[v5,18/22] s390x: implement query-hotpluggable-cpus

Message ID 20170913132417.24384-19-david@redhat.com
State New
Headers show
Series
  • s390x cleanups and CPU hotplug via device_add
Related show

Commit Message

David Hildenbrand Sept. 13, 2017, 1:24 p.m.
CPU hotplug is only possible on a per core basis on s390x. So let's
add possible_cpus and properly wire everything up.

Signed-off-by: David Hildenbrand <david@redhat.com>
---
 hw/s390x/s390-virtio-ccw.c | 41 +++++++++++++++++++++++++++++++++++++++++
 qapi-schema.json           | 16 ++++++++++++++++
 2 files changed, 57 insertions(+)

Comments

Igor Mammedov Sept. 13, 2017, 2:42 p.m. | #1
On Wed, 13 Sep 2017 15:24:13 +0200
David Hildenbrand <david@redhat.com> wrote:

> CPU hotplug is only possible on a per core basis on s390x. So let's
> add possible_cpus and properly wire everything up.
> 
> Signed-off-by: David Hildenbrand <david@redhat.com>
looks good to me from cpu hotplug infrastructure pov,

Acked-by: Igor Mammedov <imammedo@redhat.com>

> ---
>  hw/s390x/s390-virtio-ccw.c | 41 +++++++++++++++++++++++++++++++++++++++++
>  qapi-schema.json           | 16 ++++++++++++++++
>  2 files changed, 57 insertions(+)
> 
> diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
> index 3be81d96af..cc64a81321 100644
> --- a/hw/s390x/s390-virtio-ccw.c
> +++ b/hw/s390x/s390-virtio-ccw.c
> @@ -50,6 +50,7 @@ S390CPU *s390_cpu_addr2state(uint16_t cpu_addr)
>  
>  static void s390_init_cpus(MachineState *machine)
>  {
> +    MachineClass *mc = MACHINE_GET_CLASS(machine);
>      int i;
>      gchar *name;
>  
> @@ -74,6 +75,9 @@ static void s390_init_cpus(MachineState *machine)
>          g_free(name);
>      }
>  
> +    /* initialize possible_cpus */
> +    mc->possible_cpu_arch_ids(machine);
> +
>      for (i = 0; i < smp_cpus; i++) {
>          s390x_new_cpu(machine->cpu_model, i, &error_fatal);
>      }
> @@ -307,6 +311,7 @@ static void s390_cpu_plug(HotplugHandler *hotplug_dev,
>                          DeviceState *dev, Error **errp)
>  {
>      gchar *name;
> +    MachineState *ms = MACHINE(hotplug_dev);
>      S390CPU *cpu = S390_CPU(dev);
>      CPUState *cs = CPU(dev);
>  
> @@ -314,6 +319,9 @@ static void s390_cpu_plug(HotplugHandler *hotplug_dev,
>      object_property_set_link(OBJECT(hotplug_dev), OBJECT(cs), name,
>                               errp);
>      g_free(name);
> +
> +    g_assert(!ms->possible_cpus->cpus[cpu->env.core_id].cpu);
> +    ms->possible_cpus->cpus[cpu->env.core_id].cpu = OBJECT(dev);
>  }
>  
>  static void s390_machine_reset(void)
> @@ -346,6 +354,36 @@ static void s390_machine_device_unplug_request(HotplugHandler *hotplug_dev,
>      }
>  }
>  
> +static CpuInstanceProperties s390_cpu_index_to_props(MachineState *machine,
> +                                                     unsigned cpu_index)
> +{
> +    g_assert(machine->possible_cpus && cpu_index < machine->possible_cpus->len);
> +
> +    return machine->possible_cpus->cpus[cpu_index].props;
> +}
> +
> +static const CPUArchIdList *s390_possible_cpu_arch_ids(MachineState *ms)
> +{
> +    int i;
> +
> +    if (ms->possible_cpus) {
> +        g_assert(ms->possible_cpus && ms->possible_cpus->len == max_cpus);
> +        return ms->possible_cpus;
> +    }
> +
> +    ms->possible_cpus = g_malloc0(sizeof(CPUArchIdList) +
> +                                  sizeof(CPUArchId) * max_cpus);
> +    ms->possible_cpus->len = max_cpus;
> +    for (i = 0; i < ms->possible_cpus->len; i++) {
> +        ms->possible_cpus->cpus[i].vcpus_count = 1;
> +        ms->possible_cpus->cpus[i].arch_id = i;
> +        ms->possible_cpus->cpus[i].props.has_core_id = true;
> +        ms->possible_cpus->cpus[i].props.core_id = i;
> +    }
> +
> +    return ms->possible_cpus;
> +}
> +
>  static HotplugHandler *s390_get_hotplug_handler(MachineState *machine,
>                                                  DeviceState *dev)
>  {
> @@ -393,7 +431,10 @@ static void ccw_machine_class_init(ObjectClass *oc, void *data)
>      mc->no_sdcard = 1;
>      mc->use_sclp = 1;
>      mc->max_cpus = 248;
> +    mc->has_hotpluggable_cpus = true;
>      mc->get_hotplug_handler = s390_get_hotplug_handler;
> +    mc->cpu_index_to_instance_props = s390_cpu_index_to_props;
> +    mc->possible_cpu_arch_ids = s390_possible_cpu_arch_ids;
>      hc->plug = s390_machine_device_plug;
>      hc->unplug_request = s390_machine_device_unplug_request;
>      nc->nmi_monitor_handler = s390_nmi;
> diff --git a/qapi-schema.json b/qapi-schema.json
> index f3af2cb851..79e9f85404 100644
> --- a/qapi-schema.json
> +++ b/qapi-schema.json
> @@ -3121,6 +3121,22 @@
>  #      }
>  #    ]}
>  #
> +# For s390x-virtio-ccw machine type started with -smp 1,maxcpus=2 -cpu qemu
> +# (Since: 2.11):
> +#
> +# -> { "execute": "query-hotpluggable-cpus" }
> +# <- {"return": [
> +#      {
> +#         "type": "qemu-s390-cpu", "vcpus-count": 1,
> +#         "props": { "core-id": 1 }
> +#      },
> +#      {
> +#         "qom-path": "/machine/unattached/device[0]",
> +#         "type": "qemu-s390-cpu", "vcpus-count": 1,
> +#         "props": { "core-id": 0 }
> +#      }
> +#    ]}
> +#
>  ##
>  { 'command': 'query-hotpluggable-cpus', 'returns': ['HotpluggableCPU'] }
>
Cornelia Huck Sept. 13, 2017, 3:49 p.m. | #2
On Wed, 13 Sep 2017 15:24:13 +0200
David Hildenbrand <david@redhat.com> wrote:

