Re: Possible bug in Xen

[Joe Tretter <j.tretter@xxxxxxxxx>]

On 12/19/23 10:05, Andrew Cooper wrote:

Is it always the same test which fails, or is it random?

Which test fails seems to be random (see attached screenshot).

Looking at https://github.com/Tarsnap/scrypt it's only a trivial piece
of userspace crypto.

The fact that running multiple instances makes it fail more easily
points towards some kind of register handling issue, but the fact that
it repros only under Xen, and even with eager-fpu (which isn't the
default on AMD, sadly), is weird.

Looking at the scrypt source, it has alternative routines for the AESNI
and SHANI instruction groups.  However, because it's a Zen1, we don't
have a useful way of filtering visible for PV dom0 userspace.

First of all, can you get the exact CPU model and microcode version. 
`head /proc/cpuinfo` will be enough.  But while you're at it, can you
include `xl dmesg` too just in case there's something obvious showing up
there too.

I have attachted text files with the (full) cpuinfo and the dmesg.

Thanks

~Joe

Attachment: cpuinfo.txt
Description: Text document

Attachment: xl dmesg.txt
Description: Text document

Attachment: RandomFail.jpg
Description: JPEG image