Re: [Qemu-devel] [PATCH v5] NUMA: Enable adding NUMA node implicitly

[Dou Liyang]

Hi Michael,

[...]
> Seems to cause build failures:
> /scm/qemu/numa.c:452:13: error: too many arguments to function ‘parse_numa_node’
>              parse_numa_node(ms, &node, NULL, NULL);

Yes, commit

  cc001888b780 ("numa: fixup parsed NumaNodeOptions earlier")

removed a argument from the function recently.

I will rebase this patch.

Thanks,
        dou.

> > ---
> > changelog V4 --> V5:
> >
> >   - Avoid calling qemu_opts_parse*()
> >   - Add a new NUMA node by calling parse_numa_node() directly
> >   - Remove the redundant argument in parse_numa_opts()
> >
> > These all were suggested by Eduardo.
> >
> > ---
> >  hw/i386/pc.c        |  1 +
> >  hw/i386/pc_piix.c   |  1 +
> >  hw/i386/pc_q35.c    |  1 +
> >  include/hw/boards.h |  1 +
> >  numa.c              | 21 ++++++++++++++++++++-
> >  vl.c                |  3 +--
> >  6 files changed, 25 insertions(+), 3 deletions(-)
> >
> > diff --git a/hw/i386/pc.c b/hw/i386/pc.c
> > index 8e307f7..ec4eb97 100644
> > --- a/hw/i386/pc.c
> > +++ b/hw/i386/pc.c
> > @@ -2325,6 +2325,7 @@ static void pc_machine_class_init(ObjectClass *oc, void 
> > *data)
> >      mc->cpu_index_to_instance_props = pc_cpu_index_to_props;
> >      mc->get_default_cpu_node_id = pc_get_default_cpu_node_id;
> >      mc->possible_cpu_arch_ids = pc_possible_cpu_arch_ids;
> > +    mc->auto_enable_numa_with_memhp = true;
> >      mc->has_hotpluggable_cpus = true;
> >      mc->default_boot_order = "cad";
> >      mc->hot_add_cpu = pc_hot_add_cpu;
> > diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
> > index f79d5cb..5e47528 100644
> > --- a/hw/i386/pc_piix.c
> > +++ b/hw/i386/pc_piix.c
> > @@ -446,6 +446,7 @@ static void pc_i440fx_2_10_machine_options(MachineClass *m)
> >      m->is_default = 0;
> >      m->alias = NULL;
> >      SET_MACHINE_COMPAT(m, PC_COMPAT_2_10);
> > +    m->auto_enable_numa_with_memhp = false;
> >  }
> >
> >  DEFINE_I440FX_MACHINE(v2_10, "pc-i440fx-2.10", NULL,
> > diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
> > index da3ea60..d606004 100644
> > --- a/hw/i386/pc_q35.c
> > +++ b/hw/i386/pc_q35.c
> > @@ -318,6 +318,7 @@ static void pc_q35_2_10_machine_options(MachineClass *m)
> >      m->alias = NULL;
> >      SET_MACHINE_COMPAT(m, PC_COMPAT_2_10);
> >      m->numa_auto_assign_ram = numa_legacy_auto_assign_ram;
> > +    m->auto_enable_numa_with_memhp = false;
> >  }
> >
> >  DEFINE_Q35_MACHINE(v2_10, "pc-q35-2.10", NULL,
> > diff --git a/include/hw/boards.h b/include/hw/boards.h
> > index 191a5b3..f1077f1 100644
> > --- a/include/hw/boards.h
> > +++ b/include/hw/boards.h
> > @@ -192,6 +192,7 @@ struct MachineClass {
> >      bool ignore_memory_transaction_failures;
> >      int numa_mem_align_shift;
> >      const char **valid_cpu_types;
> > +    bool auto_enable_numa_with_memhp;
> >      void (*numa_auto_assign_ram)(MachineClass *mc, NodeInfo *nodes,
> >                                   int nb_nodes, ram_addr_t size);
> >
> > diff --git a/numa.c b/numa.c
> > index 100a67f..4d12f30 100644
> > --- a/numa.c
> > +++ b/numa.c
> > @@ -221,6 +221,7 @@ 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++;
> >  }
> >
> >  static void parse_numa_distance(NumaDistOptions *dist, Error **errp)
> > @@ -281,7 +282,6 @@ static int parse_numa(void *opaque, QemuOpts *opts, Error 
> > **errp)
> >          if (err) {
> >              goto end;
> >          }
> > -        nb_numa_nodes++;
> >          break;
> >      case NUMA_OPTIONS_TYPE_DIST:
> >          parse_numa_distance(&object->u.dist, &err);
> > @@ -432,6 +432,25 @@ void parse_numa_opts(MachineState *ms)
> >          exit(1);
> >      }
> >
> > +    /*
> > +     * If memory hotplug is enabled (slots > 0) but without '-numa'
> > +     * options explicitly on CLI, guestes will break.
> > +     *
> > +     *   Windows: won't enable memory hotplug without SRAT table at all
> > +     *
> > +     *   Linux: if QEMU is started with initial memory all below 4Gb
> > +     *   and no SRAT table present, guest kernel will use nommu DMA ops,
> > +     *   which breaks 32bit hw drivers when memory is hotplugged and
> > +     *   guest tries to use it with that drivers.
> > +     *
> > +     * Enable NUMA implicitly by adding a new NUMA node automatically.
> > +     */
> > +    if (ms->ram_slots > 0 && nb_numa_nodes == 0 &&
> > +        mc->auto_enable_numa_with_memhp) {
> > +            NumaNodeOptions node = { };
> > +            parse_numa_node(ms, &node, NULL, NULL);
> > +    }
> > +
> >      assert(max_numa_nodeid <= MAX_NODES);
> >
> >      /* No support for sparse NUMA node IDs yet: */
> > diff --git a/vl.c b/vl.c
> > index ec29909..be332d1 100644
> > --- a/vl.c
> > +++ b/vl.c
> > @@ -4675,8 +4675,6 @@ int main(int argc, char **argv, char **envp)
> >      default_drive(default_floppy, snapshot, IF_FLOPPY, 0, FD_OPTS);
> >      default_drive(default_sdcard, snapshot, IF_SD, 0, SD_OPTS);
> >
> > -    parse_numa_opts(current_machine);
> > -
> >      if (qemu_opts_foreach(qemu_find_opts("mon"),
> >                            mon_init_func, NULL, NULL)) {
> >          exit(1);
> > @@ -4726,6 +4724,7 @@ int main(int argc, char **argv, char **envp)
> >      current_machine->boot_order = boot_order;
> >      current_machine->cpu_model = cpu_model;
> >
> > +    parse_numa_opts(current_machine);
> >
> >      /* parse features once if machine provides default cpu_type */
> >      if (machine_class->default_cpu_type) {
> > --
> > 2.5.5