[PATCH v6 0/9] kexec-tools, x86: E820 memmap pass for kdump

WANG Chao chaowang at redhat.com
Mon Apr 14 07:55:32 PDT 2014

Hi, All

This patchset enables passing memory map via E820 map on x86 platform instead
of memmap=exactmap. It's a better design and will solve the following problem
so far:

- kernel cmdline is limited resource and large machines tend to have many
    memory ranges that may excceed kernel cmdline limit size.
- kASLR doesn't work with memmap=exactmap, because kASLR happens early than
    user defined memmap=exactmap takes effect.

Unfortunately, saved_max_pfn still got its user out there (calgry pci, it looks
like the only one). So for backward compatibility, I'm introducing a new option
--pass-memmap-cmdline to force kexec-tools to pass memmap=exactmap, the old way.

This patchset contains massive updates from the previous one. I take some
suggestions from reviewers. I try to split the changes into smaller pieces and
keep the whole change as minimal as I can so it wouldn't be too harsh to review
the patch.

Any comment is appreciate!

 - use nr_memmap instead of nr_memmap_p
 - .end inclusive
 - more description on some patches

 - separate add_setup_data() to another patch.
 - adding comments for setup_data.
 - store crash memory range info golobally in kexec_info.
 -remove dbgprint_mem_range defination, Simon has merged the patch.

Linn: check return value of malloc (use xmalloc).
me: fix dbgprintf_mem_range.

 - do not free sd (setup_data) buffer.
 - reuse code in setup_e820 and setup_e820_ext.

 - Use function instead of macro for dbgprint_mem_range
 - Do not pass reserved memory range for kdump. It could addressed later

WANG Chao (9):
  x86, cleanup: add extra arguments to add_memmap() and delete_memmap()
  x86, cleanup: add_memmap() only do alignment check on RANGE_RAM
  x86, cleanup: add other types of memory range for 2nd kernel boot to
  x86, cleanup: use dbgprint_mem_range for memory range debugging
  x86, cleanup: increase CRASH_MAX_MEMMAP_NR up to
  x86, cleanup: Store crash memory ranges kexec_info
  x86, cleanup: kexec memory range .end to be inclusive
  x86: add --pass-memmap-cmdline option
  x86: Pass memory range via E820 for kdump

 kexec/arch/i386/crashdump-x86.c        |  69 +++++++--------
 kexec/arch/i386/crashdump-x86.h        |   2 +-
 kexec/arch/i386/include/arch/options.h |   2 +
 kexec/arch/i386/kexec-x86-common.c     |   3 +-
 kexec/arch/i386/kexec-x86.c            |   4 +
 kexec/arch/i386/kexec-x86.h            |   1 +
 kexec/arch/i386/x86-linux-setup.c      | 149 ++++++++++++++++++++++-----------
 kexec/arch/i386/x86-linux-setup.h      |   1 +
 kexec/arch/x86_64/kexec-x86_64.c       |   5 ++
 kexec/firmware_memmap.c                |   1 -
 kexec/kexec.h                          |   2 +
 11 files changed, 147 insertions(+), 92 deletions(-)


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