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

[Chris Venteicher]

Quoting Boris Fiuczynski (2018-10-25 07:35:44)
> 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

Thanks for the info.  The Halil 2018 doc was good for orienting.

Can't say I understand the details but I don't see problems in the
source code it's self.

Reviewed-by: Chris Venteicher <cventeic at redhat.com>
> >
> >
> >>
> >>>>
> >>>> @@ -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>
> >>>
> >>> -- 
> >>> libvir-list mailing list
> >>> libvir-list at redhat.com
> >>> https://www.redhat.com/mailman/listinfo/libvir-list
> >>
> >> -- 
> >> libvir-list mailing list
> >> libvir-list at redhat.com
> >> https://www.redhat.com/mailman/listinfo/libvir-list
> >>
> > 
> > 
> 
> 
> -- 
> Mit freundlichen Grüßen/Kind regards
>     Boris Fiuczynski
> 
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