If all kernel boot memory regions are not registered for MPIPL before system crashes, try processing the partial crashdump but warn the user before proceeding.
Signed-off-by: Hari Bathini <hbath...@linux.ibm.com> --- arch/powerpc/platforms/powernv/opal-fadump.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) diff --git a/arch/powerpc/platforms/powernv/opal-fadump.c b/arch/powerpc/platforms/powernv/opal-fadump.c index 10f6086..6a05d51 100644 --- a/arch/powerpc/platforms/powernv/opal-fadump.c +++ b/arch/powerpc/platforms/powernv/opal-fadump.c @@ -71,6 +71,30 @@ static void opal_fadump_get_config(struct fw_dump *fadump_conf, */ fadump_conf->reserve_dump_area_start = fdm->rgn[0].dest; + /* + * Rarely, but it can so happen that system crashes before all + * boot memory regions are registered for MPIPL. In such + * cases, warn that the vmcore may not be accurate and proceed + * anyway as that is the best bet considering free pages, cache + * pages, user pages, etc are usually filtered out. + * + * Hope the memory that could not be preserved only has pages + * that are usually filtered out while saving the vmcore. + */ + if (fdm->region_cnt > fdm->registered_regions) { + pr_warn("Not all memory regions are saved as system seems to have crashed before all the memory regions could be registered for MPIPL!\n"); + pr_warn(" The below boot memory regions could not be saved:\n"); + i = fdm->registered_regions; + while (i < fdm->region_cnt) { + pr_warn("\t%d. base: 0x%llx, size: 0x%llx\n", (i + 1), + fdm->rgn[i].src, fdm->rgn[i].size); + i++; + } + + pr_warn(" Wishing for the above regions to have only pages that are usually filtered out (user pages, free pages, etc..) and proceeding anyway..\n"); + pr_warn(" But the sanity of the '/proc/vmcore' file depends on whether the above region(s) have any kernel pages or not.\n"); + } + opal_fadump_update_config(fadump_conf, fdm); }