Re: [PATCH 4/4] xen-blkback: support dynamic unbind/bind

From: Roger Pau Monné
Date: Mon Dec 09 2019 - 07:17:55 EST


On Thu, Dec 05, 2019 at 02:01:23PM +0000, Paul Durrant wrote:
> By simply re-attaching to shared rings during connect_ring() rather than
> assuming they are freshly allocated (i.e assuming the counters are zero)
> it is possible for vbd instances to be unbound and re-bound from and to
> (respectively) a running guest.
>
> This has been tested by running:
>
> while true; do dd if=/dev/urandom of=test.img bs=1M count=1024; done
>
> in a PV guest whilst running:
>
> while true;
> do echo vbd-$DOMID-$VBD >unbind;
> echo unbound;
> sleep 5;
> echo vbd-$DOMID-$VBD >bind;
> echo bound;
> sleep 3;
> done

So this does unbind blkback while leaving the PV interface as
connected?

Thanks, Roger.