conf: don't format memtune with unlimited values

When changing memtune limits to unlimited with AFFECT_CONFIG, the
values in virDomainDef are set to PARAM_UNLIMITED, which causes the
whole <memtune> to be formatted.  This can be changed in all drivers,
but it also makes sense to use the default (0) as another value for
"unlimited", since zero memory limit makes no sense.

Signed-off-by: Martin Kletzander <mkletzan@redhat.com>

src/conf/domain_conf.c

@@ -16643,8 +16643,13 @@ virDomainDefFormatInternal(virDomainDefPtr def,
     }
 
     /* add memtune only if there are any */
-    if (def->mem.hard_limit || def->mem.soft_limit || def->mem.min_guarantee ||
+    if ((def->mem.hard_limit &&
-        def->mem.swap_hard_limit)
+         def->mem.hard_limit != VIR_DOMAIN_MEMORY_PARAM_UNLIMITED) ||
+        (def->mem.soft_limit &&
+         def->mem.hard_limit != VIR_DOMAIN_MEMORY_PARAM_UNLIMITED) ||
+        (def->mem.swap_hard_limit &&
+         def->mem.hard_limit != VIR_DOMAIN_MEMORY_PARAM_UNLIMITED) ||
+        def->mem.min_guarantee) {
         virBufferAddLit(buf, "  <memtune>\n");
         if (def->mem.hard_limit) {
             virBufferAsprintf(buf, "    <hard_limit unit='KiB'>"
@@ -16662,9 +16667,8 @@ virDomainDefFormatInternal(virDomainDefPtr def,
             virBufferAsprintf(buf, "    <swap_hard_limit unit='KiB'>"
                               "%llu</swap_hard_limit>\n", def->mem.swap_hard_limit);
         }
-    if (def->mem.hard_limit || def->mem.soft_limit || def->mem.min_guarantee ||
-        def->mem.swap_hard_limit)
         virBufferAddLit(buf, "  </memtune>\n");
+    }
 
     if (def->mem.hugepage_backed || def->mem.nosharepages || def->mem.locked) {
         virBufferAddLit(buf, "  <memoryBacking>\n");

tests/qemuxml2argvdata/qemuxml2argv-memtune-unlimited.args

@@ -0,0 +1,6 @@
+LC_ALL=C PATH=/bin HOME=/home/test USER=test LOGNAME=test QEMU_AUDIO_DRV=none \
+/usr/bin/qemu \
+-name QEMUGuest1 -S -M pc -m 214 -smp 1 -nographic -monitor \
+unix:/tmp/test-monitor,server,nowait -no-acpi -boot c -usb \
+-hda /dev/HostVG/QEMUGuest1 -net none -serial \
+none -parallel none

tests/qemuxml2argvdata/qemuxml2argv-memtune-unlimited.xml

@@ -0,0 +1,29 @@
+<domain type='qemu'>
+  <name>QEMUGuest1</name>
+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+  <memory unit='MiB'>214</memory>
+  <currentMemory unit='KiB'>219136</currentMemory>
+  <memtune>
+    <hard_limit unit='KiB'>9007199254740991</hard_limit>
+  </memtune>
+  <vcpu placement='static'>1</vcpu>
+  <os>
+    <type arch='i686' machine='pc'>hvm</type>
+    <boot dev='hd'/>
+  </os>
+  <clock offset='utc'/>
+  <on_poweroff>destroy</on_poweroff>
+  <on_reboot>restart</on_reboot>
+  <on_crash>destroy</on_crash>
+  <devices>
+    <emulator>/usr/bin/qemu</emulator>
+    <disk type='block' device='disk'>
+      <source dev='/dev/HostVG/QEMUGuest1'/>
+      <target dev='hda' bus='ide'/>
+      <address type='drive' controller='0' bus='0' target='0' unit='0'/>
+    </disk>
+    <controller type='usb' index='0'/>
+    <controller type='ide' index='0'/>
+    <memballoon model='virtio'/>
+  </devices>
+</domain>

tests/qemuxml2argvtest.c

@@ -1126,6 +1126,7 @@ mymain(void)
                     QEMU_CAPS_KVM, QEMU_CAPS_CPU_HOST);
 
     DO_TEST("memtune", QEMU_CAPS_NAME);
+    DO_TEST("memtune-unlimited", QEMU_CAPS_NAME);
     DO_TEST("blkiotune", QEMU_CAPS_NAME);
     DO_TEST("blkiotune-device", QEMU_CAPS_NAME);
     DO_TEST("cputune", QEMU_CAPS_NAME);

tests/qemuxml2xmloutdata/qemuxml2xmlout-memtune-unlimited.xml

@@ -0,0 +1,27 @@
+<domain type='qemu'>
+  <name>QEMUGuest1</name>
+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+  <memory unit='KiB'>219136</memory>
+  <currentMemory unit='KiB'>219136</currentMemory>
+  <vcpu placement='static'>1</vcpu>
+  <os>
+    <type arch='i686' machine='pc'>hvm</type>
+    <boot dev='hd'/>
+  </os>
+  <clock offset='utc'/>
+  <on_poweroff>destroy</on_poweroff>
+  <on_reboot>restart</on_reboot>
+  <on_crash>destroy</on_crash>
+  <devices>
+    <emulator>/usr/bin/qemu</emulator>
+    <disk type='block' device='disk'>
+      <source dev='/dev/HostVG/QEMUGuest1'/>
+      <target dev='hda' bus='ide'/>
+      <address type='drive' controller='0' bus='0' target='0' unit='0'/>
+    </disk>
+    <controller type='usb' index='0'/>
+    <controller type='ide' index='0'/>
+    <controller type='pci' index='0' model='pci-root'/>
+    <memballoon model='virtio'/>
+  </devices>
+</domain>

tests/qemuxml2xmltest.c

@@ -247,6 +247,7 @@ mymain(void)
 
     DO_TEST("encrypted-disk");
     DO_TEST_DIFFERENT("memtune");
+    DO_TEST_DIFFERENT("memtune-unlimited");
     DO_TEST("blkiotune");
     DO_TEST("blkiotune-device");
     DO_TEST("cputune");