From e67ccd3cf8415b78ce0b800de3e51cc28f9a2d7c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= <berrange@redhat.com>
Date: Wed, 18 Dec 2019 06:31:53 -0500
Subject: [PATCH] conf: fix populating of fake NUMA in multi-node hosts
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If the host OS doesn't have NUMA present, we fallback to
populating fake NUMA info and the code thus assumes only a
single NUMA node.

Unfortunately we also fallback to fake NUMA if numactl-devel
was not present, and in this case we can still have multiple
NUMA nodes. In this case we create all CPUs, but only the
CPUs in the first node have any data filled in, resulting in
capabilities like:

    <topology>
      <cells num='1'>
        <cell id='0'>
          <memory unit='KiB'>15977572</memory>
          <cpus num='48'>
            <cpu id='0' socket_id='0' core_id='0' siblings='0'/>
            <cpu id='1' socket_id='0' core_id='0' siblings='1'/>
            <cpu id='2' socket_id='0' core_id='1' siblings='2'/>
            <cpu id='3' socket_id='0' core_id='1' siblings='3'/>
            <cpu id='4' socket_id='0' core_id='2' siblings='4'/>
            <cpu id='5' socket_id='0' core_id='2' siblings='5'/>
            <cpu id='6' socket_id='0' core_id='3' siblings='6'/>
            <cpu id='7' socket_id='0' core_id='3' siblings='7'/>
            <cpu id='8' socket_id='0' core_id='4' siblings='8'/>
            <cpu id='9' socket_id='0' core_id='4' siblings='9'/>
            <cpu id='10' socket_id='0' core_id='5' siblings='10'/>
            <cpu id='11' socket_id='0' core_id='5' siblings='11'/>
            <cpu id='0'/>
            <cpu id='0'/>
            <cpu id='0'/>
            <cpu id='0'/>
            <cpu id='0'/>
            <cpu id='0'/>
            <cpu id='0'/>
            <cpu id='0'/>
            <cpu id='0'/>
            <cpu id='0'/>
            <cpu id='0'/>
          </cpus>
        </cell>
      </cells>
    </topology>

With this new code we get something slightly less broken

    <topology>
      <cells num='4'>
        <cell id='0'>
          <memory unit='KiB'>15977572</memory>
          <cpus num='12'>
            <cpu id='0' socket_id='0' core_id='0' siblings='0-1'/>
            <cpu id='1' socket_id='0' core_id='0' siblings='0-1'/>
            <cpu id='2' socket_id='0' core_id='1' siblings='2-3'/>
            <cpu id='3' socket_id='0' core_id='1' siblings='2-3'/>
            <cpu id='4' socket_id='0' core_id='2' siblings='4-5'/>
            <cpu id='5' socket_id='0' core_id='2' siblings='4-5'/>
            <cpu id='6' socket_id='0' core_id='3' siblings='6-7'/>
            <cpu id='7' socket_id='0' core_id='3' siblings='6-7'/>
            <cpu id='8' socket_id='0' core_id='4' siblings='8-9'/>
            <cpu id='9' socket_id='0' core_id='4' siblings='8-9'/>
            <cpu id='10' socket_id='0' core_id='5' siblings='10-11'/>
            <cpu id='11' socket_id='0' core_id='5' siblings='10-11'/>
          </cpus>
        </cell>
        <cell id='0'>
          <memory unit='KiB'>15977572</memory>
          <cpus num='12'>
            <cpu id='12' socket_id='0' core_id='0' siblings='12-13'/>
            <cpu id='13' socket_id='0' core_id='0' siblings='12-13'/>
            <cpu id='14' socket_id='0' core_id='1' siblings='14-15'/>
            <cpu id='15' socket_id='0' core_id='1' siblings='14-15'/>
            <cpu id='16' socket_id='0' core_id='2' siblings='16-17'/>
            <cpu id='17' socket_id='0' core_id='2' siblings='16-17'/>
            <cpu id='18' socket_id='0' core_id='3' siblings='18-19'/>
            <cpu id='19' socket_id='0' core_id='3' siblings='18-19'/>
            <cpu id='20' socket_id='0' core_id='4' siblings='20-21'/>
            <cpu id='21' socket_id='0' core_id='4' siblings='20-21'/>
            <cpu id='22' socket_id='0' core_id='5' siblings='22-23'/>
            <cpu id='23' socket_id='0' core_id='5' siblings='22-23'/>
          </cpus>
        </cell>
      </cells>
    </topology>

The topology at least now reflects what 'virsh nodeinfo' reports.
The main bug is that the CPU "id" values won't match what the Linux
host actually uses.

