Re: event notification

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

On Wed, 2010-03-10 at 23:20 +0000, ravi kerur wrote:
> Thanks Ian and Konrad. I thought monitoring udev events or xen store
> watch can be done from user-level apps. I am wondering can they be
> used from kernel modules as well?

xenstore can. I don't think udev can.

Ian.

> 
> Thanks
> -RK
> 
> On Wed, Mar 10, 2010 at 8:09 AM, Ian Campbell
> <Ian.Campbell@citrix.com> wrote:
>         On Mon, 2010-03-08 at 16:47 +0000, Konrad Rzeszutek Wilk
>         wrote:
>         > On Sat, Mar 06, 2010 at 07:12:02PM -0800, ravi kerur wrote:
>         > > Hi,
>         > >
>         > > Is there a mechanism available in Xen such that a kernel
>         module in dom0 can
>         > > register to it and when a VM(domU) is installed or deleted
>         or suspend or
>         > > resumed kernel module in domU can send notification to its
>         counterpart in
>         > > dom0. I have looked into xenbus mechanism used by PV
>         drivers and it won't
>         > > work for us. Inputs appreciated.
>         >
>         > You can listen on udev events and see when a vif device has
>         been added.
>         > Also you can add pieces to the dom0 kernel to send uevents
>         when a device
>         > is suspended and do something.
>         >
>         > Attached is a simple program to listen to all uevents..
>         
>         
>         Also if you are specifically interested in domain
>         create/destruction
>         (from the hypervisors PoV) then I think you can add a xenstore
>         watch on
>         "@releaseDomain" and "@introduceDomain".
>         
>         As far as the hypervisor is concerned things like migration or
>         suspend/resume are just domain creation or destruction, the
>         "illusion"
>         of anything more is provided by the tools.
>         
>         If you are interested in the creation/suspension/migration/etc
>         of
>         domains at the toolstack level then it depends which toolstack
>         you are
>         targeting.
>         
>         
>