[libvirt] [PATCH v2 1/3] qemu: add vfio-ap capability

[Boris Fiuczynski]

On 10/25/18 1:54 PM, Boris Fiuczynski wrote:
> On 10/25/18 5:17 AM, Chris Venteicher wrote:
>> Quoting Thomas Huth (2018-10-19 06:58:34)
>>> On 2018-10-18 16:54, Boris Fiuczynski wrote:
>>>> Introduce vfio-ap capability.
>>>>
>>>> Signed-off-by: Boris Fiuczynski <fiuczy at linux.ibm.com>
>>>> Reviewed-by: Bjoern Walk <bwalk at linux.ibm.com>
>>>> ---
>>>>   src/qemu/qemu_capabilities.c | 2 ++
>>>>   src/qemu/qemu_capabilities.h | 1 +
>>>>   2 files changed, 3 insertions(+)
>>>>
>>>> diff --git a/src/qemu/qemu_capabilities.c 
>>>> b/src/qemu/qemu_capabilities.c
>>>> index e228f52ec0..2ca5af3297 100644
>>>> --- a/src/qemu/qemu_capabilities.c
>>>> +++ b/src/qemu/qemu_capabilities.c
>>>> @@ -508,6 +508,7 @@ VIR_ENUM_IMPL(virQEMUCaps, QEMU_CAPS_LAST,
>>>>                 /* 315 */
>>>>                 "vfio-pci.display",
>>>>                 "blockdev",
>>>> +              "vfio-ap",
>>>>       );
>>
>> The statement "On s390, we have cryptographic coprocessor cards,
>> which are modeled on Linux as devices on the AP bus."
>> was made in email titled "s390: vfio-ap: guest dedicated crypto adapters"
>>
> Patch 6 of the qemu patch series 
> (https://lists.gnu.org/archive/html/qemu-devel/2018-10/msg01997.html) 
> has a very detailed documentation (docs/vfio-ap.txt) covering IBM 
> Adjunct Processor (AP) Cryptographic Facility.
> 
>> Does this imply other devices can exist on an AP Bus?
> The AP bus is a linux construct used to represent the cryptographic 
> devices available via the Adjunct Processor Cryptographic Facility.
> This implies even so there are different cards they all are crypto cards.
> 
>>
>> Any chance this should be something like "vfio-ap.crypto" in the same
>> way a "vfio-pci.display" entry is listed above seemingly implying a
>> display device on a more generic pci bus? Or does "vfio-ap" always imply
>> crypto?
> Yes, it always is crypto only. Actually a vfio-ap mediated device is 
> used to specify the configuration of the ap bus including all cards, 
> usage domains and control domains passed into a qemu guest.
> 
>>
>> Having difficulty sorting out the relationships between adjunct
>> processor, crypto processor and ap bus from the patch docs and initial
>> review of the references.
> Maybe the KVM forum session of Halil Pasic can help a bit...?
> https://events.linuxfoundation.org/wp-content/uploads/2017/12/vfio-ap-The-Perils-of-the-Weird-Halil-Pasic-IBM.pdf 
Or you could have a look at "Chapter 47. Generic cryptographic device 
driver" here: 
http://public.dhe.ibm.com/software/dw/linux390/docu/l418dd35.pdf

> 
> 
>>
>>>>
>>>> @@ -1092,6 +1093,7 @@ struct virQEMUCapsStringFlags 
>>>> virQEMUCapsObjectTypes[] = {
>>>>       { "vhost-vsock-device", QEMU_CAPS_DEVICE_VHOST_VSOCK },
>>>>       { "mch", QEMU_CAPS_DEVICE_MCH },
>>>>       { "sev-guest", QEMU_CAPS_SEV_GUEST },
>>>> +    { "vfio-ap", QEMU_CAPS_DEVICE_VFIO_AP },
>>>>   };
>>>>   static struct virQEMUCapsStringFlags 
>>>> virQEMUCapsDevicePropsVirtioBalloon[] = {
>>>> diff --git a/src/qemu/qemu_capabilities.h 
>>>> b/src/qemu/qemu_capabilities.h
>>>> index 934620ed31..6bb9a2c8f0 100644
>>>> --- a/src/qemu/qemu_capabilities.h
>>>> +++ b/src/qemu/qemu_capabilities.h
>>>> @@ -492,6 +492,7 @@ typedef enum { /* virQEMUCapsFlags grouping 
>>>> marker for syntax-check */
>>>>       /* 315 */
>>>>       QEMU_CAPS_VFIO_PCI_DISPLAY, /* -device vfio-pci.display */
>>>>       QEMU_CAPS_BLOCKDEV, /* -blockdev and blockdev-add are 
>>>> supported */
>>>> +    QEMU_CAPS_DEVICE_VFIO_AP, /* -device vfio-ap */
>>>>       QEMU_CAPS_LAST /* this must always be the last item */
>>>>   } virQEMUCapsFlags;
>>>>
>>>
>>> Reviewed-by: Thomas Huth <thuth at redhat.com>
>>>
>>> -- 
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>>
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>>
> 
> 


-- 
Mit freundlichen Grüßen/Kind regards
    Boris Fiuczynski

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