Re: [libvirt] [Qemu-devel] [PATCH v4 1/3] machine: show if CLI option '-numa node, mem' is supported in QAPI schema

Igor Mammedov <imammedo(a)redhat.com&gt; writes: > Legacy '-numa node,mem' option has a number of issues and mgmt often > defaults to it. Unfortunately it's no possible to replace it with > an alternative '-numa memdev' without breaking migration compatibility. > What's possible though is to deprecate it, keeping option working with > old machine types only. > > In order to help users to find out if being deprecated CLI option > '-numa node,mem' is still supported by particular machine type, add new > "numa-mem-supported" property to MachineInfo description in QAPI schema. Suggest s/to MachineInfo description in QAPI schema/to output of query-machines/, because query-machines is the external interface people know.

> "numa-mem-supported" is set to 'true' for machines that currently support > NUMA, but it will be flipped to 'false' later on, once deprecation period > expires and kept 'true' only for old machine types that used to support > the legacy option so it won't break existing configuration that are using > it. > > Signed-off-by: Igor Mammedov <imammedo(a)redhat.com&gt; > --- > > Notes: > v4: > * drop idea to use "qom-list-properties" and use MachineInfo instead > which could be inspected with 'query-machines' > > include/hw/boards.h | 3 +++ > hw/arm/virt.c | 1 + > hw/i386/pc.c | 1 + > hw/ppc/spapr.c | 1 + > qapi/misc.json | 5 ++++- > vl.c | 1 + > 6 files changed, 11 insertions(+), 1 deletion(-) > > diff --git a/include/hw/boards.h b/include/hw/boards.h > index 6f7916f..86894b6 100644 > --- a/include/hw/boards.h > +++ b/include/hw/boards.h > @@ -158,6 +158,8 @@ typedef struct { > * @kvm_type: > * Return the type of KVM corresponding to the kvm-type string option or > * computed based on other criteria such as the host kernel capabilities. > + * @numa_mem_supported: > + * true if '--numa node.mem' option is supported and false otherwise > */ > struct MachineClass { > /*< private >*/ > @@ -210,6 +212,7 @@ struct MachineClass { > bool ignore_boot_device_suffixes; > bool smbus_no_migration_support; > bool nvdimm_supported; > + bool numa_mem_supported; > > HotplugHandler *(*get_hotplug_handler)(MachineState *machine, > DeviceState *dev); > diff --git a/hw/arm/virt.c b/hw/arm/virt.c > index bf54f10..481a603 100644 > --- a/hw/arm/virt.c > +++ b/hw/arm/virt.c > @@ -1943,6 +1943,7 @@ static void virt_machine_class_init(ObjectClass *oc, void *data) > assert(!mc->get_hotplug_handler); > mc->get_hotplug_handler = virt_machine_get_hotplug_handler; > hc->plug = virt_machine_device_plug_cb; > + mc->numa_mem_supported = true; > } > > static void virt_instance_init(Object *obj) > diff --git a/hw/i386/pc.c b/hw/i386/pc.c > index 2632b73..05b8368 100644 > --- a/hw/i386/pc.c > +++ b/hw/i386/pc.c > @@ -2747,6 +2747,7 @@ static void pc_machine_class_init(ObjectClass *oc, void *data) > nc->nmi_monitor_handler = x86_nmi; > mc->default_cpu_type = TARGET_DEFAULT_CPU_TYPE; > mc->nvdimm_supported = true; > + mc->numa_mem_supported = true; > > object_class_property_add(oc, PC_MACHINE_DEVMEM_REGION_SIZE, "int", > pc_machine_get_device_memory_region_size, NULL, > diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c > index 2ef3ce4..265ecfb 100644 > --- a/hw/ppc/spapr.c > +++ b/hw/ppc/spapr.c > @@ -4336,6 +4336,7 @@ static void spapr_machine_class_init(ObjectClass *oc, void *data) > * in which LMBs are represented and hot-added > */ > mc->numa_mem_align_shift = 28; > + mc->numa_mem_supported = true; > > smc->default_caps.caps[SPAPR_CAP_HTM] = SPAPR_CAP_OFF; > smc->default_caps.caps[SPAPR_CAP_VSX] = SPAPR_CAP_ON; This is correct when the TYPE_VIRT_MACHINE, TYPE_PC_MACHINE and TYPE_SPAPR_MACHINE are exactly the machines supporting NUMA. How could I check that?

> diff --git a/qapi/misc.json b/qapi/misc.json > index 8b3ca4f..d0bdccb 100644 > --- a/qapi/misc.json > +++ b/qapi/misc.json > @@ -2018,12 +2018,15 @@ > # > # @hotpluggable-cpus: cpu hotplug via -device is supported (since 2.7.0) > # > +# @numa-mem-supported: true if '-numa node,mem' option is supported by machine > +# type and false otherwise (since 4.1) "by the machine type", for consistency with @cpu-max. Also, rather long line.

> +# > # Since: 1.2.0 > ## > { 'struct': 'MachineInfo', > 'data': { 'name': 'str', '*alias': 'str', > '*is-default': 'bool', 'cpu-max': 'int', > - 'hotpluggable-cpus': 'bool'} } > + 'hotpluggable-cpus': 'bool', 'numa-mem-supported': 'bool'} } > > ## > # @query-machines: > diff --git a/vl.c b/vl.c > index 5550bd7..5bf17f5 100644 > --- a/vl.c > +++ b/vl.c > @@ -1520,6 +1520,7 @@ MachineInfoList *qmp_query_machines(Error **errp) > info->name = g_strdup(mc->name); > info->cpu_max = !mc->max_cpus ? 1 : mc->max_cpus; > info->hotpluggable_cpus = mc->has_hotpluggable_cpus; > + info->numa_mem_supported = mc->numa_mem_supported; > > entry = g_malloc0(sizeof(*entry)); > entry->value = info;