system/s390x/vfio-ccw.rst

1 Subchannel passthrough via vfio-ccw
4 vfio-ccw (based upon the mediated vfio device infrastructure) allows to
8 Note that while vfio-ccw should work with most non-QDIO devices, only ECKD
12 ---------------------
20   7e270a25-e163-4922-af60-757fc8ed48c6
30    [root@host ~]# driverctl -b css set-override 0.0.0313 vfio_ccw
31    [root@host ~]# mdevctl define -u 7e270a25-e163-4922-af60-757fc8ed48c6 \
32                   -p 0.0.0313 -t vfio_ccw-io -a
43   I/O subchannel driver and bind it to the vfio-ccw driver::
50     [root@host ~]# echo "7e270a25-e163-4922-af60-757fc8ed48c6" > \
51     /sys/bus/css/devices/0.0.0313/mdev_supported_types/vfio_ccw-io/create
60     -device vfio-ccw,devno=fe.0.1234,sysfsdev=\
61     /sys/bus/mdev/devices/7e270a25-e163-4922-af60-757fc8ed48c6
65     [root@guest ~]# lscss -d 0.0.1234
67     ----------------------------------------------------------------------
69     [root@guest ~]# chccwdev -e 0.0.1234
72     [root@guest ~]# dmesg -t
74     dasd-eckd 0.0.1234: A channel path to the device has become operational
75     dasd-eckd 0.0.1234: New DASD 3390/0E (CU 3990/01) with 10017 cylinders, 15 heads, 224 sectors
76 …dasd-eckd 0.0.1234: DASD with 4 KB/block, 7212240 KB total size, 48 KB/track, compatible disk layo…