Re: [Qemu-devel] [PATCH v2] xen-block: handle resize callback

[Paul Durrant <Paul.Durrant@citrix.com>]

> -----Original Message-----
> From: Anthony PERARD [mailto:anthony.perard@citrix.com]
> Sent: 31 January 2019 15:21
> To: Paul Durrant <Paul.Durrant@citrix.com>
> Cc: qemu-devel@nongnu.org; qemu-block@nongnu.org; xen-
> devel@lists.xenproject.org; Stefan Hajnoczi <stefanha@redhat.com>; Stefano
> Stabellini <sstabellini@kernel.org>; Kevin Wolf <kwolf@redhat.com>; Max
> Reitz <mreitz@redhat.com>
> Subject: Re: [PATCH v2] xen-block: handle resize callback
> 
> On Wed, Jan 30, 2019 at 04:19:48PM +0000, Paul Durrant wrote:
> > Some frontend drivers will handle dynamic resizing of PV disks, so set
> up
> > the BlockDevOps resize_cb() method during xen_block_realize() to allow
> > this to be done.
> >
> > Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
> > ---
> 
> 
> > +    /*
> > +     * Mimic the behaviour of Linux xen-blkback and re-write the state
> > +     * to trigger the frontend watch.
> > +     */
> > +    xen_device_backend_set_state(xendev, backend_state);
> 
> :(, that function doesn't write the state again if it hasn't changed.
> So in my testing, Linux never did anything.

Gah! I forgot about that. Alright, it's going to have to be a bit more crude.

  Paul

> 
> --
> Anthony PERARD