Re: [Qemu-devel] [PATCH v3 0/3] Implement basic MSA functions

[Cornelia Huck <cohuck@redhat.com>]

On Wed, 20 Sep 2017 17:30:13 +0200
David Hildenbrand <david@redhat.com> wrote:

> Some leftover from "target/s390x: tcg improvments + MSA functions".
> 
> Implement all basic MSA (cpacf/crypto) instructions <= z13. Only provide
> the query subfunction (to query available subfunctions), no actual
> de/encryption yet. Good enough to unlock the STFL bits.
> 
> I have written kvm-unit-tests for MSA functions and for SPM/IPM. Will
> send them out soon. I use the following cpu model to test with an upstream
> kernel compiled for z10:
> 
> ... -cpu qemu,mvcos=on,stfle=on,ldisp=on,ldisphp=on,\
>               eimm=on,stckf=on,csst=on,csst2=on,ginste=on,\
>               exrl=on,msa-base=on,msa3-base=on,msa4-base=on,msa5-base=on ...
> 
> Available on: https://github.com/davidhildenbrand/qemu.git s390x-msa

I used the following cpu model:

-cpu qemu,eimm=on,ldisp=on,stckf=on,msa-base=on,msa3-base=on,msa4-base=on,msa5-base=on

and got

qemu-system-s390x: warning: 'msa5-base' requires 'kimd-sha-512'.
qemu-system-s390x: warning: 'msa5-base' requires 'klmd-sha-512'.

(It works anyway.)

However,

-cpu qemu,eimm=on,ldisp=on,stckf=on,msa-base=on,msa3-base=on,msa4-base=on,msa5-base=on,kimd-sha-512=on

gives

qemu-system-s390x: can't apply global qemu-s390-cpu.kimd-sha-512=on: Feature 'kimd-sha-512' is not available for CPU model 'z900', it was introduced with later models.

which is a bit confusing.

So I'm wondering whether providing msa5-base without the providing the
algorithms above is sane - or whether it is just enough to satisfy some
kernels.

[Double-checking the various dependencies looks impossible without
access to IBM doc, anyway - I just hope you got it right back then :)]