[libvirt] [PATCH v2 2/2] qemu: Figure out nodeset bitmap size correctly

[Andrea Bolognani]

The current private XML parsing code relies on the assumption
that NUMA node IDs start from 0 and are densely allocated,
neither of which is necessarily the case.

Change it so that the bitmap size is dynamically calculated by
looking at NUMA node IDs instead, which ensures all nodes will
be able to fit and thus the bitmap will be parsed successfully.

Update one of the test cases so that it would fail with the
previous approach, but passes with the new one.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1490158
Signed-off-by: Andrea Bolognani <abologna at redhat.com>
---
 src/qemu/qemu_domain.c                    | 10 +++++++++-
 tests/qemustatusxml2xmldata/modern-in.xml |  2 +-
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
index 21897cb47a..2670a10119 100644
--- a/src/qemu/qemu_domain.c
+++ b/src/qemu/qemu_domain.c
@@ -2233,6 +2233,8 @@ qemuDomainObjPrivateXMLParseAutomaticPlacement(xmlXPathContextPtr ctxt,
     virCapsPtr caps = NULL;
     char *nodeset;
     char *cpuset;
+    int nodesetSize = 0;
+    size_t i;
     int ret = -1;
 
     nodeset = virXPathString("string(./numad/@nodeset)", ctxt);
@@ -2244,8 +2246,14 @@ qemuDomainObjPrivateXMLParseAutomaticPlacement(xmlXPathContextPtr ctxt,
     if (!(caps = virQEMUDriverGetCapabilities(driver, false)))
         goto cleanup;
 
+    /* Figure out how big the nodeset bitmap needs to be.
+     * This is necessary because NUMA node IDs are not guaranteed to
+     * start from 0 or be densely allocated */
+    for (i = 0; i < caps->host.nnumaCell; i++)
+        nodesetSize = MAX(nodesetSize, caps->host.numaCell[i]->num + 1);
+
     if (nodeset &&
-        virBitmapParse(nodeset, &priv->autoNodeset, caps->host.nnumaCell_max) < 0)
+        virBitmapParse(nodeset, &priv->autoNodeset, nodesetSize) < 0)
         goto cleanup;
 
     if (cpuset) {
diff --git a/tests/qemustatusxml2xmldata/modern-in.xml b/tests/qemustatusxml2xmldata/modern-in.xml
index 2e166e6e67..c1e57618b6 100644
--- a/tests/qemustatusxml2xmldata/modern-in.xml
+++ b/tests/qemustatusxml2xmldata/modern-in.xml
@@ -252,7 +252,7 @@
     <device alias='usb'/>
     <device alias='ide0-0-0'/>
   </devices>
-  <numad nodeset='0' cpuset='0-7'/>
+  <numad nodeset='6' cpuset='0-7'/>
   <libDir path='/var/lib/libvirt/qemu/domain-1-upstream'/>
   <channelTargetDir path='/var/lib/libvirt/qemu/channel/target/domain-1-upstream'/>
   <chardevStdioLogd/>
-- 
2.14.3