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 2db3b0192eac7412d3eef676e98366b2437f5f1e..978a1cace3410bf53e438156bd1721f94c0c1e9e 100644 (file)
--- 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;
 }