> CPU hotplug is only possible on a per core basis on s390x. So let's
> add possible_cpus and properly wire everything up.

s/properly wire everything up/wire everything up properly/

?

(fixing while... you get the idea)

> 
> Signed-off-by: David Hildenbrand <david@redhat.com>
> ---
>  hw/s390x/s390-virtio-ccw.c | 41 +++++++++++++++++++++++++++++++++++++++++
>  qapi-schema.json           | 16 ++++++++++++++++
>  2 files changed, 57 insertions(+)
David Hildenbrand Sept. 13, 2017, 3:50 p.m. | #3
On 13.09.2017 17:49, Cornelia Huck wrote:
> On Wed, 13 Sep 2017 15:24:13 +0200
> David Hildenbrand <david@redhat.com> wrote:
> 
>> CPU hotplug is only possible on a per core basis on s390x. So let's
>> add possible_cpus and properly wire everything up.
> 
> s/properly wire everything up/wire everything up properly/
> 
> ?
> 
> (fixing while... you get the idea)

:) Sure!
Cornelia Huck Oct. 4, 2017, 8:04 a.m. | #4
On Mon, 02 Oct 2017 09:46:41 +0200
Markus Armbruster <armbru@redhat.com> wrote:

> David Hildenbrand <david@redhat.com> writes:
> 
> > CPU hotplug is only possible on a per core basis on s390x. So let's
> > add possible_cpus and properly wire everything up.
> >
> > Signed-off-by: David Hildenbrand <david@redhat.com>  
> [...]
> > diff --git a/qapi-schema.json b/qapi-schema.json
> > index f3af2cb851..79e9f85404 100644
> > --- a/qapi-schema.json
> > +++ b/qapi-schema.json
> > @@ -3121,6 +3121,22 @@
> >  #      }
> >  #    ]}
> >  #
> > +# For s390x-virtio-ccw machine type started with -smp 1,maxcpus=2 -cpu qemu
> > +# (Since: 2.11):
> > +#
> > +# -> { "execute": "query-hotpluggable-cpus" }
> > +# <- {"return": [
> > +#      {
> > +#         "type": "qemu-s390-cpu", "vcpus-count": 1,
> > +#         "props": { "core-id": 1 }
> > +#      },
> > +#      {
> > +#         "qom-path": "/machine/unattached/device[0]",
> > +#         "type": "qemu-s390-cpu", "vcpus-count": 1,
> > +#         "props": { "core-id": 0 }
> > +#      }
> > +#    ]}
> > +#
> >  ##
> >  { 'command': 'query-hotpluggable-cpus', 'returns': ['HotpluggableCPU'] }  
> 
> Please stick in '# Example:' like we do in query-hotpluggable-cpus's doc
> comment.  I expect the generated documentation to be illegible[*]
> without it.

