From ae27b925a8cda59917f47b834492fc77d341d898 Mon Sep 17 00:00:00 2001
From: Suraj Jitindar Singh <sursingh@redhat.com>
Date: Tue, 5 Dec 2017 05:55:19 +0100
Subject: [PATCH 14/21] target/ppc: Fix setting of cpu->compat_pvr on incoming
migration
RH-Author: Suraj Jitindar Singh <sursingh@redhat.com>
Message-id: <1512453319-16676-3-git-send-email-sursingh@redhat.com>
Patchwork-id: 78133
O-Subject: [RHEL7.5 qemu-kvm-rhev PATCH 2/2] target/ppc: Fix setting of cpu->compat_pvr on incoming migration
Bugzilla: 1517051
RH-Acked-by: Laurent Vivier <lvivier@redhat.com>
RH-Acked-by: David Gibson <dgibson@redhat.com>
RH-Acked-by: Thomas Huth <thuth@redhat.com>
From: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
cpu->compat_pvr is used to store the current compat mode of the cpu.
On the receiving side during incoming migration we check compatibility
with the compat mode by calling ppc_set_compat(). However we fail to set
the compat mode with the hypervisor since the "new" compat mode doesn't
differ from the current (due to a "cpu->compat_pvr != compat_pvr" check).
This means that kvm runs the vcpus without a compat mode, which is the
incorrect behaviour. The implication being that a compatibility mode
will never be in effect after migration.
To fix this so that the compat mode is correctly set with the
hypervisor, store the desired compat mode and reset cpu->compat_pvr to
zero before calling ppc_set_compat().
Fixes: 5dfaa532 ("ppc: fix ppc_set_compat() with KVM PR")
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
(cherry picked from commit e07cc1929515cfb808b5c2fcc60c079e6be110cf)
Signed-off-by: Suraj Jitindar Singh <sursingh@redhat.com>
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
target/ppc/machine.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/target/ppc/machine.c b/target/ppc/machine.c
index e36b710..760be64d 100644
--- a/target/ppc/machine.c
+++ b/target/ppc/machine.c
@@ -235,9 +235,11 @@ static int cpu_post_load(void *opaque, int version_id)
#if defined(TARGET_PPC64)
if (cpu->compat_pvr) {
+ uint32_t compat_pvr = cpu->compat_pvr;
Error *local_err = NULL;
- ppc_set_compat(cpu, cpu->compat_pvr, &local_err);
+ cpu->compat_pvr = 0;
+ ppc_set_compat(cpu, compat_pvr, &local_err);
if (local_err) {
error_report_err(local_err);
return -1;
--
1.8.3.1