From abc24acfa1982a0ffccbe08a006ac7c7a9f4ecda Mon Sep 17 00:00:00 2001
From: Breno Leitao <breno.leitao@gmail.com>
Date: Fri, 26 Aug 2016 18:36:00 -0300
Subject: [PATCH] libvirt: add hugepages support for Power

Power architectures (arch.PPC64LE and arch.PPC64) support huge pages and
transparent huge pages. This patch just enables it on nova libvirt driver. A
reno note was also added to track this new feature.

This change also enables the test_does_want_hugepages unit test to run on the
architectures that support huge pages.

Closes-bug: #1617081
Change-Id: I22bc57a0b244667c716a54ca37c175f26a87a1e9
---
 nova/tests/unit/virt/libvirt/test_driver.py               | 8 +++++++-
 nova/virt/libvirt/driver.py                               | 2 +-
 ...libvirt_ppc64le_hugepage_support-b9fd39cf20c8e91d.yaml | 3 +++
 3 files changed, 11 insertions(+), 2 deletions(-)
 create mode 100644 releasenotes/notes/libvirt_ppc64le_hugepage_support-b9fd39cf20c8e91d.yaml

diff --git a/nova/tests/unit/virt/libvirt/test_driver.py b/nova/tests/unit/virt/libvirt/test_driver.py
index aed6404c6256..648a94240034 100644
--- a/nova/tests/unit/virt/libvirt/test_driver.py
+++ b/nova/tests/unit/virt/libvirt/test_driver.py
@@ -2909,6 +2909,12 @@ class LibvirtConnTestCase(test.NoDBTestCase):
                        return_value=True)
     @mock.patch.object(host.Host, "get_capabilities")
     def test_does_want_hugepages(self, mock_caps, mock_hp, mock_numa):
+        for each_arch in [arch.I686, arch.X86_64, arch.PPC64LE, arch.PPC64]:
+            self._test_does_want_hugepages(
+                mock_caps, mock_hp, mock_numa, each_arch)
+
+    def _test_does_want_hugepages(self, mock_caps, mock_hp, mock_numa,
+                                  architecture):
         self.flags(reserved_huge_pages=[
             {'node': 0, 'size': 2048, 'count': 128},
             {'node': 1, 'size': 2048, 'count': 1},
@@ -2926,7 +2932,7 @@ class LibvirtConnTestCase(test.NoDBTestCase):
         caps = vconfig.LibvirtConfigCaps()
         caps.host = vconfig.LibvirtConfigCapsHost()
         caps.host.cpu = vconfig.LibvirtConfigCPU()
-        caps.host.cpu.arch = "x86_64"
+        caps.host.cpu.arch = architecture
         caps.host.topology = self._fake_caps_numa_topology()
 
         mock_caps.return_value = caps
diff --git a/nova/virt/libvirt/driver.py b/nova/virt/libvirt/driver.py
index 2daaabe878d4..53c3292993b5 100644
--- a/nova/virt/libvirt/driver.py
+++ b/nova/virt/libvirt/driver.py
@@ -5113,7 +5113,7 @@ class LibvirtDriver(driver.ComputeDriver):
     def _has_hugepage_support(self):
         # This means that the host can support multiple values for the size
         # field in LibvirtConfigGuestMemoryBackingPage
-        supported_archs = [arch.I686, arch.X86_64]
+        supported_archs = [arch.I686, arch.X86_64, arch.PPC64LE, arch.PPC64]
         caps = self._host.get_capabilities()
         return ((caps.host.cpu.arch in supported_archs) and
                 self._host.has_min_version(MIN_LIBVIRT_HUGEPAGE_VERSION,
diff --git a/releasenotes/notes/libvirt_ppc64le_hugepage_support-b9fd39cf20c8e91d.yaml b/releasenotes/notes/libvirt_ppc64le_hugepage_support-b9fd39cf20c8e91d.yaml
new file mode 100644
index 000000000000..fb84d83f7d6c
--- /dev/null
+++ b/releasenotes/notes/libvirt_ppc64le_hugepage_support-b9fd39cf20c8e91d.yaml
@@ -0,0 +1,3 @@
+---
+features:
+  - Added hugepage support for POWER architectures.