From: Tony Krowiak <akrowiak@linux.ibm.com>
To: Halil Pasic <pasic@linux.ibm.com>,
Christian Borntraeger <borntraeger@de.ibm.com>,
pmorel@linux.ibm.com, Cornelia Huck <cohuck@redhat.com>
Cc: 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, 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
Subject: Re: [PATCH v9 12/22] s390: vfio-ap: sysfs interfaces to configure control domains
Date: Wed, 22 Aug 2018 15:16:19 -0400 [thread overview]
Message-ID: <9ef5fcb9-02e0-88e3-007c-eedb14e6db80@linux.ibm.com> (raw)
In-Reply-To: <dbb74c9c-93ab-ed05-fad4-ea2aa5f2b71e@linux.ibm.com>
On 08/22/2018 01:11 PM, Halil Pasic wrote:
>
>
> On 08/22/2018 05:48 PM, Christian Borntraeger wrote:
>> On 08/22/2018 05:34 PM, Pierre Morel wrote:
>>> On 22/08/2018 17:11, Christian Borntraeger wrote:
>>>>
>>>>
>>>> On 08/22/2018 01:03 PM, Pierre Morel wrote:
>>>>>> 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.
>>>>
>>>> Huh? My HMC allows to add a domain as
>>>> - control only domain
>>>> - control and usage domain.
>>>>
>>>> But I am not able to configure a usage-only domain for my LPAR.
>>>> That seems to match
>>>> the current code, no?
>>>>
>>>
>>> Yes, it may not be configurable by the HMC but if we start a guest
>>> with no control domain it is not a problem to access the hardware
>>> through the usage domain.
>>>
>>> I tested this a long time ago, but tested again today to be sure on
>>> my LPAR.
>>>
>>> AFAIU adding a control only domain and a control and usage domain
>>> allows say:
>>> control and usage domain 1
>>> control only domain 2
>>>
>>> Allow to send a message to domain 2 using queue 1
>>>
>>> Allow also to send a domain modifying message to domain 1 using queue 1
>>>
>>> control domain are domain which are controlled
>>
>> So you have changed the code to not automatically make a usage domain a
>> control domain in the bitfield (and you could still use it as a usage
>> domain). Correct?
>
> I tested basically the same yesterday, with the same results.
>
>> I think this is probably expected. the "usage implies control" seems to
>> be a convention implemented by HMC (lpar) and z/VM but millicode offers
>> the bits to have usage-only domains. As LPAR and z/VM will always enable
>> any usage-domain to also be a control domain we should do the same.
>
> I'm fine either way, but slightly prefer higher level management software
> and not the kernel accommodating this convention.
>
> Please consider a quote from Harald's mail in another sub-thread
>
>
> """
> ... about control domains
>
> Talked with the s390 firmware guys. The convention that the control
> domain
> mask is a superset of the usage domain mask is only true for 1st level
> guests.
>
> It is absolutely valid to run a kvm guest with restricted control domain
> mask bitmap in the CRYCB. It is valid to have an empty control domain
> mask
> and the guest should be able to run crypto CPRBs on the usage
> domain(s) without
> any problems. However, nobody has tried this.
> """
>
> I'm yet to get an explanation why was this convention established in
> the first
> place. And I can not figure it out myself. For me a setup where I know
> that
> the domains used by some guest can not be modified by the same guest
> makes
> perfect sense. If I try to think in analogies, I kind of compare
> modification
> (that is control domain) with write access, and usage (that is usage
> domain)
> with read access to, let's say a regular file. For me, all options
> (rw, r, and w)
> do make sense, and if I had to pick the one that makes the least sense
> I would
> pick write only. The convention is in these terms making read-only
> illegal. But
> should 'usage only domains' ever get identified as something somebody
> wants to do
> we can just add an attribute for that. So I'm fine either way.
One of the things I suggested in a private conversation with Christian
earlier
today was to provide an additional rw sysfs attribute - a boolean - that
indicates
whether all usage domains should also be control domains. The default
could be
true. This would allow one to configure guests with usage-only domains
as well
as satisfy the convention.
>
>
> Still I find the commit message for this patch, the implementation of
> assign_control_domain() and also the documentation slightly misleading
> regarding
> what does one get from assign_domain.
