Re: [Qemu-devel] [PATCH v4 01/11] numa: move numa global variable nb_numa_nodes into MachineState

[Igor Mammedov]

On Wed,  8 May 2019 14:17:16 +0800
Tao Xu <address@hidden> wrote:

> The aim of this patch is to add struct NumaState in MachineState
> and move existing numa global nb_numa_nodes(renamed as "num_nodes")
> into NumaState. And add variable numa_support into MachineClass to
> decide which submachines support NUMA.

patch looks fine to me (modulo minor comments to be addressed/answered).

> 
> Reviewed-by: Liu Jingqi <address@hidden>
> Suggested-by: Igor Mammedov <address@hidden>
> Suggested-by: Eduardo Habkost <address@hidden>
> Signed-off-by: Tao Xu <address@hidden>
> ---
> 
> Changes in v4 -> v3:
>     - send the patch together with HMAT patches
> 
> Changes in v3 -> v2:
>     - rename the "NumaState::nb_numa_nodes" as "NumaState::num_nodes"
>     (Eduardo)
>     - use machine_num_numa_nodes(MachineState *ms) to check if
>     ms->numa_state is NULL before using NumaState::num_nodes (Eduardo)
>     - check if ms->numa_state == NULL in the set_numa_options to avoid
>     using -numa in a machine-type which don't support numa
> 
> Changes in v2:
>     - fix the mistake in numa_complete_configuration in numa.c
>     - add MachineState into some functions to avoid using
>     qdev_get_machine
>     - add some if experssion to avoid the NumaState is null
> ---
>  exec.c                              |  5 ++-
>  hw/acpi/aml-build.c                 |  3 +-
>  hw/arm/boot.c                       |  2 ++
>  hw/arm/virt-acpi-build.c            |  8 +++--
>  hw/arm/virt.c                       |  5 ++-
>  hw/core/machine.c                   | 21 ++++++++---
>  hw/i386/acpi-build.c                |  2 +-
>  hw/i386/pc.c                        |  7 +++-
>  hw/mem/pc-dimm.c                    |  2 ++
>  hw/pci-bridge/pci_expander_bridge.c |  2 ++
>  hw/ppc/spapr.c                      | 12 ++++++-
>  include/hw/acpi/aml-build.h         |  2 +-
>  include/hw/boards.h                 | 10 ++++++
>  include/sysemu/numa.h               |  3 +-
>  monitor.c                           |  4 ++-
>  numa.c                              | 54 ++++++++++++++++++-----------
>  16 files changed, 105 insertions(+), 37 deletions(-)
> 
> diff --git a/exec.c b/exec.c
> index 4e734770c2..c7eb4af42d 100644
> --- a/exec.c
> +++ b/exec.c
> @@ -1733,6 +1733,7 @@ long qemu_minrampagesize(void)
>      long hpsize = LONG_MAX;
>      long mainrampagesize;
>      Object *memdev_root;
> +    MachineState *ms = MACHINE(qdev_get_machine());
>  
>      mainrampagesize = qemu_mempath_getpagesize(mem_path);
>  
> @@ -1760,7 +1761,9 @@ long qemu_minrampagesize(void)
>       * so if its page size is smaller we have got to report that size 
> instead.
>       */
>      if (hpsize > mainrampagesize &&
> -        (nb_numa_nodes == 0 || numa_info[0].node_memdev == NULL)) {
> +        (ms->numa_state == NULL ||
> +         ms->numa_state->num_nodes == 0 ||
> +         numa_info[0].node_memdev == NULL)) {
>          static bool warned;
>          if (!warned) {
>              error_report("Huge page support disabled (n/a for main 
> memory).");
> diff --git a/hw/acpi/aml-build.c b/hw/acpi/aml-build.c
> index 555c24f21d..c67f4561a4 100644
> --- a/hw/acpi/aml-build.c
> +++ b/hw/acpi/aml-build.c
> @@ -1726,10 +1726,11 @@ void build_srat_memory(AcpiSratMemoryAffinity 
> *numamem, uint64_t base,
>   * ACPI spec 5.2.17 System Locality Distance Information Table
>   * (Revision 2.0 or later)
>   */
> -void build_slit(GArray *table_data, BIOSLinker *linker)
> +void build_slit(GArray *table_data, BIOSLinker *linker, MachineState *ms)
>  {
>      int slit_start, i, j;
>      slit_start = table_data->len;
> +    int nb_numa_nodes = machine_num_numa_nodes(ms);
>  
>      acpi_data_push(table_data, sizeof(AcpiTableHeader));
>  
> diff --git a/hw/arm/boot.c b/hw/arm/boot.c
> index a830655e1a..8ff08814fd 100644
> --- a/hw/arm/boot.c
> +++ b/hw/arm/boot.c
> @@ -532,6 +532,8 @@ int arm_load_dtb(hwaddr addr, const struct arm_boot_info 
> *binfo,
>      hwaddr mem_base, mem_len;
>      char **node_path;
>      Error *err = NULL;
> +    MachineState *ms = MACHINE(qdev_get_machine());
> +    int nb_numa_nodes = machine_num_numa_nodes(ms);
instead of calling qdev_get_machine() here, I suggest to add
nb_numa_nodes field to arm_boot_info and make board that cares about numa (virt)
to set it to the configured value.

>  
>      if (binfo->dtb_filename) {
>          char *filename;
> diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
> index bf9c0bc2f4..6805b4de51 100644
> --- a/hw/arm/virt-acpi-build.c
> +++ b/hw/arm/virt-acpi-build.c
> @@ -516,7 +516,9 @@ build_srat(GArray *table_data, BIOSLinker *linker, 
> VirtMachineState *vms)
>      int i, srat_start;
>      uint64_t mem_base;
>      MachineClass *mc = MACHINE_GET_CLASS(vms);
> -    const CPUArchIdList *cpu_list = mc->possible_cpu_arch_ids(MACHINE(vms));
> +    MachineState *ms = MACHINE(vms);
> +    const CPUArchIdList *cpu_list = mc->possible_cpu_arch_ids(ms);
> +    int nb_numa_nodes = machine_num_numa_nodes(ms);
>  
>      srat_start = table_data->len;
>      srat = acpi_data_push(table_data, sizeof(*srat));
> @@ -780,6 +782,8 @@ void virt_acpi_build(VirtMachineState *vms, 
> AcpiBuildTables *tables)
>      GArray *table_offsets;
>      unsigned dsdt, xsdt;
>      GArray *tables_blob = tables->table_data;
> +    MachineState *ms = MACHINE(vms);
> +    int nb_numa_nodes = machine_num_numa_nodes(ms);
>  
>      table_offsets = g_array_new(false, true /* clear */,
>                                          sizeof(uint32_t));
> @@ -813,7 +817,7 @@ void virt_acpi_build(VirtMachineState *vms, 
> AcpiBuildTables *tables)
>          build_srat(tables_blob, tables->linker, vms);
>          if (have_numa_distance) {
>              acpi_add_table(table_offsets, tables_blob);
> -            build_slit(tables_blob, tables->linker);
> +            build_slit(tables_blob, tables->linker, ms);
>          }
>      }
>  
> diff --git a/hw/arm/virt.c b/hw/arm/virt.c
> index 16ba67f7a7..70954b658d 100644
> --- a/hw/arm/virt.c
> +++ b/hw/arm/virt.c
> @@ -195,6 +195,8 @@ static bool cpu_type_valid(const char *cpu)
>  
>  static void create_fdt(VirtMachineState *vms)
>  {
> +    MachineState *ms = MACHINE(vms);
> +    int nb_numa_nodes = machine_num_numa_nodes(ms);
>      void *fdt = create_device_tree(&vms->fdt_size);
>  
>      if (!fdt) {
> @@ -1780,7 +1782,7 @@ virt_cpu_index_to_props(MachineState *ms, unsigned 
> cpu_index)
>  
>  static int64_t virt_get_default_cpu_node_id(const MachineState *ms, int idx)
>  {
> -    return idx % nb_numa_nodes;
> +    return idx % machine_num_numa_nodes(ms);
>  }
>  
>  static const CPUArchIdList *virt_possible_cpu_arch_ids(MachineState *ms)
> @@ -1886,6 +1888,7 @@ static void virt_machine_class_init(ObjectClass *oc, 
> void *data)
>      mc->kvm_type = virt_kvm_type;
>      assert(!mc->get_hotplug_handler);
>      mc->get_hotplug_handler = virt_machine_get_hotplug_handler;
> +    mc->numa_supported = true;
>      hc->plug = virt_machine_device_plug_cb;
>  }
>  
> diff --git a/hw/core/machine.c b/hw/core/machine.c
> index 5d046a43e3..90bebb8d3a 100644
> --- a/hw/core/machine.c
> +++ b/hw/core/machine.c
> @@ -857,6 +857,11 @@ static void machine_initfn(Object *obj)
>                                          NULL);
>      }
>  
> +    if (mc->numa_supported) {
> +        ms->numa_state = g_new0(NumaState, 1);
> +    } else {

> +        ms->numa_state = NULL;
it's not necessary, all QOM objects are zero initialized on allocation.