Should '# Example:' go before each of the examples (instead of the
beginning of the example block), then?

> 
> 
> [*] If you want to perform a quick eye-over, try running "make
> tests/qapi-schema/doc-good.test.txt" and examine the result.

Hmm... I might be missing something in my setup:

[cohuck@gondolin build]$ make tests/qapi-schema/doc-good.test.txt
  GEN     tests/qapi-schema/doc-good.test.txt
tests/qapi-schema/doc-good.test.texi:79: @subsection seen before @end deftp
tests/qapi-schema/doc-good.test.texi:90: unmatched `@end deftp'
make: *** [Makefile:695: tests/qapi-schema/doc-good.test.txt] Error 1
Markus Armbruster Oct. 4, 2017, 12:42 p.m. | #5
Cornelia Huck <cohuck@redhat.com> writes:

> On Mon, 02 Oct 2017 09:46:41 +0200
> Markus Armbruster <armbru@redhat.com> wrote:
>
>> David Hildenbrand <david@redhat.com> writes:
>> 
>> > CPU hotplug is only possible on a per core basis on s390x. So let's
>> > add possible_cpus and properly wire everything up.
>> >
>> > Signed-off-by: David Hildenbrand <david@redhat.com>  
>> [...]
>> > diff --git a/qapi-schema.json b/qapi-schema.json
>> > index f3af2cb851..79e9f85404 100644
>> > --- a/qapi-schema.json
>> > +++ b/qapi-schema.json
>> > @@ -3121,6 +3121,22 @@
>> >  #      }
>> >  #    ]}
>> >  #
>> > +# For s390x-virtio-ccw machine type started with -smp 1,maxcpus=2 -cpu qemu
>> > +# (Since: 2.11):
>> > +#
>> > +# -> { "execute": "query-hotpluggable-cpus" }
>> > +# <- {"return": [
>> > +#      {
>> > +#         "type": "qemu-s390-cpu", "vcpus-count": 1,
>> > +#         "props": { "core-id": 1 }
>> > +#      },
>> > +#      {
>> > +#         "qom-path": "/machine/unattached/device[0]",
>> > +#         "type": "qemu-s390-cpu", "vcpus-count": 1,
>> > +#         "props": { "core-id": 0 }
>> > +#      }
>> > +#    ]}
>> > +#
>> >  ##
>> >  { 'command': 'query-hotpluggable-cpus', 'returns': ['HotpluggableCPU'] }  
>> 
>> Please stick in '# Example:' like we do in query-hotpluggable-cpus's doc
>> comment.  I expect the generated documentation to be illegible[*]
>> without it.
>
> Should '# Example:' go before each of the examples (instead of the
> beginning of the example block), then?

Whatever makes the generated documentation look better.

>> [*] If you want to perform a quick eye-over, try running "make
>> tests/qapi-schema/doc-good.test.txt" and examine the result.
>
> Hmm... I might be missing something in my setup:
>
> [cohuck@gondolin build]$ make tests/qapi-schema/doc-good.test.txt
>   GEN     tests/qapi-schema/doc-good.test.txt
> tests/qapi-schema/doc-good.test.texi:79: @subsection seen before @end deftp
> tests/qapi-schema/doc-good.test.texi:90: unmatched `@end deftp'
> make: *** [Makefile:695: tests/qapi-schema/doc-good.test.txt] Error 1

Pasto, sorry!  Try "make docs/interop/qemu-qmp-ref.txt".  .pdf and .html
also work.
Cornelia Huck Oct. 4, 2017, 1:09 p.m. | #6
On Wed, 04 Oct 2017 14:42:55 +0200
Markus Armbruster <armbru@redhat.com> wrote:

