conf: Introduce virDomainDefPostParseMemtune

Previously we were ignoring "nodeset" attribute for hugepage pages
if there was no guest NUMA topology configured in the domain XML.
Commit <fa6bdf6afa878b8d7c5ed71664ee72be8967cdc5> partially fixed
that issue but it introduced a somehow valid regression.

In case that there is no guest NUMA topology configured and the
"nodeset" attribute is set to "0" it was accepted and was working
properly even though it was not completely valid XML.

This patch introduces a workaround that it will ignore the nodeset="0"
only in case that there is no guest NUMA topology in order not to
hit the validation error.

After this commit the following XML configuration is valid:

  <memoryBacking>
    <hugepages>
      <page size='2048' unit='KiB' nodeset='0'/>
    </hugepages>
  </memoryBacking>

but this configuration remains invalid:

  <memoryBacking>
    <hugepages>
      <page size='2048' unit='KiB' nodeset='0'/>
      <page size='1048576' unit='KiB'/>
    </hugepages>
  </memoryBacking>

The issue with the second configuration is that it was originally
working, however changing the order of the <page> elements resolved
into using different page size for the guest.  The code is written
in a way that it expect only one page configured and always uses only
the first page in case that there is no guest NUMA topology configured.
See qemuBuildMemPathStr() function for details.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1591235

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>

diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index f88576b5ccb26fb0ccdf99a8a77f68d4aaf6847e..f0d44bb75da3b407ab061a8a3a422f5bb666f83f 100644 (file)
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -4088,6 +4088,31 @@ virDomainDefPostParseMemory(virDomainDefPtr def,
 }
 
 
+static void
+virDomainDefPostParseMemtune(virDomainDefPtr def)
+{
+    size_t i;
+
+    if (virDomainNumaGetNodeCount(def->numa) == 0) {
+        /* If guest NUMA is not configured and any hugepage page has nodemask
+         * set to "0" free and clear that nodemas, otherwise we would rise
+         * an error that there is no guest NUMA node configured. */
+        for (i = 0; i < def->mem.nhugepages; i++) {
+            ssize_t nextBit;
+
+            if (!def->mem.hugepages[i].nodemask)
+                continue;
+
+            nextBit = virBitmapNextSetBit(def->mem.hugepages[i].nodemask, 0);
+            if (nextBit < 0) {
+                virBitmapFree(def->mem.hugepages[i].nodemask);
+                def->mem.hugepages[i].nodemask = NULL;
+            }
+        }
+    }
+}
+
+
 static int
 virDomainDefAddConsoleCompat(virDomainDefPtr def)
 {
@@ -5145,6 +5170,8 @@ virDomainDefPostParseCommon(virDomainDefPtr def,
     if (virDomainDefPostParseMemory(def, data->parseFlags) < 0)
         return -1;
 
+    virDomainDefPostParseMemtune(def);
+
     if (virDomainDefRejectDuplicateControllers(def) < 0)
         return -1;
 

diff --git a/tests/qemuxml2argvdata/hugepages-nodeset.args b/tests/qemuxml2argvdata/hugepages-nodeset.args
new file mode 100644 (file)
index 0000000..6c5ade2
--- /dev/null
+++ b/tests/qemuxml2argvdata/hugepages-nodeset.args
@@ -0,0 +1,25 @@
+LC_ALL=C \
+PATH=/bin \
+HOME=/home/test \
+USER=test \
+LOGNAME=test \
+QEMU_AUDIO_DRV=none \
+/usr/bin/qemu-system-i686 \
+-name SomeDummyHugepagesGuest \
+-S \
+-machine pc,accel=tcg,usb=off,dump-guest-core=off \
+-m 1024 \
+-mem-prealloc \
+-mem-path /dev/hugepages2M/libvirt/qemu/-1-SomeDummyHugepagesGu \
+-smp 2,sockets=2,cores=1,threads=1 \
+-uuid ef1bdff4-27f3-4e85-a807-5fb4d58463cc \
+-display none \
+-no-user-config \
+-nodefaults \
+-chardev socket,id=charmonitor,\
+path=/tmp/lib/domain--1-SomeDummyHugepagesGu/monitor.sock,server,nowait \
+-mon chardev=charmonitor,id=monitor,mode=control \
+-rtc base=utc \
+-no-shutdown \
+-no-acpi \
+-usb

diff --git a/tests/qemuxml2argvtest.c b/tests/qemuxml2argvtest.c
index 8d883efafd1a08d2c8592edb8e021f712557083f..96482a84a19a92b73b048b11a18a2929e91a095f 100644 (file)
--- a/tests/qemuxml2argvtest.c
+++ b/tests/qemuxml2argvtest.c
@@ -959,7 +959,7 @@ mymain(void)
     DO_TEST("hugepages-default-2M", NONE);
     DO_TEST("hugepages-default-system-size", NONE);
     DO_TEST_PARSE_ERROR("hugepages-default-1G-nodeset-2M", NONE);
-    DO_TEST_PARSE_ERROR("hugepages-nodeset", NONE);
+    DO_TEST("hugepages-nodeset", NONE);
     DO_TEST_PARSE_ERROR("hugepages-nodeset-nonexist",
                         QEMU_CAPS_DEVICE_PC_DIMM,
                         QEMU_CAPS_OBJECT_MEMORY_FILE,

diff --git a/tests/qemuxml2xmloutdata/hugepages-nodeset.xml b/tests/qemuxml2xmloutdata/hugepages-nodeset.xml
new file mode 100644 (file)
index 0000000..ac219a7
--- /dev/null
+++ b/tests/qemuxml2xmloutdata/hugepages-nodeset.xml
@@ -0,0 +1,30 @@
+<domain type='qemu'>
+  <name>SomeDummyHugepagesGuest</name>
+  <uuid>ef1bdff4-27f3-4e85-a807-5fb4d58463cc</uuid>
+  <memory unit='KiB'>1048576</memory>
+  <currentMemory unit='KiB'>1048576</currentMemory>
+  <memoryBacking>
+    <hugepages>
+      <page size='2048' unit='KiB'/>
+    </hugepages>
+  </memoryBacking>
+  <vcpu placement='static'>2</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-system-i686</emulator>
+    <controller type='usb' index='0'>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x2'/>
+    </controller>
+    <controller type='pci' index='0' model='pci-root'/>
+    <input type='mouse' bus='ps2'/>
+    <input type='keyboard' bus='ps2'/>
+    <memballoon model='none'/>
+  </devices>
+</domain>

diff --git a/tests/qemuxml2xmltest.c b/tests/qemuxml2xmltest.c
index d5f6db5504ba36d080791c0b2d1b61eb5fe3f857..7fe504351973bbced75d941eb1a52f1ef8760f81 100644 (file)
--- a/tests/qemuxml2xmltest.c
+++ b/tests/qemuxml2xmltest.c
@@ -331,6 +331,7 @@ mymain(void)
     DO_TEST("hugepages-default", NONE);
     DO_TEST("hugepages-default-2M", NONE);
     DO_TEST("hugepages-default-system-size", NONE);
+    DO_TEST("hugepages-nodeset", NONE);
     DO_TEST("hugepages-numa-default-2M", NONE);
     DO_TEST("hugepages-numa-default-dimm", NONE);
     DO_TEST("hugepages-numa-nodeset", NONE);