From 91995f02cd4c100d26edd6df3dae0813b8685c02 Mon Sep 17 00:00:00 2001
From: David Hildenbrand <david@redhat.com>
Date: Fri, 21 Dec 2018 15:36:08 +0000
Subject: [PATCH 06/22] s390x/tcg: SET CLOCK COMPARATOR can clear CKC
 interrupts

RH-Author: David Hildenbrand <david@redhat.com>
Message-id: <20181221153614.27961-7-david@redhat.com>
Patchwork-id: 83750
O-Subject: [RHEL-8.0 qemu-kvm v2 PATCH 06/12] s390x/tcg: SET CLOCK COMPARATOR can clear CKC interrupts
Bugzilla: 1653569
RH-Acked-by: Cornelia Huck <cohuck@redhat.com>
RH-Acked-by: Thomas Huth <thuth@redhat.com>
RH-Acked-by: Laurent Vivier <lvivier@redhat.com>

Let's stop the timer and delete any pending CKC IRQ before doing
anything else.

While at it, add a comment why the check for ckc == -1ULL is needed.

Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20180627134410.4901-7-david@redhat.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
(cherry picked from commit 345f1ab96e8279a537f32ae7447296d23308c7d1)
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Danilo C. L. de Paula <ddepaula@redhat.com>
---
 target/s390x/misc_helper.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/target/s390x/misc_helper.c b/target/s390x/misc_helper.c
index 4f675c7..cada7af 100644
--- a/target/s390x/misc_helper.c
+++ b/target/s390x/misc_helper.c
@@ -155,6 +155,13 @@ void HELPER(sckc)(CPUS390XState *env, uint64_t time)
 {
     S390TODState *td = s390_get_todstate();
 
+    /* stop the timer and remove pending CKC IRQs */
+    timer_del(env->tod_timer);
+    qemu_mutex_lock_iothread();
+    env->pending_int &= ~INTERRUPT_EXT_CLOCK_COMPARATOR;
+    qemu_mutex_unlock_iothread();
+
+    /* the tod has to exceed the ckc, this can never happen if ckc is all 1's */
     if (time == -1ULL) {
         return;
     }
-- 
1.8.3.1