[Qemu-devel] [RFC PATCH] numa: add auto_enable_numa to fix broken check in spapr

[Tao Xu <tao3.xu@intel.com>]

Introduce MachineClass::auto_enable_numa for one implicit NUMA node,
and enable it to fix broken check in spapr_validate_node_memory(), when
spapr_populate_memory() creates a implicit node and info then use
nb_numa_nodes which is 0.

Suggested-by: Igor Mammedov <imammedo@redhat.com>
Suggested-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Tao Xu <tao3.xu@intel.com>
---

This patch has a dependency on
https://patchwork.kernel.org/cover/11063235/
---
 hw/core/numa.c      | 9 +++++++--
 hw/ppc/spapr.c      | 9 +--------
 include/hw/boards.h | 1 +
 3 files changed, 9 insertions(+), 10 deletions(-)

diff --git a/hw/core/numa.c b/hw/core/numa.c
index 75db35ac19..756d243d3f 100644
--- a/hw/core/numa.c
+++ b/hw/core/numa.c
@@ -580,9 +580,14 @@ void numa_complete_configuration(MachineState *ms)
      *   guest tries to use it with that drivers.
      *
      * Enable NUMA implicitly by adding a new NUMA node automatically.
+     *
+     * Or if MachineClass::auto_enable_numa is true and no NUMA nodes,
+     * assume there is just one node with whole RAM.
      */
-    if (ms->ram_slots > 0 && ms->numa_state->num_nodes == 0 &&
-        mc->auto_enable_numa_with_memhp) {
+    if (ms->numa_state->num_nodes == 0 &&
+        ((ms->ram_slots > 0 &&
+        mc->auto_enable_numa_with_memhp) ||
+        mc->auto_enable_numa)) {
             NumaNodeOptions node = { };
             parse_numa_node(ms, &node, &error_abort);
     }
diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index f607ca567b..e50343f326 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -400,14 +400,6 @@ static int spapr_populate_memory(SpaprMachineState *spapr, void *fdt)
     hwaddr mem_start, node_size;
     int i, nb_nodes = machine->numa_state->num_nodes;
     NodeInfo *nodes = machine->numa_state->nodes;
-    NodeInfo ramnode;
-
-    /* No NUMA nodes, assume there is just one node with whole RAM */
-    if (!nb_nodes) {
-        nb_nodes = 1;
-        ramnode.node_mem = machine->ram_size;
-        nodes = &ramnode;
-    }
 
     for (i = 0, mem_start = 0; i < nb_nodes; ++i) {
         if (!nodes[i].node_mem) {
@@ -4369,6 +4361,7 @@ static void spapr_machine_class_init(ObjectClass *oc, void *data)
      */
     mc->numa_mem_align_shift = 28;
     mc->numa_mem_supported = true;
+    mc->auto_enable_numa = true;
 
     smc->default_caps.caps[SPAPR_CAP_HTM] = SPAPR_CAP_OFF;
     smc->default_caps.caps[SPAPR_CAP_VSX] = SPAPR_CAP_ON;
diff --git a/include/hw/boards.h b/include/hw/boards.h
index 2eb9a0b4e0..4a350b87d2 100644
--- a/include/hw/boards.h
+++ b/include/hw/boards.h
@@ -220,6 +220,7 @@ struct MachineClass {
     bool smbus_no_migration_support;
     bool nvdimm_supported;
     bool numa_mem_supported;
+    bool auto_enable_numa;
 
     HotplugHandler *(*get_hotplug_handler)(MachineState *machine,
                                            DeviceState *dev);
-- 
2.20.1