> Cornelia Huck <cohuck@redhat.com> writes:
> 
> > On Mon, 02 Oct 2017 09:46:41 +0200
> > Markus Armbruster <armbru@redhat.com> wrote:
> >  
> >> David Hildenbrand <david@redhat.com> writes:
> >>   
> >> > CPU hotplug is only possible on a per core basis on s390x. So let's
> >> > add possible_cpus and properly wire everything up.
> >> >
> >> > Signed-off-by: David Hildenbrand <david@redhat.com>    
> >> [...]  
> >> > diff --git a/qapi-schema.json b/qapi-schema.json
> >> > index f3af2cb851..79e9f85404 100644
> >> > --- a/qapi-schema.json
> >> > +++ b/qapi-schema.json
> >> > @@ -3121,6 +3121,22 @@
> >> >  #      }
> >> >  #    ]}
> >> >  #
> >> > +# For s390x-virtio-ccw machine type started with -smp 1,maxcpus=2 -cpu qemu
> >> > +# (Since: 2.11):
> >> > +#
> >> > +# -> { "execute": "query-hotpluggable-cpus" }
> >> > +# <- {"return": [
> >> > +#      {
> >> > +#         "type": "qemu-s390-cpu", "vcpus-count": 1,
> >> > +#         "props": { "core-id": 1 }
> >> > +#      },
> >> > +#      {
> >> > +#         "qom-path": "/machine/unattached/device[0]",
> >> > +#         "type": "qemu-s390-cpu", "vcpus-count": 1,
> >> > +#         "props": { "core-id": 0 }
> >> > +#      }
> >> > +#    ]}
> >> > +#
> >> >  ##
> >> >  { 'command': 'query-hotpluggable-cpus', 'returns': ['HotpluggableCPU'] }    
> >> 
> >> Please stick in '# Example:' like we do in query-hotpluggable-cpus's doc
> >> comment.  I expect the generated documentation to be illegible[*]
> >> without it.  
> >
> > Should '# Example:' go before each of the examples (instead of the
> > beginning of the example block), then?  
> 
> Whatever makes the generated documentation look better.

The pdf indeed looks ugly, but that's a preexisting problem, and adding
more '# Example:' lines does not really help.

The basic issue is that the code expects just one example and no
additional text for the '# Example:' tag -- the explaining text for the
various statements ends up looking like the qmp examples. That should
be improved before doing a patch on top for this command (and I don't
really have the skills or time to improve the output, sorry.)
Markus Armbruster Oct. 6, 2017, 5:17 p.m. | #7
Cornelia Huck <cohuck@redhat.com> writes:

> On Wed, 04 Oct 2017 14:42:55 +0200
> Markus Armbruster <armbru@redhat.com> wrote:
>
>> Cornelia Huck <cohuck@redhat.com> writes:
>> 
>> > On Mon, 02 Oct 2017 09:46:41 +0200
>> > Markus Armbruster <armbru@redhat.com> wrote:
>> >  
>> >> David Hildenbrand <david@redhat.com> writes:
>> >>   
>> >> > CPU hotplug is only possible on a per core basis on s390x. So let's
>> >> > add possible_cpus and properly wire everything up.
>> >> >
>> >> > Signed-off-by: David Hildenbrand <david@redhat.com>    
>> >> [...]  
>> >> > diff --git a/qapi-schema.json b/qapi-schema.json
>> >> > index f3af2cb851..79e9f85404 100644
>> >> > --- a/qapi-schema.json
>> >> > +++ b/qapi-schema.json
>> >> > @@ -3121,6 +3121,22 @@
>> >> >  #      }
>> >> >  #    ]}
>> >> >  #
>> >> > +# For s390x-virtio-ccw machine type started with -smp 1,maxcpus=2 -cpu qemu
>> >> > +# (Since: 2.11):
>> >> > +#
>> >> > +# -> { "execute": "query-hotpluggable-cpus" }
>> >> > +# <- {"return": [
>> >> > +#      {
>> >> > +#         "type": "qemu-s390-cpu", "vcpus-count": 1,
>> >> > +#         "props": { "core-id": 1 }
>> >> > +#      },
>> >> > +#      {
>> >> > +#         "qom-path": "/machine/unattached/device[0]",
>> >> > +#         "type": "qemu-s390-cpu", "vcpus-count": 1,
>> >> > +#         "props": { "core-id": 0 }
>> >> > +#      }
>> >> > +#    ]}
>> >> > +#
>> >> >  ##
>> >> >  { 'command': 'query-hotpluggable-cpus', 'returns': ['HotpluggableCPU'] }    
>> >> 
>> >> Please stick in '# Example:' like we do in query-hotpluggable-cpus's doc
>> >> comment.  I expect the generated documentation to be illegible[*]
>> >> without it.  
>> >
>> > Should '# Example:' go before each of the examples (instead of the
>> > beginning of the example block), then?  
>> 
>> Whatever makes the generated documentation look better.
>
> The pdf indeed looks ugly, but that's a preexisting problem, and adding
> more '# Example:' lines does not really help.
>
> The basic issue is that the code expects just one example and no
> additional text for the '# Example:' tag -- the explaining text for the
> various statements ends up looking like the qmp examples. That should
> be improved before doing a patch on top for this command (and I don't
> really have the skills or time to improve the output, sorry.)

