summaryrefslogtreecommitdiff
path: root/Documentation
diff options
context:
space:
mode:
authorSunil Muthuswamy <sunilmut@microsoft.com>2018-07-08 02:56:51 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-07-08 15:54:31 +0200
commit81b18bce48af3e222ca9eebb3b931f59141b7b49 (patch)
tree6b54ead39883ffb38b2665882a5a7ebdfe8086f6 /Documentation
parente464d28273f895bfc57bfec2beb8a894eb45237c (diff)
Drivers: HV: Send one page worth of kmsg dump over Hyper-V during panic
In the VM mode on Hyper-V, currently, when the kernel panics, an error code and few register values are populated in an MSR and the Hypervisor notified. This information is collected on the host. The amount of information currently collected is found to be limited and not very actionable. To gather more actionable data, such as stack trace, the proposal is to write one page worth of kmsg data on an allocated page and the Hypervisor notified of the page address through the MSR. - Sysctl option to control the behavior, with ON by default. Cc: K. Y. Srinivasan <kys@microsoft.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Signed-off-by: Sunil Muthuswamy <sunilmut@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/sysctl/kernel.txt11
1 files changed, 11 insertions, 0 deletions
diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt
index eded671d55eb..59585030cbaf 100644
--- a/Documentation/sysctl/kernel.txt
+++ b/Documentation/sysctl/kernel.txt
@@ -39,6 +39,7 @@ show up in /proc/sys/kernel:
- hung_task_check_count
- hung_task_timeout_secs
- hung_task_warnings
+- hyperv_record_panic_msg
- kexec_load_disabled
- kptr_restrict
- l2cr [ PPC only ]
@@ -374,6 +375,16 @@ This file shows up if CONFIG_DETECT_HUNG_TASK is enabled.
==============================================================
+hyperv_record_panic_msg:
+
+Controls whether the panic kmsg data should be reported to Hyper-V.
+
+0: do not report panic kmsg data.
+
+1: report the panic kmsg data. This is the default behavior.
+
+==============================================================
+
kexec_load_disabled:
A toggle indicating if the kexec_load syscall has been disabled. This