target/ppc: Return default CPU for max CPU

All ppc CPUs represent hardware that exists in the real world, i.e.: we
do not have a "max" CPU with all possible emulated features enabled.
Return the default CPU type for the machine because that has greater
chance of being useful as the "max" CPU.

Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1038
Cc: Cédric Le Goater <clg@kaod.org>
Cc: Daniel Henrique Barboza <danielhb413@gmail.com>
Cc: Daniel P. Berrangé <berrange@redhat.com>
Cc: Greg Kurz <groug@kaod.org>
Cc: Matheus K. Ferst <matheus.ferst@eldorado.org.br>
Cc: Thomas Huth <thuth@redhat.com>
Signed-off-by: Murilo Opsfelder Araujo <muriloo@linux.ibm.com>
Signed-off-by: Fabiano Rosas <farosas@linux.ibm.com>
Reviewed-by: Víctor Colombo <victor.colombo@eldorado.org.br>
Message-Id: <20220628205513.81917-1-muriloo@linux.ibm.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>

1 files changed, 19 insertions, 0 deletions

diff --git a/target/ppc/cpu_init.c b/target/ppc/cpu_init.c
index bdfb1a5c6f..86ad28466a 100644
--- a/target/ppc/cpu_init.c
+++ b/target/ppc/cpu_init.c
@@ -47,6 +47,10 @@
 #include "spr_common.h"
 #include "power8-pmu.h"
 
+#ifndef CONFIG_USER_ONLY
+#include "hw/boards.h"
+#endif
+
 /* #define PPC_DEBUG_SPR */
 /* #define USE_APPLE_GDB */
 
@@ -6965,6 +6969,21 @@ static ObjectClass *ppc_cpu_class_by_name(const char *name)
         }
     }
 
+    /*
+     * All ppc CPUs represent hardware that exists in the real world, i.e.: we
+     * do not have a "max" CPU with all possible emulated features enabled.
+     * Return the default CPU type for the machine because that has greater
+     * chance of being useful as the "max" CPU.
+     */
+#if !defined(CONFIG_USER_ONLY)
+    if (strcmp(name, "max") == 0) {
+        MachineClass *mc = MACHINE_GET_CLASS(qdev_get_machine());
+        if (mc) {
+            return object_class_by_name(mc->default_cpu_type);
+        }
+    }
+#endif
+
     cpu_model = g_ascii_strdown(name, -1);
     p = ppc_cpu_lookup_alias(cpu_model);
     if (p) {