Re: [PATCH 2/6] xen/hvm kexec: unregister shutdown+sysrq watches during reboot

[Olaf Hering <olaf@aepfle.de>]

On Thu, Jul 28, Keir Fraser wrote:

> > Unfortunately do_introduce() is not preprared for that.
> > 
> > On enter, conn->id contains the domain_id, so it errors out early.
> > Later it compares domain->conn != conn and does not enter the correct path.
> 
> Oh of course you want to do it from *inside* the guest...
> 
> > If I remove both checks the kexec appears to work ok.
> > Is it save to remove both checks?
> 
> Hmm, no. Attached patch would be safer, give it a try.
> 
> And note that it is *dangerous* to reset the domain xenstore connection if
> there could be any other concurrent activity on the connection that could
> confuse the guest kernel. So doing the reset during kernel bringup might be
> safest, there you can do it in the kernel before the whole xenbus subsystem
> is fully up.

I sent a different xenstored patch which takes DOMID_SELF into account.

Olaf