Re: [PATCH v13 1/7] s390x/cpu topology: Creating CPU topology device

[Pierre Morel]

On 12/9/22 14:50, Thomas Huth wrote:
> On 08/12/2022 10.44, Pierre Morel wrote:
> > We will need a Topology device to transfer the topology
> > during migration and to implement machine reset.
> >
> > The device creation is fenced by s390_has_topology().
> >
> > Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
> > ---
> [...]
> > diff --git a/hw/s390x/cpu-topology.c b/hw/s390x/cpu-topology.c
> > new file mode 100644
> > index 0000000000..b3e59873f6
> > --- /dev/null
> > +++ b/hw/s390x/cpu-topology.c
> > @@ -0,0 +1,149 @@
> > +/*
> > + * CPU Topology
> > + *
> > + * Copyright IBM Corp. 2022
> > + * Author(s): Pierre Morel <pmorel@linux.ibm.com>
> > +
> > + * This work is licensed under the terms of the GNU GPL, version 2 or 
> > (at
> > + * your option) any later version. See the COPYING file in the top-level
> > + * directory.
> > + */
> > +
> > +#include "qemu/osdep.h"
> > +#include "qapi/error.h"
> > +#include "qemu/error-report.h"
> > +#include "hw/qdev-properties.h"
> > +#include "hw/boards.h"
> > +#include "qemu/typedefs.h"
> > +#include "target/s390x/cpu.h"
> > +#include "hw/s390x/s390-virtio-ccw.h"
> > +#include "hw/s390x/cpu-topology.h"
> > +
> > +/**
> > + * s390_has_topology
> > + *
> > + * Return false until the commit activating the topology is
> > + * commited.
> > + */
> > +bool s390_has_topology(void)
> > +{
> > +    return false;
> > +}
> > +
> > +/**
> > + * s390_get_topology
> > + *
> > + * Returns a pointer to the topology.
> > + *
> > + * This function is called when we know the topology exist.
> > + * Testing if the topology exist is done with s390_has_topology()
> > + */
> > +S390Topology *s390_get_topology(void)
> > +{
> > +    static S390Topology *s390Topology;
> > +
> > +    if (!s390Topology) {
> > +        s390Topology = S390_CPU_TOPOLOGY(
> > +            object_resolve_path(TYPE_S390_CPU_TOPOLOGY, NULL));
> > +    }
> > +
> > +    assert(s390Topology);
>
> I think you can move the assert() into the body of the if-statement.

Yes, clearly.

> > +    return s390Topology;
> > +}
> > +
> > +/**
> > + * s390_init_topology
> > + * @machine: The Machine state, used to retrieve the SMP parameters
> > + * @errp: the error pointer in case of problem
> > + *
> > + * This function creates and initialize the S390Topology with
> > + * the QEMU -smp parameters we will use during adding cores to the
> > + * topology.
> > + */
> > +void s390_init_topology(MachineState *machine, Error **errp)
> > +{
> > +    DeviceState *dev;
> > +
> > +    if (machine->smp.threads > 1) {
> > +        error_setg(errp, "CPU Topology do not support multithreading");
>
> s/CPU Toplogy do/CPU topology does/

Yes, thanks.

Regards,
Pierre

--
Pierre Morel
IBM Lab Boeblingen