block: Add backend_defaults property
commit12a521b56d0538ca0363dd79db8f359cef40da69
authorAkihiko Odaki <akihiko.odaki@gmail.com>
Mon, 5 Jul 2021 13:04:57 +0000 (5 22:04 +0900)
committerStefan Hajnoczi <stefanha@redhat.com>
Tue, 6 Jul 2021 13:28:55 +0000 (6 14:28 +0100)
tree88d59a52c8e2525549b78b0069810c0650f96942
parent0dfc7af2b287323dde0725c04f5765e0e508d9fd
block: Add backend_defaults property

backend_defaults property allow users to control if default block
properties should be decided with backend information.

If it is off, any backend information will be discarded, which is
suitable if you plan to perform live migration to a different disk backend.

If it is on, a block device may utilize backend information more
aggressively.

By default, it is auto, which uses backend information for block
sizes and ignores the others, which is consistent with the older
versions.

Signed-off-by: Akihiko Odaki <akihiko.odaki@gmail.com>
Message-id: 20210705130458.97642-2-akihiko.odaki@gmail.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
hw/block/block.c
include/hw/block/block.h
tests/qemu-iotests/172.out