Re: [PATCH] libxl: ignore run_hotplug_scripts setting when backend_domid!=0

[George Dunlap <george.dunlap@eu.citrix.com>]

On 04/07/13 14:51, Wei Liu wrote:
> On Thu, Jul 04, 2013 at 03:23:51PM +0200, Roger Pau Monné wrote:
>> On 04/07/13 14:40, George Dunlap wrote:
>>> On 04/07/13 12:39, Roger Pau Monné wrote:
>>>> On 04/07/13 12:42, George Dunlap wrote:
>>>>> On Tue, Apr 9, 2013 at 9:49 AM, Marek Marczykowski
>>>>> <marmarek@invisiblethingslab.com> wrote:
>>>>>> Instead of forcing the user to change run_hotplug_scripts setting
>>>>>> globally, just ignore it for backends outside of dom0.
>>>>>>
>>>>>> Signed-off-by: Marek Marczykowski <marmarek@invisiblethingslab.com>
>>>>> This seems like a good idea -- Roger / Ian, any thoughts?
>>>> We already have this behaviour in libxl (see
>>>> libxl_device.c:device_hotplug):
>>>>
>>>> /*
>>>>    * If device is attached from a driver domain don't try to execute
>>>>    * hotplug scripts
>>>>    */
>>>> if (aodev->dev->backend_domid != LIBXL_TOOLSTACK_DOMID)
>>>>       goto out;
>>>>
>>>> This was introduced by commit 05bfd984dfe7014f1f5ea1133608b9bab589c120
> What Marek's patch does is effectively Roger's commit 05bfd984 plus some
> network specific bits. N.B. this patch predates 05bfd984.
>
>>> But you still get an error on domain creation if you actually set a
>>> non-dom0 backend and run_hotplug_scripts is set; so you can't actually
>>> run in "mixed mode" anyway.  This patch should, I think, enable you to
>>> have libxl run the scripts in dom0, but udev run them in domu.
> Long time ago Konrad sent me an email about running network backend in
> another domain. The first thing to do is to disable hotplug script
> globally.

Sure, that's easy.  The problem is, there's no reason to disable it 
globally -- you can run udev in the domnet, but have libxl run the 
scripts in dom0.

I'll try just taking out that check and seeing what happens...

  -George