[RFC PATCH v5 21/21] hw/arm/virt: Get default CPU type at runtime

["Philippe Mathieu-Daudé" <philmd@linaro.org>]

Prefer MachineClass::get_default_cpu_type() over
MachineClass::default_cpu_type to get CPU type,
evaluating TCG availability at runtime calling
tcg_enabled().

It's worth noting that this is a behavior change:

- Previously only

  ./configure --disable-tcg --enable-kvm
  ./qemu-system-aarch64 -M virt -accel kvm

  would default to 'max' and

  ./configure --enable-tcg --enable-kvm
  ./qemu-system-aarch64 -M virt -accel kvm

  would default to 'cortex-a15'.

- Afterward, -accel kvm will always default to 'max'.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
---
 hw/arm/virt.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index 566afa4c978..b59cc90bd36 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -3127,6 +3127,12 @@ static int virt_hvf_get_physical_address_range(MachineState *ms)
     return requested_ipa_size;
 }
 
+static const char *virt_get_default_cpu_type(const MachineState *ms)
+{
+    return tcg_enabled() ? ARM_CPU_TYPE_NAME("cortex-a15")
+                         : ARM_CPU_TYPE_NAME("max");
+}
+
 static GPtrArray *virt_get_valid_cpu_types(const MachineState *ms)
 {
     GPtrArray *vct = g_ptr_array_new_with_free_func(g_free);
@@ -3184,11 +3190,7 @@ static void virt_machine_class_init(ObjectClass *oc, const void *data)
     mc->minimum_page_bits = 12;
     mc->possible_cpu_arch_ids = virt_possible_cpu_arch_ids;
     mc->cpu_index_to_instance_props = virt_cpu_index_to_props;
-#ifdef CONFIG_TCG
-    mc->default_cpu_type = ARM_CPU_TYPE_NAME("cortex-a15");
-#else
-    mc->default_cpu_type = ARM_CPU_TYPE_NAME("max");
-#endif
+    mc->get_default_cpu_type = virt_get_default_cpu_type;
     mc->get_valid_cpu_types = virt_get_valid_cpu_types;
     mc->get_default_cpu_node_id = virt_get_default_cpu_node_id;
     mc->kvm_type = virt_kvm_type;
-- 
2.47.1