AMD Microcode updates not working?

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1

On my latest NixOS install I suddenly noticed that during the boot process I received the now-famous message:

RDRAND gives funky smelling output, might consider not using it by booting with nordrand

And a just a few hours later, when trying to start the Nheko Matrix client, I got this:

šŗ nheko
WARNING: CPU random generator seem to be failing, disabling hardware random number generation
WARNING: RDRND generated: 0xffffffff 0xffffffff 0xffffffff 0xffffffff

Now, I have Ryzen 7 3700x CPU, which I know did have some issues regarding RdRand a while back. My motherboardā€™s (an MSI B450 Tomahawk) BIOS is not up to date with the latest firmware version, so I assume that flashing the latest firmware version will fix this issue. Alternatively, I could probably boot with the nordrand kernel option.

However, I do find this a little strange, because I have hardware.cpu.amd.updateMicrocode = true; set in my configuration. Should this issue not have been fixed by newer CPU microcode updates? Werenā€™t these updates included in the Linux kernel a long time ago?

Iā€™m on NixOS 21.05 with Linux kernel 5.12.10:

šŗ uname -a
Linux yokohama 5.12.10 #1-NixOS SMP Thu Jun 10 11:41:49 UTC 2021 x86_64 GNU/Linux

Have a look through /proc/sysinfo reveals that I am what looks like microcode version 0x8701013, which I think might indeed be quite old, but Iā€™m unsure because itā€™s so hard to get any decent info on microcode versions out there.

šŗ grep 'model\|microcode' /proc/cpuinfo
model		: 113
model name	: AMD Ryzen 7 3700X 8-Core Processor
microcode	: 0x8701013

Iā€™m a little confused on this, can anyone provide me with some hints on how to take care of this? Iā€™d rather first figure out why this is happening before fixing it with a BIOS firmware update or using nordrand.

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2

Iā€™ve been looking around for more information on this, and it seems that the latest microcode version for my CPU is 0x8701021 dated 2020/01/25. In other words, I am most certainly not running the latest microcode patch.

3

Additionally, the AuthenticAMD.bin extracted from the initrd from a build of my configuration with hardware.cpu.amd.updateMicrocode = true; and with hardware.cpu.amd.updateMicrocode = false; both have the exact same checksum. Iā€™m not sure if this is at all signifcant.

4

the microcode comes from the linux unfree firmware:

# release-21.05
nix-repl> builtins.parseDrvName microcodeAmd.name
{ name = "amd-ucode"; version = "2021-05-11"; }

did you set hardware.enableRedistributableFirmware = true;?

5

Hah, I had just managed to figure out where the microcode was coming from myself :slightly_smiling_face:.

I have not explicitly set that option, have never seen it before. Iā€™ll give that a shot when I can, though I thought allowUnfree = true; should have been enough?

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6

Iā€™ve quickly tried it out, rebuilt my system with that flag set to true, but it did not seem to make a difference. I canā€™t figure this one out. Am I looking at something buggy or am I just doing something incredibly stupid? :thinking:

7

Hmm, I actually have the same issue. But everything seems to be built fineā€¦

One thing to remember is that the microcode is added to the initrd, so you have to reboot for the change to take effect.

8

Yes, Iā€™ve rebooted about a billion times by now :wink:

Like you said, I think everything builds just fine, the initrd that results from the build even includes an AuthenticAMD.bin, as it should, but I doubt there is a proper way to inspect what is actually makes up that imageā€¦

1 Like
9

Send the output of
dmesg | grep microcode
which bootloader are you 2 using?

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10

As you can see, no output of any microcode being loaded:

šŗ dmesg | grep microcode
[    0.231199] microcode: CPU0: patch_level=0x08701013
[    0.231202] microcode: CPU1: patch_level=0x08701013
[    0.231206] microcode: CPU2: patch_level=0x08701013
[    0.231209] microcode: CPU3: patch_level=0x08701013
[    0.231214] microcode: CPU4: patch_level=0x08701013
[    0.231219] microcode: CPU5: patch_level=0x08701013
[    0.231223] microcode: CPU6: patch_level=0x08701013
[    0.231228] microcode: CPU7: patch_level=0x08701013
[    0.231231] microcode: CPU8: patch_level=0x08701013
[    0.231233] microcode: CPU9: patch_level=0x08701013
[    0.231236] microcode: CPU10: patch_level=0x08701013
[    0.231239] microcode: CPU11: patch_level=0x08701013
[    0.231242] microcode: CPU12: patch_level=0x08701013
[    0.231246] microcode: CPU13: patch_level=0x08701013
[    0.231250] microcode: CPU14: patch_level=0x08701013
[    0.231254] microcode: CPU15: patch_level=0x08701013
[    0.231257] microcode: Microcode Update Driver: v2.2.

Iā€™m currently on systemd-boot.

1 Like
11

I tried to make some time to switch over to booting with GRUB today, but because I dual boot Windows (to play games), I ran into some trouble, so I havenā€™t been able to pull it off just yet.

12

Make sure to enable os-prober.

13

Sorry to necro this, but any of you guys ever managed to solve this? Thanks in advance!