Changes since v4: ---------------- - v4 can be seen here: https://www.spinics.net/lists/kexec/msg23850.html - Removed the patch (via [PATCH 4/4] in v3) which marked '--mem-usage' option as unsupported for arm64 architecture, as we now have a mechanism to read the 'vabits_actual' value from 'id_aa64mmfr2_el1' arm64 system architecture register. As per discussions with arm64 and gcc/binutils maintainers it turns out there is no standard ABI available between the kernel and user-space to export this value early enough to be used for page_offset calculation in the --mem-usage case. So, the next best option is to have the user-space read the system register to determine underlying hardware support for larger (52-bit) addressing support. This allows us to keep supporting '--mem-usage' option on arm64 even on newer kernels (with flipped VA space). Changes since v3: ---------------- - v3 can be seen here: http://lists.infradead.org/pipermail/kexec/2019-March/022534.html - Added a new patch (via [PATCH 4/4]) which marks '--mem-usage' option as unsupported for arm64 architecture. With the newer arm64 kernels supporting 48-bit/52-bit VA address spaces and keeping a single binary for supporting the same, the address of kernel symbols like _stext, which could be earlier used to determine VA_BITS value, can no longer to determine whether VA_BITS is set to 48 or 52 in the kernel space. Hence for now, it makes sense to mark '--mem-usage' option as unsupported for arm64 architecture until we have more clarity from arm64 kernel maintainers on how to manage the same in future kernel/makedumpfile versions. Changes since v2: ---------------- - v2 can be seen here: http://lists.infradead.org/pipermail/kexec/2019-February/022456.html - 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: http://lists.infradead.org/pipermail/kexec/2019-February/022424.html (ARMv8.2-LPA) http://lists.infradead.org/pipermail/kexec/2019-February/022425.html (ARMv8.2-LVA) - 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 cases with this patchset: - Both old (<5.4) and new kernels (>= 5.4) work well. - All VA and PA bit combinations currently supported via the kernel CONFIG options work well, including: - 48-bit kernel VA + 52-bit PA (LPA) - 52-bit kernel VA (LVA) + 52-bit PA (LPA) This has been tested for the following user-cases: 1. Analysing page information via '--mem-usage' option. 2. Creating a dumpfile using /proc/vmcore, 3. Creating a dumpfile using /proc/kcore, and 4. 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, ampere-osprey. 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). This patchset ensures backward compatibility for kernel versions in which 'TCR_EL1.T1SZ' and 'MAX_PHYSMEM_BITS' are not available in vmcoreinfo. In the newer kernels (>= 5.4.0) the following patches export these variables in the vmcoreinfo: - 1d50e5d0c505 ("crash_core, vmcoreinfo: Append 'MAX_PHYSMEM_BITS' to vmcoreinfo") - bbdbc11804ff ("arm64/crash_core: Export TCR_EL1.T1SZ in vmcoreinfo") Cc: John Donnelly <john.p.donnelly@xxxxxxxxxx> Cc: Kazuhito Hagio <k-hagio@xxxxxxxxxxxxx> Cc: kexec@xxxxxxxxxxxxxxxxxxx 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 kernel VA support) arch/arm.c | 8 +- arch/arm64.c | 520 ++++++++++++++++++++++++++++++++++++++----------- 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 +-- common.h | 10 + makedumpfile.c | 4 +- makedumpfile.h | 6 +- 12 files changed, 529 insertions(+), 182 deletions(-) -- 2.26.2 _______________________________________________ kexec mailing list kexec@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/kexec