Marc-André, any ideas?
Marc-André Lureau Oct. 9, 2017, 10:31 a.m. | #8
Hi

----- Original Message -----
> Cornelia Huck <cohuck@redhat.com> writes:
> 
> > On Wed, 04 Oct 2017 14:42:55 +0200
> > Markus Armbruster <armbru@redhat.com> wrote:
> >
> >> Cornelia Huck <cohuck@redhat.com> writes:
> >> 
> >> > On Mon, 02 Oct 2017 09:46:41 +0200
> >> > Markus Armbruster <armbru@redhat.com> wrote:
> >> >  
> >> >> David Hildenbrand <david@redhat.com> writes:
> >> >>   
> >> >> > CPU hotplug is only possible on a per core basis on s390x. So let's
> >> >> > add possible_cpus and properly wire everything up.
> >> >> >
> >> >> > Signed-off-by: David Hildenbrand <david@redhat.com>
> >> >> [...]
> >> >> > diff --git a/qapi-schema.json b/qapi-schema.json
> >> >> > index f3af2cb851..79e9f85404 100644
> >> >> > --- a/qapi-schema.json
> >> >> > +++ b/qapi-schema.json
> >> >> > @@ -3121,6 +3121,22 @@
> >> >> >  #      }
> >> >> >  #    ]}
> >> >> >  #
> >> >> > +# For s390x-virtio-ccw machine type started with -smp 1,maxcpus=2
> >> >> > -cpu qemu
> >> >> > +# (Since: 2.11):
> >> >> > +#
> >> >> > +# -> { "execute": "query-hotpluggable-cpus" }
> >> >> > +# <- {"return": [
> >> >> > +#      {
> >> >> > +#         "type": "qemu-s390-cpu", "vcpus-count": 1,
> >> >> > +#         "props": { "core-id": 1 }
> >> >> > +#      },
> >> >> > +#      {
> >> >> > +#         "qom-path": "/machine/unattached/device[0]",
> >> >> > +#         "type": "qemu-s390-cpu", "vcpus-count": 1,
> >> >> > +#         "props": { "core-id": 0 }
> >> >> > +#      }
> >> >> > +#    ]}
> >> >> > +#
> >> >> >  ##
> >> >> >  { 'command': 'query-hotpluggable-cpus', 'returns':
> >> >> >  ['HotpluggableCPU'] }
> >> >> 
> >> >> Please stick in '# Example:' like we do in query-hotpluggable-cpus's
> >> >> doc
> >> >> comment.  I expect the generated documentation to be illegible[*]
> >> >> without it.
> >> >
> >> > Should '# Example:' go before each of the examples (instead of the
> >> > beginning of the example block), then?
> >> 
> >> Whatever makes the generated documentation look better.
> >
> > The pdf indeed looks ugly, but that's a preexisting problem, and adding
> > more '# Example:' lines does not really help.
> >
> > The basic issue is that the code expects just one example and no
> > additional text for the '# Example:' tag -- the explaining text for the
> > various statements ends up looking like the qmp examples. That should
> > be improved before doing a patch on top for this command (and I don't
> > really have the skills or time to improve the output, sorry.)
> 
> Marc-André, any ideas?
> 

It's not supported atm. The ideas to fix this are pretty much a matter of taste.

I'd suggest to keep the code below the Example: section as @example/verbatim by default. And introduce a new section syntax, like Example:: to do "manual" formatting.

Example::

This text would be in regular format.
1. and allow list, *strong* etc.

| -> { then have some code }
| <- ...

And regulat text again.

