Re: [Qemu-devel] [PATCH v5 2/3] qmp: introduce query-memory-size-summary command

[Vadim Galitsyn]

Hi Guys,

Thank you for the input!

> "hotunpluggable" is ugly.  What about just "pluggable"?

Markus, I think "pluggable" is a bit misleading here. Some people can take
it like a maximum amount of memory that can be hot-added to a guest (i.e.,
difference between static memory size and value specified with "-m
...,maxmem=XXX"). I would say:

  mem_info->plugged_memory = get_plugged_memory_size();

..since it reflects actual amount which was already hot-added. Agree?

> this could be done without wrapper

Igor, your approach changes command behaviour a little. First of all it
turns it in command which can fail. As far as I understand we wanted to
avoid this.

Wrapper is needed in order to "error_abort" command only in case if (a)
CONFIG_MEM_HOTPLUG  is enabled, but (b) QOM data is somehow corrupted.
If CONFIG_MEM_HOTPLUG
is disabled for target, it does not mean to report an error -- in this case
value simply not reported and no error path triggered.

I agree with the rest of comments and will provide changes with the next
version.
Could you please leave a comment(s) if you agree or not (before I submit
next version)?

Thank you in advance,
Vadim


On Tue, Aug 15, 2017 at 9:51 AM, Igor Mammedov <address@hidden> wrote:

