[PATCH v3 1/3] kexec_load: Use new kexec flag for hotplug support

Sourabh Jain sourabhjain at linux.ibm.com
Mon Jul 8 06:22:46 PDT 2024


Hello Baoquan,

On 08/07/24 16:00, Baoquan He wrote:
> On 07/07/24 at 08:54pm, Sourabh Jain wrote:
>> Kernel commit 79365026f869 (crash: add a new kexec flag for hotplug
>> support) has introduced a new kexec flag to generalize hotplug support.
>> The newly introduced kexec flags for hotplug allow architectures to
>> exclude all the required kexec segments from SHA calculation so that
>> the kernel can update them on hotplug events. This was not possible
>> earlier with the KEXEC_UPDATE_ELFCOREHDR kexec flags since it was added
>> only for the elfcorehdr segment.
>>
>> To enable architectures to control the list of kexec segments to exclude
>> when hotplug support is enabled, add a new architecture-specific
>> function named arch_do_exclude_segment. During the SHA calculation, this
>> function gets called to let the architecture decide whether a specific
>> kexec segment should be considered for SHA calculation or not.
>>
>> Note: To avoid breaking backward compatibility, the new kexec flag
>> KEXEC_CRASH_HOTPLUG_SUPPORT is not used for x86 for now.
>>
>> Cc: Aditya Gupta <adityag at linux.ibm.com>
>> Cc: Baoquan He <bhe at redhat.com>
>> Cc: Coiby Xu <coxu at redhat.com>
>> Cc: Hari Bathini <hbathini at linux.ibm.com>
>> Cc: Mahesh Salgaonkar <mahesh at linux.ibm.com>
>> Cc: Simon Horman <horms at kernel.org>
>> Signed-off-by: Sourabh Jain <sourabhjain at linux.ibm.com>
>> ---
>>   kexec/arch/arm/kexec-arm.c             |  5 ++++
>>   kexec/arch/arm64/kexec-arm64.c         |  5 ++++
>>   kexec/arch/cris/kexec-cris.c           |  4 +++
>>   kexec/arch/hppa/kexec-hppa.c           |  5 ++++
>>   kexec/arch/i386/kexec-x86.c            |  8 ++++++
>>   kexec/arch/ia64/kexec-ia64.c           |  4 +++
>>   kexec/arch/loongarch/kexec-loongarch.c |  5 ++++
>>   kexec/arch/m68k/kexec-m68k.c           |  5 ++++
>>   kexec/arch/mips/kexec-mips.c           |  4 +++
>>   kexec/arch/ppc/kexec-ppc.c             |  4 +++
>>   kexec/arch/ppc64/kexec-ppc64.c         |  5 ++++
>>   kexec/arch/s390/kexec-s390.c           |  5 ++++
>>   kexec/arch/sh/kexec-sh.c               |  5 ++++
>>   kexec/arch/x86_64/kexec-x86_64.c       |  8 ++++++
>>   kexec/kexec-syscall.h                  |  1 +
>>   kexec/kexec.c                          | 40 ++++++++++++++++++++++----
>>   kexec/kexec.h                          |  2 ++
>>   17 files changed, 109 insertions(+), 6 deletions(-)
> LGTM,
>
> Acked-by: Baoquan He <bhe at redhat.com>

Thank you for the Ack.

- Sourabh Jain



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