This implements a VDUSE block backends based on
the libvduse library. We can use it to export the BDSs
for both VM and container (host) usage.
The new command-line syntax is:
$ qemu-storage-daemon \
--blockdev file,node-name=drive0,filename=test.img \
--export vduse-blk,node-name=drive0,id=vduse-export0,writable=on
After the qemu-storage-daemon started, we need to use
the "vdpa" command to attach the device to vDPA bus:
$ vdpa dev add name vduse-export0 mgmtdev vduse
Also the device must be removed via the "vdpa" command
before we stop the qemu-storage-daemon.
Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20220523084611.91-7-xieyongji@bytedance.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>