File 0145-s390x-kvm-fix-small-race-reboot-vs..patch of Package qemu.5923

From 86361dee5eb260eef4ac912c3b315f1ed53c14dd Mon Sep 17 00:00:00 2001
From: Christian Borntraeger <borntraeger@de.ibm.com>
Date: Tue, 24 Jan 2017 22:17:47 +0100
Subject: [PATCH] s390x/kvm: fix small race reboot vs. cmma

Right now we reset all devices before we reset the cmma states.  This
can result in the host kernel discarding guest pages that were
previously in the unused state but already contain a bios or a -kernel
file before the cmma reset has finished.  This race results in random
guest crashes or hangs during very early reboot.

Fixes: 1cd4e0f6f0a6 ("s390x/cmma: clean up cmma reset")
Cc: qemu-stable@nongnu.org
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
(cherry picked from commit 1a0e4c8b02ea510508970c333ee610a90b921cbb)
Signed-off-by: Bruce Rogers <brogers@suse.com>
---
 hw/s390x/s390-virtio.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hw/s390x/s390-virtio.c b/hw/s390x/s390-virtio.c
index 544c61643d..a353794154 100644
--- a/hw/s390x/s390-virtio.c
+++ b/hw/s390x/s390-virtio.c
@@ -200,8 +200,8 @@ void s390_machine_reset(void)
 {
     S390CPU *ipl_cpu = S390_CPU(qemu_get_cpu(0));
 
-    qemu_devices_reset();
     s390_cmma_reset();
+    qemu_devices_reset();
     s390_crypto_reset();
 
     /* all cpus are stopped - configure and start the ipl cpu only */