On 07/27/2020 03:36 AM, Hari Bathini wrote: > Sorry! There was a gateway issue on my system while posting v5, due to > which some patches did not make it through. Resending... > > This patch series enables kdump support for kexec_file_load system > call (kexec -s -p) on PPC64. The changes are inspired from kexec-tools > code but heavily modified for kernel consumption. > > The first patch adds a weak arch_kexec_locate_mem_hole() function to > override locate memory hole logic suiting arch needs. There are some > special regions in ppc64 which should be avoided while loading buffer > & there are multiple callers to kexec_add_buffer making it complicated > to maintain range sanity and using generic lookup at the same time. > > The second patch marks ppc64 specific code within arch/powerpc/kexec > and arch/powerpc/purgatory to make the subsequent code changes easy > to understand. > > The next patch adds helper function to setup different memory ranges > needed for loading kdump kernel, booting into it and exporting the > crashing kernel's elfcore. > > The fourth patch overrides arch_kexec_locate_mem_hole() function to > locate memory hole for kdump segments by accounting for the special > memory regions, referred to as excluded memory ranges, and sets > kbuf->mem when a suitable memory region is found. > > The fifth patch moves walk_drmem_lmbs() out of .init section with > a few changes to reuse it for setting up kdump kernel's usable memory > ranges. The next patch uses walk_drmem_lmbs() to look up the LMBs > and set linux,drconf-usable-memory & linux,usable-memory properties > in order to restrict kdump kernel's memory usage. > > The seventh patch updates purgatory to setup r8 & r9 with opal base > and opal entry addresses respectively to aid kernels built with > CONFIG_PPC_EARLY_DEBUG_OPAL enabled. The next patch setups up backup > region as a kexec segment while loading kdump kernel and teaches > purgatory to copy data from source to destination. > > Patch 09 builds the elfcore header for the running kernel & passes > the info to kdump kernel via "elfcorehdr=" parameter to export as > /proc/vmcore file. The next patch sets up the memory reserve map > for the kexec kernel and also claims kdump support for kdump as > all the necessary changes are added. > > The last patch fixes a lookup issue for `kexec -l -s` case when > memory is reserved for crashkernel. > > Tested the changes successfully on P8, P9 lpars, couple of OpenPOWER > boxes, one with secureboot enabled, KVM guest and a simulator. > > v4 -> v5: > * Dropped patches 07/12 & 08/12 and updated purgatory to do everything > in assembly. I guess you achieve this by carefully selecting instruction to avoid relocation issue, right? Thanks, Pingfan _______________________________________________ kexec mailing list kexec@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/kexec
