From 83edaf4435f9c2d1fa5afd1dfbb1643b4f564fd1 Mon Sep 17 00:00:00 2001
From: Jim Fehlig <jfehlig@suse.com>
Date: Thu, 22 Feb 2018 11:52:56 -0700
Subject: [PATCH] libxl: don't hardcode scheduler weight

Long ago in commit dfa1e1dd53 the scheduler weight was accidentally
hardcoded to 1000. Weight is a setting with no unit since it is
relative to the weight of other domains. If no weight is specified,
libxl defaults to 256.

Instead of hardcoding the weight to 1000, honor any <shares> specified
in <cputune>. libvirt's notion of shares is synonomous to libxl's
scheduler weight setting. If shares is unspecified, defer default
weight setting to libxl.

Removing the hardcoded weight required some test fixup. While at it,
add an explicit test for <shares> conversion to scheduler weight.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
---
 src/libxl/libxl_conf.c                        |  4 +-
 tests/libxlxml2domconfigdata/basic-hvm.json   |  2 +-
 tests/libxlxml2domconfigdata/basic-pv.json    |  2 +-
 .../cpu-shares-hvm.json                       | 89 +++++++++++++++++++
 .../libxlxml2domconfigdata/cpu-shares-hvm.xml | 39 ++++++++
 .../libxlxml2domconfigdata/moredevs-hvm.json  |  2 +-
 tests/libxlxml2domconfigdata/multiple-ip.json |  2 +-
 .../variable-clock-hvm.json                   |  2 +-
 tests/libxlxml2domconfigdata/vnuma-hvm.json   |  2 +-
 tests/libxlxml2domconfigtest.c                |  1 +
 10 files changed, 138 insertions(+), 7 deletions(-)
 create mode 100644 tests/libxlxml2domconfigdata/cpu-shares-hvm.json
 create mode 100644 tests/libxlxml2domconfigdata/cpu-shares-hvm.xml

diff --git a/src/libxl/libxl_conf.c b/src/libxl/libxl_conf.c
index ea2b0c588f..0ed914e4f1 100644
--- a/src/libxl/libxl_conf.c
+++ b/src/libxl/libxl_conf.c
@@ -366,7 +366,9 @@ libxlMakeDomBuildInfo(virDomainDefPtr def,
         }
     }
 
