vga: add default display to machine class

This allows machine classes to specify which display device they want
as default.  If unspecified the current behavior (try cirrus, failing
that try stdvga, failing that use no display) will be used.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

3 files changed, 7 insertions, 1 deletions

diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index dc2fe6a666..1205db83bc 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -1526,6 +1526,7 @@ static void pc_generic_machine_class_init(ObjectClass *oc, void *data)
     mc->is_default = qm->is_default;
     mc->default_machine_opts = qm->default_machine_opts;
     mc->default_boot_order = qm->default_boot_order;
+    mc->default_display = qm->default_display;
     mc->compat_props = qm->compat_props;
     mc->hw_version = qm->hw_version;
 }
diff --git a/include/hw/boards.h b/include/hw/boards.h
index 4429a1e3a2..99a172d652 100644
--- a/include/hw/boards.h
+++ b/include/hw/boards.h
@@ -40,6 +40,7 @@ struct QEMUMachine {
     int is_default;
     const char *default_machine_opts;
     const char *default_boot_order;
+    const char *default_display;
     GlobalProperty *compat_props;
     const char *hw_version;
 };
@@ -100,6 +101,7 @@ struct MachineClass {
     int is_default;
     const char *default_machine_opts;
     const char *default_boot_order;
+    const char *default_display;
     GlobalProperty *compat_props;
     const char *hw_version;
 
diff --git a/vl.c b/vl.c
index 35c1333eee..2c4ea510f1 100644
--- a/vl.c
+++ b/vl.c
@@ -1444,6 +1444,7 @@ static void machine_class_init(ObjectClass *oc, void *data)
     mc->is_default = qm->is_default;
     mc->default_machine_opts = qm->default_machine_opts;
     mc->default_boot_order = qm->default_boot_order;
+    mc->default_display = qm->default_display;
     mc->compat_props = qm->compat_props;
     mc->hw_version = qm->hw_version;
 }
@@ -4223,7 +4224,9 @@ int main(int argc, char **argv, char **envp)
 
     /* If no default VGA is requested, the default is "none".  */
     if (default_vga) {
-        if (cirrus_vga_available()) {
+        if (machine_class->default_display) {
+            vga_model = machine_class->default_display;
+        } else if (cirrus_vga_available()) {
             vga_model = "cirrus";
         } else if (vga_available()) {
             vga_model = "std";