hw/i386/pc_piix: Mark the machine types from version 1.4 to 1.7 as deprecated

The list of machine types grows larger and larger each release ... and
it is unlikely that many people still use the very old ones for live
migration. QEMU v1.7 has been released more than 8 years ago, so most
people should have updated their machines to a newer version in those
8 years at least once. Thus let's mark the very old 1.x machine types
as deprecated now.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20220117191639.278497-1-thuth@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

docs/about/deprecated.rst

@@ -324,6 +324,14 @@ machine is hardly emulated at all (e.g. neither the LCD nor the USB part had
 been implemented), so there is not much value added by this board. Use the
 ``ref405ep`` machine instead.
 
+``pc-i440fx-1.4`` up to ``pc-i440fx-1.7`` (since 7.0)
+'''''''''''''''''''''''''''''''''''''''''''''''''''''
+
+These old machine types are quite neglected nowadays and thus might have
+various pitfalls with regards to live migration. Use a newer machine type
+instead.
+
+
 Backend options
 ---------------
 

hw/i386/pc_piix.c

@@ -757,6 +757,7 @@ static void pc_i440fx_1_7_machine_options(MachineClass *m)
     m->hw_version = "1.7.0";
     m->default_machine_opts = NULL;
     m->option_rom_has_mr = true;
+    m->deprecation_reason = "old and unattended - use a newer version instead";
     compat_props_add(m->compat_props, pc_compat_1_7, pc_compat_1_7_len);
     pcmc->smbios_defaults = false;
     pcmc->gigabyte_align = false;