[libvirt] [PATCH v2 10/14] libxl: support domain config modification in virDomainRestoreFlags

[Jim Fehlig]

Marek Marczykowski-Górecki wrote:
> Signed-off-by: Marek Marczykowski-Górecki <marmarek at invisiblethingslab.com>
> ---
>  src/libxl/libxl_driver.c | 18 +++++++++++++-----
>  1 file changed, 13 insertions(+), 5 deletions(-)
>
> diff --git a/src/libxl/libxl_driver.c b/src/libxl/libxl_driver.c
> index 8dec70b..7b50853 100644
> --- a/src/libxl/libxl_driver.c
> +++ b/src/libxl/libxl_driver.c
> @@ -2306,11 +2306,6 @@ libxlDomainRestoreFlags(virConnectPtr conn, const char *from,
>      int ret = -1;
>  
>      virCheckFlags(VIR_DOMAIN_SAVE_PAUSED, -1);
> -    if (dxml) {
> -        virReportError(VIR_ERR_ARGUMENT_UNSUPPORTED, "%s",
> -                       _("xml modification unsupported"));
> -        return -1;
> -    }
>  
>      libxlDriverLock(driver);
>  
> @@ -2318,6 +2313,19 @@ libxlDomainRestoreFlags(virConnectPtr conn, const char *from,
>      if (fd < 0)
>          goto cleanup;
>  
> +    if (dxml) {
>   

What kind of changes are supported in dxml?  I tried passing xml that
contained another vif, which caused libxl to fail the restore

libxl: error: libxl_device.c:878:device_backend_callback: unable to add
device with path /local/domain/0/backend/vif/25/0

> +        virDomainDefPtr def2 = NULL;
> +
> +        if (!(def2 = virDomainDefParseString(dxml, driver->caps, driver->xmlopt,
> +                                        1 << VIR_DOMAIN_VIRT_XEN,
> +                                        VIR_DOMAIN_XML_INACTIVE))) {
> +            goto cleanup;
> +        }
> +        virDomainDefFree(def);
> +        def = def2;
>   

But we've already thrown away the original config and replaced it with
config that subsequently fails.

The qemu driver calls virDomainDefCheckABIStability to ensure the new
config is compatible, and IMO we should do the same here.

Regards,
Jim

> +    }
> +
> +
>      if (!(vm = virDomainObjListAdd(driver->domains, def,
>                                     driver->xmlopt,
>                                     VIR_DOMAIN_OBJ_LIST_ADD_LIVE |
>