fix logic of deleting balloon

Deleting the balloon config entry means resetting it to its
default. This means having a balloon device but not actually
doing any ballooning with it (iow. resetting the VM's
'balloon' value to its specified memory.).
Hotplugging a balloon device (coming from explicit '0' to
any other value (including deleting it)) is not possible.

Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>

diff --git a/PVE/QemuServer.pm b/PVE/QemuServer.pm
index 6756abdbe6bccd48ac39f8e405aba67658230254..2a07bcecd87ec56bffc793db24eaf96bb4ae120b 100644 (file)
--- a/PVE/QemuServer.pm
+++ b/PVE/QemuServer.pm
@@ -4297,7 +4297,10 @@ sub vmconfig_hotplug_pending {
                qemu_cpu_hotplug($vmid, $conf, undef);
             } elsif ($opt eq 'balloon') {
                # enable balloon device is not hotpluggable
-               die "skip\n" if !defined($conf->{balloon}) || $conf->{balloon};
+               die "skip\n" if defined($conf->{balloon}) && $conf->{balloon} == 0;
+               # here we reset the ballooning value to memory
+               my $balloon = $conf->{memory} || $defaults->{memory};
+               vm_mon_cmd($vmid, "balloon", value => $balloon*1024*1024);
            } elsif ($fast_plug_option->{$opt}) {
                # do nothing
            } elsif ($opt =~ m/^net(\d+)$/) {