[v2,2/2] hw/arm/sbsa-ref: Add cpu-map to device tree

Commit Message

Xiong Yining March 12, 2024, 8:30 a.m. UTC

From: xiongyining1480 <[e-mail]>

Support CPU topology description through device tree.

Signed-off-by: Xiong Yining <[e-mail]>
Signed-off-by: Chen Baozi <[e-mail]>
Reviewed-by: Marcin Juszkiewicz <[e-mail]>
---
 hw/arm/sbsa-ref.c | 34 ++++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)

Patch

diff --git a/hw/arm/sbsa-ref.c b/hw/arm/sbsa-ref.c
index fde7dd528f..5b2c32515d 100644
--- a/hw/arm/sbsa-ref.c
+++ b/hw/arm/sbsa-ref.c
@@ -264,9 +264,43 @@  static void create_fdt(SBSAMachineState *sms)
                 ms->possible_cpus->cpus[cs->cpu_index].props.node_id);
         }
 
+        qemu_fdt_setprop_cell(sms->fdt, nodename, "phandle",
+                        qemu_fdt_alloc_phandle(sms->fdt));
+
         g_free(nodename);
     }
 
+    /*
+     * Add vCPU topology description through fdt node cpu-map.
+     * See fdt_add_cpu_nodes() on hw/arm/virt.c for longer description.
+     */
+    qemu_fdt_add_subnode(sms->fdt, "/cpus/cpu-map");
+
+    for (cpu = sms->smp_cpus - 1; cpu >= 0; cpu--) {
+        char *cpu_path = g_strdup_printf("/cpus/cpu@%d", cpu);
+        char *map_path;
+
+        if (ms->smp.threads > 1) {
+            map_path = g_strdup_printf(
+                "/cpus/cpu-map/socket%d/cluster%d/core%d/thread%d",
+                cpu / (ms->smp.clusters * ms->smp.cores * ms->smp.threads),
+                (cpu / (ms->smp.cores * ms->smp.threads)) % ms->smp.clusters,
+                (cpu / ms->smp.threads) % ms->smp.cores,
+                cpu % ms->smp.threads);
+        } else {
+            map_path = g_strdup_printf(
+                "/cpus/cpu-map/socket%d/cluster%d/core%d",
+                cpu / (ms->smp.clusters * ms->smp.cores),
+                (cpu / ms->smp.cores) % ms->smp.clusters,
+                cpu % ms->smp.cores);
+        }
+        qemu_fdt_add_path(sms->fdt, map_path);
+        qemu_fdt_setprop_phandle(sms->fdt, map_path, "cpu", cpu_path);
+
+        g_free(map_path);
+        g_free(cpu_path);
+    }
+
     sbsa_fdt_add_gic_node(sms);
 }