> +    }
>  
>      /* Register notifier when init is done for sysbus sanity checks */
>      ms->sysbus_notifier.notify = machine_init_notify;
> @@ -877,6 +882,7 @@ static void machine_finalize(Object *obj)
>      g_free(ms->firmware);
>      g_free(ms->device_memory);
>      g_free(ms->nvdimms_state);
> +    g_free(ms->numa_state);
>  }
>  
>  bool machine_usb(MachineState *machine)
> @@ -919,6 +925,11 @@ bool machine_mem_merge(MachineState *machine)
>      return machine->mem_merge;
>  }
>  
> +int machine_num_numa_nodes(const MachineState *machine)
> +{
> +    return machine->numa_state ? machine->numa_state->num_nodes : 0;
> +}
Wrapper looks unnecessary, I'd drop it and use
  machine->numa_state->num_nodes
directly at call sites.


>  static char *cpu_slot_to_string(const CPUArchId *cpu)
>  {
>      GString *s = g_string_new(NULL);
> @@ -948,7 +959,7 @@ static void machine_numa_finish_cpu_init(MachineState 
> *machine)
>      MachineClass *mc = MACHINE_GET_CLASS(machine);
>      const CPUArchIdList *possible_cpus = mc->possible_cpu_arch_ids(machine);
>  
> -    assert(nb_numa_nodes);
> +    assert(machine_num_numa_nodes(machine));
>      for (i = 0; i < possible_cpus->len; i++) {
>          if (possible_cpus->cpus[i].props.has_node_id) {
>              break;
> @@ -994,9 +1005,11 @@ void machine_run_board_init(MachineState *machine)
>  {
>      MachineClass *machine_class = MACHINE_GET_CLASS(machine);
>  
> -    numa_complete_configuration(machine);
> -    if (nb_numa_nodes) {
> -        machine_numa_finish_cpu_init(machine);
> +    if (machine_class->numa_supported) {
> +        numa_complete_configuration(machine);
> +        if (machine->numa_state->num_nodes) {
> +            machine_numa_finish_cpu_init(machine);
> +        }
>      }
>  
>      /* If the machine supports the valid_cpu_types check and the user
> diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
> index 416da318ae..7d9bc88ac9 100644
> --- a/hw/i386/acpi-build.c
> +++ b/hw/i386/acpi-build.c
> @@ -2687,7 +2687,7 @@ void acpi_build(AcpiBuildTables *tables, MachineState 
> *machine)
>          build_srat(tables_blob, tables->linker, machine);
>          if (have_numa_distance) {
>              acpi_add_table(table_offsets, tables_blob);
> -            build_slit(tables_blob, tables->linker);
> +            build_slit(tables_blob, tables->linker, machine);
>          }
>      }
>      if (acpi_get_mcfg(&mcfg)) {
> diff --git a/hw/i386/pc.c b/hw/i386/pc.c
> index d98b737b8f..6404ae508e 100644
> --- a/hw/i386/pc.c
> +++ b/hw/i386/pc.c
> @@ -999,6 +999,8 @@ static FWCfgState *bochs_bios_init(AddressSpace *as, 
> PCMachineState *pcms)
>      int i;
>      const CPUArchIdList *cpus;
>      MachineClass *mc = MACHINE_GET_CLASS(pcms);
> +    MachineState *ms = MACHINE(pcms);
> +    int nb_numa_nodes = machine_num_numa_nodes(ms);
>  
>      fw_cfg = fw_cfg_init_io_dma(FW_CFG_IO_BASE, FW_CFG_IO_BASE + 4, as);
>      fw_cfg_add_i16(fw_cfg, FW_CFG_NB_CPUS, pcms->boot_cpus);
> @@ -1675,6 +1677,8 @@ void pc_machine_done(Notifier *notifier, void *data)
>  void pc_guest_info_init(PCMachineState *pcms)
>  {
>      int i;
> +    MachineState *ms = MACHINE(pcms);
> +    int nb_numa_nodes = machine_num_numa_nodes(ms);
>  
