[DF-5402] probing data-carrying SG_* ioctls on /dev/sg0
    SG_GET_VERSION_NUM: rc=0 errno=0 version=30125 (OK)
    SG_GET_RESERVED_SIZE: rc=0 errno=0 size=32768
[DF-5402] ioctls work on this kernel
[sanity] SG_IO INQUIRY with a REAL 512-byte buffer
    SG_IO dxferp=0x402560 dxfer_len=512 alloclen=0xff ... rc=0 errno=0 host=0 drv=0
    inquiry data: � QEMU    QEMU DVD -ROM