On Wed, 12 Dec 2018 09:11:03 -0500 "Jason J. Herne" <jjhe...@linux.ibm.com> wrote:
Hm, I think you need to adjust your cc: list. I added some more folks (and removed Dong Jia, whose address is no longer valid AFAIK). > This is to support booting from vfio-ccw dasd devices. We basically implement > the real hardware ipl procedure. This allows for booting Linux guests on > vfio-ccw devices. > > vfio-ccw's channel program prefetch algorithm complicates ipl because most ipl > channel programs dynamically modify themselves. Details on the ipl process and > how we worked around this issue can be found in docs/devel/s390-dasd-ipl.txt. > > NOTE: It has been a while, but I've finally chased down my infamous "reset > bug". > On subsystem reset (I see this right after host ipl) we sometimes end up > getting > an unexpected unit check status from a dasd device. This causes the first > start > subchannel instruction to fail due to the pending unit check status. My > solution > to this problem, as advised by the kernel folks, is to simply retry my ssch > instructions before declaring failure when unexpected unit checks happen. In > the > event of a persistent error, after two retries we'll give up and print some > useful error info for the user. So, is that a status we only see because the vfio-ccw driver keeps the subchannel enabled (as by the other recent thread)? Is there any value in distinguishing different unit checks, or is retry the best strategy in any case? > > Changelog > ========== > > rfc -> v1 > --------- > - Retry start subchannel operations on unexpected unit check status > - Print more complete state information on i/o error > - Fixed asm constraints (Q -> QS) > - Align lowcore to 8k boundary > - Initialize next_cpa in run_dynamic_ccw_program to avoid compiler warning > - Cleanup: Rework handling of i/o interrupts in assembler > - Fix netboot image (include cio.o in make file) > - Misc cleanups > > Jason J. Herne (15): > s390 vfio-ccw: Add bootindex property and IPLB data > s390-bios: decouple cio setup from virtio > s390-bios: decouple common boot logic from virtio > s390-bios: Extend find_dev() for non-virtio devices > s390-bios: Factor finding boot device out of virtio code path > s390-bios: Clean up cio.h > s390-bios: Decouple channel i/o logic from virtio > s390-bios: Map low core memory > s390-bios: ptr2u32 and u32toptr > s390-bios: Support for running format-0/1 channel programs > s390-bios: cio error handling > s390-bios: Refactor virtio to run channel programs via cio > s390-bios: Use control unit type to determine boot method > s390-bios: Add channel command codes/structs needed for dasd-ipl > s390-bios: Support booting from real dasd device > > docs/devel/s390-dasd-ipl.txt | 132 ++++++++++++++ > hw/s390x/ipl.c | 15 ++ > hw/s390x/s390-ccw.c | 9 + > hw/vfio/ccw.c | 13 +- > include/hw/s390x/s390-ccw.h | 1 + > include/hw/s390x/vfio-ccw.h | 38 ++++ > pc-bios/s390-ccw/Makefile | 2 +- > pc-bios/s390-ccw/cio.c | 374 > +++++++++++++++++++++++++++++++++++++++ > pc-bios/s390-ccw/cio.h | 236 +++++++++++++++++++----- > pc-bios/s390-ccw/dasd-ipl.c | 249 ++++++++++++++++++++++++++ > pc-bios/s390-ccw/dasd-ipl.h | 16 ++ > pc-bios/s390-ccw/libc.h | 23 +++ > pc-bios/s390-ccw/main.c | 161 +++++++++++------ > pc-bios/s390-ccw/netboot.mak | 2 +- > pc-bios/s390-ccw/netmain.c | 1 + > pc-bios/s390-ccw/s390-arch.h | 113 ++++++++++++ > pc-bios/s390-ccw/s390-ccw.h | 10 +- > pc-bios/s390-ccw/start.S | 33 +++- > pc-bios/s390-ccw/virtio-blkdev.c | 1 + > pc-bios/s390-ccw/virtio.c | 46 +---- > roms/SLOF | 2 +- > tests/boot-serial-test.c | 2 +- > 22 files changed, 1308 insertions(+), 171 deletions(-) > create mode 100644 docs/devel/s390-dasd-ipl.txt > create mode 100644 include/hw/s390x/vfio-ccw.h > create mode 100644 pc-bios/s390-ccw/cio.c > create mode 100644 pc-bios/s390-ccw/dasd-ipl.c > create mode 100644 pc-bios/s390-ccw/dasd-ipl.h > create mode 100644 pc-bios/s390-ccw/s390-arch.h > > -- > 2.7.4 >