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
---
 src/conf/capabilities.c | 67 ++++++++++++++++++++++-------------------
 1 file changed, 36 insertions(+), 31 deletions(-)

diff --git a/src/conf/capabilities.c b/src/conf/capabilities.c
index b89fa22d74..da54591c11 100644
--- a/src/conf/capabilities.c
+++ b/src/conf/capabilities.c
@@ -1596,7 +1596,7 @@ virCapabilitiesHostNUMAInitFake(virCapsHostNUMAPtr caps)
     virNodeInfo nodeinfo;
     virCapsHostNUMACellCPUPtr cpus;
     int ncpus;
-    int s, c, t;
+    int n, s, c, t;
     int id, cid;
     int onlinecpus G_GNUC_UNUSED;
     bool tmp;
@@ -1605,47 +1605,52 @@ virCapabilitiesHostNUMAInitFake(virCapsHostNUMAPtr caps)
         return -1;
 
     ncpus = VIR_NODEINFO_MAXCPUS(nodeinfo);
-    onlinecpus = nodeinfo.cpus;
 
-    if (VIR_ALLOC_N(cpus, ncpus) < 0)
-        return -1;
 
-    id = cid = 0;
-    for (s = 0; s < nodeinfo.sockets; s++) {
-        for (c = 0; c < nodeinfo.cores; c++) {
-            for (t = 0; t < nodeinfo.threads; t++) {
-                if (virHostCPUGetOnline(id, &tmp) < 0)
-                    goto error;
-                if (tmp) {
-                    cpus[cid].id = id;
-                    cpus[cid].socket_id = s;
-                    cpus[cid].core_id = c;
-                    if (!(cpus[cid].siblings = virBitmapNew(ncpus)))
+    id = 0;
+    for (n = 0; n < nodeinfo.nodes; n++) {
+        int nodecpus = nodeinfo.sockets * nodeinfo.cores * nodeinfo.threads;
+        cid = 0;
+
+        if (VIR_ALLOC_N(cpus, nodecpus) < 0)
+            return -1;
+
+        for (s = 0; s < nodeinfo.sockets; s++) {
+            for (c = 0; c < nodeinfo.cores; c++) {
+                g_autoptr(virBitmap) siblings = virBitmapNew(ncpus);
+                for (t = 0; t < nodeinfo.threads; t++)
+                    ignore_value(virBitmapSetBit(siblings, id + t));
+
+                for (t = 0; t < nodeinfo.threads; t++) {
+                    if (virHostCPUGetOnline(id, &tmp) < 0)
                         goto error;
-                    ignore_value(virBitmapSetBit(cpus[cid].siblings, id));
-                    cid++;
+                    if (tmp) {
+                        cpus[cid].id = id;
+                        cpus[cid].socket_id = s;
+                        cpus[cid].core_id = c;
+                        if (!(cpus[cid].siblings = virBitmapNew(ncpus)))
+                            goto error;
+                        virBitmapCopy(cpus[cid].siblings, siblings);
+                        cid++;
+                    }
+
+                    id++;
                 }
-
-                id++;
             }
         }
-    }
 
-    virCapabilitiesHostNUMAAddCell(caps, 0,
-                                   nodeinfo.memory,
-#ifdef __linux__
-                                   onlinecpus, cpus,
-#else
-                                   ncpus, cpus,
-#endif
-                                   0, NULL,
-                                   0, NULL);
+        virCapabilitiesHostNUMAAddCell(caps, 0,
+                                       nodeinfo.memory,
+                                       cid, cpus,
+                                       0, NULL,
+                                       0, NULL);
+    }
 
     return 0;
 
  error:
-    for (; id >= 0; id--)
-        virBitmapFree(cpus[id].siblings);
+    for (; cid >= 0; cid--)
+        virBitmapFree(cpus[cid].siblings);
     VIR_FREE(cpus);
     return -1;
 }
-- 
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