Hi all, Friendly ping... On 2021/1/30 15:10, Chen Zhou wrote: > There are following issues in arm64 kdump: > 1. We use crashkernel=X to reserve crashkernel below 4G, which > will fail when there is no enough low memory. > 2. If reserving crashkernel above 4G, in this case, crash dump > kernel will boot failure because there is no low memory available > for allocation. > > To solve these issues, change the behavior of crashkernel=X. > crashkernel=X tries low allocation in DMA zone and fall back to high > allocation if it fails. > > We can also use "crashkernel=X,high" to select a high region above > DMA zone, which also tries to allocate at least 256M low memory in > DMA zone automatically and "crashkernel=Y,low" can be used to allocate > specified size low memory. > > When reserving crashkernel in high memory, some low memory is reserved > for crash dump kernel devices. So there may be two regions reserved for > crash dump kernel. > In order to distinct from the high region and make no effect to the use > of existing kexec-tools, rename the low region as "Crash kernel (low)", > and pass the low region by reusing DT property > "linux,usable-memory-range". We made the low memory region as the last > range of "linux,usable-memory-range" to keep compatibility with existing > user-space and older kdump kernels. > > Besides, we need to modify kexec-tools: > arm64: support more than one crash kernel regions(see [1]) > > Another update is document about DT property 'linux,usable-memory-range': > schemas: update 'linux,usable-memory-range' node schema(see [2]) > > This patchset contains the following eleven patches: > 0001-x86-kdump-replace-the-hard-coded-alignment-with-macr.patch > 0002-x86-kdump-make-the-lower-bound-of-crash-kernel-reser.patch > 0003-x86-kdump-use-macro-CRASH_ADDR_LOW_MAX-in-functions-.patch > 0004-x86-kdump-move-xen_pv_domain-check-and-insert_resour.patch > 0005-x86-kdump-move-reserve_crashkernel-_low-into-crash_c.patch > 0006-x86-elf-Move-vmcore_elf_check_arch_cross-to-arch-x86.patch > 0007-arm64-kdump-introduce-some-macroes-for-crash-kernel-.patch > 0008-arm64-kdump-reimplement-crashkernel-X.patch > 0009-x86-arm64-Add-ARCH_WANT_RESERVE_CRASH_KERNEL-config.patch > 0010-arm64-kdump-add-memory-for-devices-by-DT-property-li.patch > 0011-kdump-update-Documentation-about-crashkernel.patch > > 0001-0004 are some x86 cleanups which prepares for making > functionsreserve_crashkernel[_low]() generic. > 0005 makes functions reserve_crashkernel[_low]() generic. > 0006 fix compiling warning. > 0007-0009 reimplements arm64 crashkernel=X. > 0010 adds memory for devices by DT property linux,usable-memory-range. > 0011 updates the doc. > > Changes since [v13] > - Rebased on top of 5.11-rc5. > - Introduce config CONFIG_ARCH_WANT_RESERVE_CRASH_KERNEL. > Since reserve_crashkernel[_low]() implementations are quite similar on > other architectures, so have CONFIG_ARCH_WANT_RESERVE_CRASH_KERNEL in > arch/Kconfig and select this by X86 and ARM64. > - Some minor cleanup. > > Changes since [v12] > - Rebased on top of 5.10-rc1. > - Keep CRASH_ALIGN as 16M suggested by Dave. > - Drop patch "kdump: add threshold for the required memory". > - Add Tested-by from John. > > Changes since [v11] > - Rebased on top of 5.9-rc4. > - Make the function reserve_crashkernel() of x86 generic. > Suggested by Catalin, make the function reserve_crashkernel() of x86 generic > and arm64 use the generic version to reimplement crashkernel=X. > > Changes since [v10] > - Reimplement crashkernel=X suggested by Catalin, Many thanks to Catalin. > > Changes since [v9] > - Patch 1 add Acked-by from Dave. > - Update patch 5 according to Dave's comments. > - Update chosen schema. > > Changes since [v8] > - Reuse DT property "linux,usable-memory-range". > Suggested by Rob, reuse DT property "linux,usable-memory-range" to pass the low > memory