>      pcms->apic_xrupt_override = kvm_allows_irq0_override();
>      pcms->numa_nodes = nb_numa_nodes;
> @@ -2658,7 +2662,7 @@ static int64_t pc_get_default_cpu_node_id(const 
> MachineState *ms, int idx)
>     assert(idx < ms->possible_cpus->len);
>     x86_topo_ids_from_apicid(ms->possible_cpus->cpus[idx].arch_id,
>                              smp_cores, smp_threads, &topo);
> -   return topo.pkg_id % nb_numa_nodes;
> +   return topo.pkg_id % machine_num_numa_nodes(ms);
>  }
>  
>  static const CPUArchIdList *pc_possible_cpu_arch_ids(MachineState *ms)
> @@ -2752,6 +2756,7 @@ 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_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/mem/pc-dimm.c b/hw/mem/pc-dimm.c
> index 152400b1fc..48cbd53e6b 100644
> --- a/hw/mem/pc-dimm.c
> +++ b/hw/mem/pc-dimm.c
> @@ -160,6 +160,8 @@ static void pc_dimm_realize(DeviceState *dev, Error 
> **errp)
>  {
>      PCDIMMDevice *dimm = PC_DIMM(dev);
>      PCDIMMDeviceClass *ddc = PC_DIMM_GET_CLASS(dimm);
> +    MachineState *ms = MACHINE(qdev_get_machine());
> +    int nb_numa_nodes = machine_num_numa_nodes(ms);
>  
>      if (!dimm->hostmem) {
>          error_setg(errp, "'" PC_DIMM_MEMDEV_PROP "' property is not set");
> diff --git a/hw/pci-bridge/pci_expander_bridge.c 
> b/hw/pci-bridge/pci_expander_bridge.c
> index e62de4218f..d0590c0973 100644
> --- a/hw/pci-bridge/pci_expander_bridge.c
> +++ b/hw/pci-bridge/pci_expander_bridge.c
> @@ -217,6 +217,8 @@ static void pxb_dev_realize_common(PCIDevice *dev, bool 
> pcie, Error **errp)
>      PCIBus *bus;
>      const char *dev_name = NULL;
>      Error *local_err = NULL;
> +    MachineState *ms = MACHINE(qdev_get_machine());
> +    int nb_numa_nodes = machine_num_numa_nodes(ms);
>  
>      if (pxb->numa_node != NUMA_NODE_UNASSIGNED &&
>          pxb->numa_node >= nb_numa_nodes) {
> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> index 2ef3ce4362..4f0a8d4e2e 100644
> --- a/hw/ppc/spapr.c
> +++ b/hw/ppc/spapr.c
> @@ -290,6 +290,8 @@ static int spapr_fixup_cpu_dt(void *fdt, 
> SpaprMachineState *spapr)
>      CPUState *cs;
>      char cpu_model[32];
>      uint32_t pft_size_prop[] = {0, cpu_to_be32(spapr->htab_shift)};
> +    MachineState *ms = MACHINE(spapr);
> +    int nb_numa_nodes = machine_num_numa_nodes(ms);
>  
>      CPU_FOREACH(cs) {
>          PowerPCCPU *cpu = POWERPC_CPU(cs);
> @@ -344,6 +346,7 @@ static int spapr_fixup_cpu_dt(void *fdt, 
> SpaprMachineState *spapr)
>  
>  static hwaddr spapr_node0_size(MachineState *machine)
>  {
> +    int nb_numa_nodes = machine_num_numa_nodes(machine);
>      if (nb_numa_nodes) {
>          int i;
>          for (i = 0; i < nb_numa_nodes; ++i) {
> @@ -390,6 +393,7 @@ static int spapr_populate_memory_node(void *fdt, int 
> nodeid, hwaddr start,
>  static int spapr_populate_memory(SpaprMachineState *spapr, void *fdt)
>  {
>      MachineState *machine = MACHINE(spapr);
> +    int nb_numa_nodes = machine_num_numa_nodes(machine);
>      hwaddr mem_start, node_size;
>      int i, nb_nodes = nb_numa_nodes;
>      NodeInfo *nodes = numa_info;
> @@ -444,6 +448,8 @@ static void spapr_populate_cpu_dt(CPUState *cs, void 
> *fdt, int offset,
>      PowerPCCPU *cpu = POWERPC_CPU(cs);
>      CPUPPCState *env = &cpu->env;
