[Qemu-ppc] [PATCH 0/5] target-arm: enable qmp-dump-guest-memory

[Andrew Jones]

This series brings qmp-dump-guest-memory to arm and aarch64
targets. I've detailed my testing and the results in the
following table.

arm/aarch64 kvm guest kdump testing (P - PASS, F - FAIL). Testing done
with a latest mainline crash utility patched with [*]

.-----------------------------------------------------------------------.
|                               Host    | arm32 | arm64 | arm64 | arm64 |
|---------------------------------------|-------|-------|-------|-------|
|                               Guest   | arm32 | arm64 | arm64 | arm32 |
|---------------------------------------|-------|-------|-------|-------|
|                               Pagesize| 4K    | 4K    | 64K   | 4K    |
|=======================================================================|
| kdump in guest                        | F[1]  | P[2]  | P[3]  | F[1]  |
|---------------------------------------|-------|-------|-------|-------|
| qmp-dump-guest-memory <filename>[4]   | P     | P     | P     | P     |
|---------------------------------------|-------|-------|-------|-------|
| qmp-dump-guest-memory -z <filename>[5]| F[8]  | P     | P     | F[8]  |
|---------------------------------------|-------|-------|-------|-------|
| qmp-dump-guest-memory -l <filename>[6]| F[8]  | P     | P     | F[8]  |
|---------------------------------------|-------|-------|-------|-------|
| qmp-dump-guest-memory -s <filename>[7]| F[8]  | P     | P     | F[8]  |
.-----------------------------------------------------------------------.

[1] Kernel v4.4-rc1 crashes with a NULL pointer dereference at virtual
    address 00000000 in a memcpy (crash_kexec/machine_kexec/fncpy/memcpy).
    Needs kernel debugging.
[2] Not sure about mainline, but works with the RHEL kernel,
    makedumpfile does not yet support arm64 with 4K pages, but using
    'core_collector cp' in /etc/kdump.conf allows saving an uncompressed
    elf file.
[3] Not sure about mainline, but works with the RHEL kernel,
    uses makedumpfile, thus generates a makedumpfile formatted file
    using zlib compression.
[4] No format specified, creates an uncompressed elf formatted file.
[5] makedumpfile format, with zlib compression
[6] makedumpfile format, with lzo compression
[7] makedumpfile format, with snappy compression
[8] The crash utility doesn't seem to like arm32 dumps in makedumpfile
    format. Looks like the physical page bitmap is all zeros? Needs
    qemu and crash debugging.

Additional notes:
1) QEMU also has scripts/dump-guest-memory.py, which can and should be
   updated to support multiple architectures, pagesizes, and physbases.
   This is currently left as future work.

[*] https://www.redhat.com/archives/crash-utility/2015-November/msg00031.html

Andrew Jones (5):
  qapi-schema: dump-guest-memory: Improve text
  dump: qemunotes aren't commonly needed
  dump: allow target to set the page size
  dump: allow target to set the phys_base
  target-arm: support QMP dump-guest-memory

 dump.c                      | 129 +++++++++++++++----------
 include/sysemu/dump-arch.h  |   9 +-
 include/sysemu/dump.h       |  11 +--
 qapi-schema.json            |   4 +-
 qom/cpu.c                   |   4 +-
 target-arm/Makefile.objs    |   3 +-
 target-arm/arch_dump.c      | 222 ++++++++++++++++++++++++++++++++++++++++++++
 target-arm/cpu-qom.h        |   5 +
 target-arm/cpu.c            |   3 +
 target-ppc/arch_dump.c      |   6 --
 target-ppc/cpu-qom.h        |   2 -
 target-ppc/translate_init.c |   1 -
 target-s390x/arch_dump.c    |   6 --
 target-s390x/cpu-qom.h      |   2 -
 target-s390x/cpu.c          |   1 -
 15 files changed, 321 insertions(+), 87 deletions(-)
 create mode 100644 target-arm/arch_dump.c

-- 
2.4.3