[libvirt] [PATCHv2] conf: rework the cpu check for vm numa settings

[Luyao Huang]

https://bugzilla.redhat.com/show_bug.cgi?id=1176020

We had a check for the vcpu count total number in <numa>
before, however this check is not good enough. There are
some examples:

1. one of cpu id is out of maxvcpus, can set success(cpu count = 5 < 10):

<vcpu placement='static'>10</vcpu>
<cell id='0' cpus='0-3,100' memory='512000' unit='KiB'/>

2. use the same cpu in 2 cell, can set success(cpu count = 8 < 10):
<vcpu placement='static'>10</vcpu>
<cell id='0' cpus='0-3' memory='512000' unit='KiB'/>
<cell id='1' cpus='0-3' memory='512000' unit='KiB'/>

3. use the same cpu in 2 cell, cannot set success(cpu count = 11 > 10):
<vcpu placement='static'>10</vcpu>
<cell id='0' cpus='0-6' memory='512000' unit='KiB'/>
<cell id='1' cpus='0-3' memory='512000' unit='KiB'/>

Use a new check for numa cpus, check if use a cpu exceeds maxvcpus
and if duplicate use one cpu in more than one cell.

Signed-off-by: Luyao Huang <lhuang at redhat.com>
---
 src/conf/domain_conf.c |  6 +-----
 src/conf/numa_conf.c   | 37 ++++++++++++++++++++++++++++++-------
 src/conf/numa_conf.h   |  2 +-
 3 files changed, 32 insertions(+), 13 deletions(-)

diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index 479b4c2..a4a2abb 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -14234,12 +14234,8 @@ virDomainDefParseXML(xmlDocPtr xml,
     if (virDomainNumaDefCPUParseXML(def->numa, ctxt) < 0)
         goto error;
 
-    if (virDomainNumaGetCPUCountTotal(def->numa) > def->maxvcpus) {
-        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
-                       _("Number of CPUs in <numa> exceeds the"
-                         " <vcpu> count"));
+    if (virDomainNumaCheckCPU(def->numa, def->maxvcpus) < 0)
         goto error;
-    }
 
     if (virDomainNumatuneParseXML(def->numa,
                                   def->placement_mode ==
diff --git a/src/conf/numa_conf.c b/src/conf/numa_conf.c
index 7ad3f66..2b18225 100644
--- a/src/conf/numa_conf.c
+++ b/src/conf/numa_conf.c
@@ -805,16 +805,39 @@ virDomainNumaDefCPUFormat(virBufferPtr buf,
 }
 
 
-unsigned int
-virDomainNumaGetCPUCountTotal(virDomainNumaPtr numa)
+int
+virDomainNumaCheckCPU(virDomainNumaPtr numa,
+                      unsigned short maxvcpus)
 {
-    size_t i;
-    unsigned int ret = 0;
+    size_t i,j;
 
-    for (i = 0; i < numa->nmem_nodes; i++)
-        ret += virBitmapCountBits(virDomainNumaGetNodeCpumask(numa, i));
+    for (i = 0; i < numa->nmem_nodes; i++) {
+        virBitmapPtr nodeset = NULL;
+        ssize_t bit = -1;
+
+        nodeset = virDomainNumaGetNodeCpumask(numa, i);
+        for (j = 0; j < i; j++) {
+            if (virBitmapOverlaps(virDomainNumaGetNodeCpumask(numa, j),
+                                  nodeset)) {
+                virReportError(VIR_ERR_INTERNAL_ERROR,
+                               _("Cannot binding one vCPU in 2 NUMA cell"
+                                 " %zu and %zu"), i, j);
+                return -1;
+            }
+        }
 
-    return ret;
+        while ((bit = virBitmapNextSetBit(nodeset, bit)) >= 0) {
+            if (bit <= maxvcpus-1)
+                continue;
+
+            virReportError(VIR_ERR_INTERNAL_ERROR,
+                           _("vcpu '%zu' in <numa> cell '%zu' exceeds the maxvcpus"),
+                           bit, i);
+            return -1;
+        }
+    }
+
+    return 0;
 }
 
 
diff --git a/src/conf/numa_conf.h b/src/conf/numa_conf.h
index ded6e01..d7713c8 100644
--- a/src/conf/numa_conf.h
+++ b/src/conf/numa_conf.h
@@ -149,7 +149,7 @@ bool virDomainNumatuneNodeSpecified(virDomainNumaPtr numatune,
 int virDomainNumaDefCPUParseXML(virDomainNumaPtr def, xmlXPathContextPtr ctxt);
 int virDomainNumaDefCPUFormat(virBufferPtr buf, virDomainNumaPtr def);
 
-unsigned int virDomainNumaGetCPUCountTotal(virDomainNumaPtr numa);
+int virDomainNumaCheckCPU(virDomainNumaPtr numa, unsigned short maxvcpus);
 
 
 #endif /* __NUMA_CONF_H__ */
-- 
1.8.3.1