[libvirt] [PATCH 1/2] qemuProcessBuildDestroyHugepagesPath: create path more frequently

[Michal Privoznik]

https://bugzilla.redhat.com/show_bug.cgi?id=1455819

Currently, the per-domain path for huge pages mmap() for qemu is
created iff domain has memoryBacking and hugepages in it
configured. However, this alone is not enough because there can
be a DIMM module with hugepages configured too.

Signed-off-by: Michal Privoznik <mprivozn at redhat.com>
---
 src/qemu/qemu_process.c | 24 +++++++++++++++++++++++-
 1 file changed, 23 insertions(+), 1 deletion(-)

diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
index 32ba8e373..a219a8080 100644
--- a/src/qemu/qemu_process.c
+++ b/src/qemu/qemu_process.c
@@ -3289,11 +3289,33 @@ qemuProcessBuildDestroyHugepagesPath(virQEMUDriverPtr driver,
                                      bool build)
 {
     virQEMUDriverConfigPtr cfg = virQEMUDriverGetConfig(driver);
+    const long system_pagesize = virGetSystemPageSizeKB();
     char *hugepagePath = NULL;
     size_t i;
+    bool shouldBuild = false;
     int ret = -1;
 
-    if (vm->def->mem.nhugepages) {
+    if (vm->def->mem.source == VIR_DOMAIN_MEMORY_SOURCE_FILE)
+        shouldBuild = true;
+
+    for (i = 0; !shouldBuild && i < vm->def->mem.nhugepages; i++) {
+        if (vm->def->mem.hugepages[i].size != system_pagesize) {
+            shouldBuild = true;
+            break;
+        }
+    }
+
+    for (i = 0; !shouldBuild &&  vm->def->nmems; i++) {
+        if (vm->def->mems[i]->model == VIR_DOMAIN_MEMORY_MODEL_DIMM &&
+            vm->def->mems[i]->pagesize &&
+            vm->def->mems[i]->pagesize != system_pagesize) {
+            shouldBuild = true;
+            break;
+        }
+    }
+
+    if (!build ||
+        (build && shouldBuild)) {
         for (i = 0; i < cfg->nhugetlbfs; i++) {
             VIR_FREE(hugepagePath);
             hugepagePath = qemuGetDomainHugepagePath(vm->def, &cfg->hugetlbfs[i]);
-- 
2.13.0