>      PowerPCCPUClass *pcc = POWERPC_CPU_GET_CLASS(cs);
> +    MachineState *ms = MACHINE(spapr);
> +    int nb_numa_nodes = machine_num_numa_nodes(ms);
>      int index = spapr_get_vcpu_id(cpu);
>      uint32_t segs[] = {cpu_to_be32(28), cpu_to_be32(40),
>                         0xffffffff, 0xffffffff};
> @@ -849,6 +855,7 @@ static int spapr_populate_drmem_v1(SpaprMachineState 
> *spapr, void *fdt,
>  static int spapr_populate_drconf_memory(SpaprMachineState *spapr, void *fdt)
>  {
>      MachineState *machine = MACHINE(spapr);
> +    int nb_numa_nodes = machine_num_numa_nodes(machine);
>      int ret, i, offset;
>      uint64_t lmb_size = SPAPR_MEMORY_BLOCK_SIZE;
>      uint32_t prop_lmb_size[] = {0, cpu_to_be32(lmb_size)};
> @@ -1693,6 +1700,7 @@ static void spapr_machine_reset(void)
>  {
>      MachineState *machine = MACHINE(qdev_get_machine());
>      SpaprMachineState *spapr = SPAPR_MACHINE(machine);
> +    int nb_numa_nodes = machine_num_numa_nodes(machine);
>      PowerPCCPU *first_ppc_cpu;
>      uint32_t rtas_limit;
>      hwaddr rtas_addr, fdt_addr;
> @@ -2509,6 +2517,7 @@ static void 
> spapr_create_lmb_dr_connectors(SpaprMachineState *spapr)
>  static void spapr_validate_node_memory(MachineState *machine, Error **errp)
>  {
>      int i;
> +    int nb_numa_nodes = machine_num_numa_nodes(machine);
>  
>      if (machine->ram_size % SPAPR_MEMORY_BLOCK_SIZE) {
>          error_setg(errp, "Memory size 0x" RAM_ADDR_FMT
> @@ -4111,7 +4120,7 @@ spapr_cpu_index_to_props(MachineState *machine, 
> unsigned cpu_index)
>  
>  static int64_t spapr_get_default_cpu_node_id(const MachineState *ms, int idx)
>  {
> -    return idx / smp_cores % nb_numa_nodes;
> +    return idx / smp_cores % machine_num_numa_nodes(ms);
>  }
>  
>  static const CPUArchIdList *spapr_possible_cpu_arch_ids(MachineState 
> *machine)
> @@ -4315,6 +4324,7 @@ static void spapr_machine_class_init(ObjectClass *oc, 
> void *data)
>      smc->update_dt_enabled = true;
>      mc->default_cpu_type = POWERPC_CPU_TYPE_NAME("power9_v2.0");
>      mc->has_hotpluggable_cpus = true;
> +    mc->numa_supported = true;
>      smc->resize_hpt_default = SPAPR_RESIZE_HPT_ENABLED;
>      fwc->get_dev_path = spapr_get_fw_dev_path;
>      nc->nmi_monitor_handler = spapr_nmi;
> diff --git a/include/hw/acpi/aml-build.h b/include/hw/acpi/aml-build.h
> index 1a563ad756..991cf05134 100644
> --- a/include/hw/acpi/aml-build.h
> +++ b/include/hw/acpi/aml-build.h
> @@ -414,7 +414,7 @@ build_append_gas_from_struct(GArray *table, const struct 
> AcpiGenericAddress *s)
>  void build_srat_memory(AcpiSratMemoryAffinity *numamem, uint64_t base,
>                         uint64_t len, int node, MemoryAffinityFlags flags);
>  
> -void build_slit(GArray *table_data, BIOSLinker *linker);
> +void build_slit(GArray *table_data, BIOSLinker *linker, MachineState *ms);
>  
>  void build_fadt(GArray *tbl, BIOSLinker *linker, const AcpiFadtData *f,
>                  const char *oem_id, const char *oem_table_id);
> diff --git a/include/hw/boards.h b/include/hw/boards.h
> index 6f7916f88f..5f102e3075 100644
> --- a/include/hw/boards.h
> +++ b/include/hw/boards.h
> @@ -5,6 +5,7 @@
>  
>  #include "sysemu/blockdev.h"
>  #include "sysemu/accel.h"
> +#include "sysemu/sysemu.h"
why it's here?

