[60/81] s390x/kvm: fix small race reboot vs. cmma

Submitted by Michael Roth on March 20, 2017, 11:08 p.m.

Details

Message ID 1490051325-3770-61-git-send-email-mdroth@linux.vnet.ibm.com
State New
Headers show

Commit Message

Michael Roth March 20, 2017, 11:08 p.m.
From: Christian Borntraeger <borntraeger@de.ibm.com>

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: Michael Roth <mdroth@linux.vnet.ibm.com>
---
 hw/s390x/s390-virtio.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Patch hide | download patch | download mbox

diff --git a/hw/s390x/s390-virtio.c b/hw/s390x/s390-virtio.c
index 0a96347..7a3a7fe 100644
--- a/hw/s390x/s390-virtio.c
+++ b/hw/s390x/s390-virtio.c
@@ -204,8 +204,8 @@  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 */