Re: [Qemu-devel] [PATCH] s390/kvm_virtio/linux-headers: remove traces of old virtio transport

[Cornelia Huck <cohuck@redhat.com>]

On Thu, 16 Nov 2017 08:45:09 +0100
Christian Borntraeger <borntraeger@de.ibm.com> wrote:

> On 11/15/2017 06:10 PM, Cornelia Huck wrote:
> > On Wed, 15 Nov 2017 16:42:23 +0100
> > Christian Borntraeger <borntraeger@de.ibm.com> wrote:
> >   
> >> We no longer support the old s390 transport, neither does the newest
> >> Linux kernel. Remove it from the linux header script as well as the
> >> s390x virtio code.  We still should handle the VIRTIO_NOTIFY hypercall,
> >> to tolerate early printk on older guest kernels without an sclp console.  
> > 
> > Are there any such guests still around? Wouldn't they be unable to run
> > because of the missing old transport anyway?  
> 
> As far as I can see even an 4.13 will do
> 
> static int __init s390_virtio_console_init(void)
> {
>         if (sclp.has_vt220 || sclp.has_linemode)
>                 return -ENODEV;
>         return virtio_cons_early_init(early_put_chars);
> }
> console_initcall(s390_virtio_console_init);
> 
> No matter if there is the old transport or not available.
> 
> So as soon as somebody chooses virtio-console you should see the diag500 from the early
> printk.

Grmpf, and the first condition does not trigger when you don't define
any sclp console.

Oh well, it seems we still have to drag this along :(
 
> >   
> >> We continue to ignore these events.
> >>
> >> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
> >> ---
> >>  hw/s390x/s390-virtio-hcall.h                   |  6 ++-
> >>  include/standard-headers/asm-s390/kvm_virtio.h | 64
> >> --------------------------
> >> scripts/update-linux-headers.sh                |  1 - 3 files
> >> changed, 4 insertions(+), 67 deletions(-) delete mode 100644
> >> include/standard-headers/asm-s390/kvm_virtio.h  
> >   

I think this becomes relevant only when someone does a headers update
against 4.15+, which is unlikely to happen in freeze. So I'll queue
this to s390-next only.