Make BlockExportType.iothread an alternate between a single-thread
variant 'str' and a multi-threading variant '[str]'.
In contrast to the single-thread setting, the multi-threading setting
will not change the BDS's context (and so is incompatible with the
fixed-iothread setting), but instead just pass a list to the export
driver, with which it can do whatever it wants.
Currently no export driver supports multi-threading, so they all return
an error when receiving such a list.
Suggested-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Hanna Czenczek <hreitz@redhat.com>
Message-ID: <20260309150856.26800-21-hreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>