Accept both 1 and Y as AMD SEV KVM kernel param value

The libvirt virt dirver checks the AMD KVM kernel module parameter SEV
to see if that feature is enabled. However it seems that the
/sys/module/kvm_amd/parameters/sev file can either contain "1\n" or
"Y\n" to indicate that the feature is enabled. Nova only checked for
"1\n" so far making the feature disabled on compute nodes with "Y\n"
value. Now the logic is extended to accept both.

Closes-Bug: #1975686
Change-Id: I737e1d73242430b6756178eb0bf9bd6ec5c94160
(cherry picked from commit ab51a5dd25b8d4c66562148b43b1022eb5ceed7e)

2 files changed, 25 insertions, 15 deletions

diff --git a/nova/tests/unit/virt/libvirt/test_host.py b/nova/tests/unit/virt/libvirt/test_host.py
index d71d13ab37..1eb26572aa 100644
--- a/nova/tests/unit/virt/libvirt/test_host.py
+++ b/nova/tests/unit/virt/libvirt/test_host.py
@@ -16,6 +16,7 @@
 
 import os
 
+import ddt
 import eventlet
 from eventlet import greenthread
 from eventlet import tpool
@@ -1928,6 +1929,7 @@ class TestLibvirtSEV(test.NoDBTestCase):
         self.host = host.Host("qemu:///system")
 
 
+@ddt.ddt
 class TestLibvirtSEVUnsupported(TestLibvirtSEV):
     @mock.patch.object(os.path, 'exists', return_value=False)
     def test_kernel_parameter_missing(self, fake_exists):
@@ -1935,19 +1937,26 @@ class TestLibvirtSEVUnsupported(TestLibvirtSEV):
         fake_exists.assert_called_once_with(
             '/sys/module/kvm_amd/parameters/sev')
 
+    @ddt.data(
+        ('0\n', False),
+        ('N\n', False),
+        ('1\n', True),
+        ('Y\n', True),
+    )
+    @ddt.unpack
     @mock.patch.object(os.path, 'exists', return_value=True)
-    @mock.patch('builtins.open', mock.mock_open(read_data="0\n"))
-    def test_kernel_parameter_zero(self, fake_exists):
-        self.assertFalse(self.host._kernel_supports_amd_sev())
-        fake_exists.assert_called_once_with(
-            '/sys/module/kvm_amd/parameters/sev')
-
-    @mock.patch.object(os.path, 'exists', return_value=True)
-    @mock.patch('builtins.open', mock.mock_open(read_data="1\n"))
-    def test_kernel_parameter_one(self, fake_exists):
-        self.assertTrue(self.host._kernel_supports_amd_sev())
-        fake_exists.assert_called_once_with(
-            '/sys/module/kvm_amd/parameters/sev')
+    def test_kernel_parameter(
+        self, sev_param_value, expected_support, mock_exists
+    ):
+        with mock.patch(
+            'builtins.open', mock.mock_open(read_data=sev_param_value)
+        ):
+            self.assertIs(
+                expected_support,
+                self.host._kernel_supports_amd_sev()
+            )
+            mock_exists.assert_called_once_with(
+                '/sys/module/kvm_amd/parameters/sev')
 
     @mock.patch.object(os.path, 'exists', return_value=True)
     @mock.patch('builtins.open', mock.mock_open(read_data="1\n"))
diff --git a/nova/virt/libvirt/host.py b/nova/virt/libvirt/host.py
index cdf47008de..63f1a9c6e4 100644
--- a/nova/virt/libvirt/host.py
+++ b/nova/virt/libvirt/host.py
@@ -46,6 +46,7 @@ from oslo_log import log as logging
 from oslo_serialization import jsonutils
 from oslo_utils import excutils
 from oslo_utils import importutils
+from oslo_utils import strutils
 from oslo_utils import units
 from oslo_utils import versionutils
 
@@ -1656,9 +1657,9 @@ class Host(object):
             return False
 
         with open(SEV_KERNEL_PARAM_FILE) as f:
-            contents = f.read()
-            LOG.debug("%s contains [%s]", SEV_KERNEL_PARAM_FILE, contents)
-            return contents == "1\n"
+            content = f.read()
+            LOG.debug("%s contains [%s]", SEV_KERNEL_PARAM_FILE, content)
+            return strutils.bool_from_string(content)
 
     @property
     def supports_amd_sev(self) -> bool: