From 9545edc79d75e75d47c51d5da651975c01e919ec Mon Sep 17 00:00:00 2001 From: Stephen Finucane Date: Thu, 3 Oct 2019 15:23:53 +0100 Subject: [PATCH] docs: Highlight the current broken state of SEV This won't be resolved in time for Train GA, so add a release note highlighting the problem until such a time as the release is fixed. Change-Id: Iae30e12084640d1c0f072d2db18653111988929e Signed-off-by: Stephen Finucane Related-Bug: #1845986 Stable-Only --- .../admin/configuration/hypervisor-kvm.rst | 10 +++++++++ .../notes/bug-1845986-95cbede0a296b088.yaml | 21 +++++++++++++++++++ 2 files changed, 31 insertions(+) create mode 100644 releasenotes/notes/bug-1845986-95cbede0a296b088.yaml diff --git a/doc/source/admin/configuration/hypervisor-kvm.rst b/doc/source/admin/configuration/hypervisor-kvm.rst index b0bd8ecc5d39..2802ba84cb74 100644 --- a/doc/source/admin/configuration/hypervisor-kvm.rst +++ b/doc/source/admin/configuration/hypervisor-kvm.rst @@ -684,6 +684,16 @@ explained above. Impermanent limitations ----------------------- +The following image metadata options are incompatible with the feature due to +`bug #1845986 `__. + +- ``hw_scsi_model=virtio-scsi`` and either ``hw_disk_bus=scsi`` or + ``hw_cdrom_bus=scsi`` +- ``hw_video_model=virtio`` +- ``hw_qemu_guest_agent=yes`` + +This limitation will be resolved in the future. + The following limitations may be removed in the future as the hardware, firmware, and various layers of software receive new features: diff --git a/releasenotes/notes/bug-1845986-95cbede0a296b088.yaml b/releasenotes/notes/bug-1845986-95cbede0a296b088.yaml new file mode 100644 index 000000000000..cbb54cc1ac08 --- /dev/null +++ b/releasenotes/notes/bug-1845986-95cbede0a296b088.yaml @@ -0,0 +1,21 @@ +--- +issues: + - | + The support for guest RAM encryption using AMD SEV (Secure Encrypted + Virtualization) added in Train is incompatible with a number of image + metadata options: + + - ``hw_scsi_model=virtio-scsi`` and either ``hw_disk_bus=scsi`` or + ``hw_cdrom_bus=scsi`` + - ``hw_video_model=virtio`` + - ``hw_qemu_guest_agent=yes`` + + When used together, the guest kernel can malfunction with repeated warnings + like:: + + NMI watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [system-udevd:272] + + This will be resolved in a future patch release. For more information, + refer to `bug 1845986`__ + + __ https://bugs.launchpad.net/nova/+bug/1845986