CSIT-337 Improve Qemu affinity setting

Improve Qemu affinity setting by getting the list of Qemu thread IDs via
QMP and pin each thread PID to specific host core by taskset.

Change-Id: I1b0ee8d8425cf1f97b16d6761fff0be2fadc44a8
Signed-off-by: pmikus <pmikus@cisco.com>

1 files changed, 21 insertions, 11 deletions

diff --git a/resources/libraries/python/QemuUtils.py b/resources/libraries/python/QemuUtils.py
index 3751cd6da9..16ade29167 100644
--- a/resources/libraries/python/QemuUtils.py
+++ b/resources/libraries/python/QemuUtils.py
@@ -53,8 +53,6 @@ class QemuUtils(object):
         self._qemu_opt['huge_allocate'] = False
         # Default image for CSIT virl setup
         self._qemu_opt['disk_image'] = '/var/lib/vm/vhost-nested.img'
-        # Affinity of qemu processes
-        self._qemu_opt['affinity'] = False
         # VM node info dict
         self._vm_info = {
             'type': NodeType.VM,
@@ -128,13 +126,28 @@ class QemuUtils(object):
         """
         self._qemu_opt['disk_image'] = disk_image
 
-    def qemu_set_affinity(self, mask):
-        """Set qemu affinity by taskset with cpu mask.
+    def qemu_set_affinity(self, *host_cpus):
+        """Set qemu affinity by getting thread PIDs via QMP and taskset to list
+        of CPU cores.
 
-       :param mask: Hex CPU mask.
-       :type mask: str
+        :param host_cpus: List of CPU cores.
+        :type host_cpus: list
         """
-        self._qemu_opt['affinity'] = mask
+        qemu_cpus = self._qemu_qmp_exec('query-cpus')['return']
+
+        if len(qemu_cpus) != len(host_cpus):
+            logger.debug('Host CPU count {0}, Qemu Thread count {1}'.format(
+                len(host_cpus), len(qemu_cpus)))
+            raise ValueError('Host CPU count must match Qemu Thread count')
+
+        for qemu_cpu, host_cpu in zip(qemu_cpus, host_cpus):
+            cmd = 'taskset -p {0} {1}'.format(hex(1 << int(host_cpu)),
+                                              qemu_cpu['thread_id'])
+            (ret_code, _, stderr) = self._ssh.exec_command_sudo(cmd)
+            if int(ret_code) != 0:
+                logger.debug('Set affinity failed {0}'.format(stderr))
+                raise RuntimeError('Set affinity failed on {0}'.format(
+                    self._node['host']))
 
     def qemu_set_node(self, node):
         """Set node to run QEMU on.
@@ -409,12 +422,9 @@ class QemuUtils(object):
             '-device isa-serial,chardev=qga0'
         # Graphic setup
         graphic = '-monitor none -display none -vga none'
-        qbin = 'taskset {0} {1}'.format(self._qemu_opt.get('affinity'),
-            self.__QEMU_BIN) if self._qemu_opt.get(
-            'affinity') else self.__QEMU_BIN
         # Run QEMU
         cmd = '{0} {1} {2} {3} {4} -hda {5} {6} {7} {8} {9}'.format(
-            qbin, self._qemu_opt.get('smp'), mem, ssh_fwd,
+            self.__QEMU_BIN, self._qemu_opt.get('smp'), mem, ssh_fwd,
             self._qemu_opt.get('options'),
             self._qemu_opt.get('disk_image'), qmp, serial, qga, graphic)
         (ret_code, _, stderr) = self._ssh.exec_command_sudo(cmd, timeout=300)