On 8/28/23 17:18, Avihai Horon wrote:
> Add vfio_migratable_devices_num() function, which returns the number of
> VFIO devices that are using VFIO migration, and use it in
> vfio_multiple_devices_migration_is_supported().
>
> This is done in preparation for next patches which will block VFIO
> migration with postcopy migration or background snapshot, as they are
> not compatible together.
>
> Signed-off-by: Avihai Horon <avihaih@nvidia.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Thanks,
C.
> ---
> hw/vfio/common.c | 22 ++++++++++++++++++----
> 1 file changed, 18 insertions(+), 4 deletions(-)
>
> diff --git a/hw/vfio/common.c b/hw/vfio/common.c
> index 237101d038..57a76feab1 100644
> --- a/hw/vfio/common.c
> +++ b/hw/vfio/common.c
> @@ -363,6 +363,23 @@ bool vfio_mig_active(void)
>
> static Error *multiple_devices_migration_blocker;
>
> +static unsigned int vfio_migratable_devices_num(void)
> +{
> + VFIOGroup *group;
> + VFIODevice *vbasedev;
> + unsigned int device_num = 0;
> +
> + QLIST_FOREACH(group, &vfio_group_list, next) {
> + QLIST_FOREACH(vbasedev, &group->device_list, next) {
> + if (vbasedev->migration) {
> + device_num++;
> + }
> + }
> + }
> +
> + return device_num;
> +}
> +
> /*
> * Multiple devices migration is allowed only if all devices support P2P
> * migration. Single device migration is allowed regardless of P2P migration
> @@ -372,14 +389,11 @@ static bool vfio_multiple_devices_migration_is_supported(void)
> {
> VFIOGroup *group;
> VFIODevice *vbasedev;
> - unsigned int device_num = 0;
> bool all_support_p2p = true;
>
> QLIST_FOREACH(group, &vfio_group_list, next) {
> QLIST_FOREACH(vbasedev, &group->device_list, next) {
> if (vbasedev->migration) {
> - device_num++;
> -
> if (!(vbasedev->migration->mig_flags & VFIO_MIGRATION_P2P)) {
> all_support_p2p = false;
> }
> @@ -387,7 +401,7 @@ static bool vfio_multiple_devices_migration_is_supported(void)
> }
> }
>
> - return all_support_p2p || device_num <= 1;
> + return all_support_p2p || vfio_migratable_devices_num() <= 1;
> }
>
> int vfio_block_multiple_devices_migration(VFIODevice *vbasedev, Error **errp)