Re: [Xen-devel] [PATCH v1 04/10] libxl: separate device add/rm complete callbacks

[Ian Campbell <Ian.Campbell@xxxxxxxxxx>]

On Thu, 2014-07-10 at 15:32 +0100, Wei Liu wrote:
> This is in preparation for device hotplug / unplug configuration
> synchronisation. No functional change introduced. This change is
> necessary because we need to do different things for add and remove.
> Using a single callback won't meet our need anymore.

Looking at the next two patches it seems like this is because on add you
do it at the start and on rm you do it at the end?

I did wonder if it was possible that you could continue to share the
same callback if you could add a flag, but the real reason for not
sharing is that the code you want to add to the remove case is device
type specific, so you need multiple rm callbacks. I misunderstood your
comment about a single callback to mean a single add+rm callback as
opposed to a single vs. multiple rm callbacks.

Given that the actual implementation looks ok to me.

> +DEFINE_DEVICE_RM_AOCOMPLETE(vtpm);
> +DEFINE_DEVICE_RM_AOCOMPLETE(nic);
> +DEFINE_DEVICE_RM_AOCOMPLETE(disk);
> +DEFINE_DEVICE_RM_AOCOMPLETE(vfb);
> +DEFINE_DEVICE_RM_AOCOMPLETE(vkb);

Elsewhere in this file there is:
/* disk */
DEFINE_DEVICE_REMOVE(disk, remove, 0)
DEFINE_DEVICE_REMOVE(disk, destroy, 1)
...

Perhaps add this call there too? Also that place has a comment with the
resulting function names to serve as grep fodder. That would be nice
here too.

Ian.



_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel