[PATCH v17 00/13] arm64 kexec kernel patches

AKASHI Takahiro takahiro.akashi at linaro.org
Mon Jun 6 18:36:19 PDT 2016


On Fri, Jun 03, 2016 at 06:13:40PM +0000, Geoff Levand wrote:
> This series adds the core support for kexec re-boot and kdump on ARM64.  This
> version of the series combines Takahiro's kdump patches with my kexec patches.
> Please consider all patches for inclusion.
> 
> Takahiro has done some extensive testing for this version with various
> configurations af endian, image format, memory options and layouts, etc.
> 
> To load a second stage kernel and execute a kexec re-boot or to work with kdump
> on ARM64 systems a series of patches to kexec-tools [2], which have not yet been
> merged upstream, are needed.  Please update to the latest if you have been using
> an older version.
> 
> To examine vmcore (/proc/vmcore), you should use
>   - gdb v7.7 or later
>   - crash v7.1.1 or later

If KASLR (CONFIG_RANDOMIZE_BASE) is activated at runtime, those tools won't
work at this moment. For crash utility, we need to apply the following patch:

 [3] https://www.redhat.com/archives/crash-utility/2016-May/msg00078.html

> [1]  https://git.kernel.org/cgit/linux/kernel/git/geoff/linux-kexec.git
> [2]  https://git.kernel.org/cgit/linux/kernel/git/geoff/kexec-tools.git
>
> Changes for v17 (June 3, 2016, 25m):
> 
>   o Rebase to Linux-4.7-rc1.
>   o Added one VMCOREINFO parameter to vmcore for crash utility.
>   o Added a check for CPUs stuck in kernel.

For completeness, apart from some minor/cosmetic changes,
    o Re-implemented cpu_soft_restart() to be executed only in hyp-stub.
    o Added some kernel documentation about added device tree properties.
      (contributed by James)

