On Tue, Mar 07, 2023 at 08:21:54AM +0100, Jiri Pirko wrote:
> Mon, Mar 06, 2023 at 11:54:45PM CET, wrote:
>
>On Mon, Mar 06, 2023 at 01:29:30PM +0100, Jiri Pirko wrote:
> >> Thu, Mar 02, 2023 at 02:04:48PM CET, wrote:
> >>
> >> [...]
> >>
> >> >
> >>
>TODO (maybe?) - probably ok to defer until this part is upstream:
> >> >
> >>
> Add "all members" member id.
> >> >
> >>
> Add commands for MSI, feature discovery.
> >> >
> >>
> Add commands for transport vq.
> >> >
> >> >
> >>
>My intent is to try and support both SR-IOV and SIOV
> >>
>usecases with the same structure and maybe even the same
> >>
>VQ.
> >>
> >> Sorry to be late to the party, I'm trying to catch up. Is it common to
> >> have cover letter for features this brief? I mean, from the cover
> >> letter, I'm totally unable to understand what you are introducing here.
> >>
> >> Could you elaborate about what you are aiming to achive with this?
> >> Could you shed some usecases perhaps?
> >>
> >> I have to be missing something obvious, but I don't get why any notion
> >> of SR-IOV could be beneficial for virtio.
> >>
> >
>
>Good point, I'll add a bit of motivation.
> >
>
>For SR-IOV, it is not unusual for PFs to excercise control over VFs.
>
> I understand the concepts of SR-IOV. Yet I fail to see the need of such
> concept in virtio world. SR-IOV is very specific solution for PCI
> functions instantiation, and I believe that it is already considered
> quite limiting in many aspects. Does not make sense to me to introduce
> it for virtio. But again, I may be missing something crucial, I just
> would like to see the motivation, needs, usecases for this crystal
> clear, which is opposite to the current cover letter I'm afraid :/
First people are asking for it because it's out there, however limiting
it is. In fact Nvidia is - why don't you talk to Parav here and tell
him that SR-IOV is legacy and there's no need to support.
>
>
>There is interest in the community to include an interface to allow this
>
>in the virtio spec, when the PF is a virtio device. This is what this
>
>patch does.
>
> Yeah, but why? As I asked before, what are the usecases? The fact there
> is interest in the community does not mean it makes sense to have it :)
>
If people want to build such hardware it will need some interface.
Far better to have it standard.
But generally e.g. intel already said they will reuse this
same structure with a different group type for SIOV support.
I'll mention this in the cover letter.
> >
> >
> >
> >
> >> >
> >>
>For example, it might make sense to split creating/destroying
> >>
>SIOV devices from the transport passing data from the guest - the
> >>
>driver would then not negotiate VIRTIO_F_SR_IOV (which
> >>
>then means auto-provisioning).
> >> >
> >>
>This is out of RFC, since we have two commands which are useful
> >>
>to discover supported group types (ATM can be none or SR-IOV).
> >> >
> >> >
> >>
>Michael S. Tsirkin (10):
> >>
> virtio: document forward compatibility guarantees
> >>
> admin: introduce device group and related concepts
> >>
> admin: introduce group administration commands
> >>
> admin: introduce virtio admin virtqueues
> >>
> pci: add admin vq registers to virtio over pci
> >>
> mmio: document ADMIN_VQ as reserved
> >>
> ccw: document ADMIN_VQ as reserved
> >>
> admin: command list discovery
> >>
> admin: conformance clauses
> >>
> ccw: document more reserved features
> >> >
> >>
> admin.tex
| 540 +++++++++++++++++++++++++++++++++++++++++++++++
> >>
> content.tex
| 112 +++++++++-
> >>
> introduction.tex |
3 +
> >>
> 3 files changed, 653 insertions(+), 2 deletions(-)
> >>
> create mode 100644 admin.tex
> >> >
> >> >--
> >>
>MST
> >> >
> >> >
> >>
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> >>
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> >> >
> >>
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> >>
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