libvirt: Remove QEMU_VERSION_REQ_SHARED

The updated minimum required libvirt (4.0.0) and QEMU (2.11)
for "Ussuri" satisfy the version requirements; this was done
in Change-Id: Ia18e9be4d (22c1916b49 — libvirt: Bump
MIN_{LIBVIRT,QEMU}_VERSION for "Ussuri", 2019-11-19).

Drop the version constant  QEMU_VERSION_REQ_SHARED and now-needless
compatibility code; adjust/remove tests.

Change-Id: If878a023c69f25a9ea45b7de2ff9eb1976aaeb8c
Signed-off-by: Stephen Finucane <sfinucan@redhat.com>

5 files changed, 20 insertions, 78 deletions

diff --git a/nova/privsep/qemu.py b/nova/privsep/qemu.py
index 55bdfe2a77..2b2acfd3e8 100644
--- a/nova/privsep/qemu.py
+++ b/nova/privsep/qemu.py
@@ -16,7 +16,6 @@
 Helpers for qemu tasks.
 """
 
-import operator
 import os
 
 from oslo_concurrency import processutils
@@ -33,8 +32,6 @@ QEMU_IMG_LIMITS = processutils.ProcessLimits(
     cpu_time=30,
     address_space=1 * units.Gi)
 
-QEMU_VERSION_REQ_SHARED = 2010000
-
 
 @nova.privsep.sys_admin_pctxt.entrypoint
 def convert_image(source, dest, in_format, out_format, instances_path,
@@ -85,20 +82,17 @@ def unprivileged_convert_image(source, dest, in_format, out_format,
 
 
 @nova.privsep.sys_admin_pctxt.entrypoint
-def privileged_qemu_img_info(path, format=None, qemu_version=None,
-                             output_format=None):
+def privileged_qemu_img_info(path, format=None, output_format=None):
     """Return an oject containing the parsed output from qemu-img info
 
     This is a privileged call to qemu-img info using the sys_admin_pctxt
     entrypoint allowing host block devices etc to be accessed.
     """
     return unprivileged_qemu_img_info(
-        path, format=format, qemu_version=qemu_version,
-        output_format=output_format)
+        path, format=format, output_format=output_format)
 
 
-def unprivileged_qemu_img_info(path, format=None, qemu_version=None,
-                               output_format=None):
+def unprivileged_qemu_img_info(path, format=None, output_format=None):
     """Return an object containing the parsed output from qemu-img info."""
     try:
         # The following check is about ploop images that reside within
@@ -107,15 +101,14 @@ def unprivileged_qemu_img_info(path, format=None, qemu_version=None,
             os.path.exists(os.path.join(path, "DiskDescriptor.xml"))):
             path = os.path.join(path, "root.hds")
 
-        cmd = ('env', 'LC_ALL=C', 'LANG=C', 'qemu-img', 'info', path)
+        cmd = (
+            'env', 'LC_ALL=C', 'LANG=C', 'qemu-img', 'info', path,
+            '--force-share',
+        )
         if format is not None:
             cmd = cmd + ('-f', format)
         if output_format is not None:
             cmd = cmd + ("--output=%s" % (output_format),)
-        # Check to see if the qemu version is >= 2.10 because if so, we need
-        # to add the --force-share flag.
-        if qemu_version and operator.ge(qemu_version, QEMU_VERSION_REQ_SHARED):
-            cmd = cmd + ('--force-share',)
         out, err = processutils.execute(*cmd, prlimit=QEMU_IMG_LIMITS)
     except processutils.ProcessExecutionError as exp:
         if exp.exit_code == -9:
diff --git a/nova/tests/unit/virt/libvirt/test_driver.py b/nova/tests/unit/virt/libvirt/test_driver.py
index bb16260c25..671b65f763 100644
--- a/nova/tests/unit/virt/libvirt/test_driver.py
+++ b/nova/tests/unit/virt/libvirt/test_driver.py
@@ -105,7 +105,6 @@ from nova.virt import driver
 from nova.virt import fake
 from nova.virt import hardware
 from nova.virt.image import model as imgmodel
-from nova.virt import images
 from nova.virt.libvirt import blockinfo
 from nova.virt.libvirt import config as vconfig
 from nova.virt.libvirt import designer
@@ -1310,23 +1309,6 @@ class LibvirtConnTestCase(test.NoDBTestCase,
                 break
         self.assertFalse(version_arg_found)
 
