The encryption offered by Nova (via `live_migration_tunnelled`, i.e.
"tunnelling via libvirtd") today secures only two migration streams:
guest RAM and device state; but it does _not_ encrypt the NBD (Network
Block Device) transport—which is used to migrate disks that are on
non-shared storage setup (also called: "block migration"). Further, the
"tunnelling via libvirtd" has a huge performance penalty and latency,
because it burns more CPU and memory bandwidth due to increased number
of data copies on both source and destination hosts.
To solve this existing limitation, introduce a new config option
`live_migration_with_native_tls`, which will take advantage of "native
TLS" (i.e. TLS built into QEMU, and relevant support in libvirt). The
native TLS transport will encrypt all migration streams, *including*
disks that are not on shared storage — all of this without incurring the
limitations of the "tunnelled via libvirtd" transport.
Closes-Bug: #1798796
Blueprint: support-qemu-native-tls-for-live-migration
Change-Id: I78f5fef41b6fbf118880cc8aa4036d904626b342
Signed-off-by: Kashyap Chamarthy <kchamart@redhat.com>