[PATCH v3 5/6] mshv: clean up SynIC state on kexec for L1VH

[Jork Loeser]

The reboot notifier that tears down the SynIC cpuhp state guards the
cleanup with hv_root_partition(), so on L1VH (where
hv_root_partition() is false) SINT0, SINT5, and SIRBP are never
cleaned up before kexec. The kexec'd kernel then inherits stale
unmasked SINTs and an enabled SIRBP pointing to freed memory.

Remove the hv_root_partition() guard so the cleanup runs for all
parent partitions.

Signed-off-by: Jork Loeser <jloeser@xxxxxxxxxxxxxxxxxxx>
---
 drivers/hv/mshv_synic.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/drivers/hv/mshv_synic.c b/drivers/hv/mshv_synic.c
index f71d5dfce1c1..8fe673c876fd 100644
--- a/drivers/hv/mshv_synic.c
+++ b/drivers/hv/mshv_synic.c
@@ -719,9 +719,6 @@ mshv_unregister_doorbell(u64 partition_id, int doorbell_portid)
 static int mshv_synic_reboot_notify(struct notifier_block *nb,
 			      unsigned long code, void *unused)
 {
-	if (!hv_root_partition())
-		return 0;
-
 	cpuhp_remove_state(synic_cpuhp_online);
 	return 0;
 }
-- 
2.43.0