cpu: Introduce cpu_virtio_is_big_endian()

Introduce the cpu_virtio_is_big_endian() generic helper to avoid
calling CPUClass internal virtio_is_big_endian() one.

Similarly to commit bf7663c4bd8 ("cpu: introduce
CPUClass::virtio_is_big_endian()"), we keep 'virtio' in the method
name to hint this handler shouldn't be called anywhere but from the
virtio code.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210517105140.1062037-8-f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

hw/core/cpu-common.c

@@ -185,11 +185,6 @@ static int cpu_common_gdb_write_register(CPUState *cpu, uint8_t *buf, int reg)
     return 0;
 }
 
-static bool cpu_common_virtio_is_big_endian(CPUState *cpu)
-{
-    return target_words_bigendian();
-}
-
 void cpu_dump_state(CPUState *cpu, FILE *f, int flags)
 {
     CPUClass *cc = CPU_GET_CLASS(cpu);
@@ -388,7 +383,6 @@ static void cpu_class_init(ObjectClass *klass, void *data)
     k->write_elf64_note = cpu_common_write_elf64_note;
     k->gdb_read_register = cpu_common_gdb_read_register;
     k->gdb_write_register = cpu_common_gdb_write_register;
-    k->virtio_is_big_endian = cpu_common_virtio_is_big_endian;
     set_bit(DEVICE_CATEGORY_CPU, dc->categories);
     dc->realize = cpu_common_realizefn;
     dc->unrealize = cpu_common_unrealizefn;

hw/core/cpu-sysemu.c

@@ -54,6 +54,16 @@ int cpu_asidx_from_attrs(CPUState *cpu, MemTxAttrs attrs)
     return ret;
 }
 
+bool cpu_virtio_is_big_endian(CPUState *cpu)
+{
+    CPUClass *cc = CPU_GET_CLASS(cpu);
+
+    if (cc->virtio_is_big_endian) {
+        return cc->virtio_is_big_endian(cpu);
+    }
+    return target_words_bigendian();
+}
+
 GuestPanicInformation *cpu_get_crash_info(CPUState *cpu)
 {
     CPUClass *cc = CPU_GET_CLASS(cpu);

hw/virtio/virtio.c

@@ -1972,9 +1972,7 @@ static enum virtio_device_endian virtio_default_endian(void)
 
 static enum virtio_device_endian virtio_current_cpu_endian(void)
 {
-    CPUClass *cc = CPU_GET_CLASS(current_cpu);
-
-    if (cc->virtio_is_big_endian(current_cpu)) {
+    if (cpu_virtio_is_big_endian(current_cpu)) {
         return VIRTIO_DEVICE_ENDIAN_BIG;
     } else {
         return VIRTIO_DEVICE_ENDIAN_LITTLE;

include/hw/core/cpu.h

@@ -610,6 +610,15 @@ hwaddr cpu_get_phys_page_debug(CPUState *cpu, vaddr addr);
  */
 int cpu_asidx_from_attrs(CPUState *cpu, MemTxAttrs attrs);
 
+/**
+ * cpu_virtio_is_big_endian:
+ * @cpu: CPU
+
+ * Returns %true if a CPU which supports runtime configurable endianness
+ * is currently big-endian.
+ */
+bool cpu_virtio_is_big_endian(CPUState *cpu);
+
 #endif /* CONFIG_USER_ONLY */
 
 /**