Thanks,
-Takahiro AKASHI

> Changes for v16 (Apr 14, 2016, 23m):
> 
>   o Rebase to Linux-4.6-rc3.
>   o Don't try to explicitly enter EL2 at machine_kexec() when VHE in use
>   o Add unreachable() in case of ipi_cpu_crash_stop()
>   o Add more "#ifdef" to eliminate code unused when !CONFIG_KEXEC_CORE
>   o Fix a build error around ipi_cpu_crash_stop() when !CONFIG_HOTPLUG_CPU
>   o Revert "arm64: Add new hcall HVC_CALL_FUNC"
>   o Revert "Convert hcalls to use HVC immediate value"
>     (replaced by James' "hyp/kvm: Extend hyp-stub API to allow function calls
>      at EL2")
> 
>   Modified by James:
>   o Add missing icache maintenance + isb to __kvm_hyp_reset()
>   o Rework kvm cpu hotplug for VHE
> 
>   Added by James:
>   o arm64: head.S: el2_setup() to accept sctlr_el1 as an argument
>   o arm64: hyp/kvm: Extend hyp-stub API to allow function calls at EL2
>   o arm64: kvm: Move lr save/restore from do_el2_call into EL1
>   o arm64: kvm: Move the do_el2_call macro to a header file
> 
> Changes for v15 (Mar 14, 2016, 22m):
> 
>   o Rebase to Linux-4.5.
>   o Remove DEBUG conditional in 'Add pr_debug output'.
> 
> Changes for v14 (Mar 4, 2016, 22m):
> 
>   o Rebase to Linux-4.5-rc6.
>   o Rename setup_mm_for_reboot to cpu_install_idmap.
>   o kdump: leave non-boot cpus online at crash dump
>     As we don't have to make non-boot (crashed) cpus offline at crash dump,
>     this patch adds a variant of smp_send_stop().
>   o kdump: use a new device-tree property, "linux,elfcorehdr", instead of
>     traditional "elfcorehdr=" kernel parameter
>   o limit memory regions based on DT property, "usable-memory", instead of
>     "mem=" kernel parameter
>   o kdump: fix a build error when !CONFIG_KEXEC_CORE
>   o kvm: use generic kvm_call_hyp() interface instead of kvm_cpu_reset()
>   o kvm: initialize only a primary cpu at init_hyp_mode()
> 
> Changes for v13 (Jan 15, 2016, 20m):
> 
>   o Rebase to Linux-4.4.
>   o Remove align directive from cpu_reset.c.
>   o Use inline C wrapper for cpu_soft_restart.
>   o Revert the new image d-cache flush changes of v10.
>   o Add SCTLR cleanup patch.
>   o Change pr_devel to pr_debug.
>   o Call flush_icache_range() for reboot_code_buffer.
>   o Add .ltorg directive to arm64_relocate_new_kernel.
>   o Make new asm macro copy_page.
>   o Change cache maintenence from inner-shareable to non-shareable.
>   o Rename KEXEC_ARCH_ARM64 to KEXEC_ARCH_AARCH64.
> 
>   o arm64: kvm: allows kvm cpu hotplug
>     - remove some garbage code from kvm_host.h
>   o arm64: kdump: reserve memory for crash dump kernel
>     - change CONFIG_KEXEC to CONFIG_KEXEC_CORE
>     - don't panic on crash kernel alloc failure
>       (thanks to Mark Salter, RH)
>   o arm64: kdump: implement machine_crash_shutdown()
>     - change "boot/non-boot cpu" to "crashing/non-crashing cpu"
>     - introduce is_in_crash_kexec() for readability
>     - re-introduce machine_kexec_mask_interrupts(), as arch/arm has,
>       to discard unexpected interrupts
>     - call crash_save_cpu() before making cpus offline to avoid a possible race
>       (thanks to Pratyush Anand/Mark Salter, RH)
>   o arm64: kdump: update a kernel doc
>     - clarify that we support "Image" format as well as vmlinux in kdump.txt
>   o arm64: kdump: relax BUG_ON() if more than one cpus are still active
>     - change a warning message at the failure of shooting down non-crahsing cpus
> 
> Changes for v12 (Nov 24, 2015, 18m):
> 
>   o No changes, rebase to Linux-4.4-rc2.
> 
> Changes for v11 (Nov 6, 2015, 18m):
> 
>   o Rebase to Linux-4.3.
>   o Move the new image d-cache flush from arm64_relocate_new_kernel to machine_kexec.
>   o Pass values to arm64_relocate_new_kernel in registers, not in global variables.
>   o Fixups to setting the sctlr_el1 and sctlr_el2 flags.
> 
> Changes for v10 (Oct 18, 2015, 17m):
> 
>   o Rebase to Linux-4.3-rc6.
>   o Move tcr_set_idmap_t0sz to assembler.h.
>   o Add back simplified cpu_reset routines.
>   o Combine kexec + kdump patches.
> 
> Changes for v9 (Apr 7, 2015, 11m):
> 
>   o Use new upstream flag IND_FLAGS.
> 
> Changes for v8 (Mar 19, 2015, 10m):
> 
>   o Rebase to Linux-4.0-rc4.
>   o Re-boot using purgatory only.
> 
> Changes for v7 (Jan 16, 2015, 8m):
> 
>   o Rebase to Linux-3.19-rc4.
>   o Change from ESR_EL2_ to ESR_ELx_.
>   o Remove work-arounds for EFI systems.
>   
> Changes for v6 (Dec 2, 2014, 7m):
> 
>   o Rebase to Linux-3.18-rc2
> 
> Changes for v5 (Nov 16, 2014, 6m):
> 
> Changes for v4 (Oct 3, 2014, 5m):
> 
> Changes for v3 (Sept 23, 2014, 4m):
> 
> Changes for v2 (Sep 9, 2014, 4m):
> 
>   o Rebase to Linux-3.17-rc4.
>   o Move macros from proc-macros.S to assembler.h.
>   o Convert hcalls to use ISS field.
>   o Add new hcall HVC_CALL_FUNC.
>   o Add EL2 switch to soft_restart.
> 
> First submission v1 (May 13, 2014):
> 
>   o Based on Linux-3.15-rc4.
> 
> -Geoff
> 
> The following changes since commit 1a695a905c18548062509178b98bc91e67510864:
> 
>   Linux 4.7-rc1 (2016-05-29 09:29:24 -0700)
> 
> are available in the git repository at:
> 
>   git://git.kernel.org/pub/scm/linux/kernel/git/geoff/linux-kexec.git kexec-v17
> 
> for you to fetch changes up to 89f1e3dfe16477c732dac8f407300039c0947568:
> 
>   Documentation: dt: usable-memory and elfcorehdr nodes for arm64 kexec (2016-06-03 10:12:45 -0700)
> 
> ----------------------------------------------------------------
> AKASHI Takahiro (7):
>       arm64: kdump: reserve memory for crash dump kernel
>       arm64: limit memory regions based on DT property, usable-memory
>       arm64: kdump: implement machine_crash_shutdown()
>       arm64: kdump: add kdump support
>       arm64: kdump: add VMCOREINFO for user-space coredump tools
>       arm64: kdump: enable kdump in the arm64 defconfig
>       arm64: kdump: update a kernel doc
> 
> Geoff Levand (4):
>       arm64: Add back cpu reset routines
>       arm64/kexec: Add core kexec support
>       arm64/kexec: Add pr_debug output
>       arm64/kexec: Enable kexec in the arm64 defconfig
> 
> James Morse (2):
>       arm64: Add cpus_are_stuck_in_kernel
>       Documentation: dt: usable-memory and elfcorehdr nodes for arm64 kexec
> 
>  Documentation/devicetree/bindings/chosen.txt |  28 +++
>  Documentation/kdump/kdump.txt                |  15 +-
>  arch/arm64/Kconfig                           |  21 ++
>  arch/arm64/configs/defconfig                 |   2 +
>  arch/arm64/include/asm/hardirq.h             |   2 +-
>  arch/arm64/include/asm/kexec.h               |  87 ++++++++
>  arch/arm64/include/asm/smp.h                 |  14 ++
>  arch/arm64/include/asm/virt.h                |   5 +
>  arch/arm64/kernel/Makefile                   |   3 +
>  arch/arm64/kernel/cpu-reset.S                |  54 +++++
>  arch/arm64/kernel/cpu-reset.h                |  29 +++
>  arch/arm64/kernel/crash_dump.c               |  71 ++++++
>  arch/arm64/kernel/hyp-stub.S                 |  11 +-
>  arch/arm64/kernel/machine_kexec.c            | 309 +++++++++++++++++++++++++++
>  arch/arm64/kernel/relocate_kernel.S          | 131 ++++++++++++
>  arch/arm64/kernel/setup.c                    |   7 +-
>  arch/arm64/kernel/smp.c                      |  66 ++++++
>  arch/arm64/mm/init.c                         | 154 +++++++++++++
>  include/uapi/linux/kexec.h                   |   1 +
>  19 files changed, 1006 insertions(+), 4 deletions(-)
>  create mode 100644 arch/arm64/include/asm/kexec.h
>  create mode 100644 arch/arm64/kernel/cpu-reset.S
>  create mode 100644 arch/arm64/kernel/cpu-reset.h
>  create mode 100644 arch/arm64/kernel/crash_dump.c
>  create mode 100644 arch/arm64/kernel/machine_kexec.c
>  create mode 100644 arch/arm64/kernel/relocate_kernel.S
> 
> -- 
> 2.5.0
> 

-- 
Thanks,
-Takahiro AKASHI



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