From: Jork Loeser <jloeser@linux.microsoft.com>
Date: Mon, 27 Apr 2026 21:38:53 +0000 (-0700)
Subject: mshv: clean up SynIC state on kexec for L1VH
X-Git-Url: http://git.ipfire.org/gitweb/index.cgi?a=commitdiff_plain;h=efe0fb8c3fe2b996522f7418fd311eeff43c1148;p=thirdparty%2Flinux.git

mshv: clean up SynIC state on kexec for L1VH

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@linux.microsoft.com>
Reviewed-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Reviewed-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
---

diff --git a/drivers/hv/mshv_synic.c b/drivers/hv/mshv_synic.c
index 2db3b0192eac..978a1cace341 100644
--- a/drivers/hv/mshv_synic.c
+++ b/drivers/hv/mshv_synic.c
@@ -723,9 +723,6 @@ 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;
 }