>
>
> Regards,
> Halil
>
>
>
>
>
>>
>>
>>> It seems that the HMC enforce the LPARs to have access to their
>>> usage domain (AFAIU from Harald)
>>
next prev parent reply other threads:[~2018-08-22 19:26 UTC|newest]
Thread overview: 138+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-13 21:47 [PATCH v9 00/22] guest dedicated crypto adapters Tony Krowiak
2018-08-13 21:47 ` [PATCH v9 01/22] s390/zcrypt: Add ZAPQ inline function Tony Krowiak
2018-08-13 21:47 ` [PATCH v9 02/22] s390/zcrypt: Review inline assembler constraints Tony Krowiak
2018-08-13 21:48 ` [PATCH v9 03/22] s390/zcrypt: Show load of cards and queues in sysfs Tony Krowiak
2018-08-13 21:48 ` [PATCH v9 04/22] s390/zcrypt: Integrate ap_asm.h into include/asm/ap.h Tony Krowiak
2018-08-14 8:43 ` Cornelia Huck
2018-08-17 13:18 ` Tony Krowiak
2018-08-17 13:27 ` Cornelia Huck
2018-08-17 19:09 ` Tony Krowiak
2018-08-13 21:48 ` [PATCH v9 05/22] KVM: s390: vsie: simulate VCPU SIE entry/exit Tony Krowiak
2018-08-14 8:50 ` Cornelia Huck
2018-08-14 12:46 ` Tony Krowiak
2018-08-13 21:48 ` [PATCH v9 06/22] KVM: s390: introduce and use KVM_REQ_VSIE_RESTART Tony Krowiak
2018-08-13 21:48 ` [PATCH v9 07/22] KVM: s390: refactor crypto initialization Tony Krowiak
2018-08-20 16:41 ` David Hildenbrand
2018-08-20 20:33 ` Tony Krowiak
2018-08-20 20:41 ` David Hildenbrand
2018-08-21 13:29 ` Tony Krowiak
2018-08-13 21:48 ` [PATCH v9 08/22] s390: vfio-ap: base implementation of VFIO AP device driver Tony Krowiak
2018-08-14 10:42 ` Cornelia Huck
2018-08-14 23:30 ` Tony Krowiak
2018-08-13 21:48 ` [PATCH v9 09/22] s390: vfio-ap: register matrix device with VFIO mdev framework Tony Krowiak
2018-08-14 11:19 ` Cornelia Huck
2018-08-15 16:51 ` Tony Krowiak
2018-08-16 16:24 ` Tony Krowiak
2018-08-17 8:43 ` Cornelia Huck
2018-08-17 19:02 ` Tony Krowiak
2018-09-06 8:49 ` Pierre Morel
2018-09-10 13:38 ` Tony Krowiak
2018-09-10 21:58 ` Halil Pasic
2018-08-13 21:48 ` [PATCH v9 10/22] s390: vfio-ap: sysfs interfaces to configure adapters Tony Krowiak
2018-08-15 9:52 ` Cornelia Huck
2018-08-15 16:59 ` Tony Krowiak
2018-08-16 7:30 ` Cornelia Huck
2018-08-17 13:23 ` Tony Krowiak
2018-08-13 21:48 ` [PATCH v9 11/22] s390: vfio-ap: sysfs interfaces to configure domains Tony Krowiak
2018-08-15 12:05 ` Cornelia Huck
2018-08-15 17:00 ` Tony Krowiak
2018-08-13 21:48 ` [PATCH v9 12/22] s390: vfio-ap: sysfs interfaces to configure control domains Tony Krowiak
2018-08-20 14:23 ` Cornelia Huck
2018-08-20 16:43 ` Halil Pasic
2018-08-20 17:41 ` Tony Krowiak
2018-08-21 15:25 ` Cornelia Huck
2018-08-21 17:07 ` Tony Krowiak
2018-08-21 23:18 ` Halil Pasic
2018-08-22 9:42 ` Cornelia Huck
2018-08-22 10:43 ` Halil Pasic
2018-08-22 11:03 ` Pierre Morel
2018-08-22 15:11 ` Christian Borntraeger
2018-08-22 15:34 ` Pierre Morel
2018-08-22 15:48 ` Christian Borntraeger
2018-08-22 15:53 ` Pierre Morel
2018-08-22 17:11 ` Halil Pasic
2018-08-22 19:16 ` Tony Krowiak [this message]
2018-08-23 9:26 ` Halil Pasic
2018-08-23 10:41 ` Pierre Morel
2018-08-23 10:25 ` Cornelia Huck
2018-08-23 10:43 ` Pierre Morel
2018-08-23 11:31 ` Cornelia Huck
2018-08-23 11:44 ` Pierre Morel
2018-08-23 14:16 ` Tony Krowiak
2018-08-27 8:33 ` Cornelia Huck
2018-08-27 13:47 ` Tony Krowiak
2018-08-27 13:51 ` Cornelia Huck
