Re: [PATCH v13 00/10] Introduce device group and device management

["Michael S. Tsirkin" <mst@redhat.com>]

On Fri, May 05, 2023 at 11:40:33AM -0400, Michael S. Tsirkin wrote:
> 
> 
> 
> Change log:
> 
> since 13:
> 	command specific data is u8 again
> 	exclude admin queues in blk's num_queues
> 	minor other tweaks
> 
> since 11:
> 	addressed lots of comments, all minor. consistency with
> 	outstanding number->index and queue->enqueue work
> 	i did not intentionally drop any reviewed-by tags
> 	as all changes are minor - if yours is missing it is
> 	because I forgot to record it, sorry
> 
> 	one "breaking" change in response to stefan's comment:
> 	in patch 5, num_queues has been specified not to include admin
> 	queues: just regular ones.
> 
> since v10:
> 	addressed lots of comments by Jiri, Stefan. Cornelia, Lngshan, Parav, Max
> 
> since v9:
> 	addressed comments by Parav, Max, Cornelia, David and Zhu Lingshan:
> 		added link to errno header from Linux
> 		rename _MEM to _MEMBER
> 		admin vq num is zero based
> 		clarify who sends commands where
> 		minor english tweaks
> 		clarify command length
> 		specify interaction with sriov capability
> 		correct commit log - NumVFs can be 0
> 
> 	i could not decide what should happen when VFs are
> 	disabled. for now did not specify.
> 
> since v8:
> 	addressed comments by Cornelia - as we agreed on list
> 	
> since v7:
> 	make high level error codes match linux, with virtio specific codes
> 		in a separate field
> 	renamed _ACCEPT to _USE since that's what it does
> 	clarified forward compatibility and non pci transports
> 	support multiple admin vqs
> 	conformance statements
> 	lots of changes all over the place to I changed author from Max
> 	to myself. Don't need to take credit but also don't want
> 	to blame Max for my mistakes.
> 
> since v6:
> 
> 	- removed some extentions intended for future use.
> 	  We'll do them when we get there.
> 
> 	- brought back command list query from v5 in a simplified form -
> 	  it's here to address the case where a single parent
> 	  can address multiple groups, such as PF addressing
> 	  transport vq and sriov vfs.
> 
> 	- attempt to make terminology more formal.
> 	In particular a term for whoever controls the group.
>  	I am still going back
> 	and forth between "parent" and "owner" - owner might
> 	be better after all since it will work if we ever
> 	have a self group. For now it's parent.
> 
> 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.


Fixes: https://github.com/oasis-tcs/virtio-spec/issues/171

As there have only been tiny tweaks since v12, I'm starting a vote now.

> 
> My intent is to try and support both SR-IOV and SIOV
> usecases with the same structure and maybe even the same
> VQ.
> 
> 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).
> 
> More ideas for use-cases:
> virtio VF features query and configuration space provisioning
> virtio VF resource (queues, msix vectors count) provisioning
> 
> 
> Future directions (shouldn't block this patch)
> - aborting commands - left for later. or is vq reset enough?
> - should we rename structures from admin to group admin?
> 
> 
> 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                        | 584 +++++++++++++++++++++++++++++++
>  content.tex                      |  62 +++-
>  device-types/blk/description.tex |   2 +-
>  introduction.tex                 |   3 +
>  transport-ccw.tex                |  14 +
>  transport-mmio.tex               |  12 +
>  transport-pci.tex                |  33 ++
>  7 files changed, 707 insertions(+), 3 deletions(-)
>  create mode 100644 admin.tex
> 
> -- 
> MST