On Mon, 26 Nov 2018 13:57:06 -0500 Farhan Ali <alifm@xxxxxxxxxxxxx> wrote: > On 11/22/2018 11:54 AM, Cornelia Huck wrote: > > [This is the Linux kernel part, git tree is available at > > https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/vfio-ccw.git vfio-ccw-caps > > > > The companion QEMU patches are available at > > https://github.com/cohuck/qemu vfio-ccw-caps] > > > > Currently, vfio-ccw only relays START SUBCHANNEL requests to the real > > device. This tends to work well for the most common 'good path' scenarios; > > however, as we emulate {HALT,CLEAR} SUBCHANNEL in QEMU, things like > > clearing pending requests at the device is currently not supported. > > This may be a problem for e.g. error recovery. > > > > This patch series introduces capabilities (similar to what vfio-pci uses) > > and exposes a new async region for handling hsch/csch. > > > > Very lightly tested (I can interact with a dasd as before; I have not > > found a reliable way to trigger hsch/csch in the Linux dasd guest driver.) > > > > I was able to trigger the guest DASD driver to issue a csch instruction, > and from my brief testing it seems to be working just like it would on > the LPAR. (I basically tested with 2 threads trying to issue DASD device > reserve and release ioctls, on the same DASD device, in a busy loop). > > I am going to spend some time doing a deeper review. Cool, thanks a lot!
