +    }
> +    return rv;
>   }
> +
> diff --git a/qemu-config.h b/qemu-config.h
> index dca69d4..2e15556 100644
> --- a/qemu-config.h
> +++ b/qemu-config.h
> @@ -23,6 +23,6 @@ void qemu_add_globals(void);
>   void qemu_config_write(FILE *fp);
>   int qemu_config_parse(FILE *fp, QemuOptsList **lists, const char *fname);
>
> -int qemu_read_config_file(const char *filename);
> +int qemu_read_config_file(const char *filename, int vflag);
>
>   #endif /* QEMU_CONFIG_H */
> diff --git a/vl.c b/vl.c
> index 7121cd0..23c7276 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -2582,6 +2582,7 @@ int main(int argc, char **argv, char **envp)
>   #endif
>       int show_vnc_port = 0;
>       int defconfig = 1;
> +    int defconfig_verbose = 0;	
>
>       error_set_progname(argv[0]);
>
> @@ -2657,6 +2658,10 @@ int main(int argc, char **argv, char **envp)
>               case QEMU_OPTION_nodefconfig:
>                   defconfig=0;
>                   break;
> +            case QEMU_OPTION_readconfig:
> +                if (!strcmp(optarg, "?"))
> +                    defconfig_verbose = 1;
> +                break;
>               }
>           }
>       }
> @@ -2664,12 +2669,14 @@ int main(int argc, char **argv, char **envp)
>       if (defconfig) {
>           int ret;
>
> -        ret = qemu_read_config_file(CONFIG_QEMU_CONFDIR "/qemu.conf");
> +        ret = qemu_read_config_file(CONFIG_QEMU_CONFDIR "/qemu.conf",
> +                                    defconfig_verbose);
>           if (ret<  0&&  ret != -ENOENT) {
>               exit(1);
>           }
>
> -        ret = qemu_read_config_file(arch_config_name);
> +        ret = qemu_read_config_file(arch_config_name,
> +                                    defconfig_verbose);
>           if (ret<  0&&  ret != -ENOENT) {
>               exit(1);
>           }
> @@ -3386,15 +3393,9 @@ int main(int argc, char **argv, char **envp)
>                   xen_mode = XEN_ATTACH;
>                   break;
>               case QEMU_OPTION_readconfig:
> -                {
> -                    int ret = qemu_read_config_file(optarg);
> -                    if (ret<  0) {
> -                        fprintf(stderr, "read config %s: %s\n", optarg,
> -                            strerror(-ret));
> -                        exit(1);
> -                    }
> -                    break;
> -                }
> +                if (!defconfig_verbose&&  qemu_read_config_file(optarg, 1)<  0)
> +                    exit(1);
> +                break;
>               case QEMU_OPTION_writeconfig:
>                   {
>                       FILE *fp;
>
>