Re: [PATCH v7 5/9] x86: spp: Introduce user-space SPP IOCTLs

From: Yang Weijiang <weijiang.yang@intel.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: Yang Weijiang <weijiang.yang@intel.com>,
	kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
	jmattson@google.com, sean.j.christopherson@intel.com,
	yu.c.zhang@linux.intel.com, alazar@bitdefender.com,
	edwin.zhai@intel.com
Subject: Re: [PATCH v7 5/9] x86: spp: Introduce user-space SPP IOCTLs
Date: Sat, 23 Nov 2019 00:20:20 +0800	[thread overview]
Message-ID: <20191122162020.GB10458@local-michael-cet-test> (raw)
In-Reply-To: <f8cd7d7c-7ffd-3ee4-bf5f-203f9a030fef@redhat.com>

On Thu, Nov 21, 2019 at 11:03:52AM +0100, Paolo Bonzini wrote:
> On 19/11/19 09:49, Yang Weijiang wrote:
> > +	case KVM_INIT_SPP: {
> > +		r = kvm_vm_ioctl_init_spp(kvm);
> > +		break;
> > +	}
> >  	default:
> >  		r = -ENOTTY;
> >  	}
> > diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
> > index 9460830de536..700f0825336d 100644
> > --- a/include/uapi/linux/kvm.h
> > +++ b/include/uapi/linux/kvm.h
> > @@ -1257,6 +1257,9 @@ struct kvm_vfio_spapr_tce {
> >  					struct kvm_userspace_memory_region)
> >  #define KVM_SET_TSS_ADDR          _IO(KVMIO,   0x47)
> >  #define KVM_SET_IDENTITY_MAP_ADDR _IOW(KVMIO,  0x48, __u64)
> > +#define KVM_SUBPAGES_GET_ACCESS   _IOR(KVMIO,  0x49, __u64)
> > +#define KVM_SUBPAGES_SET_ACCESS   _IOW(KVMIO,  0x4a, __u64)
> > +#define KVM_INIT_SPP              _IOW(KVMIO,  0x4b, __u64)
> 
> You also need to define a capability and return a value for it in
> kvm_vm_ioctl_check_extension.  We could return SUBPAGE_MAX_BITMAP (now
> KVM_SUBPAGE_MAX_PAGES).  And instead of introducing KVM_INIT_SPP, you
> can then use KVM_ENABLE_CAP on the new capability.
>
Yep, will change these stuffs, thanks.

> Paolo