Re: [PATCH 1/2] KVM: PPC: epapr: Add idle hcall support for host

[Scott Wood <scottwood@freescale.com>]

On 12/31/2011 12:16 AM, Liu Yu wrote:
> Add a new field opt_feature in struct kvm_ppc_pvinfo
> to tell userspace whether it support hcall idle.
> 
> Signed-off-by: Liu Yu <yu.liu@freescale.com>
> ---
>  arch/powerpc/include/asm/kvm_para.h |   18 ++++++++++++++----
>  arch/powerpc/kvm/powerpc.c          |    9 +++++++++
>  include/linux/kvm.h                 |    5 ++++-
>  3 files changed, 27 insertions(+), 5 deletions(-)
> 
> diff --git a/arch/powerpc/include/asm/kvm_para.h b/arch/powerpc/include/asm/kvm_para.h
> index 50533f9..0686377 100644
> --- a/arch/powerpc/include/asm/kvm_para.h
> +++ b/arch/powerpc/include/asm/kvm_para.h
> @@ -40,17 +40,27 @@ struct kvm_vcpu_arch_shared {
>  	__u32 sr[16];
>  };
>  
> +#ifdef __KERNEL__
> +
>  #define KVM_SC_MAGIC_R0		0x4b564d21 /* "KVM!" */
> -#define HC_VENDOR_KVM		(42 << 16)
> +
> +#include <asm/epapr_hcalls.h>
> +
> +/* ePAPR Hypercall Vendor ID */
> +#define HC_VENDOR_EPAPR		(EV_EPAPR_VENDOR_ID << 16)
> +#define HC_VENDOR_KVM		(EV_KVM_VENDOR_ID << 16)
> +
> +/* ePAPR Hypercall Token */
> +#define HC_EV_IDLE		EV_IDLE
> +
> +/* ePAPR Hypercall Return Codes */
>  #define HC_EV_SUCCESS		0
> -#define HC_EV_UNIMPLEMENTED	12
> +#define HC_EV_UNIMPLEMENTED	EV_UNIMPLEMENTED
>  
>  #define KVM_FEATURE_MAGIC_PAGE	1
>  
>  #define KVM_MAGIC_FEAT_SR	(1 << 0)
>  
> -#ifdef __KERNEL__
> -

We don't want this stuff to be kernel-only.

> diff --git a/include/linux/kvm.h b/include/linux/kvm.h
> index c107fae..5af21f3 100644
> --- a/include/linux/kvm.h
> +++ b/include/linux/kvm.h
> @@ -426,9 +426,12 @@ struct kvm_ppc_pvinfo {
>  	/* out */
>  	__u32 flags;
>  	__u32 hcall[4];
> -	__u8  pad[108];
> +	__u32 opt_features;
> +	__u8  pad[104];
>  };

If the features weren't "opt"ional, there wouldn't be a bitmap of them. :-)

Just call it "features".  Or maybe just use "flags"?

-Scott