[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [PATCH 2/2] hw/char/serial: Allow migration of the I/O serial device
From: |
Peter Maydell |
Subject: |
Re: [PATCH 2/2] hw/char/serial: Allow migration of the I/O serial device |
Date: |
Fri, 10 Jul 2020 09:34:59 +0100 |
On Tue, 7 Jul 2020 at 11:40, Paolo Bonzini <pbonzini@redhat.com> wrote:
>
> On 03/07/20 20:58, Philippe Mathieu-Daudé wrote:
> > The serial device mapped on the I/O bus hold a migratable
> > SerialState. Keep the same version range from SerialState:
> >
> > 837 const VMStateDescription vmstate_serial = {
> > 838 .name = "serial",
> > 839 .version_id = 3,
> > 840 .minimum_version_id = 2,
> >
> > Fixes: 10315a7089 ("serial: make SerialIO a sysbus device")
> > Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> > ---
> > 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 9eebcb27e7..c167b584fb 100644
> > --- a/hw/char/serial.c
> > +++ b/hw/char/serial.c
> > @@ -1002,12 +1002,22 @@ static void serial_io_realize(DeviceState *dev,
> > Error **errp)
> > sysbus_init_irq(SYS_BUS_DEVICE(sio), &s->irq);
> > }
> >
> > +static const VMStateDescription vmstate_serial_io = {
> > + .name = "serial",
> > + .version_id = 3,
> > + .minimum_version_id = 2,
> > + .fields = (VMStateField[]) {
> > + VMSTATE_STRUCT(serial, SerialIO, 0, vmstate_serial, SerialState),
> > + VMSTATE_END_OF_LIST()
> > + }
> > +};
> > +
> > static void serial_io_class_init(ObjectClass *klass, void* data)
> > {
> > DeviceClass *dc = DEVICE_CLASS(klass);
> >
> > dc->realize = serial_io_realize;
> > - /* No dc->vmsd: class has no migratable state */
> > + dc->vmsd = &vmstate_serial_io;
> > }
> >
> > static void serial_io_instance_init(Object *o)
> >
>
> Is there any difference between SerialMM and SerialIO at this point?
SerialIO insists on 1-byte wide accesses; SerialMM allows the
creator of the device to specify the spacing between registers
and the endianness. So I suppose SerialIO is kind of a subset of
SerialMM.
It looks like the only user of TYPE_SERIAL_IO is hw/mips/mipssim.c,
Adding the migration state here would be a forwards migration
compat break anyway, so I think we could just change that
machine to use TYPE_SERIAL_MM and then delete TYPE_SERIAL_IO ?
thanks
-- PMM