Re: [RFC PATCH v1 1/1] migration: Disable postcopy + multifd migration

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

* Leonardo Bras (leobras@redhat.com) wrote:
> Since the introduction of multifd, it's possible to perform a multifd
> migration and finish it using postcopy.
> 
> A bug introduced by yank (fixed on cfc3bcf373) was previously preventing
> a successful use of this migration scenario, and now it should be
> working on most cases.
> 
> But since there is not enough testing/support nor any reported users for
> this scenario, we should disable this combination before it may cause any
> problems for users.
> 
> Suggested-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> Signed-off-by: Leonardo Bras <leobras@redhat.com>

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

> ---
>  migration/migration.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/migration/migration.c b/migration/migration.c
> index ae2025d9d8..c601964b0e 100644
> --- a/migration/migration.c
> +++ b/migration/migration.c
> @@ -1356,6 +1356,11 @@ static bool migrate_caps_check(bool *cap_list,
>              error_setg(errp, "Postcopy is not compatible with ignore-shared");
>              return false;
>          }
> +
> +        if (cap_list[MIGRATION_CAPABILITY_MULTIFD]) {
> +            error_setg(errp, "Postcopy is not yet compatible with multifd");
> +            return false;
> +        }
>      }
>  
>      if (cap_list[MIGRATION_CAPABILITY_BACKGROUND_SNAPSHOT]) {
> -- 
> 2.40.0
> 
-- 
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK