target-ppc: enable virtio endian ambivalent support

The device endianness is the cpu endianness at device reset time.
Signed-off-by: NGreg Kurz <gkurz@linux.vnet.ibm.com>
Reviewed-by: NAlexander Graf <agraf@suse.de>
Reviewed-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>

target-ppc/cpu.h

@@ -29,6 +29,8 @@
 #define TARGET_LONG_BITS 64
 #define TARGET_PAGE_BITS 12
 
+#define TARGET_IS_BIENDIAN 1
+
 /* Note that the official physical address space bits is 62-M where M
    is implementation dependent.  I've not looked up M for the set of
    cpus we emulate at the system level.  */

target-ppc/translate_init.c

@@ -9597,6 +9597,18 @@ static void ppc_cpu_reset(CPUState *s)
     tlb_flush(s, 1);
 }
 
+#ifndef CONFIG_USER_ONLY
+static bool ppc_cpu_is_big_endian(CPUState *cs)
+{
+    PowerPCCPU *cpu = POWERPC_CPU(cs);
+    CPUPPCState *env = &cpu->env;
+
+    cpu_synchronize_state(cs);
+
+    return !msr_le;
+}
+#endif
+
 static void ppc_cpu_initfn(Object *obj)
 {
     CPUState *cs = CPU(obj);
@@ -9692,6 +9704,9 @@ static void ppc_cpu_class_init(ObjectClass *oc, void *data)
 #else
     cc->gdb_core_xml_file = "power-core.xml";
 #endif
+#ifndef CONFIG_USER_ONLY
+    cc->virtio_is_big_endian = ppc_cpu_is_big_endian;
+#endif
 
     dc->fw_name = "PowerPC,UNKNOWN";
 }