[Qemu-devel] [PATCH v2 10/10] pc: acpi: drop intermediate PCMachineState.node_cpu

[Igor Mammedov <imammedo@redhat.com>]

PCMachineState.node_cpu was used for mapping APIC ID
to numa node id as CPU entries in SRAT used to be
built on sparse APIC ID bitmap (up to apic_id_limit).
However since commit
  5803fce pc: acpi: SRAT: create only valid processor lapic entries
CPU entries in SRAT aren't build using apic bitmap
but using 0..maxcpus index instead which is also used
for creating numa_info[x].node_cpu map.
So instead of doing useless intermediate conversion from
  1. node by cpu index -> node by apic id
       i.e. numa_info[x].node_cpu -> PCMachineState.node_cpu
  2. apic id -> srat entry PMX
       PCMachineState.node_cpu[apic id] -> PMX value
use numa_info[x].node_cpu map directly like ARM does and do
  1. numa_info[x].node_cpu -> PMX value using index
     in range 0..maxcpus
and drop not necessary PCMachineState.node_cpu and related
code.

That also removes the last (not counting legacy hotplug)
dependency of ACPI code on apic_id_limit and need to allocate
huge sparse PCMachineState.node_cpu array in case of 32-bit
APIC IDs.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
---
 hw/i386/acpi-build.c | 11 ++++++++---
 hw/i386/pc.c         | 16 +---------------
 include/hw/i386/pc.h |  1 -
 3 files changed, 9 insertions(+), 19 deletions(-)

diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
index 0642cf8..3f7e9fb 100644
--- a/hw/i386/acpi-build.c
+++ b/hw/i386/acpi-build.c
@@ -44,6 +44,7 @@
 #include "hw/acpi/tpm.h"
 #include "sysemu/tpm_backend.h"
 #include "hw/timer/mc146818rtc_regs.h"
+#include "sysemu/numa.h"
 
 /* Supported chipsets: */
 #include "hw/acpi/piix4.h"
@@ -2316,7 +2317,6 @@ build_srat(GArray *table_data, BIOSLinker *linker, MachineState *machine)
     AcpiSratMemoryAffinity *numamem;
 
     int i;
-    uint64_t curnode;
     int srat_start, numa_start, slots;
     uint64_t mem_len, mem_base, next_base;
     MachineClass *mc = MACHINE_GET_CLASS(machine);
@@ -2332,14 +2332,19 @@ build_srat(GArray *table_data, BIOSLinker *linker, MachineState *machine)
     srat->reserved1 = cpu_to_le32(1);
 
     for (i = 0; i < apic_ids->len; i++) {
+        int j;
         int apic_id = apic_ids->cpus[i].arch_id;
 
         core = acpi_data_push(table_data, sizeof *core);
         core->type = ACPI_SRAT_PROCESSOR_APIC;
         core->length = sizeof(*core);
         core->local_apic_id = apic_id;
-        curnode = pcms->node_cpu[apic_id];
-        core->proximity_lo = curnode;
+        for (j = 0; j < nb_numa_nodes; j++) {
+            if (test_bit(i, numa_info[j].node_cpu)) {
+                core->proximity_lo = j;
+                break;
+            }
+        }
         memset(core->proximity_hi, 0, 3);
         core->local_sapic_eid = 0;
         core->flags = cpu_to_le32(1);
diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index dbfba5c..b8fead3 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -1179,7 +1179,7 @@ void pc_machine_done(Notifier *notifier, void *data)
 
 void pc_guest_info_init(PCMachineState *pcms)
 {
-    int i, j;
+    int i;
 
     pcms->apic_xrupt_override = kvm_allows_irq0_override();
     pcms->numa_nodes = nb_numa_nodes;
@@ -1189,20 +1189,6 @@ void pc_guest_info_init(PCMachineState *pcms)
         pcms->node_mem[i] = numa_info[i].node_mem;
     }
 
-    pcms->node_cpu = g_malloc0(pcms->apic_id_limit *
-                                     sizeof *pcms->node_cpu);
-
-    for (i = 0; i < max_cpus; i++) {
-        unsigned int apic_id = x86_cpu_apic_id_from_index(i);
-        assert(apic_id < pcms->apic_id_limit);
-        for (j = 0; j < nb_numa_nodes; j++) {
-            if (test_bit(i, numa_info[j].node_cpu)) {
-                pcms->node_cpu[apic_id] = j;
-                break;
-            }
-        }
-    }
-
     pcms->machine_done.notify = pc_machine_done;
     qemu_add_machine_init_done_notifier(&pcms->machine_done);
 }
diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
index 884224e..948ed0c 100644
--- a/include/hw/i386/pc.h
+++ b/include/hw/i386/pc.h
@@ -72,7 +72,6 @@ struct PCMachineState {
     /* NUMA information: */
     uint64_t numa_nodes;
     uint64_t *node_mem;
-    uint64_t *node_cpu;
 };
 
 #define PC_MACHINE_ACPI_DEVICE_PROP "acpi-device"
-- 
1.8.3.1