From 0f41423f2bb57e77400cfec0683b7514c9798c55 Mon Sep 17 00:00:00 2001
From: Laurent Vivier <lvivier@redhat.com>
Date: Wed, 4 Aug 2021 07:10:13 -0400
Subject: [PATCH 22/39] migration: failover: continue to wait card unplug on
 error

RH-Author: Miroslav Rezanina <mrezanin@redhat.com>
RH-MergeRequest: 32: Synchronize with RHEL-AV 8.5 release 27 to RHEL 9
RH-Commit: [14/15] e3bfdeee808b2ecd5b141464193b6ee97a4bca3a (mrezanin/centos-src-qemu-kvm)
RH-Bugzilla: 1957194
RH-Acked-by: Stefano Garzarella <sgarzare@redhat.com>
RH-Acked-by: Kevin Wolf <kwolf@redhat.com>
RH-Acked-by: Igor Mammedov <imammedo@redhat.com>
RH-Acked-by: Andrew Jones <drjones@redhat.com>

If the user cancels the migration in the unplug-wait state,
QEMU will try to plug back the card and this fails because the card
is partially unplugged.
To avoid the problem, continue to wait the card unplug, but to
allow the migration to be canceled if the card never finishes to unplug
use a timeout.

Bug: https://bugzilla.redhat.com/show_bug.cgi?id=1976852
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20210629155007.629086-3-lvivier@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
(cherry picked from commit 944bc528421aa848ca218ee535ea923a4147a525)
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
 migration/migration.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/migration/migration.c b/migration/migration.c
index 58df1dac05..fc1d0db04a 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -3696,6 +3696,17 @@ static void qemu_savevm_wait_unplug(MigrationState *s, int old_state,
                qemu_savevm_state_guest_unplug_pending()) {
             qemu_sem_timedwait(&s->wait_unplug_sem, 250);
         }
+        if (s->state != MIGRATION_STATUS_WAIT_UNPLUG) {
+            int timeout = 120; /* 30 seconds */
+            /*
+             * migration has been canceled
+             * but as we have started an unplug we must wait the end
+             * to be able to plug back the card
+             */
+            while (timeout-- && qemu_savevm_state_guest_unplug_pending()) {
+                qemu_sem_timedwait(&s->wait_unplug_sem, 250);
+            }
+        }
 
         migrate_set_state(&s->state, MIGRATION_STATUS_WAIT_UNPLUG, new_state);
     } else {
-- 
2.27.0