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From c9b5ec980523f458cf0e4cfd9f9d014e853f15aa Mon Sep 17 00:00:00 2001
From: Miroslav Rezanina <>
Date: Wed, 31 Jul 2013 08:01:44 +0200
Subject: qemu-kvm: Fix migration from older version due to i8254 changes

Message-id: <>
Patchwork-id: 52815
O-Subject: [RHEL-7 PATCH v3 01/15] qemu-kvm: Fix migration from older version due to i8254 changes
Bugzilla: 983991
RH-Acked-by: Paolo Bonzini <>
RH-Acked-by: Bandan Das <>
RH-Acked-by: Miroslav Rezanina <>

Old qemu-kvm already contained an equivalent field to i8254's
irq_disabled. We therefore have to remove upstream's version restriction
here to allow migration from older versions.

Signed-off-by: Jan Kiszka <>
Signed-off-by: Avi Kivity <>
(cherry picked from commit 81bdec908fb2be0ccaff1d4ee67956c509e440ad)


Picked from qemu-kvm-1.1.

qemu-kvm-0.11.0 commit f69b3e2 added PITState member flags, added it
to migration section "i8254", and bumped its version to 2.

qemu v0.12.0 commit 5122b43 ported i8254 to VMState, and also bumped
section version to 2.  Version 2 now means different things in qemu
and qemu-kvm.

This got merged into qemu-kvm-0.12.0 in commit f4f2edc.  The merge
added migration of flags to qemu's code.  Yet another version of
version 2.  This is what we got in RHEL-6.

qemu v1.1.0 commit ce967e2 added PITState member irq_disabled,
included it in migration section "i8254", and bumped its version to 3.
Because qemu's irq_disabled is compatible with qemu-kvm's flags,
qemu's version 3 is migration compatible with the latest instance of
qemu-kvm's version 2.

When this got merged into qemu-kvm-1.1.0, it changed qemu-kvm's
version 2 to no longer include flags / irq_disabled.  Commit 81bdec9
reverted the change of version 2.

We need to do the same to enable incoming migration from RHEL-6.

Signed-off-by: Markus Armbruster <>

diff --git a/hw/timer/i8254_common.c b/hw/timer/i8254_common.c
index 5342df4..f6f9d26 100644
--- a/hw/timer/i8254_common.c
+++ b/hw/timer/i8254_common.c
@@ -275,7 +275,7 @@ static const VMStateDescription vmstate_pit_common = {
     .pre_save = pit_dispatch_pre_save,
     .post_load = pit_dispatch_post_load,
     .fields = (VMStateField[]) {
-        VMSTATE_UINT32_V(channels[0].irq_disabled, PITCommonState, 3),
+        VMSTATE_UINT32(channels[0].irq_disabled, PITCommonState), /* qemu-kvm's v2 had 'flags' here */
         VMSTATE_STRUCT_ARRAY(channels, PITCommonState, 3, 2,
                              vmstate_pit_channel, PITChannelState),