From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([209.51.188.92]:36234) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gopoq-0000sR-S9 for qemu-devel@nongnu.org; Wed, 30 Jan 2019 08:22:21 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gopop-0005hC-Ru for qemu-devel@nongnu.org; Wed, 30 Jan 2019 08:22:20 -0500 From: Cornelia Huck Date: Wed, 30 Jan 2019 14:22:06 +0100 Message-Id: <20190130132212.7376-1-cohuck@redhat.com> Subject: [Qemu-devel] [PATCH v3 0/6] vfio-ccw: support hsch/csch (kernel part) List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Halil Pasic , Eric Farman , Farhan Ali , Pierre Morel Cc: linux-s390@vger.kernel.org, kvm@vger.kernel.org, qemu-devel@nongnu.org, qemu-s390x@nongnu.org, Alex Williamson , Cornelia Huck [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-eagain-caps-v3 The companion QEMU patches are available at https://github.com/cohuck/qemu vfio-ccw-caps This is the previously posted v2 version, which should continue to work.] 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. Lightly tested (I can interact with a dasd as before, and reserve/release seems to work well.) Not sure if there is a better way to test this, ideas welcome. Changes v2->v3: - Unb0rked patch 1, improved scope - Split out the new mutex from patch 2 into new patch 3; added missing locking and hopefully improved description - Patch 2 now reworks the state handling by splitting the BUSY state into CP_PROCESSING and CP_PENDING - Patches 3 and 5 adapted on top of the reworked patches; hsch/csch are allowed in CP_PENDING, but not in CP_PROCESSING (did not add any R-b due to that) - Added missing free in patch 5 - Probably some small changes I forgot to note down Changes v1->v2: - New patch 1: make it safe to use the cp accessors at any time; this should avoid problems with unsolicited interrupt handling - New patch 2: handle concurrent accesses to the io region; the idea is to return -EAGAIN to userspace more often (so it can simply retry) - also handle concurrent accesses to the async io region - change VFIO_REGION_TYPE_CCW - merge events for halt and clear to a single async event; this turned out to make the code quite a bit simpler - probably some small changes I forgot to note down Cornelia Huck (6): vfio-ccw: make it safe to access channel programs vfio-ccw: rework ssch state handling vfio-ccw: protect the I/O region vfio-ccw: add capabilities chain s390/cio: export hsch to modules vfio-ccw: add handling for async 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_cp.c | 20 ++- drivers/s390/cio/vfio_ccw_cp.h | 2 + drivers/s390/cio/vfio_ccw_drv.c | 57 ++++++-- drivers/s390/cio/vfio_ccw_fsm.c | 143 ++++++++++++++++++- drivers/s390/cio/vfio_ccw_ops.c | 210 +++++++++++++++++++++++----- drivers/s390/cio/vfio_ccw_private.h | 48 ++++++- include/uapi/linux/vfio.h | 4 + include/uapi/linux/vfio_ccw.h | 12 ++ 11 files changed, 531 insertions(+), 57 deletions(-) create mode 100644 drivers/s390/cio/vfio_ccw_async.c -- 2.17.2