On 12/09/14 00:45, Arianna Avanzini wrote: > On Fri, Aug 22, 2014 at 02:15:58PM +0100, David Vrabel wrote: >> What >> behaviour do we want when a domain is migrated to a host with different >> storage? >> > > This first patchset does not include support to migrate a multi-queue-capable > domU to a host with different storage. The second version, which I am posting > now, includes it. The behavior I have implemented as of now lets the frontend > use the same number of rings, if the backend is still multi-queue-capable > after the migration, otherwise it exposes one only ring.
It would be preferable to allow the number of queues to be renegotiated on reconnection. This is what netfront does (but netfront is easier since it can safely discard any queued packets but blkfront cannot). If the number of queues is fixed then a maximum number of queues must be part of the ABI specification. i.e., all backends must support at least N queues (even if this is more than its preferred number). The backend can still hint what its preferred number of queues is, but this can never be more than the maximum. David -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
