openstack
/
nova
Code Issues Proposed changes

libvirt: Skip CPU compatibility check for emulated guests 

Comparing host to guest CPU model for emulated guests (<domain
type='qemu'>) should not matter -- in this mode the CPU is fully
emulated in software and no hardware acceleration, like KVM, is
involved.

So, skip the CPU compatibility check for the QEMU domain type,
and retain it for KVM guests.

Closes-Bug: #1588003

Co-Authored-By: Daniel P. Berrange <berrange@redhat.com>
Change-Id: I8b782678a6dfa7bcfc203381037e1df4475c3194
(cherry picked from commit afa31e67c3)
(cherry picked from commit 54448676db)
This commit is contained in:
Kashyap Chamarthy 2016-05-31 17:50:51 +02:00 committed by Matt Riedemann
parent c29ea41ba0
commit 895e7da327
2 changed files with 13 additions and 2 deletions
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6
nova/tests/unit/virt/libvirt/test_driver.py
View File

@ -5826,6 +5826,12 @@ class LibvirtConnTestCase(test.NoDBTestCase):
ret = conn._compare_cpu(None, None)
self.assertIsNone(ret)
def test_compare_cpu_virt_type_qemu(self):
self.flags(virt_type='qemu', group='libvirt')
conn = libvirt_driver.LibvirtDriver(fake.FakeVirtAPI(), False)
ret = conn._compare_cpu(None, None)
self.assertIsNone(ret)
@mock.patch.object(host.Host, 'compare_cpu')
@mock.patch.object(nova.virt.libvirt, 'config')
def test_compare_cpu_invalid_cpuinfo_raises(self, mock_vconfig,

9
nova/virt/libvirt/driver.py
View File

@ -5390,8 +5390,13 @@ class LibvirtDriver(driver.ComputeDriver):
raise exception.
"""
# NOTE(berendt): virConnectCompareCPU not working for Xen
if CONF.libvirt.virt_type not in ['qemu', 'kvm']:
# NOTE(kchamart): Comparing host to guest CPU model for emulated
# guests (<domain type='qemu'>) should not matter -- in this
# mode (QEMU "TCG") the CPU is fully emulated in software and no
# hardware acceleration, like KVM, is involved. So, skip the CPU
# compatibility check for the QEMU domain type, and retain it for
# KVM guests.
if CONF.libvirt.virt_type not in ['kvm']:
return
if guest_cpu is None: