[PATCH v17 00/13] arm64 kexec kernel patches

Tue Jun 7 23:31:19 PDT 2016

On Tue, Jun 07, 2016 at 10:36:19AM +0900, AKASHI Takahiro wrote:
> 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)

and
      o Fixed a returned value of pstate in crash_setup_regs(). Now return
        a faked pstate since we have no way to get the current pstate.

> 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