Re: [kvm-unit-tests PATCH 1/2] s390x: diag10: Fence tcg and pv environments

[Claudio Imbrenda <imbrenda@linux.ibm.com>]

On Wed, 28 May 2025 13:13:45 +0200
Janosch Frank <frankja@linux.ibm.com> wrote:

> On 5/28/25 11:41 AM, Claudio Imbrenda wrote:
> > On Wed, 28 May 2025 09:13:49 +0000
> > Janosch Frank <frankja@linux.ibm.com> wrote:
> >   
> >> Diag10 isn't supported under either of these environments so let's
> >> make sure that the test bails out accordingly.  
> > 
> > does KVM always implement diag10?  
> 
> It was introduced October of 2011 and there's no way of disabling it 
> that I can see.
> 
> > 
> > is there no other way to check whether diag10 is available?  
> 
> The z/VM CP programming services doesn't specify a feature bit or any 
> other way to check as far as I can see.
> 
> > 
> > we could, for example, try to run it "correctly" and see whether we get
> > a Specification exception, and then fence.  
> 
> We could move the content test to the top and bail out if there's a 
> spec. That would allow us to handle the addition of diag10 support for 
> TCG without a test change.
> 
> But:
> How likely is it that we want to implement diag10 in TCG?
> My guess is that adding it to PV is even less likely.
> Not running them under PV and TCG gives us back some CI time although 
> it's likely minuscule.

fair points

Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>