Re: [Qemu-devel] [PATCH v4 07/07] s390: make sclp ascii console the default

[Alexander Graf]

On 07/31/2012 02:44 PM, Christian Borntraeger wrote:
> On 30/07/12 16:05, Alexander Graf wrote:
> > On 26.07.2012, at 10:59, Christian Borntraeger wrote:
> >
> > > This patch makes the sclp ascii default for S390. It requires a guest
> > > kernel that autodetects the console and which not blindly assumes
> > > that kvm means virtio console.
> > > (commit cd1834591fe9564720ac4b0193bf1c790fe89f0d
> > >     KVM: s390: Perform early event mask processing during boot)
> > > Otherwise the guest admin has to explicitely add console=ttyS1 to the
> > > command line.
> > Hrm. Could we make this the non-default for the time being with a simple 
> > -machine option to switch it to the default? When enough kernels are aware of 
> > the switch, we could then make it the default.
> No problem, we can defer that patch. It was merely a testing aid for those who 
> want to test the
> sclp code. Later on maybe we can make that decision based on other thing.

Well, I'd like to have the logic around and easy to choose. Basically 
what I envision is that one day we do a flag day that introduces a 
compatibility machine type which only differs from the current one in 
that it sets said machine opt to "use ascii console as default".

That way for the time being, people who want to play with it only need 
to do -machine ascii_console=on and everything else would happen 
automatically. It'd definitely make it easier for everyone involved.


Alex