Messages in this thread | | | Subject | Re: [PATCH v9 12/22] s390: vfio-ap: sysfs interfaces to configure control domains | From | Pierre Morel <> | Date | Wed, 22 Aug 2018 17:34:02 +0200 |
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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 It seems that the HMC enforce the LPARs to have access to their usage domain (AFAIU from Harald)
-- Pierre Morel Linux/KVM/QEMU in Böblingen - Germany
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