x86/hyperv: move stimer cleanup to hv_machine_shutdown()

Move hv_stimer_global_cleanup() from vmbus's hv_kexec_handler() to
hv_machine_shutdown() in the platform code. This ensures stimer cleanup
happens before the vmbus unload, which is required for root partition
kexec to work correctly.

Co-developed-by: Anirudh Rayabharam <anrayabh@linux.microsoft.com>
Signed-off-by: Anirudh Rayabharam <anrayabh@linux.microsoft.com>
Signed-off-by: Jork Loeser <jloeser@linux.microsoft.com>
Reviewed-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>

arch/x86/kernel/cpu/mshyperv.c

@@ -235,8 +235,12 @@ void hv_remove_crash_handler(void)
 #ifdef CONFIG_KEXEC_CORE
 static void hv_machine_shutdown(void)
 {
-	if (kexec_in_progress && hv_kexec_handler)
-		hv_kexec_handler();
+	if (kexec_in_progress) {
+		hv_stimer_global_cleanup();
+
+		if (hv_kexec_handler)
+			hv_kexec_handler();
+	}
 
 	/*
 	 * Call hv_cpu_die() on all the CPUs, otherwise later the hypervisor

drivers/hv/vmbus_drv.c

@@ -2883,7 +2883,6 @@ static struct platform_driver vmbus_platform_driver = {
 
 static void hv_kexec_handler(void)
 {
-	hv_stimer_global_cleanup();
 	vmbus_initiate_unload(false);
 	/* Make sure conn_state is set as hv_synic_cleanup checks for it */
 	mb();