Merge "Remove use of nomodeset by default"

11 files changed, 48 insertions, 18 deletions

diff --git a/devstack/lib/ironic b/devstack/lib/ironic
index 51b2e2ba8..d82e1882d 100644
--- a/devstack/lib/ironic
+++ b/devstack/lib/ironic
@@ -1793,7 +1793,7 @@ function configure_ironic_conductor {
             -subj '/O=OpenStack/OU=DevStack Servers'
     fi
 
-    local pxe_params="nofb nomodeset console=${IRONIC_TTY_DEV}"
+    local pxe_params="nofb console=${IRONIC_TTY_DEV}"
     pxe_params+=" systemd.journald.forward_to_console=yes"
     if is_service_enabled tls-proxy; then
         pxe_params+=" ipa-insecure=1"
@@ -1805,7 +1805,7 @@ function configure_ironic_conductor {
         iniset $IRONIC_CONF_FILE pxe kernel_append_params "$pxe_params"
     fi
 
-    local kernel_append_params="nofb nomodeset console=${IRONIC_TTY_DEV}"
+    local kernel_append_params="nofb console=${IRONIC_TTY_DEV}"
     kernel_append_params+=" systemd.journald.forward_to_console=yes"
 
     # NOTE(dtantsur): avoid setting ipa-insecure for redfish, we have a way to
diff --git a/devstack/tools/ironic/scripts/cirros-partition.sh b/devstack/tools/ironic/scripts/cirros-partition.sh
index facf9b030..38e1764c4 100755
--- a/devstack/tools/ironic/scripts/cirros-partition.sh
+++ b/devstack/tools/ironic/scripts/cirros-partition.sh
@@ -18,7 +18,7 @@ IRONIC_TTY_DEV=${IRONIC_TTY_DEV:-ttyS0,115200}
 # rdroot : boot from the ramdisk present on the root partition instead of
 #          mounting the root partition.
 # dslist : disable Nova metadata support, it takes a long time on boot.
-KARGS=${KARGS:-nofb nomodeset vga=normal console=${IRONIC_TTY_DEV} rdroot dslist=configdrive}
+KARGS=${KARGS:-nofb vga=normal console=${IRONIC_TTY_DEV} rdroot dslist=configdrive}
 
 workdir=$(mktemp -d)
 root_mp=$workdir/root
diff --git a/doc/source/admin/drivers/redfish.rst b/doc/source/admin/drivers/redfish.rst
index 063dd1fe5..771908838 100644
--- a/doc/source/admin/drivers/redfish.rst
+++ b/doc/source/admin/drivers/redfish.rst
@@ -214,7 +214,7 @@ user-specified kernel command line parameters.
 .. code-block:: bash
 
   baremetal node set node-0 \
-    --driver-info kernel_append_params="nofb nomodeset vga=normal"
+    --driver-info kernel_append_params="nofb vga=normal"
 
 .. note::
    The ``driver_info`` field is supported starting with the Xena release.
diff --git a/doc/source/admin/interfaces/boot.rst b/doc/source/admin/interfaces/boot.rst
index b9f0bda3e..a4b4cf2a3 100644
--- a/doc/source/admin/interfaces/boot.rst
+++ b/doc/source/admin/interfaces/boot.rst
@@ -49,7 +49,7 @@ configuration option:
 .. code-block:: ini
 
     [pxe]
-    kernel_append_params = nofb nomodeset vga=normal
+    kernel_append_params = nofb vga=normal
 
 .. note::
    The option was called ``pxe_append_params`` before the Xena cycle.
@@ -59,9 +59,9 @@ Per-node and per-instance overrides are also possible, for example:
 .. code-block:: bash
 
   baremetal node set node-0 \
-    --driver-info kernel_append_params="nofb nomodeset vga=normal"
+    --driver-info kernel_append_params="nofb vga=normal"
   baremetal node set node-0 \
-    --instance-info kernel_append_params="nofb nomodeset vga=normal"
+    --instance-info kernel_append_params="nofb vga=normal"
 
 Starting with the Zed cycle, you can combine the parameters from the
 configuration and from the node using the special ``%default%`` syntax:
@@ -74,13 +74,21 @@ configuration and from the node using the special ``%default%`` syntax:
 Together with the configuration above, the following parameters will be
 appended to the kernel command line::
 
-    nofb nomodeset vga=normal console=ttyS0,115200n8
+    nofb vga=normal console=ttyS0,115200n8
 
 .. note::
    Ironic does not do any de-duplication of the resulting kernel parameters.
    Both kernel itself and dracut seem to give priority to the last instance
    of the same parameter.
 
