File ff3112f3-qemu-hugepage-align-fix.patch of Package libvirt.6751

commit ff3112f3dc2c276a7e387ff7bb86f4fbbdf7bf2c
Author: Martin Kletzander <mkletzan@redhat.com>
Date:   Fri Sep 23 11:31:30 2016 +0200

    qemu: Only use memory-backend-file with NUMA if needed
    
    If this reminds you of a commit message from around a year ago, it's
    41c2aa729f0af084ede95ee9a06219a2dd5fb5df and yes, we're dealing with
    "the same thing" again.  Or f309db1f4d51009bad0d32e12efc75530b66836b and
    it's similar.
    
    There is a logic in place that if there is no real need for
    memory-backend-file, qemuBuildMemoryBackendStr() returns 0.  However
    that wasn't the case with hugepage backing.  The reason for that was
    that we abused the 'pagesize' variable for storing that information, but
    we should rather have a separate one that specifies whether we really
    need the new object for hugepage backing.  And that variable should be
    set only if this particular NUMA cell needs special treatment WRT
    hugepages.
    
    Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1372153
    
    Signed-off-by: Martin Kletzander <mkletzan@redhat.com>

Index: libvirt-2.0.0/src/qemu/qemu_command.c
===================================================================
--- libvirt-2.0.0.orig/src/qemu/qemu_command.c
+++ libvirt-2.0.0/src/qemu/qemu_command.c
@@ -2935,6 +2935,7 @@ qemuBuildMemoryBackendStr(unsigned long
     int ret = -1;
     virJSONValuePtr props = NULL;
     bool nodeSpecified = virDomainNumatuneNodeSpecified(def->numa, guestNode);
+    bool needHugepage = !!pagesize;
 
     *backendProps = NULL;
     *backendType = NULL;
@@ -2957,10 +2958,10 @@ qemuBuildMemoryBackendStr(unsigned long
         mode = VIR_DOMAIN_NUMATUNE_MEM_STRICT;
 
     if (pagesize == 0) {
+        bool thisHugepage = false;
+
         /* Find the huge page size we want to use */
         for (i = 0; i < def->mem.nhugepages; i++) {
-            bool thisHugepage = false;
-
             hugepage = &def->mem.hugepages[i];
 
             if (!hugepage->nodemask) {
@@ -2982,6 +2983,7 @@ qemuBuildMemoryBackendStr(unsigned long
 
             if (thisHugepage) {
                 /* Hooray, we've found the page size */
+                needHugepage = true;
                 break;
             }
         }
@@ -3088,7 +3090,7 @@ qemuBuildMemoryBackendStr(unsigned long
     }
 
     /* If none of the following is requested... */
-    if (!pagesize && !userNodeset && !memAccess && !nodeSpecified && !force) {
+    if (!needHugepage && !userNodeset && !memAccess && !nodeSpecified && !force) {
         /* report back that using the new backend is not necessary
          * to achieve the desired configuration */
         ret = 1;
Index: libvirt-2.0.0/tests/qemuxml2argvdata/qemuxml2argv-hugepages-pages2.args
===================================================================
--- libvirt-2.0.0.orig/tests/qemuxml2argvdata/qemuxml2argv-hugepages-pages2.args
+++ libvirt-2.0.0/tests/qemuxml2argvdata/qemuxml2argv-hugepages-pages2.args
@@ -10,12 +10,10 @@ QEMU_AUDIO_DRV=none \
 -M pc \
 -m 1024 \
 -smp 2 \
--object memory-backend-file,id=ram-node0,prealloc=yes,\
-mem-path=/dev/hugepages2M/libvirt/qemu,size=268435456 \
--numa node,nodeid=0,cpus=0,memdev=ram-node0 \
--object memory-backend-file,id=ram-node1,prealloc=yes,\
-mem-path=/dev/hugepages2M/libvirt/qemu,size=805306368 \
--numa node,nodeid=1,cpus=1,memdev=ram-node1 \
+-mem-prealloc \
+-mem-path /dev/hugepages2M/libvirt/qemu \
+-numa node,nodeid=0,cpus=0,mem=256 \
+-numa node,nodeid=1,cpus=1,mem=768 \
 -uuid ef1bdff4-27f3-4e85-a807-5fb4d58463cc \
 -nographic \
 -nodefaults \