From: Andrea Bolognani <abologna@redhat.com>
Date: Tue, 10 Apr 2018 14:12:05 +0000 (+0200)
Subject: qemu: Figure out nodeset bitmap size correctly
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=931144858f7f6f7b82f343c8dc7e4db5d8570d0f;p=libvirt.git

qemu: Figure out nodeset bitmap size correctly

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@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
---

diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
index 4c62a44449..326c939c85 100644
--- a/src/qemu/qemu_domain.c
+++ b/src/qemu/qemu_domain.c
@@ -2236,6 +2236,8 @@ 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);
@@ -2247,8 +2249,14 @@ 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/>