On my HPE ProLiant BL460c Gen9, it just hangs suddenly without any screen output, and log info. iLO IML shows: An Unrecoverable System Error (NMI) has occurred (Service Information: 0x00000008, 0x89480000) Other people also meet this problem: HP ProLiant DL380G6 and DL360G7 https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=995773 If I disable intel_iommu by boot time option or just disable CONFIG_INTEL_IOMMU_DEFAULT_ON the problem has gone.
And another workaround is disable hpwdt. https://www.claudiokuenzler.com/blog/1125/debian-11-bullseye-boot-freeze-kernel-panic-hp-proliant-dl380
since proxmox7 ( 5.13.19-2-pve kernel), several people reporting console freeze / installer sluggishness with hp servers ( e.g. https://forum.proxmox.com/threads/updated-to-ve-7-0-no-web-gui-dmar-errors-on-console.92022/ ) on my dl380e gen8 , console prints [12925.378093] DMAR: DRHD: handling fault status reg 2 [12925.378158] DMAR: [INTR-REMAP] Request device [01:00.0] fault index 17 [fault reason 38] Blocked an interrupt request due to source-id verification failure and is frozen afterards.