Re: [libvirt] [PATCH V4] libxl: add migration support

This patch adds initial migration support to the libxl driver, using the VIR_DRV_FEATURE_MIGRATION_PARAMS family of migration functions. Signed-off-by: Jim Fehlig <jfehlig(a)suse.com&gt; --- V3 here https://www.redhat.com/archives/libvir-list/2014-April/msg00968.html In V4: - Code cleanup - Improved error handling Although this patch has been floating around for a long time, not sure if it is 1.2.4 material since it brings a new feature to the libxl driver.

+/* + * For future extensibility, a simple messaging protocol used to send migration + * data between libxl hosts. The message is encapsulated in json and currently + * includes the following entries: + * + * {"libvirt-libxl-mig-msg" : + * {"version" : $ver}, + * {"state" : $state}, + * {"status" : $status} + * } + * + * Possible $state values are "negotiate-version", "send-binary-data", + * "sending-binary-data", "received-binary-data", "done", and "error". + * + * Migration between source and destination libxl hosts is performed with the + * following message exchange: + * + * - src->dst: connect + * - dst->src: state="negotiate-version", version=LIBXL_MIGRATION_PROTO_VERSION + * - src->dst: state-"negotiate-version", + * version=min(dst ver, LIBXL_MIGRATION_PROTO_VERSION) + * - dst->src: state="send-binary-data", version=negotiated_version + * - src->dst: state="sending-binary-data", version=negotiated_version + * _ src->dst: binary migration data + * - dst->src: state="received-binary-data", version=negotiated_version + * - src->dst: state="done", version=negotiated_version + * + */