>  #include "hw/qdev.h"
>  #include "qom/object.h"
>  #include "qom/cpu.h"
> @@ -68,6 +69,7 @@ int machine_kvm_shadow_mem(MachineState *machine);
>  int machine_phandle_start(MachineState *machine);
>  bool machine_dump_guest_core(MachineState *machine);
>  bool machine_mem_merge(MachineState *machine);
> +int machine_num_numa_nodes(const MachineState *machine);
>  HotpluggableCPUList *machine_query_hotpluggable_cpus(MachineState *machine);
>  void machine_set_cpu_numa_node(MachineState *machine,
>                                 const CpuInstanceProperties *props,
> @@ -210,6 +212,7 @@ struct MachineClass {
>      bool ignore_boot_device_suffixes;
>      bool smbus_no_migration_support;
>      bool nvdimm_supported;
> +    bool numa_supported;
>  
>      HotplugHandler *(*get_hotplug_handler)(MachineState *machine,
>                                             DeviceState *dev);
> @@ -230,6 +233,12 @@ typedef struct DeviceMemoryState {
>      MemoryRegion mr;
>  } DeviceMemoryState;
>  
> +typedef struct NumaState {
> +    /* Number of NUMA nodes */
> +    int num_nodes;
> +
> +} NumaState;
> +
>  /**
>   * MachineState:
>   */
> @@ -273,6 +282,7 @@ struct MachineState {
>      AccelState *accelerator;
>      CPUArchIdList *possible_cpus;
>      struct NVDIMMState *nvdimms_state;
> +    NumaState *numa_state;
>  };
>  
>  #define DEFINE_MACHINE(namestr, machine_initfn) \
> diff --git a/include/sysemu/numa.h b/include/sysemu/numa.h
> index b6ac7de43e..a55e2be563 100644
> --- a/include/sysemu/numa.h
> +++ b/include/sysemu/numa.h
> @@ -6,7 +6,6 @@
>  #include "sysemu/hostmem.h"
>  #include "hw/boards.h"
>  
> -extern int nb_numa_nodes;   /* Number of NUMA nodes */
>  extern bool have_numa_distance;
>  
>  struct NodeInfo {
> @@ -24,7 +23,7 @@ struct NumaNodeMem {
>  extern NodeInfo numa_info[MAX_NODES];
>  void parse_numa_opts(MachineState *ms);
>  void numa_complete_configuration(MachineState *ms);
> -void query_numa_node_mem(NumaNodeMem node_mem[]);
> +void query_numa_node_mem(NumaNodeMem node_mem[], MachineState *ms);
>  extern QemuOptsList qemu_numa_opts;
>  void numa_legacy_auto_assign_ram(MachineClass *mc, NodeInfo *nodes,
>                                   int nb_nodes, ram_addr_t size);
> diff --git a/monitor.c b/monitor.c
> index bb48997913..28ea45a731 100644
> --- a/monitor.c
> +++ b/monitor.c
> @@ -1926,11 +1926,13 @@ static void hmp_info_numa(Monitor *mon, const QDict 
> *qdict)
>      int i;
>      NumaNodeMem *node_mem;
>      CpuInfoList *cpu_list, *cpu;
> +    MachineState *ms = MACHINE(qdev_get_machine());
> +    int nb_numa_nodes = machine_num_numa_nodes(ms);
>  
>      cpu_list = qmp_query_cpus(&error_abort);
>      node_mem = g_new0(NumaNodeMem, nb_numa_nodes);
>  
> -    query_numa_node_mem(node_mem);
> +    query_numa_node_mem(node_mem, ms);
>      monitor_printf(mon, "%d nodes\n", nb_numa_nodes);
>      for (i = 0; i < nb_numa_nodes; i++) {
>          monitor_printf(mon, "node %d cpus:", i);
> diff --git a/numa.c b/numa.c
> index 3875e1efda..343fcaf13f 100644
> --- a/numa.c
> +++ b/numa.c
> @@ -52,7 +52,6 @@ static int have_memdevs = -1;
>  static int max_numa_nodeid; /* Highest specified NUMA node ID, plus one.
