From: David Hildenbrand <david@redhat.com>
To: Tony Krowiak <akrowiak@linux.ibm.com>,
pmorel@linux.ibm.com, Halil Pasic <pasic@linux.ibm.com>,
Tony Krowiak <akrowiak@linux.vnet.ibm.com>,
linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org,
kvm@vger.kernel.org
Cc: freude@de.ibm.com, schwidefsky@de.ibm.com,
heiko.carstens@de.ibm.com, borntraeger@de.ibm.com,
cohuck@redhat.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 21/22] KVM: s390: CPU model support for AP virtualization
Date: Thu, 23 Aug 2018 19:40:59 +0200 [thread overview]
Message-ID: <a228497a-ce48-28bd-0244-b557405c0a84@redhat.com> (raw)
In-Reply-To: <79ae3a9c-70c3-7b08-09ee-0b8308cbca56@linux.ibm.com>
On 23.08.2018 19:35, Tony Krowiak wrote:
> On 08/23/2018 10:59 AM, Pierre Morel wrote:
>> On 23/08/2018 15:38, David Hildenbrand wrote:
>>> On 23.08.2018 15:22, Halil Pasic wrote:
>>>>
>>>>
>>>> On 08/23/2018 02:47 PM, Pierre Morel wrote:
>>>>> On 23/08/2018 13:12, David Hildenbrand wrote:
>>>> [..]
>>>>>>>>>
>>>>>>>>> I'm confused, which 128 bit?
>>>>>>>>
>>>>>>>>
>>>>>>>> Me too :) , I was assuming this block to be 128bit, but the qci
>>>>>>>> block
>>>>>>>> has 128 bytes....
>>>>>>>>
>>>>>>>> And looking at arch/s390/include/asm/ap.h, there is a lot of
>>>>>>>> information
>>>>>>>> contained that is definitely not of interest for CPU models...
>>>>>>>>
>>>>>>>> I wonder if there is somewhere defined which bits are reserved for
>>>>>>>> future features/facilities, compared to ap masks and such.
>>>>>>>>
>>>>>>>> This is really hard to understand/plan without access to
>>>>>>>> documentation.
>>>>>>>>
>>>>>>>> You (Halil, Tony, Pier, ...) should have a look if what I described
>>>>>>>> related to PQAP(QCI) containing features that should get part of
>>>>>>>> the CPU
>>>>>>>> model makes sense or not. For now I was thinking that there is
>>>>>>>> some part
>>>>>>>> inside of QCI that is strictly reserved for facilities/features
>>>>>>>> that we
>>>>>>>> can use.
>>>>
>>>> No there is no such part. The architecture documentation is quite
>>>> confusing
>>>> with some aspects (e.g. persistence) of how exactly some of these
>>>> features
>>>> work and are indicated. I'm having a hard time finding my opinion. I
>>>> may
>>>> end up asking some questions later, but for now i have to think first.
>>>>
>>>> Just one hint. There is a programming note stating that if bit 2 of the
>>>> QCI block is one there is at least one AP card in the machine that
>>>> actually
>>>> has APXA installed.
>>>>
>>>> I read the architecture so that the APXA has a 'cpu part' (if we are
>>>> doing APXA the cpu can't spec exception on certain bits not being zor9)
>>>> and a 'card(s) part'.
>>>>
>>>> Since the stuff seems quite difficult to sort out properly, I ask
>>>> myself
>>>> are there real problems we must solve?
>>>>
>>>> This ultimately seems to be about the migration, right? You say
>>>> 'This helps
>>>> to catch nasty migration bugs (e.g. APXA suddenly disappearing).' at
>>>> the very
>>>> beginning of the discussion. Yes, we don't have to have an vfio_ap
>>>> device,
>>>> he guest can and will start looking for AP resources if
>>>> only the cpu model features installed. So the guest could observe
>>>> a disappearing APXA, but I don't think that would lead to problems
>>>> (with
>>>> Linux at least).
>>>>
>>>> And there ain't much AP a guest can sanely do without if no AP
>>>> resources
>>>> are there.
>>>>
>>>> I would really prefer not rushing a solution if we don't have to.
>>>>
>>>>>
>>>>>
>>>>>>
>>>>>> What is apsc, qact, rc8a in the qci blocks? are the facility bits?
>>>>>
>>>>> Yes, facility bits concerning the AP instructions
>>>>>
>>>>
>>>> According to the current AR document rc8a ain't a facility but bits
>>>> 0-2 and 4-7 kind of are.
>>>>
>>>
>>> Easy ( :) ) answer. Everything that is the CPU part should get into the
>>> CPU model. Everything that is AP specific not. If APXA is not a CPU
>>> facility, fine with me to leave it out.
>>>
>>> Ack to not rushing, but also ack to not leaving out important things.
>>> Ack that this stuff is hard to ficure out.
>>
>> APXA is not a CPU part, it is a machine part (SIE) and a AP part
>> (QCI,TAPQ),
>> it has no influence on CPU instructions but on the AP instructions.
>> Consequently, if I understood the definition correctly, it should not
>> go in the CPU model.
>
> The APXA bit returned via the PQAP(QCI) instruction indicates the APXA
> facility is
> installed in the CPUs of the configuration. This means that the facility is
> installed in one or more adjunct processors but not necessarily all.
> Given that
> it indicates a CPU property, maybe it does belong in the CPU model?
>
Hmmm, I tend to agree - especially as it affects SIE behavior. But as
this is not a feature block (compared to what I thought), this clould be
model as a CPU feature like AP.
What about the other facilities? Do they smell more like AP card
specific stuff?
--
Thanks,
David / dhildenb
next prev parent reply other threads:[~2018-08-23 17:41 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
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 [this message]
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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