From mboxrd@z Thu Jan 1 00:00:00 1970 From: Farhan Ali Subject: Re: [PATCH 0/3] vfio-ccw: support hsch/csch (kernel part) Date: Mon, 26 Nov 2018 13:57:06 -0500 Message-ID: References: <20181122165432.4437-1-cohuck@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20181122165432.4437-1-cohuck@redhat.com> Content-Language: en-US List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+gceq-qemu-devel2=m.gmane.org@nongnu.org Sender: "Qemu-devel" List-Archive: List-Post: To: Cornelia Huck , Halil Pasic , Eric Farman , Pierre Morel Cc: linux-s390@vger.kernel.org, qemu-s390x@nongnu.org, Alex Williamson , qemu-devel@nongnu.org, kvm@vger.kernel.org List-ID: 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. Thanks Farhan > Cornelia Huck (3): > vfio-ccw: add capabilities chain > s390/cio: export hsch to modules > vfio-ccw: add handling for asnyc channel instructions > > drivers/s390/cio/Makefile | 3 +- > drivers/s390/cio/ioasm.c | 1 + > drivers/s390/cio/vfio_ccw_async.c | 88 +++++++++++++ > drivers/s390/cio/vfio_ccw_drv.c | 48 +++++-- > drivers/s390/cio/vfio_ccw_fsm.c | 158 +++++++++++++++++++++- > drivers/s390/cio/vfio_ccw_ops.c | 195 ++++++++++++++++++++++++---- > drivers/s390/cio/vfio_ccw_private.h | 44 +++++++ > include/uapi/linux/vfio.h | 5 + > include/uapi/linux/vfio_ccw.h | 12 ++ > 9 files changed, 509 insertions(+), 45 deletions(-) > create mode 100644 drivers/s390/cio/vfio_ccw_async.c >