Re: [PATCH] kvm tools: Fix type mismatches on GCC 4.4 on 32-bit systems

[Ingo Molnar <mingo@elte.hu>]

* Pekka Enberg <penberg@kernel.org> wrote:

> On Fri, May 13, 2011 at 11:19 AM, Ingo Molnar <mingo@elte.hu> wrote:
> > @@ -162,7 +162,7 @@ static void kvm_register_mem_slot(struct kvm *kvm, u32 slot, u64 guest_phys, u64
> >                .slot                   = slot,
> >                .guest_phys_addr        = guest_phys,
> >                .memory_size            = size,
> > -               .userspace_addr         = (u64)userspace_addr,
> > +               .userspace_addr         = (u64)(long)userspace_addr,
> >        };
> 
> Isn't
> 
> +               .userspace_addr         = (unsigned long)userspace_addr,
> 
> the right thing to do here?

Yeah, you are right - and userspace_addr will always be 32-bit on 32-bit hosts 
so this is unrelated to the guest-pfn conversion thing.

More than 1-2 GB of RAM can be supported in the future by mmap()-ing a chunk, 
passing the address to KVM and then unmapping it. In theory it is possible to 
implement more than 4GB RAM support on 32-bit hosts without having to do 
highmem alike tricks in tools/kvm/, but i doubt there's much interest in that - 
everything is so much easier on 64-bit systems ...

Thanks,

	Ingo