Re: [Qemu-devel] [PATCH] s390-ccw: Fix alignment for CCW1

[Farhan Ali]

On 08/28/2017 10:05 AM, Cornelia Huck wrote:
> > > > It's the alignment of the CCW which causes the problem.
> > > >
> > > > The exact error message when starting the guest was:
> > > >
> > > > ! No virtio device found !
> > > >
> > > > Since it worked for SCSI and CDL, and failed for LDL disks on that particular 
> > > > system, we are not really sure what caused the failure.
> > > > Debugging it further showed the CCW for LDL disks were not aligned at double 
> > > > word boundary.
> This is really, really odd, as the low-level ccw code is the same for
> any disk type...
Exactly!

> > > > Trying the test on a different system with LDL disks worked fine, with the 
> > > > aligned(8) fix.
> > > Do you happen to have an old s390-ccw.img laying around in the test folder? 
> > > QEMU might pick up
> > > this one (e.g. when calling it without libvirt from the command line).
> > I explicitly mention the bios to use with '-bios' option and pick up the
> > latest bios. Without the aligned fix I see the error and with the fix it
> > works fine.
> Wait, so the fix fixes it? Or am I confused now?

It fixes in my system and one other system we tried on. But fails on a 
system where this issue was first noticed.