[RFC v2 07/12] hw/core: Re-implement topology helpers to honor max limitations

[Zhao Liu <zhao1.liu@intel.com>]

For custom topology case, the valid and reliable topology information
be obtained from topology max limitations.

Therefore, re-implement machine_topo_get_cores_per_socket() and
machine_topo_get_threads_per_socket() to consider the custom topology
case. And further, use the wrapped helper to set CPUState.nr_threads/
nr_cores, avoiding topology mismatches in custom topology scenarios.

Additionally, since test-smp-parse needs more stubs to compile with
cpu-slot.c, keep the old helpers for test-smp-parse' use for now. The
legacy old helpers will be cleaned up when full compilation support is
added later on.

Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
---
 hw/core/machine-smp.c       |  8 +++++---
 hw/cpu/cpu-slot.c           | 18 ++++++++++++++++++
 include/hw/boards.h         |  9 +++++++--
 include/hw/cpu/cpu-slot.h   |  2 ++
 system/cpus.c               |  2 +-
 tests/unit/test-smp-parse.c |  4 ++--
 6 files changed, 35 insertions(+), 8 deletions(-)

diff --git a/hw/core/machine-smp.c b/hw/core/machine-smp.c
index d3be4352267d..2965b042fd92 100644
--- a/hw/core/machine-smp.c
+++ b/hw/core/machine-smp.c
@@ -376,14 +376,16 @@ bool machine_parse_smp_cache(MachineState *ms,
     return true;
 }
 
-unsigned int machine_topo_get_cores_per_socket(const MachineState *ms)
+unsigned int machine_topo_get_cores_per_socket_old(const MachineState *ms)
 {
+    assert(!ms->topo);
     return ms->smp.cores * ms->smp.modules * ms->smp.clusters * ms->smp.dies;
 }
 
-unsigned int machine_topo_get_threads_per_socket(const MachineState *ms)
+unsigned int machine_topo_get_threads_per_socket_old(const MachineState *ms)
 {
-    return ms->smp.threads * machine_topo_get_cores_per_socket(ms);
+    assert(!ms->topo);
+    return ms->smp.threads * machine_topo_get_cores_per_socket_old(ms);
 }
 
 CpuTopologyLevel machine_get_cache_topo_level(const MachineState *ms,
diff --git a/hw/cpu/cpu-slot.c b/hw/cpu/cpu-slot.c
index f2b9c412926f..8c0d55e835e2 100644
--- a/hw/cpu/cpu-slot.c
+++ b/hw/cpu/cpu-slot.c
@@ -204,6 +204,8 @@ static int get_smp_info_by_level(const CpuTopology *smp_info,
         return smp_info->cores;
     case CPU_TOPOLOGY_LEVEL_MODULE:
         return smp_info->modules;
+    case CPU_TOPOLOGY_LEVEL_CLUSTER:
+        return smp_info->clusters;
     case CPU_TOPOLOGY_LEVEL_DIE:
         return smp_info->dies;
     case CPU_TOPOLOGY_LEVEL_SOCKET:
@@ -356,6 +358,22 @@ int get_max_topo_by_level(const MachineState *ms, CpuTopologyLevel level)
     return ms->topo->stat.entries[level].max_limit;
 }
 
