On 2019-07-16 17:03:38 Tue, Hari Bathini wrote:
> Add support in the kernel to process the crash'ed kernel's memory
> preserved during MPIPL and export it as /proc/vmcore file for the
> userland scripts to filter and analyze it later.
>
> Signed-off-by: Hari Bathini <hbath...@linux.ibm.com>
> ---
> arch/powerpc/platforms/powernv/opal-fadump.c | 190
> ++++++++++++++++++++++++++
> 1 file changed, 187 insertions(+), 3 deletions(-)
>
[...]
> + ret = opal_mpipl_query_tag(OPAL_MPIPL_TAG_KERNEL, &addr);
> + if ((ret != OPAL_SUCCESS) || !addr) {
> + pr_err("Failed to get Kernel metadata (%lld)\n", ret);
> + return 1;
> + }
> +
> + addr = be64_to_cpu(addr);
> + pr_debug("Kernel metadata addr: %llx\n", addr);
> +
> + opal_fdm_active = __va(addr);
> + r_opal_fdm_active = (void *)addr;
> + if (r_opal_fdm_active->version != OPAL_FADUMP_VERSION) {
> + pr_err("FADump active but version (%u) unsupported!\n",
> + r_opal_fdm_active->version);
> + return 1;
> + }
> +
> + /* Kernel regions not registered with f/w for MPIPL */
> + if (r_opal_fdm_active->registered_regions == 0) {
> + opal_fdm_active = NULL;
What about partial dump capture scenario ? What if opal crashes while
kernel was in middle of registering ranges ? We may have partial dump
captured which won't be useful.
e,g. If we have total of 4 ranges to be registered and opal crashes
after successful registration of only 2 ranges with 2 pending, we will get a
partial dump which needs to be ignored.
I think check shuold be comparing registered_regions against total number of
regions. What do you think ?
Thanks,
-Mahesh.
> + return 1;
> + }
> +
> + pr_info("Firmware-assisted dump is active.\n");
> + fadump_conf->dump_active = 1;
> + opal_fadump_get_config(fadump_conf, r_opal_fdm_active);
> + }
> +
> return 1;
> }
>
--
Mahesh J Salgaonkar