Patch

diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
index 3be81d96af..cc64a81321 100644
--- a/hw/s390x/s390-virtio-ccw.c
+++ b/hw/s390x/s390-virtio-ccw.c
@@ -50,6 +50,7 @@  S390CPU *s390_cpu_addr2state(uint16_t cpu_addr)
 
 static void s390_init_cpus(MachineState *machine)
 {
+    MachineClass *mc = MACHINE_GET_CLASS(machine);
     int i;
     gchar *name;
 
@@ -74,6 +75,9 @@  static void s390_init_cpus(MachineState *machine)
         g_free(name);
     }
 
+    /* initialize possible_cpus */
+    mc->possible_cpu_arch_ids(machine);
+
     for (i = 0; i < smp_cpus; i++) {
         s390x_new_cpu(machine->cpu_model, i, &error_fatal);
     }
@@ -307,6 +311,7 @@  static void s390_cpu_plug(HotplugHandler *hotplug_dev,
                         DeviceState *dev, Error **errp)
 {
     gchar *name;
+    MachineState *ms = MACHINE(hotplug_dev);
     S390CPU *cpu = S390_CPU(dev);
     CPUState *cs = CPU(dev);
 
@@ -314,6 +319,9 @@  static void s390_cpu_plug(HotplugHandler *hotplug_dev,
     object_property_set_link(OBJECT(hotplug_dev), OBJECT(cs), name,
                              errp);
     g_free(name);
+
+    g_assert(!ms->possible_cpus->cpus[cpu->env.core_id].cpu);
+    ms->possible_cpus->cpus[cpu->env.core_id].cpu = OBJECT(dev);
 }
 
 static void s390_machine_reset(void)
@@ -346,6 +354,36 @@  static void s390_machine_device_unplug_request(HotplugHandler *hotplug_dev,
     }
 }
 
+static CpuInstanceProperties s390_cpu_index_to_props(MachineState *machine,
+                                                     unsigned cpu_index)
+{
+    g_assert(machine->possible_cpus && cpu_index < machine->possible_cpus->len);
+
+    return machine->possible_cpus->cpus[cpu_index].props;
+}
+
+static const CPUArchIdList *s390_possible_cpu_arch_ids(MachineState *ms)
+{
+    int i;
+
+    if (ms->possible_cpus) {
+        g_assert(ms->possible_cpus && ms->possible_cpus->len == max_cpus);
+        return ms->possible_cpus;
+    }
+
+    ms->possible_cpus = g_malloc0(sizeof(CPUArchIdList) +
+                                  sizeof(CPUArchId) * max_cpus);
+    ms->possible_cpus->len = max_cpus;
+    for (i = 0; i < ms->possible_cpus->len; i++) {
+        ms->possible_cpus->cpus[i].vcpus_count = 1;
+        ms->possible_cpus->cpus[i].arch_id = i;
+        ms->possible_cpus->cpus[i].props.has_core_id = true;
+        ms->possible_cpus->cpus[i].props.core_id = i;
+    }
+
+    return ms->possible_cpus;
+}
+
 static HotplugHandler *s390_get_hotplug_handler(MachineState *machine,
                                                 DeviceState *dev)
 {
@@ -393,7 +431,10 @@  static void ccw_machine_class_init(ObjectClass *oc, void *data)
     mc->no_sdcard = 1;
     mc->use_sclp = 1;
     mc->max_cpus = 248;
+    mc->has_hotpluggable_cpus = true;
     mc->get_hotplug_handler = s390_get_hotplug_handler;
+    mc->cpu_index_to_instance_props = s390_cpu_index_to_props;
+    mc->possible_cpu_arch_ids = s390_possible_cpu_arch_ids;
     hc->plug = s390_machine_device_plug;
     hc->unplug_request = s390_machine_device_unplug_request;
     nc->nmi_monitor_handler = s390_nmi;
diff --git a/qapi-schema.json b/qapi-schema.json
index f3af2cb851..79e9f85404 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -3121,6 +3121,22 @@ 
 #      }
 #    ]}
 #
+# For s390x-virtio-ccw machine type started with -smp 1,maxcpus=2 -cpu qemu
+# (Since: 2.11):
+#
+# -> { "execute": "query-hotpluggable-cpus" }
+# <- {"return": [
+#      {
+#         "type": "qemu-s390-cpu", "vcpus-count": 1,
+#         "props": { "core-id": 1 }
+#      },
+#      {
+#         "qom-path": "/machine/unattached/device[0]",
+#         "type": "qemu-s390-cpu", "vcpus-count": 1,
+#         "props": { "core-id": 0 }
+#      }
+#    ]}
+#
 ##
 { 'command': 'query-hotpluggable-cpus', 'returns': ['HotpluggableCPU'] }