Re: [Qemu-devel] [PATCH] virtio-blk: switch off scsi-passthrough by default

[Cornelia Huck]

On Fri, 16 Oct 2015 10:46:31 +0200
Paolo Bonzini <address@hidden> wrote:

> 
> 
> On 16/10/2015 10:41, Paolo Bonzini wrote:
> > 
> > 
> > On 16/10/2015 10:40, Cornelia Huck wrote:
> >> --- a/hw/s390x/s390-virtio-ccw.c
> >> +++ b/hw/s390x/s390-virtio-ccw.c
> >> @@ -272,6 +272,10 @@ static const TypeInfo ccw_machine_info = {
> >>              .driver   = "vhost-scsi-ccw",\
> >>              .property = "max_revision",\
> >>              .value    = "0",\
> >> +        },{\
> >> +            .driver   = "virtio-blk-ccw",\
> >> +            .property = "scsi",\
> >> +            .value    = "true",\
> >>          },
> >>  
> >>  static void ccw_machine_2_4_class_init(ObjectClass *oc, void *data)
> >> diff --git a/include/hw/compat.h b/include/hw/compat.h
> >> index 095de5d..bbf1ab2 100644
> >> --- a/include/hw/compat.h
> >> +++ b/include/hw/compat.h
> >> @@ -2,7 +2,11 @@
> >>  #define HW_COMPAT_H
> >>  
> >>  #define HW_COMPAT_2_4 \
> >> -        /* empty */
> >> +        {\
> >> +            .driver   = "virtio-blk-pci",\
> >> +            .property = "scsi",\
> >> +            .value    = "true",\
> >> +        },
> >>  
> >>  #define HW_COMPAT_2_3 \
> >>          {\
> >>
> > 
> > s390 should use HW_COMPAT_2_4 as well.  Otherwise looks good.
> 
> Hmm, ECONCISE probably.  Sorry.
> 
> I mean that virtio-blk-ccw's scsi property should IMO go in
> HW_COMPAT_2_4 as well.

I was wondering about the semantics of HW_COMPAT_*: Does any hw-related
compat stuff go in there, even if it is architecture specific (like
ccw)?
> 
> But I noticed now that:
> 
> * if it works it would be even better if the compat property used
> virtio-blk-device;

Hm. Previous virtio-compat always treated -pci explicitly, but we only
gained s390x compat handling with 2.4, so it didn't really matter. But
if it works, this is the saner approach.

> 
> * a new pseries-2.4 machine also needs to be created.

Ah, wasn't aware they do compat as well.