Re: [PATCH for 4.6 v4 2/3] xl/libxl: disallow saving a guest with vNUMA configured

[Ian Campbell <ian.campbell@citrix.com>]

On Fri, 2015-09-11 at 15:14 +0100, Wei Liu wrote:
@@ -1636,6 +1638,20 @@ void libxl__domain_save(libxl__egc *egc,
> libxl__domain_suspend_state *dss)
>            | (debug ? XCFLAGS_DEBUG : 0)
>            | (dss->hvm ? XCFLAGS_HVM : 0);
>  
> +    /* Disallow saving a guest with vNUMA configured because migration
> +     * stream does not preserve node information.
> +     *
> +     * Do not differentiate "no vnuma configuration" from "empty vnuma
> +     * configuration".
> +     */
> +    rc = xc_domain_getvnuma(CTX->xch, domid, &nr_vnodes, &nr_vmemranges,
> +                            &nr_vcpus, NULL, NULL, NULL);

Sorry for not noticing this before but this is putting a non-libxl error
code in a variable named rc, which is verboten in coding style.

Not least because I think it is now possible to get through this function
successfully without changing it from the rc == -1 which might be assigned
here (in the case where xs_suspend_evtchn_port returns < 0).

Ian.

> +    if (rc != -1 || errno != XEN_EOPNOTSUPP) {
> +        LOG(ERROR, "Cannot save a guest with vNUMA configured");
> +        rc = ERROR_FAIL;
> +        goto out;
> +    }
> +
>      dss->guest_evtchn.port = -1;
>      dss->guest_evtchn_lockfd = -1;
>      dss->guest_responded = 0;