Support the virtio RO flag, so that read-only devices
will successfully initialize now. Also do not allow
issuing any writes on a read-only device, so we don't
flood it with requests that are to fail.
Change-Id: I6b77f2338e4478a9abf2d5286344f6412d79284c
Signed-off-by: Dariusz Stojaczyk <dariuszx.stojaczyk@intel.com>
Reviewed-on: https://review.gerrithub.io/393461
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Daniel Verkamp <daniel.verkamp@intel.com>
Reviewed-by: Changpeng Liu <changpeng.liu@intel.com>