On Wed, 21 Mar 2018 03:08:18 +0100 Dong Jia Shi <bjsdjshi@xxxxxxxxxxxxxxxxxx> wrote: > Hi Conny, > > Halil reported a host crash when using vfio-ccw. The root cause of the problem > is that vfio_pin_pages fails with EINVAL for reasons unknown. He has > experienced such failures after online-ing a dasd in the guest (the dasd has 3 > partitions, hat may or may not have any significance). The problem isn't > experienced on every attempt to online the dasd, and breaking at css_do_ssch > seems to make things work. > > One thing is sure: the host kernel should not crash under the described > circumstances. > > To fix the problem, the first patch of this series fixes the cleanup when > cp_prefetch fails in the higher level. The 2nd and the 3rd patches provide > correctness and denfensive actions for the interfaces in the lower level. So, is the first patch stable material? > > The 4th patch is trying to add tracepoints for vfio-ccw, so that we can debug > such issue easier in future. Tracepoints are nice :) > > For details see the commit message portions of the inividual patches. Still digging through the post-vacation mail pile, will do more looking later. > Thanks. > > Dong Jia Shi (2): > vfio: ccw: refactor and improve pfn_array_alloc_pin() > vfio: ccw: set ccw->cda to NULL defensively > > Halil Pasic (2): > vfio: ccw: fix cleanup if cp_prefetch fails > vfio: ccw: add traceponits for interesting error paths > > drivers/s390/cio/Makefile | 1 + > drivers/s390/cio/vfio_ccw_cp.c | 121 ++++++++++++++++++++------------------ > drivers/s390/cio/vfio_ccw_fsm.c | 13 ++++ > drivers/s390/cio/vfio_ccw_trace.h | 86 +++++++++++++++++++++++++++ > 4 files changed, 163 insertions(+), 58 deletions(-) > create mode 100644 drivers/s390/cio/vfio_ccw_trace.h >
