From d3e302f2ab9543e1fb52c9d7b6c2167d054a62f5 Mon Sep 17 00:00:00 2001
From: Alex Williamson <alex.williamson@redhat.com>
Date: Mon, 3 Dec 2018 21:52:37 +0100
Subject: [PATCH 18/34] balloon: Allow multiple inhibit users
RH-Author: Alex Williamson <alex.williamson@redhat.com>
Message-id: <154387395708.26945.11708135028435449926.stgit@gimli.home>
Patchwork-id: 83227
O-Subject: [RHEL-7.7 qemu-kvm-rhev PATCH 1/7] balloon: Allow multiple inhibit users
Bugzilla: 1619778
RH-Acked-by: Peter Xu <peterx@redhat.com>
RH-Acked-by: Cornelia Huck <cohuck@redhat.com>
RH-Acked-by: Auger Eric <eric.auger@redhat.com>
RH-Acked-by: David Hildenbrand <david@redhat.com>
Bugzilla: 1619778
A simple true/false internal state does not allow multiple users. Fix
this within the existing interface by converting to a counter, so long
as the counter is elevated, ballooning is inhibited.
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
(cherry picked from commit 01ccbec7bdf6f89f1b7d46dda05e4c1fd2dd5ade)
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
balloon.c | 13 ++++++++++---
1 file changed, 10 insertions(+), 3 deletions(-)
diff --git a/balloon.c b/balloon.c
index 6bf0a96..9319879 100644
--- a/balloon.c
+++ b/balloon.c
@@ -26,6 +26,7 @@
#include "qemu/osdep.h"
#include "qemu-common.h"
+#include "qemu/atomic.h"
#include "exec/cpu-common.h"
#include "sysemu/kvm.h"
#include "sysemu/balloon.h"
@@ -37,16 +38,22 @@
static QEMUBalloonEvent *balloon_event_fn;
static QEMUBalloonStatus *balloon_stat_fn;
static void *balloon_opaque;
-static bool balloon_inhibited;
+static int balloon_inhibit_count;
bool qemu_balloon_is_inhibited(void)
{
- return balloon_inhibited;
+ return atomic_read(&balloon_inhibit_count) > 0;
}
void qemu_balloon_inhibit(bool state)
{
- balloon_inhibited = state;
+ if (state) {
+ atomic_inc(&balloon_inhibit_count);
+ } else {
+ atomic_dec(&balloon_inhibit_count);
+ }
+
+ assert(atomic_read(&balloon_inhibit_count) >= 0);
}
static bool have_balloon(Error **errp)
--
1.8.3.1