On 14/06/2017 15:29, Greg Kurz wrote:
> The ICPState objects are currently registered to vmstate as qdev objects.
> Their instance ids are hence computed automatically in the migration code,
> and thus depends on the order the CPU cores were plugged.
>
> If the destination had its CPU cores plugged in a different order than the
> source, then ICPState objects will have different instance_ids and load
> the wrong state.
>
> Since CPU objects have a reliable cpu_index which is already used as
> instance_id in vmstate, let's use it for ICPState as well.
>
> Please note that this doesn't break migration. Older machine types used to
> allocate and realize all ICPState objects at machine init time, for the whole
> lifetime of the machine. The qdev instance ids are thus 0,1,2... nr_servers
> and happen to map to the vCPU indexes.
>
> Signed-off-by: Greg Kurz <gr...@kaod.org>
Reviewed-by: Laurent Vivier <lviv...@redhat.com>
CC: dgilbert
> ---
> v5: - explain why it doesn't break migration in the changelog
> ---
> hw/intc/xics.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/hw/intc/xics.c b/hw/intc/xics.c
> index 7ccfb53c55a0..faa5c631f655 100644
> --- a/hw/intc/xics.c
> +++ b/hw/intc/xics.c
> @@ -344,10 +344,14 @@ static void icp_realize(DeviceState *dev, Error **errp)
> }
>
> qemu_register_reset(icp_reset, dev);
> + vmstate_register(NULL, icp->cs->cpu_index, &vmstate_icp_server, icp);
> }
>
> static void icp_unrealize(DeviceState *dev, Error **errp)
> {
> + ICPState *icp = ICP(dev);
> +
> + vmstate_unregister(NULL, &vmstate_icp_server, icp);
> qemu_unregister_reset(icp_reset, dev);
> }
>
> @@ -355,7 +359,6 @@ static void icp_class_init(ObjectClass *klass, void *data)
> {
> DeviceClass *dc = DEVICE_CLASS(klass);
>
> - dc->vmsd = &vmstate_icp_server;
> dc->realize = icp_realize;
> dc->unrealize = icp_unrealize;
> }
>
