Re: [Qemu-devel] [PATCH RFC] vfio-ap: flag as compatible with balloon

[Cornelia Huck <cohuck@redhat.com>]

On Fri, 7 Dec 2018 13:32:14 +0100
Christian Borntraeger <borntraeger@de.ibm.com> wrote:

> On 07.12.2018 13:29, Cornelia Huck wrote:
> > On Fri, 7 Dec 2018 13:17:02 +0100
> > Christian Borntraeger <borntraeger@de.ibm.com> wrote:
> >   
> >> On 05.12.2018 15:51, Cornelia Huck wrote:  
> >>> vfio-ap devices do not pin any pages in the host. Therefore, they
> >>> are belived to be compatible with memory ballooning.
> >>>
> >>> Flag them as compatible, so both vfio-ap and a balloon can be
> >>> used simultaneously.
> >>>
> >>> Signed-off-by: Cornelia Huck <cohuck@redhat.com>    
> >>
> >> Does it make sense to add cc stable for 3.1?  
> > 
> > Can do that, given that s390x systems really rely on the ballooner in
> > general.  
> 
> Well, not relying is the wrong word. It is just strange that things like
> 
>   <memory unit='GiB'>2</memory>
>   <currentMemory unit='GiB'>1</currentMemory>
> 
> do work 
> but suddenly no longer work when an AP device is added.
> 

Let me rephrase that: Current setups rely on the functionality, and we
don't want to break them by adding ap :)