[PATCH v3 0/3] makedumpfile/arm64: Add support for ARMv8.2 extensions

Bhupesh Sharma bhsharma at redhat.com
Sun Mar 10 03:57:32 PDT 2019

Changes since v2:
- v2 can be seen here:
- I missed some comments from Kazu sent on the LVA v1 patch when I sent
  out the v2. So, addressing them now in v3.
- Also added a patch that adds a tree-wide feature to read
  'MAX_PHYSMEM_BITS' from vmcoreinfo (if available).

Changes since v1:
- v1 was sent as two separate patches:
- v2 combined the two in a single patchset and also addresses Kazu's
  review comments.

This patchset adds support for ARMv8.2 extensions in makedumpfile code.
I cover the following two cases with this patchset:
 - 48-bit VA + 52-bit PA (LPA)
 - 48-bit kernel VA + 52-bit virtual VA (LVA)

This has been tested for the following user-cases:
1. Calculating --mem-usage on the primary kernel,
2. Creating a dumpfile using /proc/vmcore, and
3. Post-processing a vmcore.

I have tested this patchset on the following platforms, with kernels
which support/do-not-support ARMv8.2 features:
1. CPUs which don't support ARMv8.2 features, e.g. qualcomm-amberwing,
2. Prototype models which support ARMv8.2 extensions (e.g. ARMv8 FVP
   simulation model).

Also a preparation patch has been added in this patchset which adds a
common feature for archs (except arm64, for which similar support is
added via subsequent patch) to retrieve 'MAX_PHYSMEM_BITS' from
vmcoreinfo (if available).

I recently posted two kernel patches (see [0] and [1]) which append
'PTRS_PER_PGD' and 'MAX_PHYSMEM_BITS' to vmcoreinfo in the kernel
code, so that user-space code can benefit from the same.

This patchset ensures backward compatibility for kernel versions in
which 'PTRS_PER_PGD' and 'MAX_PHYSMEM_BITS' are not available in

[0]. http://lists.infradead.org/pipermail/kexec/2019-March/022532.html
[1]. http://lists.infradead.org/pipermail/kexec/2019-March/022533.html

Bhupesh Sharma (3):
  tree-wide: Retrieve 'MAX_PHYSMEM_BITS' from vmcoreinfo (if available)
  makedumpfile/arm64: Add support for ARMv8.2-LPA (52-bit PA support)
  makedumpfile/arm64: Add support for ARMv8.2-LVA (52-bit user-space VA

 arch/arm.c     |   8 +-
 arch/arm64.c   | 394 ++++++++++++++++++++++++++++++++++++++++-----------------
 arch/ia64.c    |   7 +-
 arch/ppc.c     |   8 +-
 arch/ppc64.c   |  49 ++++---
 arch/s390x.c   |  29 +++--
 arch/sparc64.c |   9 +-
 arch/x86.c     |  34 +++--
 arch/x86_64.c  |  27 ++--
 makedumpfile.c |   2 +
 makedumpfile.h |   1 +
 11 files changed, 390 insertions(+), 178 deletions(-)


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