[Qemu-devel] [PATCH v3 1/9] i386: Add die-level cpu topology to x86CPU on PCMachine

[Like Xu <like.xu@linux.intel.com>]

The die-level as the first PC-specific cpu topology is added to the leagcy
cpu topology model, which has one die per package implicitly and only the
numbers of sockets/cores/threads are configurable.

In the new model with die-level support, the total number of logical
processors (including offline) on board will be calculated as:

     #cpus = #sockets * #dies * #cores * #threads

and considering compatibility, the default value for #dies would be
initialized to one in x86_cpu_initfn() and pc_machine_initfn().

Signed-off-by: Like Xu <like.xu@linux.intel.com>
---
 hw/i386/pc.c         | 9 +++++++--
 include/hw/i386/pc.h | 2 ++
 target/i386/cpu.c    | 1 +
 target/i386/cpu.h    | 2 ++
 4 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index 12c1e08b85..9e9a42f007 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -2308,9 +2308,13 @@ static void pc_cpu_pre_plug(HotplugHandler *hotplug_dev,
         return;
     }
 
-    /* if APIC ID is not set, set it based on socket/core/thread properties */
+    /*
+     * If APIC ID is not set,
+     * set it based on socket/die/core/thread properties.
+     */
     if (cpu->apic_id == UNASSIGNED_APIC_ID) {
-        int max_socket = (ms->smp.max_cpus - 1) / smp_threads / smp_cores;
+        int max_socket = (ms->smp.max_cpus - 1) /
+                                smp_threads / smp_cores / pcms->smp_dies;
 
         if (cpu->socket_id < 0) {
             error_setg(errp, "CPU socket-id is not set");
@@ -2620,6 +2624,7 @@ static void pc_machine_initfn(Object *obj)
     pcms->smbus_enabled = true;
     pcms->sata_enabled = true;
     pcms->pit_enabled = true;
+    pcms->smp_dies = 1;
 
     pc_system_flash_create(pcms);
 }
diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
index b260262640..fae9217e34 100644
--- a/include/hw/i386/pc.h
+++ b/include/hw/i386/pc.h
@@ -24,6 +24,7 @@
  * PCMachineState:
  * @acpi_dev: link to ACPI PM device that performs ACPI hotplug handling
  * @boot_cpus: number of present VCPUs
+ * @smp_dies: number of dies per one package
  */
 struct PCMachineState {
     /*< private >*/
@@ -59,6 +60,7 @@ struct PCMachineState {
     bool apic_xrupt_override;
     unsigned apic_id_limit;
     uint16_t boot_cpus;
+    unsigned smp_dies;
 
     /* NUMA information: */
     uint64_t numa_nodes;
diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index 23119699de..a16be205fe 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -5619,6 +5619,7 @@ static void x86_cpu_initfn(Object *obj)
     CPUX86State *env = &cpu->env;
     FeatureWord w;
 
+    env->nr_dies = 1;
     cpu_set_cpustate_pointers(cpu);
 
     object_property_add(obj, "family", "int",
diff --git a/target/i386/cpu.h b/target/i386/cpu.h
index edad6e1efb..5daa2eeafa 100644
--- a/target/i386/cpu.h
+++ b/target/i386/cpu.h
@@ -1349,6 +1349,8 @@ typedef struct CPUX86State {
     uint64_t xss;
 
     TPRAccess tpr_access_type;
+
+    unsigned nr_dies;
 } CPUX86State;
 
 struct kvm_msrs;
-- 
2.21.0