Message-Id: <D3GKA618AGIM.36RB2FW9Z21JE@cknow.org>
Date: Thu, 15 Aug 2024 16:40:03 +0200
From: "Diederik de Haas" <didi.debian@...ow.org>
To: "Tom Lendacky" <thomas.lendacky@....com>, "John Allen"
 <john.allen@....com>
Cc: "Herbert Xu" <herbert@...dor.apana.org.au>, "David S. Miller"
 <davem@...emloft.net>, <linux-crypto@...r.kernel.org>,
 <linux-kernel@...r.kernel.org>, "Diederik de Haas" <didi.debian@...ow.org>
Subject: Re: [BUG] Non working HWRNG on AMD Ryzen 5 5500GT

On Thu Aug 15, 2024 at 4:16 PM CEST, Tom Lendacky wrote:
> On 8/15/24 08:56, Diederik de Haas wrote:
> > I recently bought an Asus ROG STRIX B550-F GAMING MB with an
> > AMD Ryzen 5 5500GT CPU (and installed the latest BIOS: 3607).
> > I'm running Debian Testing/Sid on it with kernel 6.9 and now 6.10
> > and it seems to work great.
> > I've been doing some (unrelated) tests with `rngtest` from the
> > `rng-tools5` package and wondered how it would fare on my AMD CPU.
>
> I'm not very familiar with this test. What is the command line that you
> are using to invoke it?

```
root@...4:~# cat /dev/hwrng | rngtest -c 1000
rngtest 5
Copyright (c) 2004 by Henrique de Moraes Holschuh
This is free software; see the source for copying conditions.
There is NO warranty; not even for MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE.

rngtest: starting FIPS tests...
cat: /dev/hwrng: No such device
rngtest: entropy source drained
```

Or when using ``dd`` you'd get a similar output:

```
root@...4:~# dd if=/dev/hwrng bs%6 | rngtest -c 1000
rngtest 5
...

rngtest: starting FIPS tests...
dd: error reading '/dev/hwrng': No such device
0+0 records in
0+0 records out
rngtest: entropy source drained
0 bytes copied, 4.8214e-05 s, 0.0 kB/s
``

Debian package page: https://packages.debian.org/unstable/rng-tools5
Debian hasn't switched to the new upstream (yet?), but that can be found
here: https://github.com/nhorman/rng-tools

> > And I found out it doesn't work at all!
> > But on another system I have (Asus ROG CROSSHAIR VII HERO MB +
> > AMD Ryzen 1800X CPU) it works absolutely fine.
> > 
> > # dmesg | grep ccp
> > [    5.399853] ccp 0000:07:00.2: ccp: unable to access the device: you might
> > be running a broken BIOS.
> > [    5.401031] ccp 0000:07:00.2: tee enabled
> > [    5.401113] ccp 0000:07:00.2: psp enabled
>
> Which system is this output from?

My new system ("cs04") with AMD Ryzen 5 5500GT CPU/APU.

> Can you provide the output from lspci -nn?

