From 8e0778982e9a71000c6a1d999e0caf5934bebd61 Mon Sep 17 00:00:00 2001 From: Alex Williamson Date: Thu, 13 Dec 2018 21:54:44 +0100 Subject: [PATCH 2/5] balloon: Allow multiple inhibit users RH-Author: Alex Williamson Message-id: <154473808463.22725.5535931320059757090.stgit@gimli.home> Patchwork-id: 83494 O-Subject: [RHEL-7.7 qemu-kvm PATCH 2/5] balloon: Allow multiple inhibit users Bugzilla: 1659229 RH-Acked-by: Peter Xu RH-Acked-by: Cornelia Huck RH-Acked-by: Auger Eric Bugzilla: 1659229 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 Reviewed-by: Peter Xu Reviewed-by: Cornelia Huck Signed-off-by: Alex Williamson (cherry picked from commit 01ccbec7bdf6f89f1b7d46dda05e4c1fd2dd5ade) Signed-off-by: Miroslav Rezanina --- balloon.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/balloon.c b/balloon.c index c7a0cf1..6a17096 100644 --- a/balloon.c +++ b/balloon.c @@ -25,6 +25,7 @@ */ #include "monitor/monitor.h" +#include "qemu/atomic.h" #include "exec/cpu-common.h" #include "sysemu/kvm.h" #include "sysemu/balloon.h" @@ -35,16 +36,22 @@ 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); } int qemu_add_balloon_handler(QEMUBalloonEvent *event_func, -- 1.8.3.1