serial: Fix double migration data
After c9808d60281 we have both an object representing the serial-isa
device and a separate object representing the underlying common serial
uart. Both of these have vmsd's associated with them and thus the
migration stream ends up with two copies of the migration data - the
serial-isa includes the vmstate of the core serial. Besides
being wrong, it breaks backwards migration compatibility.
Fix this by removing the dc->vmsd from the core device, so it only
gets migrated by any parent devices including it.
Add a vmstate_serial_mm so that any device that uses serial_mm_init
rather than creating a device still gets migrated.
(That doesn't fix backwards migration for serial_mm_init users,
but does seem to work forwards for ppce500).
Fixes: c9808d60281 ('serial: realize the serial device')
Buglink: https://bugs.launchpad.net/qemu/+bug/1869426
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20200330164712.198282-1-dgilbert@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/hw/char/serial.c b/hw/char/serial.c
index 2ab8b69..c822a9a 100644
--- a/hw/char/serial.c
+++ b/hw/char/serial.c
@@ -1043,7 +1043,6 @@
dc->user_creatable = false;
dc->realize = serial_realize;
dc->unrealize = serial_unrealize;
- dc->vmsd = &vmstate_serial;
device_class_set_props(dc, serial_properties);
}
@@ -1113,6 +1112,16 @@
sysbus_init_irq(SYS_BUS_DEVICE(smm), &smm->serial.irq);
}
+static const VMStateDescription vmstate_serial_mm = {
+ .name = "serial",
+ .version_id = 3,
+ .minimum_version_id = 2,
+ .fields = (VMStateField[]) {
+ VMSTATE_STRUCT(serial, SerialMM, 0, vmstate_serial, SerialState),
+ VMSTATE_END_OF_LIST()
+ }
+};
+
SerialMM *serial_mm_init(MemoryRegion *address_space,
hwaddr base, int regshift,
qemu_irq irq, int baudbase,
@@ -1162,6 +1171,7 @@
device_class_set_props(dc, serial_mm_properties);
dc->realize = serial_mm_realize;
+ dc->vmsd = &vmstate_serial_mm;
}
static const TypeInfo serial_mm_info = {