-    b_info->sched_params.weight = 1000;
+    if (def->cputune.sharesSpecified)
+        b_info->sched_params.weight = def->cputune.shares;
+
     /* Xen requires the memory sizes to be rounded to 1MiB increments */
     virDomainDefSetMemoryTotal(def,
                                VIR_ROUND_UP(virDomainDefGetMemoryInitial(def), 1024));
diff --git a/tests/libxlxml2domconfigdata/basic-hvm.json b/tests/libxlxml2domconfigdata/basic-hvm.json
index 6fa41f34f9..ccd5853854 100644
--- a/tests/libxlxml2domconfigdata/basic-hvm.json
+++ b/tests/libxlxml2domconfigdata/basic-hvm.json
@@ -19,7 +19,7 @@
         "device_model_version": "qemu_xen",
         "device_model": "/bin/true",
         "sched_params": {
-            "weight": 1000
+
         },
         "type.hvm": {
             "pae": "True",
diff --git a/tests/libxlxml2domconfigdata/basic-pv.json b/tests/libxlxml2domconfigdata/basic-pv.json
index 7e1abd3d6a..0f846daabd 100644
--- a/tests/libxlxml2domconfigdata/basic-pv.json
+++ b/tests/libxlxml2domconfigdata/basic-pv.json
@@ -15,7 +15,7 @@
         "max_memkb": 524288,
         "target_memkb": 524288,
         "sched_params": {
-            "weight": 1000
+
         },
         "type.pv": {
             "bootloader": "pygrub"
diff --git a/tests/libxlxml2domconfigdata/cpu-shares-hvm.json b/tests/libxlxml2domconfigdata/cpu-shares-hvm.json
new file mode 100644
index 0000000000..2e647eada2
--- /dev/null
+++ b/tests/libxlxml2domconfigdata/cpu-shares-hvm.json
@@ -0,0 +1,89 @@
+{
+    "c_info": {
+        "type": "hvm",
+        "name": "test-hvm",
+        "uuid": "2147d599-9cc6-c0dc-92ab-4064b5446e9b"
+    },
+    "b_info": {
+        "max_vcpus": 4,
+        "avail_vcpus": [
+            0,
+            1,
+            2,
+            3
+        ],
+        "max_memkb": 1048576,
+        "target_memkb": 1048576,
+        "video_memkb": 8192,
+        "shadow_memkb": 12288,
+        "device_model_version": "qemu_xen",
+        "device_model": "/bin/true",
+        "sched_params": {
+            "weight": 1500
+        },
+        "type.hvm": {
+            "pae": "True",
+            "apic": "True",
+            "acpi": "True",
+            "vga": {
+                "kind": "cirrus"
+            },
+            "vnc": {
+                "enable": "True",
+                "listen": "0.0.0.0",
+                "findunused": "False"
+            },
+            "sdl": {
+                "enable": "False"
+            },
+            "spice": {
+
+            },
+            "boot": "c",
+            "rdm": {
+
+            }
+        },
+        "arch_arm": {
+
+        }
+    },
+    "disks": [
+        {
+            "pdev_path": "/var/lib/xen/images/test-hvm.img",
+            "vdev": "hda",
+            "backend": "qdisk",
+            "format": "raw",
+            "removable": 1,
+            "readwrite": 1
+        }
+    ],
+    "nics": [
+        {
+            "devid": 0,
+            "mac": "00:16:3e:66:12:b4",
+            "bridge": "br0",
+            "script": "/etc/xen/scripts/vif-bridge",
+            "nictype": "vif_ioemu"
+        }
+    ],
+    "vfbs": [
+        {
+	    "devid": -1,
+            "vnc": {
+                "enable": "True",
+                "listen": "0.0.0.0",
+                "findunused": "False"
+            },
+            "sdl": {
+                "enable": "False"
+            }
+        }
+    ],
+    "vkbs": [
+        {
+            "devid": -1
+        }
+    ],
+    "on_reboot": "restart"
+}
diff --git a/tests/libxlxml2domconfigdata/cpu-shares-hvm.xml b/tests/libxlxml2domconfigdata/cpu-shares-hvm.xml
new file mode 100644
index 0000000000..49085b4b70
--- /dev/null
+++ b/tests/libxlxml2domconfigdata/cpu-shares-hvm.xml
@@ -0,0 +1,39 @@
+<domain type='xen'>
+  <name>test-hvm</name>
+  <description>None</description>
+  <uuid>2147d599-9cc6-c0dc-92ab-4064b5446e9b</uuid>
+  <memory>1048576</memory>
+  <currentMemory>1048576</currentMemory>
+  <vcpu>4</vcpu>
+  <cputune>
+    <shares>1500</shares>
+  </cputune>
+  <on_poweroff>destroy</on_poweroff>
+  <on_reboot>restart</on_reboot>
+  <on_crash>destroy</on_crash>
+  <clock offset='utc'/>
+  <os>
+    <type>hvm</type>
+    <loader>/usr/lib/xen/boot/hvmloader</loader>
+    <boot dev='hd'/>
+  </os>
+  <features>
+    <apic/>
+    <acpi/>
+    <pae/>
+  </features>
+  <devices>
+    <emulator>/bin/true</emulator>
+    <disk type='file' device='disk'>
+      <driver name='qemu'/>
+      <source file='/var/lib/xen/images/test-hvm.img'/>
+      <target dev='hda'/>
+    </disk>
+    <interface type='bridge'>
+      <source bridge='br0'/>
+      <mac address='00:16:3e:66:12:b4'/>
+      <script path='/etc/xen/scripts/vif-bridge'/>
+    </interface>
+    <graphics type='vnc' port='-1' autoport='yes' listen='0.0.0.0'/>
+  </devices>
+</domain>
diff --git a/tests/libxlxml2domconfigdata/moredevs-hvm.json b/tests/libxlxml2domconfigdata/moredevs-hvm.json
index 8f861f34ec..7bfd68bd67 100644
--- a/tests/libxlxml2domconfigdata/moredevs-hvm.json
+++ b/tests/libxlxml2domconfigdata/moredevs-hvm.json
@@ -21,7 +21,7 @@
         "device_model_version": "qemu_xen",
         "device_model": "/bin/true",
         "sched_params": {
-            "weight": 1000
+
         },
         "type.hvm": {
             "pae": "True",
diff --git a/tests/libxlxml2domconfigdata/multiple-ip.json b/tests/libxlxml2domconfigdata/multiple-ip.json
index 4aff61d4b5..80dca82611 100644
--- a/tests/libxlxml2domconfigdata/multiple-ip.json
+++ b/tests/libxlxml2domconfigdata/multiple-ip.json
@@ -15,7 +15,7 @@
         "max_memkb": 524288,
         "target_memkb": 524288,
         "sched_params": {
-            "weight": 1000
+
         },
         "type.pv": {
             "bootloader": "pygrub"
diff --git a/tests/libxlxml2domconfigdata/variable-clock-hvm.json b/tests/libxlxml2domconfigdata/variable-clock-hvm.json
index 49d0a4330c..69be9c64cb 100644
--- a/tests/libxlxml2domconfigdata/variable-clock-hvm.json
+++ b/tests/libxlxml2domconfigdata/variable-clock-hvm.json
@@ -21,7 +21,7 @@
         "device_model_version": "qemu_xen",
         "device_model": "/bin/true",
         "sched_params": {
-            "weight": 1000
+
         },
         "type.hvm": {
             "pae": "True",
diff --git a/tests/libxlxml2domconfigdata/vnuma-hvm.json b/tests/libxlxml2domconfigdata/vnuma-hvm.json
index 3a5071e148..3b2fc5f40f 100644
--- a/tests/libxlxml2domconfigdata/vnuma-hvm.json
+++ b/tests/libxlxml2domconfigdata/vnuma-hvm.json
@@ -107,7 +107,7 @@
         "device_model_version": "qemu_xen",
         "device_model": "/bin/true",
         "sched_params": {
-            "weight": 1000
+
         },
         "type.hvm": {
             "pae": "True",
diff --git a/tests/libxlxml2domconfigtest.c b/tests/libxlxml2domconfigtest.c
index ea3d2884ef..6eec4c752d 100644
--- a/tests/libxlxml2domconfigtest.c
+++ b/tests/libxlxml2domconfigtest.c
@@ -192,6 +192,7 @@ mymain(void)
 
     DO_TEST("basic-pv");
     DO_TEST("basic-hvm");
+    DO_TEST("cpu-shares-hvm");
     DO_TEST("variable-clock-hvm");
     DO_TEST("moredevs-hvm");
     DO_TEST("vnuma-hvm");