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>
---
Changes in v6:
* Use prints suggested by mpe.
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 5ace7c4..533adae 100644
--- a/arch/powerpc/platforms/powernv/opal-fadump.c
+++ b/arch/powerpc/platforms/powernv/opal-fadump.c
@@ -69,6 +69,30 @@ 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 were saved!!!\n");
+ pr_warn(" Unsaved memory regions:\n");
+ i = fdm->registered_regions;
+ while (i < fdm->region_cnt) {
+ pr_warn("\t[%03d] base: 0x%llx, size: 0x%llx\n",
+ i, fdm->rgn[i].src, fdm->rgn[i].size);
+ i++;
+ }
+
+ pr_warn("If the unsaved regions only contain pages that are
filtered out (eg. free/user pages), the vmcore should still be usable.\n");
+ pr_warn("WARNING: If the unsaved regions contain kernel pages,
the vmcore will be corrupted.\n");
+ }
+
opal_fadump_update_config(fadump_conf, fdm);
}
