Re: [PATCH 07/13] RFC migration: icp/server is a mess

[Greg Kurz <groug@kaod.org>]

On Thu, 19 Oct 2023 21:08:25 +0200
Juan Quintela <quintela@redhat.com> wrote:

> Current code does:
> - register pre_2_10_vmstate_dummy_icp with "icp/server" and instance
>   dependinfg on cpu number
> - for newer machines, it register vmstate_icp with "icp/server" name
>   and instance 0
> - now it unregisters "icp/server" for the 1st instance.
> 
> This is wrong at many levels:
> - we shouldn't have two VMSTATEDescriptions with the same name
> - In case this is the only solution that we can came with, it needs to
>   be:
>   * register pre_2_10_vmstate_dummy_icp
>   * unregister pre_2_10_vmstate_dummy_icp
>   * register real vmstate_icp
> 
> As the initialization of this machine is already complex enough, I
> need help from PPC maintainers to fix this.
> 
> Volunteers?
> 
> CC: Cedric Le Goater <clg@kaod.org>
> CC: Daniel Henrique Barboza <danielhb413@gmail.com>
> CC: David Gibson <david@gibson.dropbear.id.au>
> CC: Greg Kurz <groug@kaod.org>
> 
> Signed-off-by: Juan Quintela <quintela@redhat.com>
> ---
>  hw/ppc/spapr.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> index cb840676d3..8531d13492 100644
> --- a/hw/ppc/spapr.c
> +++ b/hw/ppc/spapr.c
> @@ -143,7 +143,12 @@ static bool pre_2_10_vmstate_dummy_icp_needed(void *opaque)
>  }
>  
>  static const VMStateDescription pre_2_10_vmstate_dummy_icp = {
> -    .name = "icp/server",
> +    /*
> +     * Hack ahead.  We can't have two devices with the same name and
> +     * instance id.  So I rename this to pass make check.
> +     * Real help from people who knows the hardware is needed.
> +     */
> +    .name = "pre-2.10-icp/server",
>      .version_id = 1,
>      .minimum_version_id = 1,
>      .needed = pre_2_10_vmstate_dummy_icp_needed,

I guess this fix is acceptable as well and a lot simpler than
reverting the hack actually. Outcome is the same : drop
compat with pseries-2.9 and older.

Reviewed-by: Greg Kurz <groug@kaod.org>

-- 
Greg