Re: [PATCH] virtio-blk: drop deprecated scsi=on|off property

[Peter Krempa]

On Fri, Apr 30, 2021 at 09:42:05 +0200, Markus Armbruster wrote:
> Eduardo Habkost <ehabkost@redhat.com> writes:
> 
> > On Thu, Apr 29, 2021 at 04:52:21PM +0100, Stefan Hajnoczi wrote:
> >> The scsi=on|off property was deprecated in QEMU 5.0 and can be removed
> >> completely at this point.
> >> 
> >> Drop the scsi=on|off option. It was only available on Legacy virtio-blk
> >> devices. Linux v5.6 already dropped support for it.
> >> 
> >> Remove the hw_compat_2_4[] property assignment since scsi=on|off no
> >> longer exists. Old guests with Legacy virtio-blk devices no longer see
> >> the SCSI host features bit.
> >> 
> >
> > This means pc-2.4 will now break guest ABI if using virtio-blk
> > devices, correct?
> >
> > This looks like a sign we should have deprecated pc-2.4 a long
> > time ago.
> 
> The last batch of PC machine type retiring was pc-1.0 to pc-1.3:
> deprecated in 5.0 (commit 30d2a17b4, Dec 2019), dropped in 6.0 (commit
> f862ddbb1, just weeks ago).  pc-1.3 was a bit over seven years old when
> we released 5.0.  pc-2.4 will be six years old by the time we release
> 6.1.  Fair game?

As a data-point, libvirt will be dropping support for <qemu-2.10
(release, not the machine type) in the upcomming release. I'm not sure
whether that justifies more deprecation though.