```
root@...4:~# lspci -nn
00:00.0 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] Renoir/Cezanne Root Complex [1022:1630]
00:00.2 IOMMU [0806]: Advanced Micro Devices, Inc. [AMD] Renoir/Cezanne IOMMU [1022:1631]
00:01.0 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] Renoir PCIe Dummy Host Bridge [1022:1632]
00:02.0 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] Renoir PCIe Dummy Host Bridge [1022:1632]
00:02.1 PCI bridge [0604]: Advanced Micro Devices, Inc. [AMD] Renoir/Cezanne PCIe GPP Bridge [1022:1634]
00:02.2 PCI bridge [0604]: Advanced Micro Devices, Inc. [AMD] Renoir/Cezanne PCIe GPP Bridge [1022:1634]
00:08.0 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] Renoir PCIe Dummy Host Bridge [1022:1632]
00:08.1 PCI bridge [0604]: Advanced Micro Devices, Inc. [AMD] Renoir Internal PCIe GPP Bridge to Bus [1022:1635]
00:14.0 SMBus [0c05]: Advanced Micro Devices, Inc. [AMD] FCH SMBus Controller [1022:790b] (rev 51)
00:14.3 ISA bridge [0601]: Advanced Micro Devices, Inc. [AMD] FCH LPC Bridge [1022:790e] (rev 51)
00:18.0 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] Cezanne Data Fabric; Function 0 [1022:166a]
00:18.1 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] Cezanne Data Fabric; Function 1 [1022:166b]
00:18.2 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] Cezanne Data Fabric; Function 2 [1022:166c]
00:18.3 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] Cezanne Data Fabric; Function 3 [1022:166d]
00:18.4 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] Cezanne Data Fabric; Function 4 [1022:166e]
00:18.5 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] Cezanne Data Fabric; Function 5 [1022:166f]
00:18.6 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] Cezanne Data Fabric; Function 6 [1022:1670]
00:18.7 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] Cezanne Data Fabric; Function 7 [1022:1671]
01:00.0 USB controller [0c03]: Advanced Micro Devices, Inc. [AMD] 500 Series Chipset USB 3.1 XHCI Controller [1022:43ee]
01:00.1 SATA controller [0106]: Advanced Micro Devices, Inc. [AMD] 500 Series Chipset SATA Controller [1022:43eb]
01:00.2 PCI bridge [0604]: Advanced Micro Devices, Inc. [AMD] 500 Series Chipset Switch Upstream Port [1022:43e9]
02:00.0 PCI bridge [0604]: Advanced Micro Devices, Inc. [AMD] Device [1022:43ea]
02:08.0 PCI bridge [0604]: Advanced Micro Devices, Inc. [AMD] Device [1022:43ea]
02:09.0 PCI bridge [0604]: Advanced Micro Devices, Inc. [AMD] Device [1022:43ea]
05:00.0 Ethernet controller [0200]: Intel Corporation Ethernet Controller I225-V [8086:15f3] (rev 03)
06:00.0 Non-Volatile memory controller [0108]: Samsung Electronics Co Ltd NVMe SSD Controller PM9A1/PM9A3/980PRO [144d:a80a]
07:00.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. [AMD/ATI] Cezanne [Radeon Vega Series / Radeon Vega Mobile Series] [1002:1638] (rev c9)
07:00.1 Audio device [0403]: Advanced Micro Devices, Inc. [AMD/ATI] Renoir Radeon High Definition Audio Controller [1002:1637]
07:00.2 Encryption controller [1080]: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 10h-1fh) Platform Security Processor [1022:15df]
07:00.3 USB controller [0c03]: Advanced Micro Devices, Inc. [AMD] Renoir/Cezanne USB 3.1 [1022:1639]
07:00.4 USB controller [0c03]: Advanced Micro Devices, Inc. [AMD] Renoir/Cezanne USB 3.1 [1022:1639]
07:00.6 Audio device [0403]: Advanced Micro Devices, Inc. [AMD] Family 17h/19h HD Audio Controller [1022:15e3]
```

Cheers,
  Diederik

> Thanks,
> Tom
>
> > 
> > Found an article [1] which could be relevant and downloaded and ran the
> > accompanying test program (written by Jason Donenfeld):
> > # ./amd-rdrand-bug
> > Your RDRAND() does not have the AMD bug.
> > # ./test-rdrand
> > RDRAND() =x47c993c0
> > RDRAND() =xec7c697d
> > ... (more seemingly random numbers)
> > RDRAND() =xba858101
> > 
> > I tried it with the latest microcode dd 2024-07-10, but that didn't make
> > a difference.
> > 
> > So I'd like to know if this may actually be a bug on the kernel side.
> > 
> > Happy to provide additional information or run tests or try patches.
> > 
> > Cheers,
> >   Diederik
> > 
> > [1] https://arstechnica.com/gadgets/2019/10/how-a-months-old-amd-microcode-bug-destroyed-my-weekend/


Download attachment "signature.asc" of type "application/pgp-signature" (229 bytes)

Powered by blists - more mailing lists