[PATCH v2 2/3] powerpc/kexec_load: add hotplug support

Sourabh Jain sourabhjain at linux.ibm.com
Wed Jun 26 04:07:15 PDT 2024



On 26/06/24 15:37, Hari Bathini wrote:
>
>
> On 14/06/24 12:37 am, Sourabh Jain wrote:
>> Kernel commits b741092d5976 ("powerpc/crash: add crash CPU hotplug
>> support") and 849599b702ef ("powerpc/crash: add crash memory hotplug
>> support") added crash CPU/Memory hotplug support on PowerPC. This patch
>> extends that support for the kexec_load syscall.
>>
>> During CPU/Memory hotplug events on PowerPC, two kexec segments,
>> elfcorehdr, and FDT, get updated by the kernel. To ensure the kernel
>> can safely update these two kexec segments for the kdump image loaded
>> using the kexec_load system call, the following changes are made:
>>
>> 1. Extra size is allocated for both elfcorehdr and FDT to accommodate
>>     additional resources in the future. For the elfcorehdr, the size 
>> hint
>>     is taken from /sys/kernel/crash_elfcorehdr_size sysfs, while for 
>> FDT,
>>     extra size is allocated to hold possible CPU nodes.
>>
>> 2. Both elfcorehdr and FDT are skipped from SHA calculation.
>>
>> 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>
>
> LGTM.
>
> Acked-by: Hari Bathini <hbathini at linux.ibm.com>


Thanks Hari !



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