[PATCH v2 2/2] misc: pvpanic: add crash loaded event

From: zhenwei pi
Date: Wed Dec 25 2019 - 01:27:21 EST


Some users prefer kdump tools to generate guest kernel dumpfile,
at the same time, need a out-of-band kernel panic event.

Currently if booting guest kernel with 'crash_kexec_post_notifiers',
QEMU will receive PVPANIC_PANICKED event and stop VM. If booting
guest kernel without 'crash_kexec_post_notifiers', guest will not
call notifier chain.

Add PVPANIC_CRASH_LOADED bit for pvpanic event, it means that guest
kernel actually hit a kernel panic, but the guest kernel wants to
handle by itself.

Signed-off-by: zhenwei pi <pizhenwei@xxxxxxxxxxxxx>
---
drivers/misc/pvpanic.c | 9 ++++++++-
include/uapi/misc/pvpanic.h | 1 +
2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/misc/pvpanic.c b/drivers/misc/pvpanic.c
index 3f0de3be0a19..a6e1a8983e1f 100644
--- a/drivers/misc/pvpanic.c
+++ b/drivers/misc/pvpanic.c
@@ -10,6 +10,7 @@

#include <linux/acpi.h>
#include <linux/kernel.h>
+#include <linux/kexec.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_address.h>
@@ -33,7 +34,13 @@ static int
pvpanic_panic_notify(struct notifier_block *nb, unsigned long code,
void *unused)
{
- pvpanic_send_event(PVPANIC_PANICKED);
+ unsigned int event = PVPANIC_PANICKED;
+
+ if (kexec_crash_loaded())
+ event = PVPANIC_CRASH_LOADED;
+
+ pvpanic_send_event(event);
+
return NOTIFY_DONE;
}

diff --git a/include/uapi/misc/pvpanic.h b/include/uapi/misc/pvpanic.h
index cae69a822b25..54b7485390d3 100644
--- a/include/uapi/misc/pvpanic.h
+++ b/include/uapi/misc/pvpanic.h
@@ -4,5 +4,6 @@
#define __PVPANIC_H__

#define PVPANIC_PANICKED (1 << 0)
+#define PVPANIC_CRASH_LOADED (1 << 1)

#endif /* __PVPANIC_H__ */
--
2.11.0