+.. warning::
+   Previously our documentation listed the Linux kernel parameter
+   ``nomodeset`` as an option. This option is intended for troubleshooting,
+   and can greatly degrade performance with Matrox/Aspeed BMC Graphics
+   controllers which is very commonly used on physical servers. The
+   performance degredation can greatly reduce IO capacity upon every
+   console graphics update being written to the screen.
+
 Common options
 --------------
 
diff --git a/doc/source/install/include/kernel-boot-parameters.inc b/doc/source/install/include/kernel-boot-parameters.inc
index f0da59d60..82b4ecc91 100644
--- a/doc/source/install/include/kernel-boot-parameters.inc
+++ b/doc/source/install/include/kernel-boot-parameters.inc
@@ -91,7 +91,7 @@ respectively.
         [pxe]
 
         # Additional append parameters for baremetal PXE boot.
-        kernel_append_params = nofb nomodeset vga=normal console=ttyS0,115200n8
+        kernel_append_params = nofb vga=normal console=ttyS0,115200n8
 
 
 * For node web console configuration is similar with the addition of ``ttyX``
@@ -100,7 +100,7 @@ respectively.
         [pxe]
 
         # Additional append parameters for baremetal PXE boot.
-        kernel_append_params = nofb nomodeset vga=normal console=tty0 console=ttyS0,115200n8
+        kernel_append_params = nofb vga=normal console=tty0 console=ttyS0,115200n8
 
 For detailed information on how to add consoles see the reference documents
 `kernel params`_ and `serial console`_.
diff --git a/ironic/conf/ilo.py b/ironic/conf/ilo.py
index 197378ce7..6d1c52dd2 100644
--- a/ironic/conf/ilo.py
+++ b/ironic/conf/ilo.py
@@ -112,7 +112,7 @@ opts = [
                       'This setting must be set to the octal number '
                       'representation, meaning starting with ``0o``.')),
     cfg.StrOpt('kernel_append_params',
-               default='nofb nomodeset vga=normal',
+               default='nofb vga=normal',
                mutable=True,
                help=_('Additional kernel parameters to pass down to the '
                       'instance kernel. These parameters can be consumed by '
diff --git a/ironic/conf/pxe.py b/ironic/conf/pxe.py
index d96712824..e4c912192 100644
--- a/ironic/conf/pxe.py
+++ b/ironic/conf/pxe.py
@@ -24,7 +24,7 @@ from ironic.common.i18n import _
 opts = [
     cfg.StrOpt('kernel_append_params',
                deprecated_name='pxe_append_params',
-               default='nofb nomodeset vga=normal',
+               default='nofb vga=normal',
                mutable=True,
                help=_('Additional append parameters for baremetal PXE boot.')),
     cfg.StrOpt('default_ephemeral_format',
diff --git a/ironic/conf/redfish.py b/ironic/conf/redfish.py
index 3cc9fe015..68aa96141 100644
--- a/ironic/conf/redfish.py
+++ b/ironic/conf/redfish.py
@@ -64,7 +64,7 @@ opts = [
                       'auto-expire. Applies only when `use_swift` is '
                       'enabled.')),
     cfg.StrOpt('kernel_append_params',
-               default='nofb nomodeset vga=normal',
+               default='nofb vga=normal',
                mutable=True,
                help=_('Additional kernel parameters to pass down to the '
                       'instance kernel. These parameters can be consumed by '
diff --git a/ironic/tests/unit/drivers/modules/test_image_utils.py b/ironic/tests/unit/drivers/modules/test_image_utils.py
index b6c572125..fbb6318fe 100644
--- a/ironic/tests/unit/drivers/modules/test_image_utils.py
+++ b/ironic/tests/unit/drivers/modules/test_image_utils.py
@@ -583,7 +583,7 @@ class RedfishImageUtilsTestCase(db_base.DbTestCase):
             mock_create_boot_iso.assert_called_once_with(
                 mock.ANY, mock.ANY, 'http://kernel/img', 'http://ramdisk/img',
                 boot_mode='uefi', esp_image_href='http://bootloader/img',
-                kernel_params='nofb nomodeset vga=normal',
+                kernel_params='nofb vga=normal',
                 root_uuid='1be26c0b-03f2-4d2e-ae87-c02d7f33c123',
                 inject_files=None)
 
