Re: [PATCH] failover: unregister ram on unplug

[Igor Mammedov]

On Tue, 20 Jul 2021 20:16:44 +0200
Laurent Vivier <lvivier@redhat.com> wrote:

> This simple change allows to test failover with a simulated device
> like e1000e rather than a vfio device.
> 
> This is interesting to developers that want to test failover on
> a system with no vfio device. Moreover it simplifies host networking
> configuration as we can use the same bridge for virtio-net and
> the other failover networking device.
> 
> Without this change the migration of a system configured with failover
> fails with:
> 
>   Unknown ramblock "0000:00:01.1:00.0/e1000e.rom", cannot accept migration
>   error while loading state for instance 0x0 of device 'ram'
>   load of migration failed: Invalid argument
> 
> Signed-off-by: Laurent Vivier <lvivier@redhat.com>

Reviewed-by: Igor Mammedov <imammedo@redhat.com>

> ---
>  hw/net/virtio-net.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
> index 16d20cdee52a..8f7735bad4f2 100644
> --- a/hw/net/virtio-net.c
> +++ b/hw/net/virtio-net.c
> @@ -3256,6 +3256,9 @@ static void 
> virtio_net_handle_migration_primary(VirtIONet *n, MigrationState *s)
>      if (migration_in_setup(s) && !should_be_hidden) {
>          if (failover_unplug_primary(n, dev)) {
>              vmstate_unregister(VMSTATE_IF(dev), qdev_get_vmsd(dev), dev);
> +            if (PCI_DEVICE(dev)->has_rom) {
> +                vmstate_unregister_ram(&PCI_DEVICE(dev)->rom , dev);
> +            }
>              qapi_event_send_unplug_primary(dev->id);
>              qatomic_set(&n->failover_primary_hidden, true);
>          } else {