From: "Dr. David Alan Gilbert" <dgilb...@redhat.com> 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 <dgilb...@redhat.com> Message-Id: <20200330164712.198282-1-dgilb...@redhat.com> Reviewed-by: Marc-André Lureau <marcandre.lur...@redhat.com> Signed-off-by: Paolo Bonzini <pbonz...@redhat.com> --- hw/char/serial.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/hw/char/serial.c b/hw/char/serial.c index 2ab8b69e03..c822a9ae6c 100644 --- a/hw/char/serial.c +++ b/hw/char/serial.c @@ -1043,7 +1043,6 @@ static void serial_class_init(ObjectClass *klass, void* data) 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 @@ static void serial_mm_realize(DeviceState *dev, Error **errp) 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 @@ static void serial_mm_class_init(ObjectClass *oc, void *data) device_class_set_props(dc, serial_mm_properties); dc->realize = serial_mm_realize; + dc->vmsd = &vmstate_serial_mm; } static const TypeInfo serial_mm_info = { -- 2.18.2