-    # NOTE(sdague): python2.7 and python3.5 have different behaviors
-    # when it comes to comparing against the sentinel, so
-    # has_min_version is needed to pass python3.5.
-    @mock.patch.object(nova.virt.libvirt.host.Host, "has_min_version",
-                       return_value=True)
-    @mock.patch.object(fakelibvirt.Connection, 'getVersion',
-                       return_value=mock.sentinel.qemu_version)
-    def test_qemu_image_version(self, mock_get_libversion, min_ver):
-        """Test that init_host sets qemu image version
-
-        A sentinel is used here so that we aren't chasing this value
-        against minimums that get raised over time.
-        """
-        drvr = libvirt_driver.LibvirtDriver(fake.FakeVirtAPI(), True)
-        drvr.init_host("dummyhost")
-        self.assertEqual(images.QEMU_VERSION, mock.sentinel.qemu_version)
-
     @mock.patch.object(fields.Architecture, "from_host",
                        return_value=fields.Architecture.PPC64)
     def test_min_version_ppc_ok(self, mock_arch):
diff --git a/nova/tests/unit/virt/libvirt/test_utils.py b/nova/tests/unit/virt/libvirt/test_utils.py
index 24a7f375f6..97b1386145 100644
--- a/nova/tests/unit/virt/libvirt/test_utils.py
+++ b/nova/tests/unit/virt/libvirt/test_utils.py
@@ -110,7 +110,7 @@ disk size: 96K
         d_backing = libvirt_utils.get_disk_backing_file(path)
         mock_execute.assert_called_once_with(
             'env', 'LC_ALL=C', 'LANG=C', 'qemu-img', 'info', path,
-            prlimit=nova.privsep.qemu.QEMU_IMG_LIMITS)
+            '--force-share', prlimit=nova.privsep.qemu.QEMU_IMG_LIMITS)
         mock_exists.assert_called_once_with(path)
         self.assertIsNone(d_backing)
 
@@ -119,7 +119,7 @@ disk size: 96K
         self.assertEqual(expected_size, d_size)
         mock_execute.assert_called_once_with(
             'env', 'LC_ALL=C', 'LANG=C', 'qemu-img', 'info', path,
-            prlimit=nova.privsep.qemu.QEMU_IMG_LIMITS)
+            '--force-share', prlimit=nova.privsep.qemu.QEMU_IMG_LIMITS)
 
     @mock.patch('os.path.exists', return_value=True)
     def test_disk_size(self, mock_exists):
@@ -167,29 +167,7 @@ disk size: 96K
         image_info = images.qemu_img_info(path, output_format='json')
         mock_execute.assert_called_once_with(
             'env', 'LC_ALL=C', 'LANG=C', 'qemu-img', 'info', path,
-            '--output=json', prlimit=nova.privsep.qemu.QEMU_IMG_LIMITS)
-        mock_exists.assert_called_once_with(path)
-        self.assertEqual('disk.config', image_info.image)
-        self.assertEqual('raw', image_info.file_format)
-        self.assertEqual(67108864, image_info.virtual_size)
-        self.assertEqual(98304, image_info.disk_size)
-        self.assertEqual(65536, image_info.cluster_size)
-
-    @mock.patch('os.path.exists', return_value=True)
-    @mock.patch('oslo_concurrency.processutils.execute')
-    def test_qemu_info_canon(self, mock_execute, mock_exists):
-        path = "disk.config"
-        example_output = """image: disk.config
-file format: raw
-virtual size: 64M (67108864 bytes)
-cluster_size: 65536
-disk size: 96K
-blah BLAH: bb
-"""
-        mock_execute.return_value = (example_output, '')
-        image_info = images.qemu_img_info(path)
-        mock_execute.assert_called_once_with(
-            'env', 'LC_ALL=C', 'LANG=C', 'qemu-img', 'info', path,
+            '--force-share', '--output=json',
             prlimit=nova.privsep.qemu.QEMU_IMG_LIMITS)
         mock_exists.assert_called_once_with(path)
         self.assertEqual('disk.config', image_info.image)
@@ -200,8 +178,7 @@ blah BLAH: bb
 