> On Fri, 28 Jul 2017 14:10:43 +0200
> Vadim Galitsyn <address@hidden> wrote:
>
> > Command above provides the following memory information in bytes:
> >
> >   * base-memory - size of "base" memory specified with command line
> option -m.
> >
> >   * hotunpluggable-memory - amount of memory that was hot-plugged.
> >     If target does not have CONFIG_MEM_HOTPLUG enabled, no
> >     value is reported.
> >
> > Signed-off-by: Vasilis Liaskovitis <address@hidden
> >
> > Signed-off-by: Mohammed Gamal <address@hidden>
> > Signed-off-by: Eduardo Otubo <address@hidden>
> > Signed-off-by: Vadim Galitsyn <address@hidden>
> > Reviewed-by: Eugene Crosser <address@hidden>
> > Cc: Dr. David Alan Gilbert <address@hidden>
> > Cc: Markus Armbruster <address@hidden>
> > Cc: Igor Mammedov <address@hidden>
> > Cc: Eric Blake <address@hidden>
> > Cc: address@hidden
> > ---
> >  hw/mem/pc-dimm.c                                   |  5 +++++
> >  include/hw/mem/pc-dimm.h                           |  1 +
> >  qapi-schema.json                                   | 25
> ++++++++++++++++++++++
> >  qmp.c                                              | 13 +++++++++++
> >  stubs/Makefile.objs                                |  2 +-
> >  stubs/{qmp_pc_dimm_device_list.c => qmp_pc_dimm.c} |  5 +++++
> >  6 files changed, 50 insertions(+), 1 deletion(-)
> >  rename stubs/{qmp_pc_dimm_device_list.c => qmp_pc_dimm.c} (64%)
> >
> > diff --git a/hw/mem/pc-dimm.c b/hw/mem/pc-dimm.c
> > index ea67b461c2..1df8b7ee57 100644
> > --- a/hw/mem/pc-dimm.c
> > +++ b/hw/mem/pc-dimm.c
> > @@ -159,6 +159,11 @@ uint64_t pc_existing_dimms_capacity(Error **errp)
> >      return cap.size;
> >  }
> >
> > +uint64_t get_existing_hotpluggable_memory_size(void)
> > +{
> > +    return pc_existing_dimms_capacity(&error_abort);
> > +}
> > +
> >  int qmp_pc_dimm_device_list(Object *obj, void *opaque)
> >  {
> >      MemoryDeviceInfoList ***prev = opaque;
> > diff --git a/include/hw/mem/pc-dimm.h b/include/hw/mem/pc-dimm.h
> > index 1e483f2670..52c6b5e641 100644
> > --- a/include/hw/mem/pc-dimm.h
> > +++ b/include/hw/mem/pc-dimm.h
> > @@ -95,6 +95,7 @@ int pc_dimm_get_free_slot(const int *hint, int
> max_slots, Error **errp);
> >
> >  int qmp_pc_dimm_device_list(Object *obj, void *opaque);
> >  uint64_t pc_existing_dimms_capacity(Error **errp);
> > +uint64_t get_existing_hotpluggable_memory_size(void);
> >  void pc_dimm_memory_plug(DeviceState *dev, MemoryHotplugState *hpms,
> >                           MemoryRegion *mr, uint64_t align, Error
> **errp);
> >  void pc_dimm_memory_unplug(DeviceState *dev, MemoryHotplugState *hpms,
> > diff --git a/qapi-schema.json b/qapi-schema.json
> > index 9c6c3e1a53..bbedf1a7bc 100644
> > --- a/qapi-schema.json
> > +++ b/qapi-schema.json
> > @@ -4407,6 +4407,31 @@
> >    'data': { 'name': 'str', '*migration-safe': 'bool', 'static': 'bool',
> >              '*unavailable-features': [ 'str' ], 'typename': 'str' } }
> >
> > +##
> > +# @MemoryInfo:
> > +#
> > +# Actual memory information in bytes.
> > +#
> > +# @base-memory: size of "base" memory specified with command line
> > +#               option -m.
> > +#
> > +# @hotunpluggable-memory: size memory that can be hot-unplugged.
> > +#
> > +# Since: 2.10.0
> > +##
> > +{ 'struct': 'MemoryInfo',
> > +  'data'  : { 'base-memory': 'size', '*hotunpluggable-memory': 'size' }
> }
> > +
> > +##
> > +# @query-memory-size-summary:
> > +#
> > +# Return the amount of initially allocated and hot-plugged (if
> > +# enabled) memory in bytes.
> > +#
> > +# Since: 2.10.0
> > +##
> > +{ 'command': 'query-memory-size-summary', 'returns': 'MemoryInfo' }
> > +
> >  ##
> >  # @query-cpu-definitions:
> >  #
> > diff --git a/qmp.c b/qmp.c
> > index b86201e349..682d950440 100644
> > --- a/qmp.c
> > +++ b/qmp.c
> > @@ -709,3 +709,16 @@ ACPIOSTInfoList *qmp_query_acpi_ospm_status(Error
> **errp)
> >
> >      return head;
> >  }
> > +
> > +MemoryInfo *qmp_query_memory_size_summary(Error **errp)
> > +{
> > +    MemoryInfo *mem_info = g_malloc0(sizeof(MemoryInfo));
> > +
> > +    mem_info->base_memory = ram_size;
> > +
> > +    mem_info->hotunpluggable_memory = get_existing_hotpluggable_
> memory_size();
> this could be done without wrapper:
> mem_info->hotunpluggable_memory = pc_existing_dimms_capacity(&local_error)
>
> > +    mem_info->has_hotunpluggable_memory =
> > +        (mem_info->hotunpluggable_memory != (uint64_t)-1);
>
> mem_info->has_hotunpluggable_memory = !local_error;
> if (local_error)
>   cleanup
>
> and defining stub:
>
> uint64_t pc_existing_dimms_capacity(Error **errp) {
>      error_setg(errp, "not implemented");
>      return 0;
> }
>
> > +
> > +    return mem_info;
> > +}
> > diff --git a/stubs/Makefile.objs b/stubs/Makefile.objs
> > index f5b47bfd74..f7cab5b11c 100644
> > --- a/stubs/Makefile.objs
> > +++ b/stubs/Makefile.objs
> > @@ -32,7 +32,7 @@ stub-obj-y += uuid.o
> >  stub-obj-y += vm-stop.o
> >  stub-obj-y += vmstate.o
> >  stub-obj-$(CONFIG_WIN32) += fd-register.o
> > -stub-obj-y += qmp_pc_dimm_device_list.o
> > +stub-obj-y += qmp_pc_dimm.o
> >  stub-obj-y += target-monitor-defs.o
> >  stub-obj-y += target-get-monitor-def.o
> >  stub-obj-y += pc_madt_cpu_entry.o
> > diff --git a/stubs/qmp_pc_dimm_device_list.c b/stubs/qmp_pc_dimm.c
> > similarity index 64%
> > rename from stubs/qmp_pc_dimm_device_list.c
> > rename to stubs/qmp_pc_dimm.c
> > index def211564d..1d1e008b58 100644
> > --- a/stubs/qmp_pc_dimm_device_list.c
> > +++ b/stubs/qmp_pc_dimm.c
> > @@ -6,3 +6,8 @@ int qmp_pc_dimm_device_list(Object *obj, void *opaque)
> >  {
> >     return 0;
> >  }
> > +
> > +uint64_t get_existing_hotpluggable_memory_size(void)
> > +{
> > +    return (uint64_t)-1;
> > +}
>
>