2018-08-27 15:39 ` Halil Pasic
2018-09-10 13:27 ` Tony Krowiak
2018-08-22 15:18 ` Tony Krowiak
2018-08-22 14:31 ` Tony Krowiak
2018-08-13 21:48 ` [PATCH v9 13/22] s390: vfio-ap: sysfs interface to view matrix mdev matrix Tony Krowiak
2018-08-20 14:08 ` Cornelia Huck
2018-09-12 17:01 ` Tony Krowiak
2018-09-13 9:12 ` Halil Pasic
2018-08-13 21:48 ` [PATCH v9 14/22] KVM: s390: interfaces to clear CRYCB masks Tony Krowiak
2018-08-15 13:10 ` Cornelia Huck
2018-08-15 17:55 ` Tony Krowiak
2018-08-13 21:48 ` [PATCH v9 15/22] s390: vfio-ap: implement mediated device open callback Tony Krowiak
2018-08-15 16:08 ` Cornelia Huck
2018-08-15 18:21 ` Tony Krowiak
2018-08-13 21:48 ` [PATCH v9 16/22] s390: vfio-ap: implement VFIO_DEVICE_GET_INFO ioctl Tony Krowiak
2018-08-20 14:24 ` Cornelia Huck
2018-08-13 21:48 ` [PATCH v9 17/22] s390: vfio-ap: zeroize the AP queues Tony Krowiak
2018-08-15 16:24 ` Cornelia Huck
2018-08-15 20:36 ` Tony Krowiak
2018-08-17 9:34 ` Cornelia Huck
2018-08-13 21:48 ` [PATCH v9 18/22] s390: vfio-ap: implement VFIO_DEVICE_RESET ioctl Tony Krowiak
2018-08-15 16:38 ` Cornelia Huck
2018-08-15 21:05 ` Tony Krowiak
2018-08-17 9:38 ` Cornelia Huck
2018-08-17 19:03 ` Tony Krowiak
2018-08-13 21:48 ` [PATCH v9 19/22] KVM: s390: Clear Crypto Control Block when using vSIE Tony Krowiak
2018-08-13 21:48 ` [PATCH v9 20/22] KVM: s390: Handling of Cypto control block in VSIE Tony Krowiak
2018-08-21 8:30 ` David Hildenbrand
2018-08-13 21:48 ` [PATCH v9 21/22] KVM: s390: CPU model support for AP virtualization Tony Krowiak
2018-08-20 14:26 ` Cornelia Huck
2018-08-21 8:03 ` David Hildenbrand
2018-08-22 11:19 ` David Hildenbrand
2018-08-22 11:24 ` David Hildenbrand
2018-08-22 20:16 ` Tony Krowiak
2018-08-23 7:44 ` David Hildenbrand
2018-08-23 10:00 ` Halil Pasic
2018-08-23 10:28 ` David Hildenbrand
2018-08-23 11:10 ` Pierre Morel
2018-08-23 11:12 ` David Hildenbrand
2018-08-23 12:47 ` Pierre Morel
2018-08-23 13:22 ` Halil Pasic
2018-08-23 13:38 ` David Hildenbrand
2018-08-23 14:59 ` Pierre Morel
2018-08-23 17:35 ` Tony Krowiak
2018-08-23 17:40 ` David Hildenbrand
2018-08-24 10:28 ` Halil Pasic
2018-08-22 14:33 ` Pierre Morel
2018-08-22 15:04 ` David Hildenbrand
2018-08-22 15:50 ` Pierre Morel
2018-08-22 16:57 ` David Hildenbrand
2018-08-22 21:05 ` Tony Krowiak
2018-08-23 7:42 ` David Hildenbrand
2018-08-22 20:54 ` Tony Krowiak
2018-08-23 7:48 ` David Hildenbrand
2018-08-23 8:24 ` Cornelia Huck
2018-09-12 17:42 ` Tony Krowiak
2018-09-17 7:57 ` David Hildenbrand
2018-08-23 8:26 ` Pierre Morel
2018-08-13 21:48 ` [PATCH v9 22/22] s390: doc: detailed specifications " Tony Krowiak
2018-08-20 16:03 ` Cornelia Huck
2018-08-20 20:16 ` Tony Krowiak
2018-08-21 16:13 ` Cornelia Huck
2018-08-21 19:21 ` Tony Krowiak
2018-08-21 18:54 ` Halil Pasic
2018-08-22 7:38 ` Cornelia Huck
2018-08-21 9:00 ` Harald Freudenberger
2018-08-21 15:53 ` Cornelia Huck
2018-08-22 7:04 ` Harald Freudenberger
2018-08-22 10:09 ` Cornelia Huck
2018-08-22 10:13 ` Harald Freudenberger
2018-08-22 10:45 ` Halil Pasic
2018-08-22 10:19 ` [PATCH v9 00/22] guest dedicated crypto adapters Cornelia Huck
2018-08-22 10:58 ` Pierre Morel
2018-08-22 18:59 ` Tony Krowiak
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