Re: [PATCH v2 1/1] KVM: PPC: Introduce KVM_CAP_PPC_HTM

[David Gibson <david@gibson.dropbear.id.au>]

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On Wed, Jul 20, 2016 at 01:41:36PM +1000, Sam Bobroff wrote:
> Introduce a new KVM capability, KVM_CAP_PPC_HTM, that can be queried to
> determine if a PowerPC KVM guest should use HTM (Hardware Transactional
> Memory).
> 
> This will be used by QEMU to populate the pa-features bits in the
> guest's device tree.
> 
> Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com>

Reviewed-by: David Gibson <david@gibson.dropbear.id.au>

> ---
> 
> v2:
> 
> * Use CPU_FTR_TM_COMP instead of CPU_FTR_TM.
> * I didn't unbreak the line, as with the extra characters checkpatch will
>   complain if I do. I did move the break to a more usual place.
> 
>  arch/powerpc/kvm/powerpc.c | 4 ++++
>  include/uapi/linux/kvm.h   | 1 +
>  2 files changed, 5 insertions(+)
> 
> diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
> index 02416fe..5ebc8ff 100644
> --- a/arch/powerpc/kvm/powerpc.c
> +++ b/arch/powerpc/kvm/powerpc.c
> @@ -588,6 +588,10 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
>  		r = 1;
>  		break;
>  #endif
> +	case KVM_CAP_PPC_HTM:
> +		r = cpu_has_feature(CPU_FTR_TM_COMP) &&
> +		    is_kvmppc_hv_enabled(kvm);
> +		break;
>  	default:
>  		r = 0;
>  		break;
> diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
> index 05ebf47..f421d0e 100644
> --- a/include/uapi/linux/kvm.h
> +++ b/include/uapi/linux/kvm.h
> @@ -866,6 +866,7 @@ struct kvm_ppc_smmu_info {
>  #define KVM_CAP_ARM_PMU_V3 126
>  #define KVM_CAP_VCPU_ATTRIBUTES 127
>  #define KVM_CAP_MAX_VCPU_ID 128
> +#define KVM_CAP_PPC_HTM 129
>  
>  #ifdef KVM_CAP_IRQ_ROUTING
>  

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

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