Re: [PATCH v1 10/10] xl: use libxl_retrieve_domain_configuration and JSON format

[Wei Liu <wei.liu2@citrix.com>]

On Thu, Jul 17, 2014 at 12:13:17PM +0100, Ian Campbell wrote:
[...]
> >  made to the guest will be preserved when the guest is restarted.
> >  
> > +Libxl now has better capability to handle domain configuration, avoid
> > +using this command when possible.
> 
> Perhaps say:
> 
>         Libxl now has improved capabilities to handle dynamic domain
>         configuration changes and will preserve any changes made a
>         runtime when necessary. Therefore it should not normally be
>         necessary to use this command any more.
>         

I will use this.

> > +
> >  I<configfile> has to be an absolute path to a file.
> >  
[...]
> >  static void reload_domain_config(uint32_t domid,
> > -                                 uint8_t **config_data, int *config_len)
> > +                                 libxl_domain_config *d_config)
> >  {
> > +    int rc;
> >      uint8_t *t_data;
> >      int ret, t_len;
> > +    libxl_domain_config d_config_new;
> >  
> > +    /* In case user has used "config-update" to store a new config
> > +     * file.
> > +     */
> >      ret = libxl_userdata_retrieve(ctx, domid, "xl", &t_data, &t_len);
> > -    if (ret) {
> > -        LOG("failed to retrieve guest configuration (rc=%d). "
> > -            "reusing old configuration", ret);
> > +    if (ret && errno != ENOENT) {
> > +        LOG("\"xl\" file found but failed to load\n");
> 
> Perhaps "Saved \"xl\" configuration found ..."

NP.

> > +    }
> > +    if (t_len > 0) {
> > +        LOG("\"xl\" config file found, use it\n");
> 
> "using"
> 
> I wonder if at this point we should delete the saved config.
> 
> IOW do we expect xl update-config to be one shot or to persist. I think
> the one shot is the only sensible answer and it doesn't conflict with
> the previous implementation since in the old implementation the saved
> config became the new stored config.
> 

Makes sense.

Wei.

> Ian.