Re: [PATCH] libkvm-s390

[Christian Borntraeger <borntraeger@de.ibm.com>]

That patch was Carstens last job before he left into vacation. I promised to 
look after it, so I will sent an updated patch soon.

> > +/*
> > + * This header is for functions & variables that will ONLY be
> > + * used inside libkvm for s390x.
> > + * THESE ARE NOT EXPOSED TO THE USER AND ARE ONLY FOR USE
> > + * WITHIN LIBKVM.
> > + *
> >   
> 
> It isn't a header.

Will fix
> 
> > + * derived from libkvm-powerpc.c
> > + *
> >   
> 
> So it the comment above.  So much for our review.

I guess libkvm-powerpc.c will be fixed by the powerpc guys?

> > +#ifndef __s390x__
> >  #define KVM_MAX_NUM_MEM_REGIONS 8u
> > +#define MAX_VCPUS 64
> >   
> 
> 16
> 
> > +#else
> > +#define KVM_MAX_NUM_MEM_REGIONS 1u
> >  #define MAX_VCPUS 16
> >   
> 
> 64

Yes, indeed. 

> > +#define LIBKVM_S390_ORIGIN (0UL)
> 
> Thought you got rid of that?

Sort of. We have the kernel code ready to move away the guest from address 0. 
To achieve that goal we use the offset and limit field in the control block.
Thing is, on older models the offset and limit must be < 128GB. that means we 
still cannot use randomly allocated memory. LIBKVM_S390_ORIGIN=1M,2M or 16M 
would be perfectly fine, 2TB (typical malloc space) is not.
Furthermore, this change is still in kvm.git, but not in Linus git. 
Therefore, we would like to keep the guest at 0 and fix that at a later time, 
ok?

Christian