Re: RFC: s390: extension capability for new address space layout

[Alexander Graf <agraf@suse.de>]

On 09/20/2011 01:56 PM, Christian Borntraeger wrote:
> Avi,Marcelo,
>
> 598841ca9919d008b520114d8a4378c4ce4e40a1 ([S390] use gmap address
> spaces for kvm guest images) changed kvm on s390 to use a separate
> address space for kvm guests. We can now put KVM guests anywhere
> in the user address mode with a size up to 8PB - as long as the
> memory is 1MB-aligned. This change was done without KVM extension
> capability bit.
> The change was added after 3.0, but we still have a chance to add
> a feature bit before 3.1 (keeping the releases in a sane state).
>
> Can you have a look at the change below and give you ACK or NACK?
> If ok, I would push this patch to Heiko to be submitted via the
> s390 stream for 3.1.
>
> Christian
>
> Signed-off-by: Christian Borntraeger<borntraeger@de.ibm.com>
>
> --- a/arch/s390/kvm/kvm-s390.c
> +++ b/arch/s390/kvm/kvm-s390.c
> @@ -123,6 +123,7 @@ int kvm_dev_ioctl_check_extension(long ext)
>
>   	switch (ext) {
>   	case KVM_CAP_S390_PSW:
> +	case KVM_CAP_S390_GMAP:
>   		r = 1;
>   		break;
>   	default:
> diff --git a/include/linux/kvm.h b/include/linux/kvm.h
> index 2c366b5..b2e9cc1 100644
> --- a/include/linux/kvm.h
> +++ b/include/linux/kvm.h
> @@ -553,6 +553,7 @@ struct kvm_ppc_pvinfo {
>   #define KVM_CAP_SPAPR_TCE 63
>   #define KVM_CAP_PPC_SMT 64
>   #define KVM_CAP_PPC_RMA	65
> +#define KVM_CAP_S390_GMAP 66

I would really appreciate if you could take capability number 71. I 
already have patches pending (partly already in avi's tree) that occupy 
everything up to 70 :)


Alex