@@ -604,7 +604,7 @@ class RedfishImageUtilsTestCase(db_base.DbTestCase):
             mock_create_boot_iso.assert_called_once_with(
                 mock.ANY, mock.ANY, 'http://kernel/img', 'http://ramdisk/img',
                 boot_mode='uefi', esp_image_href=None,
-                kernel_params='nofb nomodeset vga=normal',
+                kernel_params='nofb vga=normal',
                 root_uuid='1be26c0b-03f2-4d2e-ae87-c02d7f33c123',
                 inject_files=None)
 
@@ -633,7 +633,7 @@ class RedfishImageUtilsTestCase(db_base.DbTestCase):
             mock_create_boot_iso.assert_called_once_with(
                 mock.ANY, mock.ANY, 'http://kernel/img', 'http://ramdisk/img',
                 boot_mode='bios', esp_image_href=None,
-                kernel_params='nofb nomodeset vga=normal',
+                kernel_params='nofb vga=normal',
                 root_uuid='1be26c0b-03f2-4d2e-ae87-c02d7f33c123',
                 inject_files=None)
 
@@ -702,7 +702,7 @@ class RedfishImageUtilsTestCase(db_base.DbTestCase):
             mock_create_boot_iso.assert_called_once_with(
                 mock.ANY, mock.ANY, 'http://kernel/img', 'http://ramdisk/img',
                 boot_mode='uefi', esp_image_href=None,
-                kernel_params=f'nofb nomodeset vga=normal {kernel_params}',
+                kernel_params=f'nofb vga=normal {kernel_params}',
                 root_uuid='1be26c0b-03f2-4d2e-ae87-c02d7f33c123',
                 inject_files=None)
 
diff --git a/ironic/tests/unit/drivers/modules/test_ipxe.py b/ironic/tests/unit/drivers/modules/test_ipxe.py
index ef37e3fc4..02d254b5a 100644
--- a/ironic/tests/unit/drivers/modules/test_ipxe.py
+++ b/ironic/tests/unit/drivers/modules/test_ipxe.py
@@ -813,7 +813,7 @@ class iPXEBootTestCase(db_base.DbTestCase):
                 'aki_path': 'http://192.1.2.3:1234/' + uuid + '/kernel',
                 'ari_path': 'http://192.1.2.3:1234/' + uuid + '/ramdisk',
                 'ramdisk_opts': 'cat meow',
-                'pxe_append_params': 'nofb nomodeset vga=normal ipa-debug=1 '
+                'pxe_append_params': 'nofb vga=normal ipa-debug=1 '
                                      'ipa-global-request-'
                                      'id=' + task.context.request_id,
                 'tftp_server': mock.ANY,
diff --git a/releasenotes/notes/remove-nomodset-7a352a9519c1045b.yaml b/releasenotes/notes/remove-nomodset-7a352a9519c1045b.yaml
new file mode 100644
index 000000000..26d10c262
--- /dev/null
+++ b/releasenotes/notes/remove-nomodset-7a352a9519c1045b.yaml
@@ -0,0 +1,22 @@
+---
+upgrade:
+  - |
+    The defaults for ``kernel_append_params`` have had the Linux kernel
+    command line parameter ``nomodeset`` removed from the defaults for the
+    ``kernel_append_params`` settings. The ``nomodeset`` option is for
+    troubleshooting and changes the behavior of the graphics interface
+    such that memory can be locked upon graphical updates on physical
+    servers with BMC graphical interfaces, which results in spikes in
+    latency and packet loss whenever graphics updates occur. Operators
+    may add the option to their local configuration, but should be aware
+    that large image transfers or other high IO operations can be impacted.
+fixes:
+  - |
+    Agents deploying on physical servers with default kernel arguments were
+    suspetible to packet loss if a Matrox VGA/Aspeed BMC Graphics interface
+    is present on the machine. The defaults have been changed to remove
+    the use of the ``nomodeset`` kernel command line parameter which
+    should only be used for troubleshooting as it has been determined
+    that the memory updates can lock all of the kernel memory upon any
+    console graphics update which can negatively impact IO for Networking
+    or Disk interactions.