Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Reply-To: pmorel@linux.ibm.com
Subject: Re: [PATCH v9 12/22] s390: vfio-ap: sysfs interfaces to configure
 control domains
To:     Cornelia Huck <cohuck@redhat.com>,
        Halil Pasic <pasic@linux.ibm.com>
Cc:     Tony Krowiak <akrowiak@linux.ibm.com>,
        Tony Krowiak <akrowiak@linux.vnet.ibm.com>,
        linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org,
        kvm@vger.kernel.org, freude@de.ibm.com, schwidefsky@de.ibm.com,
        heiko.carstens@de.ibm.com, borntraeger@de.ibm.com,
        kwankhede@nvidia.com, bjsdjshi@linux.vnet.ibm.com,
        pbonzini@redhat.com, alex.williamson@redhat.com,
        pmorel@linux.vnet.ibm.com, alifm@linux.vnet.ibm.com,
        mjrosato@linux.vnet.ibm.com, jjherne@linux.vnet.ibm.com,
        thuth@redhat.com, pasic@linux.vnet.ibm.com, berrange@redhat.com,
        fiuczy@linux.vnet.ibm.com, buendgen@de.ibm.com,
        frankja@linux.ibm.com
References: <1534196899-16987-1-git-send-email-akrowiak@linux.vnet.ibm.com>
 <1534196899-16987-13-git-send-email-akrowiak@linux.vnet.ibm.com>
 <20180820162317.08bd7d23.cohuck@redhat.com>
 <660de00a-c403-28c1-4df4-82a973ab3ad5@linux.ibm.com>
 <20180821172548.57a6c758.cohuck@redhat.com>
 <82a391ee-85b1-cdc7-0f9b-d37fd8ba8e47@linux.ibm.com>
 <a43ef10f-aa91-cb4c-a8aa-cd3ce9cfebf2@linux.ibm.com>
 <20180822114250.59a250aa.cohuck@redhat.com>
From:   Pierre Morel <pmorel@linux.ibm.com>
Date:   Wed, 22 Aug 2018 13:03:05 +0200
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101
 Thunderbird/52.9.1
MIME-Version: 1.0
In-Reply-To: <20180822114250.59a250aa.cohuck@redhat.com>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 8bit
Content-Language: en-US
Message-Id: <8bc5f207-f913-825c-f9fc-0a2c7fd280aa@linux.ibm.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On 22/08/2018 11:42, Cornelia Huck wrote:
> On Wed, 22 Aug 2018 01:18:20 +0200
> Halil Pasic <pasic@linux.ibm.com> wrote:
>
>> On 08/21/2018 07:07 PM, Tony Krowiak wrote:
>>> This convention has been enforced by the kernel since v1. This is also
>>> enforced by both the LPAR as well as in z/VM. The following is from the
>>> PR/SM Planning Guide:
>>>
>>> Control Domain
>>> A logical partition's control domains are those cryptographic domains for which remote secure
>>> administration functions can be established and administered from this logical partition. This
>>> logical partition’s control domains must include its usage domains. For each index selected in the
>>> usage domain index list, you must select the same index in the control domain index list
>>>    
> That's interesting.
>
>> IMHO this quote is quite a half-full half-empty cup one:
>> * it mandates the set of usage domains is a subset of the set
>> of the control domains, but
>> * it speaks of independent controls, namely about the 'usage domain index'
>> and the 'control domain index list' and makes the enforcement of the rule
>> a job of the administrator (instead of codifying it in the controls).
> I'm wondering if a configuration with a usage domain that is not also a
> control domain is rejected outright? Anybody tried that? :)

Yes, and no it is not.
We can use a queue (usage domain) to a AP card for SHA-512 or RSA without
having to define the queue as a control domain.

Regards,
Pierre


-- 
Pierre Morel
Linux/KVM/QEMU in Böblingen - Germany