[PATCH] misc: pvpanic: add crash loaded event

From: zhenwei pi
Date: Thu Dec 12 2019 - 07:32:35 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 recieve 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
actually hit a kernel panic, but kernel wants to handle by itself.

Signed-off-by: zhenwei pi <pizhenwei@xxxxxxxxxxxxx>
---
drivers/misc/pvpanic.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/misc/pvpanic.c b/drivers/misc/pvpanic.c
index 95ff7c5a1dfb..a8cc96c90550 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>
@@ -19,6 +20,7 @@
static void __iomem *base;

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

MODULE_AUTHOR("Hu Tao <hutao@xxxxxxxxxxxxxx>");
MODULE_DESCRIPTION("pvpanic device driver");
@@ -34,7 +36,13 @@ 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;
}

--
2.11.0