[RFC PATCH 05/12] hw/arm/virt: DT: add cpu-map

[Ying Fang]

From: Andrew Jones <drjones@redhat.com>

Support devicetree CPU topology descriptions.

Signed-off-by: Andrew Jones <drjones@redhat.com>
---
 hw/arm/virt.c         | 37 ++++++++++++++++++++++++++++++++++++-
 include/hw/arm/virt.h |  1 +
 2 files changed, 37 insertions(+), 1 deletion(-)

diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index acf9bfbece..71f7dbb317 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -348,7 +348,10 @@ static void fdt_add_cpu_nodes(const VirtMachineState *vms)
     int cpu;
     int addr_cells = 1;
     const MachineState *ms = MACHINE(vms);
-
+    VirtMachineClass *vmc = VIRT_MACHINE_GET_CLASS(vms);
+    unsigned int smp_cores = ms->smp.cores;
+    unsigned int smp_threads = ms->smp.threads;
+    bool cpu_topology_enabled = !vmc->ignore_cpu_topology;
     /*
      * From Documentation/devicetree/bindings/arm/cpus.txt
      *  On ARM v8 64-bit systems value should be set to 2,
@@ -404,8 +407,37 @@ static void fdt_add_cpu_nodes(const VirtMachineState *vms)
                 ms->possible_cpus->cpus[cs->cpu_index].props.node_id);
         }
 
+        qemu_fdt_setprop_cell(vms->fdt, nodename, "phandle",
+                              qemu_fdt_alloc_phandle(vms->fdt));
+
         g_free(nodename);
     }
+    if (cpu_topology_enabled) {
+        /* Add vcpu topology by fdt node cpu-map. */
+        qemu_fdt_add_subnode(vms->fdt, "/cpus/cpu-map");
+
+        for (cpu = vms->smp_cpus - 1; cpu >= 0; cpu--) {
+            char *cpu_path = g_strdup_printf("/cpus/cpu@%d", cpu);
+            char *map_path;
+
+            if (smp_threads > 1) {
+                map_path = g_strdup_printf(
+                           "/cpus/cpu-map/%s%d/%s%d/%s%d",
+                           "cluster", cpu / (smp_cores * smp_threads),
+                           "core", (cpu / smp_threads) % smp_cores,
+                           "thread", cpu % smp_threads);
+            } else {
+                map_path = g_strdup_printf(
+                           "/cpus/cpu-map/%s%d/%s%d",
+                           "cluster", cpu / smp_cores,
+                           "core", cpu % smp_cores);
+            }
+            qemu_fdt_add_path(vms->fdt, map_path);
+            qemu_fdt_setprop_phandle(vms->fdt, map_path, "cpu", cpu_path);
+            g_free(map_path);
+            g_free(cpu_path);
+        }
+    }
 }
 
 static void fdt_add_its_gic_node(VirtMachineState *vms)
@@ -2553,8 +2585,11 @@ DEFINE_VIRT_MACHINE_AS_LATEST(5, 2)
 
 static void virt_machine_5_1_options(MachineClass *mc)
 {
+    VirtMachineClass *vmc = VIRT_MACHINE_CLASS(OBJECT_CLASS(mc));
+
     virt_machine_5_2_options(mc);
     compat_props_add(mc->compat_props, hw_compat_5_1, hw_compat_5_1_len);
+    vmc->ignore_cpu_topology = true;
 }
 DEFINE_VIRT_MACHINE(5, 1)
 
diff --git a/include/hw/arm/virt.h b/include/hw/arm/virt.h
index dff67e1bef..d37c6b7858 100644
--- a/include/hw/arm/virt.h
+++ b/include/hw/arm/virt.h
@@ -119,6 +119,7 @@ typedef struct {
     MachineClass parent;
     bool disallow_affinity_adjustment;
     bool no_its;
+    bool ignore_cpu_topology;
     bool no_pmu;
     bool claim_edge_triggered_timers;
     bool smbios_old_sys_ver;
-- 
2.23.0