I have similar systems, where some were unstable after upgrading PVE 8 to 9. The key difference between them was that the AMD microcode and other firmware was considerably older. Downgrading to proxmox-kernel-6.14.8-2-pve-signed yielded fewer crashes (3-4 a day as opposed to every 10-40 minutes on proxmox-kernel-6.17.13-3-pve-signed) we fixed the issue by updating the BIOS.
Systems are Lenovo ThinkCentre M715q systems with `cat /proc/cpuinfo` reporting:
AMD Ryzen 5 PRO 2400GE w/ Radeon Vega Graphics
My systems were simply locking up and not restarting with the default softdog kernel module. I however got them to use the hardware TCO by updating /etc/default/pve-ha-manager to contain:
Code:
WATCHDOG_MODULE=sp5100_tco
Validation:
Code:
[admin@kvm2c ~]# wdctl
Device: /dev/watchdog0
Identity: SP5100 TCO timer [version 0]
Timeout: 10 seconds
Timeleft: 10 seconds
FLAG DESCRIPTION STATUS BOOT-STATUS
KEEPALIVEPING Keep alive ping reply 1 0
MAGICCLOSE Supports magic close char 0 0
SETTIMEOUT Set timeout (in seconds) 0 0
Before upgrade:
Code:
lshw | less
version: M1XKT34A
date: 09/04/2018
AMD microcode in BIOS:
[root@kvm2d ~]# journalctl -n 10000 | grep microcode
Apr 25 11:22:49 kvm2d kernel: microcode: Current revision: 0x08101007
Before upgrade:
Code:
lshw | less
version: M1XKT63A
date: 04/11/2024
AMD microcode in BIOS:
[root@kvm2c ~]# journalctl -n 10000 | grep microcode
Apr 25 12:42:15 kvm1 kernel: microcode: Current revision: 0x0810100b
PS: Installing the amd64-microcode package didn't help, it apparently can't help with certain parts which initialise after the kernel boots.
Google Gemini summarised the difference in the BIOS updates to be:
M1XKT63A replaces the experimental early-Zen power management logic (M1XKT34A) with the industry-standard stable AGESA 1.2.x, resolving critical CPU-idle hangs and providing hardware-level mitigations for Zen-architecture vulnerabilities.
1. AGESA & CPU Stability
The most critical change is the
AGESA (AMD Generic Encapsulated Software Architecture).
- The 2018 version was written when the Raven Ridge architecture was brand new. It had aggressive power-saving bugs that caused the CPU to drop voltage too low during idle transitions, which is what caused your Proxmox "Hard Freezes."
- The 2024 version is the "refined" logic. It ensures that even during deep idle (C-states), the CPU maintains a stable floor voltage.
2. Microcode & "Zenbleed"
The microcode revision
0x0810100b in the new BIOS is the official fix for several silicon-level bugs.
- Speculative Execution: The 2018 version was vulnerable to several side-channel attacks that could crash a kernel under specific branch-prediction loads.
- The fix: The 2024 microcode fundamentally changes how the CPU handles certain "Move" instructions, making it significantly more robust for virtualization (KVM/Proxmox) environments.
3. ACPI Tables (The Kernel Handshake)
When Linux boots, it reads the
ACPI Tables from the BIOS to learn how to manage the hardware.
- Old BIOS: Included messy tables that didn't strictly follow UEFI standards, often leading to "Spurious Interrupt" or "IOMMU" errors in the Linux dmesg.
- New BIOS: Features cleaned-up tables that match modern Linux kernel expectations. This is why you no longer need complex "boot parameters" (like idle=nomwait) to keep the system stable.
4. Security (LogoFAIL)
The 2024 update specifically addresses
LogoFAIL.
- The 2018 BIOS had a vulnerability where a malicious image file used as a boot logo could execute code at the firmware level.
- The 2024 version (the one you are using to flash your custom logos) has a hardened image parser to prevent this.
