hw/display: Compile vga.c as target-independent code

The target checks here are only during the initialization, so they
are not performance critical. We can switch these to runtime checks
to avoid that we have to compile this file multiple times during
the build, and make the code ready for an universal build one day.

Message-Id: <20230412163501.36770-1-thuth@redhat.com>
Reviewed-by: Fabiano Rosas <farosas@suse.de>
Signed-off-by: Thomas Huth <thuth@redhat.com>

hw/display/meson.build

@@ -36,7 +36,7 @@ softmmu_ss.add(when: 'CONFIG_CG3', if_true: files('cg3.c'))
 softmmu_ss.add(when: 'CONFIG_MACFB', if_true: files('macfb.c'))
 softmmu_ss.add(when: 'CONFIG_NEXTCUBE', if_true: files('next-fb.c'))
 
-specific_ss.add(when: 'CONFIG_VGA', if_true: files('vga.c'))
+softmmu_ss.add(when: 'CONFIG_VGA', if_true: files('vga.c'))
 
 if (config_all_devices.has_key('CONFIG_VGA_CIRRUS') or
     config_all_devices.has_key('CONFIG_VGA_PCI') or

hw/display/vga.c

@@ -26,7 +26,9 @@
 #include "qemu/units.h"
 #include "sysemu/reset.h"
 #include "qapi/error.h"
+#include "hw/core/cpu.h"
 #include "hw/display/vga.h"
+#include "hw/i386/x86.h"
 #include "hw/pci/pci.h"
 #include "vga_int.h"
 #include "vga_regs.h"
@@ -2244,11 +2246,8 @@ bool vga_common_init(VGACommonState *s, Object *obj, Error **errp)
      * into a device attribute set by the machine/platform to remove
      * all target endian dependencies from this file.
      */
-#if TARGET_BIG_ENDIAN
-    s->default_endian_fb = true;
-#else
-    s->default_endian_fb = false;
-#endif
+    s->default_endian_fb = target_words_bigendian();
+
     vga_dirty_log_start(s);
 
     return true;
@@ -2263,11 +2262,15 @@ static const MemoryRegionPortio vga_portio_list[] = {
     PORTIO_END_OF_LIST(),
 };
 
-static const MemoryRegionPortio vbe_portio_list[] = {
+static const MemoryRegionPortio vbe_portio_list_x86[] = {
     { 0, 1, 2, .read = vbe_ioport_read_index, .write = vbe_ioport_write_index },
-# ifdef TARGET_I386
     { 1, 1, 2, .read = vbe_ioport_read_data, .write = vbe_ioport_write_data },
-# endif
+    { 2, 1, 2, .read = vbe_ioport_read_data, .write = vbe_ioport_write_data },
+    PORTIO_END_OF_LIST(),
+};
+
+static const MemoryRegionPortio vbe_portio_list_no_x86[] = {
+    { 0, 1, 2, .read = vbe_ioport_read_index, .write = vbe_ioport_write_index },
     { 2, 1, 2, .read = vbe_ioport_read_data, .write = vbe_ioport_write_data },
     PORTIO_END_OF_LIST(),
 };
@@ -2278,9 +2281,19 @@ MemoryRegion *vga_init_io(VGACommonState *s, Object *obj,
                           const MemoryRegionPortio **vbe_ports)
 {
     MemoryRegion *vga_mem;
+    MachineState *ms = MACHINE(qdev_get_machine());
+
+    /*
+     * We unfortunately need two VBE lists since non-x86 machines might
+     * not be able to do 16-bit accesses at unaligned addresses (0x1cf)
+     */
+    if (object_dynamic_cast(OBJECT(ms), TYPE_X86_MACHINE)) {
+        *vbe_ports = vbe_portio_list_x86;
+    } else {
+        *vbe_ports = vbe_portio_list_no_x86;
+    }
 
     *vga_ports = vga_portio_list;
-    *vbe_ports = vbe_portio_list;
 
     vga_mem = g_malloc(sizeof(*vga_mem));
     memory_region_init_io(vga_mem, obj, &vga_mem_ops, s,