Re: [qemu-s390x] [Qemu-devel] [PATCH v3] s390x/cpumodel: Set up CPU model for AQIC interception

[Pierre Morel]

On 15/02/2019 10:58, Christian Borntraeger wrote:
> On 15.02.2019 10:53, Pierre Morel wrote:
> > On 14/02/2019 13:14, Pierre Morel wrote:
> > > A new CPU model facilities is introduced to support AP devices
> > > interruption interception for a KVM guest.
> > >
> > > "APQI" for "AP-Queue Interruption" facility
> > >
> > > The S390_FEAT_AP_QUEUE_INTERRUPT_CONTROL, CPU facility indicates
> > > whether the PQAP instruction with the AQIC command is available
> > > to the guest.
> > > This feature will be enabled only if the AP instructions are
> > > available on the linux host and AQIC facility is installed on
> > > the host.
> > >
> > > This feature must be turned on from userspace to intercept AP
> > > instructions on the KVM guest. The QEMU command line to turn
> > > this feature on looks something like this:
> > >
> > >       qemu-system-s390x ... -cpu xxx,apqi=on ...
> >
> >
> >
> > Hi,
> >
> > I suddenly have a very big doubt on this QEMU patch.
> >
> > Older Linux advertise PQAP/AQIC feature (65)
>
> Which Linuxes advertise PQAP/AQIC (stfle.65)?
> This was never advertised by any previous Linux as far as I can tell.

OK, very sorry, you are right, I checked on a different machine and it 
is not.
I must have left something in my system.

Sorry for the panic.
I will look at what made me experience this.

Regards,
Pierre

--
Pierre Morel
Linux/KVM/QEMU in Böblingen - Germany