+unsigned int machine_topo_get_cores_per_socket(const MachineState *ms)
+{
+    int cores = 1, i;
+
+    for (i = CPU_TOPOLOGY_LEVEL_CORE; i < CPU_TOPOLOGY_LEVEL_SOCKET; i++) {
+        cores *= get_max_topo_by_level(ms, i);
+    }
+    return cores;
+}
+
+unsigned int machine_topo_get_threads_per_socket(const MachineState *ms)
+{
+    return get_max_topo_by_level(ms, CPU_TOPOLOGY_LEVEL_THREAD) *
+           machine_topo_get_cores_per_socket(ms);
+}
+
 bool machine_parse_custom_topo_config(MachineState *ms,
                                       const SMPConfiguration *config,
                                       Error **errp)
diff --git a/include/hw/boards.h b/include/hw/boards.h
index 6ef4ea322590..faf7859debdd 100644
--- a/include/hw/boards.h
+++ b/include/hw/boards.h
@@ -48,8 +48,13 @@ void machine_parse_smp_config(MachineState *ms,
 bool machine_parse_smp_cache(MachineState *ms,
                              const SmpCachePropertiesList *caches,
                              Error **errp);
-unsigned int machine_topo_get_cores_per_socket(const MachineState *ms);
-unsigned int machine_topo_get_threads_per_socket(const MachineState *ms);
+/*
+ * TODO: Drop these old helpers when cpu-slot.c could be compiled for
+ * test-smp-parse. Pls use machine_topo_get_cores_per_socket() and
+ * machine_topo_get_threads_per_socket() instead.
+ */
+unsigned int machine_topo_get_cores_per_socket_old(const MachineState *ms);
+unsigned int machine_topo_get_threads_per_socket_old(const MachineState *ms);
 CpuTopologyLevel machine_get_cache_topo_level(const MachineState *ms,
                                               CacheLevelAndType cache);
 void machine_memory_devices_init(MachineState *ms, hwaddr base, uint64_t size);
diff --git a/include/hw/cpu/cpu-slot.h b/include/hw/cpu/cpu-slot.h
index f56a0b08dca4..230309b67fe1 100644
--- a/include/hw/cpu/cpu-slot.h
+++ b/include/hw/cpu/cpu-slot.h
@@ -81,6 +81,8 @@ struct CPUSlot {
 void machine_plug_cpu_slot(MachineState *ms);
 bool machine_create_topo_tree(MachineState *ms, Error **errp);
 int get_max_topo_by_level(const MachineState *ms, CpuTopologyLevel level);
+unsigned int machine_topo_get_cores_per_socket(const MachineState *ms);
+unsigned int machine_topo_get_threads_per_socket(const MachineState *ms);
 bool machine_parse_custom_topo_config(MachineState *ms,
                                       const SMPConfiguration *config,
                                       Error **errp);
diff --git a/system/cpus.c b/system/cpus.c
index 1c818ff6828c..53e7cfb8a55f 100644
--- a/system/cpus.c
+++ b/system/cpus.c
@@ -667,7 +667,7 @@ void qemu_init_vcpu(CPUState *cpu)
     MachineState *ms = MACHINE(qdev_get_machine());
 
     cpu->nr_cores = machine_topo_get_cores_per_socket(ms);
-    cpu->nr_threads =  ms->smp.threads;
+    cpu->nr_threads = get_max_topo_by_level(ms, CPU_TOPOLOGY_LEVEL_THREAD);
     cpu->stopped = true;
     cpu->random_seed = qemu_guest_random_seed_thread_part1();
 
diff --git a/tests/unit/test-smp-parse.c b/tests/unit/test-smp-parse.c
index f9bccb56abc7..44d2213a7163 100644
--- a/tests/unit/test-smp-parse.c
+++ b/tests/unit/test-smp-parse.c
@@ -801,8 +801,8 @@ static void check_parse(MachineState *ms, const SMPConfiguration *config,
     /* call the generic parser */
     machine_parse_smp_config(ms, config, &err);
 
-    ms_threads_per_socket = machine_topo_get_threads_per_socket(ms);
-    ms_cores_per_socket = machine_topo_get_cores_per_socket(ms);
+    ms_threads_per_socket = machine_topo_get_threads_per_socket_old(ms);
+    ms_cores_per_socket = machine_topo_get_cores_per_socket_old(ms);
     output_topo_str = cpu_topology_to_string(&ms->smp,
                                              ms_threads_per_socket,
                                              ms_cores_per_socket,
-- 
2.34.1