Public bug reported: Overview: If vmcoreinfo feature is enabled and the Guest(VM) OS includes the kernel module qemu_fw_cfg, enabling SEV will cause kernel panic.
Details: Currently, vmcoreinfo is enabled by default[1]. In addition, the module qemu_fw_cfg is included in the RHEL-based image (confirmed environment is Rocky Linux) as a builtin. ``` $ modinfo qemu_fw_cfg name: qemu_fw_cfg filename: (builtin) license: GPL file: drivers/firmware/qemu_fw_cfg description: QEMU fw_cfg sysfs support author: Gabriel L. Somlo <so...@cmu.edu> ``` At this time, kernel panic occurred when we created a VM with SEV enabled. Guess: Conflict between SEV, which limits DMA, and qemu_fw_cfg, which is supposed to use DMA. Incidentally, when we set vmcoreinfo feature to disable, we succeeded in starting the SEV-enabled VM in the same environment. References: [1] https://github.com/openstack/nova/commit/740e6f09bf5a3e5ab3c6dd6d412dd1fe33f81d9f Environment: Image: Rocky Linux 9.5 OpenStack: Dalmatial release (2024.2) ** Affects: nova Importance: Undecided Status: New ** Description changed: Overview: If vmcoreinfo feature is enabled and the Guest(VM) OS includes the kernel module qemu_fw_cfg, enabling SEV will cause kernel panic. Details: Currently, vmcoreinfo is enabled by default[1]. In addition, the module qemu_fw_cfg is included in the RHEL-based image (confirmed environment is Rocky Linux) as a builtin. ``` $ modinfo qemu_fw_cfg name: qemu_fw_cfg filename: (builtin) license: GPL file: drivers/firmware/qemu_fw_cfg description: QEMU fw_cfg sysfs support author: Gabriel L. Somlo <so...@cmu.edu> ``` - At this time, kernel panic occurred when I started a VM with SEV enabled. + At this time, kernel panic occurred when we created a VM with SEV enabled. Guess: Conflict between SEV, which limits DMA, and qemu_fw_cfg, which is supposed to use DMA. - Incidentally, when we set vmcoreinfo to disable, I succeeded in starting the SEV-enabled VM in the same environment. + Incidentally, when we set vmcoreinfo feature to disable, we succeeded in starting the SEV-enabled VM in the same environment. References: [1] https://github.com/openstack/nova/commit/740e6f09bf5a3e5ab3c6dd6d412dd1fe33f81d9f Environment: Image: Rocky Linux 9.5 OpenStack: Dalmatial release (2024.2) -- You received this bug notification because you are a member of Yahoo! Engineering Team, which is subscribed to OpenStack Compute (nova). https://bugs.launchpad.net/bugs/2116995 Title: Unable to enable SEV on RHEL image Status in OpenStack Compute (nova): New Bug description: Overview: If vmcoreinfo feature is enabled and the Guest(VM) OS includes the kernel module qemu_fw_cfg, enabling SEV will cause kernel panic. Details: Currently, vmcoreinfo is enabled by default[1]. In addition, the module qemu_fw_cfg is included in the RHEL-based image (confirmed environment is Rocky Linux) as a builtin. ``` $ modinfo qemu_fw_cfg name: qemu_fw_cfg filename: (builtin) license: GPL file: drivers/firmware/qemu_fw_cfg description: QEMU fw_cfg sysfs support author: Gabriel L. Somlo <so...@cmu.edu> ``` At this time, kernel panic occurred when we created a VM with SEV enabled. Guess: Conflict between SEV, which limits DMA, and qemu_fw_cfg, which is supposed to use DMA. Incidentally, when we set vmcoreinfo feature to disable, we succeeded in starting the SEV-enabled VM in the same environment. References: [1] https://github.com/openstack/nova/commit/740e6f09bf5a3e5ab3c6dd6d412dd1fe33f81d9f Environment: Image: Rocky Linux 9.5 OpenStack: Dalmatial release (2024.2) To manage notifications about this bug go to: https://bugs.launchpad.net/nova/+bug/2116995/+subscriptions -- Mailing list: https://launchpad.net/~yahoo-eng-team Post to : yahoo-eng-team@lists.launchpad.net Unsubscribe : https://launchpad.net/~yahoo-eng-team More help : https://help.launchpad.net/ListHelp
