* Cornelia Huck <cornelia.h...@de.ibm.com> [2017-05-18 15:13:56 +0200]:
Hi Conny, > On Wed, 17 May 2017 02:48:00 +0200 > Dong Jia Shi <bjsdj...@linux.vnet.ibm.com> wrote: > > > The patch series introduce a basic channel I/O passthrough > > infrastructure based on vfio. > > - Focus on supporting dasd-eckd(cu_type/dev_type = 0x3990/0x3390) as > > the target device. > > - Support new qemu parameters in the style of: > > -machine s390-ccw-virtio(,s390-squash-mcss=on|off) \ > > -device vfio-ccw,sysfsdev=$MDEV_PATH > > We want to support real (i.e. not virtual) channel devices even for > > guests that do not support MCSS-E (where guests may see devices from > > any channel subsystem image at once). As all virtio-ccw devices are in > > css 0xfe (and show up in the default css 0 for guests not activating > > MCSS-E), we need an option to squash e.g. passed-through channel devices > > from their real css (0-3, or 0 for hosts not activating MCSS-E) into > > the default css, that is what the new machine option s390-squash-css is > > added. > > Patches queued, with minor changes (see my comments). > > I'll push out to s390-next once this passes some of my tests. > :-D > > > > Build and install: > > 1. kernel configuration > > CONFIG_S390_CCW_IOMMU=m > > CONFIG_VFIO=m > > CONFIG_VFIO_MDEV=m > > CONFIG_VFIO_MDEV_DEVICE=m > > CONFIG_VFIO_CCW=m > > 2. modules required > > modprobe vfio.ko > > modprobe mdev.ko > > modprobe vfio_mdev.ko > > modprobe vfio_iommu_type1.ko > > modprobe vfio_ccw.ko > > 3. find a subchannel(0.0."%schid") of a DASD-ECKD device and bind it to > > vfio_ccw driver > > #find the dasd you can use with lsdasd on your host. e.g.: > > devno="7e52" > > schid="16ca" > > #unbind the ccw device from the subchannel > > echo 0.0."$devno" > /sys/bus/ccw/devices/0.0."$devno"/driver/unbind > > #unbind the subchannel from io_subchannel driver > > echo 0.0."$schid" > /sys/bus/css/devices/0.0."$schid"/driver/unbind > > #bind the subchannel with vfio_ccw driver > > echo 0.0."$schid" > /sys/bus/css/drivers/vfio_ccw/bind > > 4. create a mediated device > > #generate a uuid with uuidgen. e.g.: > > uuid="6dfd3ec5-e8b3-4e18-a6fe-57bc9eceb920" > > echo "$uuid" > \ > > /sys/bus/css/devices/0.0."$schid"/mdev_supported_types/vfio_ccw-io/create > > 5. pass-through this device to a vm > > -M s390-ccw-virtio,s390-squash-css=on \ > > -device vfio-ccw,sysfsdev=/sys/bus/mdev/devices/$uuid \ > > ... ... > > These instructions would be helpful to preserve in the qemu wiki and > could even be expanded upon. Nod. > Ping me if you need an account (hint, hint ;) (uh...) Dear Frau, could you please kindly get me an account? Then I can try to add a new page for vfio-ccw in the qemu wiki. ;) I will ping you when you online. Thanks! -- Dong Jia Shi
