Re: [PATCH v3 01/26] s390/stattrib: Add Error** argument to set_migrationmode() handler

[Cédric Le Goater]

On 3/4/24 21:49, Fabiano Rosas wrote:
> Cédric Le Goater <clg@redhat.com> writes:
>
> > This will prepare ground for futur changes adding an Error** argument
> > to the save_setup() handler. We need to make sure that on failure,
> > set_migrationmode() always sets a new error. See the Rules section in
> > qapi/error.h.
> >
> > Cc: Halil Pasic <pasic@linux.ibm.com>
> > Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
> > Cc: Thomas Huth <thuth@redhat.com>
> > Signed-off-by: Cédric Le Goater <clg@redhat.com>
> > ---
> >   include/hw/s390x/storage-attributes.h |  2 +-
> >   hw/s390x/s390-stattrib-kvm.c          | 12 ++++++++++--
> >   hw/s390x/s390-stattrib.c              | 14 +++++++++-----
> >   3 files changed, 20 insertions(+), 8 deletions(-)
> >
> > diff --git a/include/hw/s390x/storage-attributes.h 
> > b/include/hw/s390x/storage-attributes.h
> > index 
> > 5239eb538c1b087797867a247abfc14551af6a4d..8921a04d514bf64a3113255ee10ed33fc598ae06
> >  100644
> > --- a/include/hw/s390x/storage-attributes.h
> > +++ b/include/hw/s390x/storage-attributes.h
> > @@ -39,7 +39,7 @@ struct S390StAttribClass {
> >       int (*set_stattr)(S390StAttribState *sa, uint64_t start_gfn,
> >                         uint32_t count, uint8_t *values);
> >       void (*synchronize)(S390StAttribState *sa);
> > -    int (*set_migrationmode)(S390StAttribState *sa, bool value);
> > +    int (*set_migrationmode)(S390StAttribState *sa, bool value, Error **errp);
> >       int (*get_active)(S390StAttribState *sa);
> >       long long (*get_dirtycount)(S390StAttribState *sa);
> >   };
> > diff --git a/hw/s390x/s390-stattrib-kvm.c b/hw/s390x/s390-stattrib-kvm.c
> > index 
> > 24cd01382e2d74d62c2d7e980eb6aca1077d893d..357cea2c987213b867c81b0e258f7d0c293fe665
> >  100644
> > --- a/hw/s390x/s390-stattrib-kvm.c
> > +++ b/hw/s390x/s390-stattrib-kvm.c
> > @@ -17,6 +17,7 @@
> >   #include "sysemu/kvm.h"
> >   #include "exec/ram_addr.h"
> >   #include "kvm/kvm_s390x.h"
> > +#include "qapi/error.h"
> >   
> >   Object *kvm_s390_stattrib_create(void)
> >   {
> > @@ -137,14 +138,21 @@ static void 
> > kvm_s390_stattrib_synchronize(S390StAttribState *sa)
> >       }
> >   }
> >   
> > -static int kvm_s390_stattrib_set_migrationmode(S390StAttribState *sa, bool val)
> > +static int kvm_s390_stattrib_set_migrationmode(S390StAttribState *sa, bool val,
> > +                                               Error **errp)
> >   {
> >       struct kvm_device_attr attr = {
> >           .group = KVM_S390_VM_MIGRATION,
> >           .attr = val,
> >           .addr = 0,
> >       };
> > -    return kvm_vm_ioctl(kvm_state, KVM_SET_DEVICE_ATTR, &attr);
> > +    int r;
> > +
> > +    r = kvm_vm_ioctl(kvm_state, KVM_SET_DEVICE_ATTR, &attr);
> > +    if (r) {
> > +        error_setg_errno(errp, -r, "KVM_S390_SET_CMMA_BITS failed");
>
> Did you mean KVM_SET_DEVICE_ATTR?

Drat. Copy paste :)


Thanks,

C.



> > +    }
> > +    return r;
> >   }
> >   
> >   static long long kvm_s390_stattrib_get_dirtycount(S390StAttribState *sa)
> > diff --git a/hw/s390x/s390-stattrib.c b/hw/s390x/s390-stattrib.c
> > index 
> > c483b62a9b5f71772639fc180bdad15ecb6711cb..e99de190332a82363b1388bbc450013149295bc0
> >  100644
> > --- a/hw/s390x/s390-stattrib.c
> > +++ b/hw/s390x/s390-stattrib.c
> > @@ -60,11 +60,12 @@ void hmp_migrationmode(Monitor *mon, const QDict *qdict)
> >       S390StAttribState *sas = s390_get_stattrib_device();
> >       S390StAttribClass *sac = S390_STATTRIB_GET_CLASS(sas);
> >       uint64_t what = qdict_get_int(qdict, "mode");
> > +    Error *local_err = NULL;
> >       int r;
> >   
> > -    r = sac->set_migrationmode(sas, what);
> > +    r = sac->set_migrationmode(sas, what, &local_err);
> >       if (r < 0) {
> > -        monitor_printf(mon, "Error: %s", strerror(-r));
> > +        monitor_printf(mon, "Error: %s", error_get_pretty(local_err));
> >       }
> >   }
> >   
> > @@ -170,13 +171,15 @@ static int cmma_save_setup(QEMUFile *f, void *opaque)
> >   {
> >       S390StAttribState *sas = S390_STATTRIB(opaque);
> >       S390StAttribClass *sac = S390_STATTRIB_GET_CLASS(sas);
> > +    Error *local_err = NULL;
> >       int res;
> >       /*
> >        * Signal that we want to start a migration, thus needing PGSTE dirty
> >        * tracking.
> >        */
> > -    res = sac->set_migrationmode(sas, 1);
> > +    res = sac->set_migrationmode(sas, true, &local_err);
> >       if (res) {
> > +        error_report_err(local_err);
> >           return res;
> >       }
> >       qemu_put_be64(f, STATTR_FLAG_EOS);
> > @@ -260,7 +263,7 @@ static void cmma_save_cleanup(void *opaque)
> >   {
> >       S390StAttribState *sas = S390_STATTRIB(opaque);
> >       S390StAttribClass *sac = S390_STATTRIB_GET_CLASS(sas);
> > -    sac->set_migrationmode(sas, 0);
> > +    sac->set_migrationmode(sas, false, NULL);
> >   }
> >   
> >   static bool cmma_active(void *opaque)
> > @@ -293,7 +296,8 @@ static long long 
> > qemu_s390_get_dirtycount_stub(S390StAttribState *sa)
> >   {
> >       return 0;
> >   }
> > -static int qemu_s390_set_migrationmode_stub(S390StAttribState *sa, bool value)
> > +static int qemu_s390_set_migrationmode_stub(S390StAttribState *sa, bool value,
> > +                                            Error **errp)
> >   {
> >       return 0;
> >   }