>                               * For all nodes, nodeid < max_numa_nodeid
>                               */
> -int nb_numa_nodes;
>  bool have_numa_distance;
>  NodeInfo numa_info[MAX_NODES];
>  
> @@ -68,7 +67,7 @@ static void parse_numa_node(MachineState *ms, 
> NumaNodeOptions *node,
>      if (node->has_nodeid) {
>          nodenr = node->nodeid;
>      } else {
> -        nodenr = nb_numa_nodes;
> +        nodenr = machine_num_numa_nodes(ms);
>      }
>  
>      if (nodenr >= MAX_NODES) {
> @@ -136,10 +135,11 @@ static void parse_numa_node(MachineState *ms, 
> NumaNodeOptions *node,
>      }
>      numa_info[nodenr].present = true;
>      max_numa_nodeid = MAX(max_numa_nodeid, nodenr + 1);
> -    nb_numa_nodes++;
> +    ms->numa_state->num_nodes++;
>  }
>  
> -static void parse_numa_distance(NumaDistOptions *dist, Error **errp)
> +static
> +void parse_numa_distance(MachineState *ms, NumaDistOptions *dist, Error 
> **errp)
>  {
>      uint16_t src = dist->src;
>      uint16_t dst = dist->dst;
> @@ -179,6 +179,11 @@ void set_numa_options(MachineState *ms, NumaOptions 
> *object, Error **errp)
>  {
>      Error *err = NULL;
>  
> +    if (ms->numa_state == NULL) {
I'd use here
  MachineClass::numa_supported

> +        error_setg(errp, "NUMA is not supported by this machine-type");
> +        goto end;
> +    }
> +
>      switch (object->type) {
>      case NUMA_OPTIONS_TYPE_NODE:
>          parse_numa_node(ms, &object->u.node, &err);
> @@ -187,7 +192,7 @@ void set_numa_options(MachineState *ms, NumaOptions 
> *object, Error **errp)
>          }
>          break;
>      case NUMA_OPTIONS_TYPE_DIST:
> -        parse_numa_distance(&object->u.dist, &err);
> +        parse_numa_distance(ms, &object->u.dist, &err);
>          if (err) {
>              goto end;
>          }
> @@ -252,10 +257,11 @@ end:
>   * distance from a node to itself is always NUMA_DISTANCE_MIN,
>   * so providing it is never necessary.
>   */
> -static void validate_numa_distance(void)
> +static void validate_numa_distance(MachineState *ms)
>  {
>      int src, dst;
>      bool is_asymmetrical = false;
> +    int nb_numa_nodes = machine_num_numa_nodes(ms);
>  
>      for (src = 0; src < nb_numa_nodes; src++) {
>          for (dst = src; dst < nb_numa_nodes; dst++) {
> @@ -293,9 +299,10 @@ static void validate_numa_distance(void)
>      }
>  }
>  
> -static void complete_init_numa_distance(void)
> +static void complete_init_numa_distance(MachineState *ms)
>  {
>      int src, dst;
> +    int nb_numa_nodes = machine_num_numa_nodes(ms);
>  
>      /* Fixup NUMA distance by symmetric policy because if it is an
>       * asymmetric distance table, it should be a complete table and
> @@ -369,7 +376,7 @@ void numa_complete_configuration(MachineState *ms)
>       *
>       * Enable NUMA implicitly by adding a new NUMA node automatically.