region. > - Fix kdump broken with ZONE_DMA reintroduced. > - Update chosen schema. > > Changes since [v7] > - Move x86 CRASH_ALIGN to 2M > Suggested by Dave and do some test, move x86 CRASH_ALIGN to 2M. > - Update Documentation/devicetree/bindings/chosen.txt. > Add corresponding documentation to Documentation/devicetree/bindings/chosen.txt > suggested by Arnd. > - Add Tested-by from Jhon and pk. > > Changes since [v6] > - Fix build errors reported by kbuild test robot. > > Changes since [v5] > - Move reserve_crashkernel_low() into kernel/crash_core.c. > - Delete crashkernel=X,high. > - Modify crashkernel=X,low. > If crashkernel=X,low is specified simultaneously, reserve spcified size low > memory for crash kdump kernel devices firstly and then reserve memory above 4G. > In addition, rename crashk_low_res as "Crash kernel (low)" for arm64, and then > pass to crash dump kernel by DT property "linux,low-memory-range". > - Update Documentation/admin-guide/kdump/kdump.rst. > > Changes since [v4] > - Reimplement memblock_cap_memory_ranges for multiple ranges by Mike. > > Changes since [v3] > - Add memblock_cap_memory_ranges back for multiple ranges. > - Fix some compiling warnings. > > Changes since [v2] > - Split patch "arm64: kdump: support reserving crashkernel above 4G" as > two. Put "move reserve_crashkernel_low() into kexec_core.c" in a separate > patch. > > Changes since [v1]: > - Move common reserve_crashkernel_low() code into kernel/kexec_core.c. > - Remove memblock_cap_memory_ranges() i added in v1 and implement that > in fdt_enforce_memory_region(). > There are at most two crash kernel regions, for two crash kernel regions > case, we cap the memory range [min(regs[*].start), max(regs[*].end)] > and then remove the memory range in the middle. > > [1]: http://lists.infradead.org/pipermail/kexec/2020-June/020737.html > [2]: https://github.com/robherring/dt-schema/pull/19 > [v1]: https://lkml.org/lkml/2019/4/2/1174 > [v2]: https://lkml.org/lkml/2019/4/9/86 > [v3]: https://lkml.org/lkml/2019/4/9/306 > [v4]: https://lkml.org/lkml/2019/4/15/273 > [v5]: https://lkml.org/lkml/2019/5/6/1360 > [v6]: https://lkml.org/lkml/2019/8/30/142 > [v7]: https://lkml.org/lkml/2019/12/23/411 > [v8]: https://lkml.org/lkml/2020/5/21/213 > [v9]: https://lkml.org/lkml/2020/6/28/73 > [v10]: https://lkml.org/lkml/2020/7/2/1443 > [v11]: https://lkml.org/lkml/2020/8/1/150 > [v12]: https://lkml.org/lkml/2020/9/7/1037 > [v13]: https://lkml.org/lkml/2020/10/31/34 > > Chen Zhou (11): > x86: kdump: replace the hard-coded alignment with macro CRASH_ALIGN > x86: kdump: make the lower bound of crash kernel reservation > consistent > x86: kdump: use macro CRASH_ADDR_LOW_MAX in functions > reserve_crashkernel() > x86: kdump: move xen_pv_domain() check and insert_resource() to > setup_arch() > x86: kdump: move reserve_crashkernel[_low]() into crash_core.c > x86/elf: Move vmcore_elf_check_arch_cross to > arch/x86/include/asm/elf.h > arm64: kdump: introduce some macroes for crash kernel reservation > arm64: kdump: reimplement crashkernel=X > x86, arm64: Add ARCH_WANT_RESERVE_CRASH_KERNEL config > arm64: kdump: add memory for devices by DT property > linux,usable-memory-range > kdump: update Documentation about crashkernel > > Documentation/admin-guide/kdump/kdump.rst | 22 ++- > .../admin-guide/kernel-parameters.txt | 11 +- > arch/Kconfig | 3 + > arch/arm64/Kconfig | 1 + > arch/arm64/include/asm/kexec.h | 10 ++ > arch/arm64/kernel/setup.c | 13 +- > arch/arm64/mm/init.c | 111 +++++------- > arch/x86/Kconfig | 2 + > arch/x86/include/asm/elf.h | 3 + > arch/x86/include/asm/kexec.h | 31 +++- > arch/x86/kernel/setup.c | 163 ++---------------- > include/linux/crash_core.h | 3 + > include/linux/kexec.h | 2 - > kernel/crash_core.c | 156 +++++++++++++++++ > kernel/kexec_core.c | 17 -- > 15 files changed, 303 insertions(+), 245 deletions(-) >
