[SOLVED] AMD Ryzen specific configuration

[Joris L.]

Hello people,

Looking for a suitable platform to build a small lab i decided to go with proxmox ve 6.2 first. There were notable issue with installation and operation of proxmox on the X370 chipset with a AMD Ryzen CPU (1700X)

Eventually it was found the instability originates form BIOS configuration and boot time parameters.

• Configuration required to improve AMD Ryzen CPU functionality with Linux, Qemu

modify /etc/default/grub and append the below line to GRUB_CMDLINE_LINUX (between " ")​

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iommu=pt amd_iommu=on​

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now execute update-grub​

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modify /etc/modprobe/{yourfilenamehere}.conf to contain​

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options kvm ignore_msrs=1​

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• Configuration required for PCI pass-through (from the proxmox wiki)

modify /etc/modules to contain​

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vfio​

vfio_iommu_type1​

vfio_pci​

vfio_virqfd​

​

• consider this kernel boot parameters to optionally also add: rcu_nocbs=0-15
  
  BIOS configuration for CPU features is best set to enabled as a default instead of AUTO or disabled.

boot mode select: legacy+uefi​

ErP ready: enabled​

Core performance boost: disabled​

​

> CPU Features (here typically set to enabled by me instead of auto, just works, better)​

Global C-state control: disabled​

Power Supply Idle control: Auto​

P-State Adjustment : Pstate 0​

Precision Boost Overdrive: AMD Default​

Mode0: enabled​

​

now reboot​

Stability notes: (based on impressions and experience, results may vary)

observation: ​

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update-grub does no longer appears to have the desired effect of updating, this shows in instability on reboot, required to manually append the parameters on boot.​

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evidence: ​

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cat /proc/cmdline does not show the parameters appended in /etc/default/grub​

 

[Joris L.]

Worth noting. I upgraded this machine recently to 32GB. Running memtest86 showed plenty of ram errors. Next i found how to get rid of them.

Reseat the new DDR4 DIM modules from 2020 on the same channel, the 2017 ones on the other channel. Reset the BIOS to defaults. And propably most importantly, set the XML profile to 2900Mhz instead of 3200Mhz. ZERO ERRORS since. Time to buy an extra fan to point at the memory banks.

 

[CRCinAU]

I note that you don't need any tweaks above for normal proxmox operation.

Having stability issues would cause me to check RAM, as you have and found errors, or set `Power Supply Idle control: Typical idle current` (or similar phrasing in your BIOS).

You don't have to change anything further from defaults in the BIOS to run proxmox successfully (unless some are purely for PCI Passthru - but that isn't Ryzen related)

 

[Joris L.]

I agree. To my shame i am getting old and much is done automagically by now.

Basically, lowering the ram speed is most likely the only real fix required here. None of the bios settings were relevant either.