     @mock.patch('os.path.exists', return_value=True)
     @mock.patch('oslo_concurrency.processutils.execute')
-    def test_qemu_info_canon_qemu_2_10(self, mock_execute, mock_exists):
-        images.QEMU_VERSION = nova.privsep.qemu.QEMU_VERSION_REQ_SHARED
+    def test_qemu_info_canon(self, mock_execute, mock_exists):
         path = "disk.config"
         example_output = """image: disk.config
 file format: raw
@@ -237,7 +214,7 @@ backing file: /var/lib/nova/a328c7998805951a_2
         image_info = images.qemu_img_info(path)
         mock_execute.assert_called_once_with(
             'env', 'LC_ALL=C', 'LANG=C', 'qemu-img', 'info', path,
-            prlimit=nova.privsep.qemu.QEMU_IMG_LIMITS)
+            '--force-share', prlimit=nova.privsep.qemu.QEMU_IMG_LIMITS)
         mock_exists.assert_called_once_with(path)
         self.assertEqual('disk.config', image_info.image)
         self.assertEqual('qcow2', image_info.file_format)
@@ -261,7 +238,7 @@ disk size: 706M
         image_info = images.qemu_img_info(path)
         mock_execute.assert_called_once_with(
             'env', 'LC_ALL=C', 'LANG=C', 'qemu-img', 'info',
-            os.path.join(path, 'root.hds'),
+            os.path.join(path, 'root.hds'), '--force-share',
             prlimit=nova.privsep.qemu.QEMU_IMG_LIMITS)
         mock_isdir.assert_called_once_with(path)
         self.assertEqual(2, mock_exists.call_count)
@@ -292,7 +269,7 @@ backing file: /var/lib/nova/a328c7998805951a_2 (actual path: /b/3a988059e51a_2)
         image_info = images.qemu_img_info(path)
         mock_execute.assert_called_once_with(
             'env', 'LC_ALL=C', 'LANG=C', 'qemu-img', 'info', path,
-            prlimit=nova.privsep.qemu.QEMU_IMG_LIMITS)
+            '--force-share', prlimit=nova.privsep.qemu.QEMU_IMG_LIMITS)
         mock_exists.assert_called_once_with(path)
         self.assertEqual('disk.config', image_info.image)
         self.assertEqual('raw', image_info.file_format)
@@ -321,7 +298,7 @@ junk stuff: bbb
         image_info = images.qemu_img_info(path)
         mock_execute.assert_called_once_with(
             'env', 'LC_ALL=C', 'LANG=C', 'qemu-img', 'info', path,
-            prlimit=nova.privsep.qemu.QEMU_IMG_LIMITS)
+            '--force-share', prlimit=nova.privsep.qemu.QEMU_IMG_LIMITS)
         mock_exists.assert_called_once_with(path)
         self.assertEqual('disk.config', image_info.image)
         self.assertEqual('raw', image_info.file_format)
@@ -346,7 +323,7 @@ ID        TAG                 VM SIZE                DATE       VM CLOCK
         image_info = images.qemu_img_info(path)
         mock_execute.assert_called_once_with(
             'env', 'LC_ALL=C', 'LANG=C', 'qemu-img', 'info', path,
-            prlimit=nova.privsep.qemu.QEMU_IMG_LIMITS)
+            '--force-share', prlimit=nova.privsep.qemu.QEMU_IMG_LIMITS)
         mock_exists.assert_called_once_with(path)
         self.assertEqual('disk.config', image_info.image)
         self.assertEqual('raw', image_info.file_format)
@@ -503,7 +480,7 @@ disk size: 4.4M
         self.assertEqual(4592640, disk.get_disk_size('/some/path'))
         mock_execute.assert_called_once_with(
             'env', 'LC_ALL=C', 'LANG=C', 'qemu-img', 'info', path,
-            prlimit=nova.privsep.qemu.QEMU_IMG_LIMITS)
+            '--force-share', prlimit=nova.privsep.qemu.QEMU_IMG_LIMITS)
         mock_exists.assert_called_once_with(path)
 
     def test_copy_image(self):
diff --git a/nova/virt/images.py b/nova/virt/images.py
index 54db59df5c..800ebca3c7 100644
--- a/nova/virt/images.py
+++ b/nova/virt/images.py
@@ -33,10 +33,6 @@ from nova.i18n import _
 from nova.image import glance
 import nova.privsep.qemu
 
-# This is set by the libvirt driver on startup. The version is used to
-# determine what flags need to be set on the command line.
-QEMU_VERSION = None
-
 LOG = logging.getLogger(__name__)
 
 CONF = nova.conf.CONF
@@ -49,8 +45,7 @@ def qemu_img_info(path, format=None, output_format=None):
         raise exception.DiskNotFound(location=path)
 
     info = nova.privsep.qemu.unprivileged_qemu_img_info(
-        path, format=format, qemu_version=QEMU_VERSION,
-        output_format=output_format)
+        path, format=format, output_format=output_format)
     if output_format:
         return imageutils.QemuImgInfo(info, format=output_format)
     else:
@@ -63,8 +58,7 @@ def privileged_qemu_img_info(path, format=None, output_format=None):
         raise exception.DiskNotFound(location=path)
 
     info = nova.privsep.qemu.privileged_qemu_img_info(
-        path, format=format, qemu_version=QEMU_VERSION,
-        output_format=output_format)
+        path, format=format, output_format=output_format)
     if output_format:
         return imageutils.QemuImgInfo(info, format=output_format)
     else:
diff --git a/nova/virt/libvirt/driver.py b/nova/virt/libvirt/driver.py
index b4b561dee7..8f7dadf8cf 100644
--- a/nova/virt/libvirt/driver.py
+++ b/nova/virt/libvirt/driver.py
@@ -658,11 +658,7 @@ class LibvirtDriver(driver.ComputeDriver):
                 libvirt_utils.version_to_string(MIN_LIBVIRT_VERSION))
 
         if CONF.libvirt.virt_type in ("qemu", "kvm"):
-            if self._host.has_min_version(hv_ver=MIN_QEMU_VERSION):
-                # "qemu-img info" calls are version dependent, so we need to
-                # store the version in the images module.
-                images.QEMU_VERSION = self._host.get_connection().getVersion()
-            else:
+            if not self._host.has_min_version(hv_ver=MIN_QEMU_VERSION):
                 raise exception.InternalError(
                     _('Nova requires QEMU version %s or greater.') %
                     libvirt_utils.version_to_string(MIN_QEMU_VERSION))