>       */
> -    if (ms->ram_slots > 0 && nb_numa_nodes == 0 &&
> +    if (ms->ram_slots > 0 && ms->numa_state->num_nodes == 0 &&
>          mc->auto_enable_numa_with_memhp) {
>              NumaNodeOptions node = { };
>              parse_numa_node(ms, &node, &error_abort);
> @@ -387,30 +394,33 @@ void numa_complete_configuration(MachineState *ms)
>      }
>  
>      /* This must be always true if all nodes are present: */
> -    assert(nb_numa_nodes == max_numa_nodeid);
> +    assert(ms->numa_state->num_nodes == max_numa_nodeid);
>  
> -    if (nb_numa_nodes > 0) {
> +    if (ms->numa_state->num_nodes > 0) {
>          uint64_t numa_total;
>  
> -        if (nb_numa_nodes > MAX_NODES) {
> -            nb_numa_nodes = MAX_NODES;
> +        if (ms->numa_state->num_nodes > MAX_NODES) {
> +            ms->numa_state->num_nodes = MAX_NODES;
>          }
>  
>          /* If no memory size is given for any node, assume the default case
>           * and distribute the available memory equally across all nodes
>           */
> -        for (i = 0; i < nb_numa_nodes; i++) {
> +        for (i = 0; i < ms->numa_state->num_nodes; i++) {
>              if (numa_info[i].node_mem != 0) {
>                  break;
>              }
>          }
> -        if (i == nb_numa_nodes) {
> +        if (i == ms->numa_state->num_nodes) {
>              assert(mc->numa_auto_assign_ram);
> -            mc->numa_auto_assign_ram(mc, numa_info, nb_numa_nodes, ram_size);
> +            mc->numa_auto_assign_ram(mc,
> +                                     numa_info,
> +                                     ms->numa_state->num_nodes,
> +                                     ram_size);
>          }
>  
>          numa_total = 0;
> -        for (i = 0; i < nb_numa_nodes; i++) {
> +        for (i = 0; i < ms->numa_state->num_nodes; i++) {
>              numa_total += numa_info[i].node_mem;
>          }
>          if (numa_total != ram_size) {
> @@ -434,10 +444,10 @@ void numa_complete_configuration(MachineState *ms)
>           */
>          if (have_numa_distance) {
>              /* Validate enough NUMA distance information was provided. */
> -            validate_numa_distance();
> +            validate_numa_distance(ms);
>  
>              /* Validation succeeded, now fill in any missing distances. */
> -            complete_init_numa_distance();
> +            complete_init_numa_distance(ms);
>          }
>      }
>  }
> @@ -513,6 +523,8 @@ void memory_region_allocate_system_memory(MemoryRegion 
> *mr, Object *owner,
>  {
>      uint64_t addr = 0;
>      int i;
> +    MachineState *ms = MACHINE(qdev_get_machine());
> +    int nb_numa_nodes = machine_num_numa_nodes(ms);
>  
>      if (nb_numa_nodes == 0 || !have_memdevs) {
>          allocate_system_memory_nonnuma(mr, owner, name, ram_size);
> @@ -578,16 +590,16 @@ static void numa_stat_memory_devices(NumaNodeMem 
> node_mem[])
>      qapi_free_MemoryDeviceInfoList(info_list);
>  }
>  
> -void query_numa_node_mem(NumaNodeMem node_mem[])
> +void query_numa_node_mem(NumaNodeMem node_mem[], MachineState *ms)
>  {
>      int i;
>  
> -    if (nb_numa_nodes <= 0) {
> +    if (ms->numa_state == NULL || ms->numa_state->num_nodes <= 0) {
>          return;
>      }
>  
>      numa_stat_memory_devices(node_mem);
> -    for (i = 0; i < nb_numa_nodes; i++) {
> +    for (i = 0; i < ms->numa_state->num_nodes; i++) {
>          node_mem[i].node_mem += numa_info[i].node_mem;
>      }
>  }