Re: [Qemu-devel] block ais migration for machines <= 2.9

[Yi Min Zhao]

在 2017/9/21 上午12:04, Dr. David Alan Gilbert 写道:
> * Christian Borntraeger (address@hidden) wrote:
> > Something like the following seems to do the tricks.
> > Needs proper patch description, review, full test with different kernel 
> > versions.....
> Without knowing anything about 'ais' - will this break migration from
> 2.10 -> 2.10+this fix?
I think it doesn't break. I will have a try later.
> Dave
>
> > diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
> > index 1c7af39..2ff32ba 100644
> > --- a/hw/s390x/s390-virtio-ccw.c
> > +++ b/hw/s390x/s390-virtio-ccw.c
> > @@ -212,6 +212,7 @@ static void ccw_machine_class_init(ObjectClass *oc, void 
> > *data)
> >       s390mc->cpu_model_allowed = true;
> >       s390mc->css_migration_enabled = true;
> >       s390mc->gs_allowed = true;
> > +    s390mc->ais_allowed = true;
> >       mc->init = ccw_init;
> >       mc->reset = s390_machine_reset;
> >       mc->hot_add_cpu = s390_hot_add_cpu;
> > @@ -305,6 +306,11 @@ bool gs_allowed(void)
> >       return false;
> >   }
> >   
> > +bool ais_allowed(void)
> > +{
> > +    return get_machine_class()->ais_allowed;
> > +}
> > +
> >   static char *machine_get_loadparm(Object *obj, Error **errp)
> >   {
> >       S390CcwMachineState *ms = S390_CCW_MACHINE(obj);
> > @@ -533,6 +539,7 @@ static void ccw_machine_2_9_class_options(MachineClass *mc)
> >       S390CcwMachineClass *s390mc = S390_MACHINE_CLASS(mc);
> >   
> >       s390mc->gs_allowed = false;
> > +    s390mc->ais_allowed = false;
> >       ccw_machine_2_10_class_options(mc);
> >       SET_MACHINE_COMPAT(mc, CCW_COMPAT_2_9);
> >       s390mc->css_migration_enabled = false;
> > diff --git a/include/hw/s390x/s390-virtio-ccw.h 
> > b/include/hw/s390x/s390-virtio-ccw.h
> > index 41a9d28..bba8660 100644
> > --- a/include/hw/s390x/s390-virtio-ccw.h
> > +++ b/include/hw/s390x/s390-virtio-ccw.h
> > @@ -41,6 +41,7 @@ typedef struct S390CcwMachineClass {
> >       bool cpu_model_allowed;
> >       bool css_migration_enabled;
> >       bool gs_allowed;
> > +    bool ais_allowed;
> >   } S390CcwMachineClass;
> >   
> >   /* runtime-instrumentation allowed by the machine */
> > @@ -49,6 +50,8 @@ bool ri_allowed(void);
> >   bool cpu_model_allowed(void);
> >   /* guarded-storage allowed by the machine */
> >   bool gs_allowed(void);
> > +/* ais allowed by the machine */
> > +bool ais_allowed(void);
> >   
> >   /**
> >    * Returns true if (vmstate based) migration of the channel subsystem
> > diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c
> > index c4c5791..531d474 100644
> > --- a/target/s390x/kvm.c
> > +++ b/target/s390x/kvm.c
> > @@ -309,7 +309,9 @@ int kvm_arch_init(MachineState *ms, KVMState *s)
> >       }
> >   
> >       /* Try to enable AIS facility */
> > -    kvm_vm_enable_cap(s, KVM_CAP_S390_AIS, 0);
> > +    if (ais_allowed()) {
> > +       kvm_vm_enable_cap(s, KVM_CAP_S390_AIS, 0);
> > +    }
> >   
> >       qemu_mutex_init(&qemu_sigp_mutex);
> --
> Dr. David Alan Gilbert / address@hidden / Manchester, UK