Re: [Qemu-devel] [PATCH v2 06/12] boards.h: Ignore migration for SMBus devices on older machines

["Dr. David Alan Gilbert" <dgilbert@redhat.com>]

* Corey Minyard (minyard@acm.org) wrote:
> On 11/26/18 11:23 AM, Dr. David Alan Gilbert wrote:
> > * minyard@acm.org (minyard@acm.org) wrote:
> > > From: Corey Minyard <cminyard@mvista.com>
> > > 
> > > Migration capability is being added for pm_smbus and SMBus devices.
> > > This change will allow backwards compatibility to be kept when
> > > migrating back to an old qemu version.  Add a bool to the machine
> > > class tho keep smbus migration from happening.  Future changes
> > > will use this.
> > So this is also going to have to be in the 3.0 and 3.1 machine options
> > and maybe some other architectures?
> 
> I'm not sure why it would need to be in both the 3.0 and 3.1 machine
> options.
> If this goes in, I'm assuming it's for 3.1 and it should only need to be
> there.
> That's if it's too late for 3.0.

You're out by 1-2 releases;  3.0 shipped in August, 3.1 is in freeze at
the moment (hence you've missed it unless some part of this is
critical); so this will go in during the 4.0 release.

> The pm_smbus device is also used by mips fulong.  From what I can tell, that
> machine doesn't have any concept of backwards compatibility, so it seemed
> save to no worry about it there.  If it weren't for that, this bool could go
> into the

Yeh that's fine.

What about the eeprom's are they used more widely?

Dave

> PC specific structure.
> 
> Thanks,
> 
> -corey
> 
> > Dave
> > 
> > > Signed-off-by: Corey Minyard <cminyard@mvista.com>
> > > Cc: Eduardo Habkost <ehabkost@redhat.com>
> > > Cc: Marcel Apfelbaum <marcel.apfelbaum@gmail.com>
> > > ---
> > >   hw/i386/pc_piix.c   | 1 +
> > >   hw/i386/pc_q35.c    | 1 +
> > >   include/hw/boards.h | 1 +
> > >   3 files changed, 3 insertions(+)
> > > 
> > > diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
> > > index cb28227cc3..3d1ccb1af1 100644
> > > --- a/hw/i386/pc_piix.c
> > > +++ b/hw/i386/pc_piix.c
> > > @@ -443,6 +443,7 @@ static void pc_i440fx_2_12_machine_options(MachineClass *m)
> > >       pc_i440fx_3_0_machine_options(m);
> > >       m->is_default = 0;
> > >       m->alias = NULL;
> > > +    m->smbus_no_migration_support = true;
> > >       SET_MACHINE_COMPAT(m, PC_COMPAT_2_12);
> > >   }
> > > diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
> > > index 90e88c9b28..0c6fca6a40 100644
> > > --- a/hw/i386/pc_q35.c
> > > +++ b/hw/i386/pc_q35.c
> > > @@ -324,6 +324,7 @@ static void pc_q35_2_12_machine_options(MachineClass *m)
> > >   {
> > >       pc_q35_3_0_machine_options(m);
> > >       m->alias = NULL;
> > > +    m->smbus_no_migration_support = true;
> > >       SET_MACHINE_COMPAT(m, PC_COMPAT_2_12);
> > >   }
> > > diff --git a/include/hw/boards.h b/include/hw/boards.h
> > > index f82f28468b..65314fbe2a 100644
> > > --- a/include/hw/boards.h
> > > +++ b/include/hw/boards.h
> > > @@ -207,6 +207,7 @@ struct MachineClass {
> > >       void (*numa_auto_assign_ram)(MachineClass *mc, NodeInfo *nodes,
> > >                                    int nb_nodes, ram_addr_t size);
> > >       bool ignore_boot_device_suffixes;
> > > +    bool smbus_no_migration_support;
> > >       HotplugHandler *(*get_hotplug_handler)(MachineState *machine,
> > >                                              DeviceState *dev);
> > > -- 
> > > 2.17.1
> > > 
> > --
> > Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
> 
> 
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK