Re: [PATCH v1 00/13] various virtio docs, fixes and tweaks

[Michael S. Tsirkin]

On Mon, Mar 21, 2022 at 03:30:24PM +0000, Alex Bennée wrote:
> Hi,
> 
> This series is a sub-set of patches while I was trying to re-rev my
> virtio-rpmb patches. It attempts to address a few things:
> 
>   - improve documentation for virtio/vhost/vhost-user
>   - document some of the API
>   - a hacky fix for F_CONFIG handling
>   - putting VhostUserState on a diet, make VhostUserHostNotifier dynamic

So I think this is best deferred until after the release,
more of a cleanup than a bugfix.

I will tag this series, but please do remind me after the release
to help make sure it does not get lost.


> In particular I've been trying to better understand how vhost-user
> interactions are meant to work and why there are two different methods
> for instantiating them. If my supposition is correct perhaps a number
> of devices that don't have in-kernel vhost equivalents could be converted?

Hope I understand your question.  Well we started off with saying
vhost-user is just a backend, so should not affect the frontend device.
This is clean and makes migration work e.g. you can migrate between
different backends, but it makes adding features more work.


> While working onthe VhostUserHostNotifier changes I found it quite
> hard to trigger the code. Is this rarely used code or just requires
> backends we don't see in the testing?

Which function are you asking about exactly?

> Alex Bennée (10):
>   hw/virtio: move virtio-pci.h into shared include space
>   virtio-pci: add notification trace points
>   hw/virtio: add vhost_user_[read|write] trace points
>   vhost-user.rst: add clarifying language about protocol negotiation
>   libvhost-user: expose vu_request_to_string
>   docs/devel: start documenting writing VirtIO devices
>   include/hw: start documenting the vhost API
>   contrib/vhost-user-blk: fix 32 bit build and enable
>   hw/virtio/vhost-user: don't suppress F_CONFIG when supported
>   virtio/vhost-user: dynamically assign VhostUserHostNotifiers
> 
> Paolo Bonzini (3):
>   docs: vhost-user: clean up request/reply description
>   docs: vhost-user: rewrite section on ring state machine
>   docs: vhost-user: replace master/slave with front-end/back-end
> 
>  docs/devel/index-internals.rst            |   1 +
>  docs/devel/virtio-backends.rst            | 214 +++++++++
>  docs/interop/vhost-user-gpu.rst           |  10 +-
>  docs/interop/vhost-user.rst               | 555 ++++++++++++----------
>  meson.build                               |   2 +-
>  include/hw/virtio/vhost-user.h            |  43 +-
>  include/hw/virtio/vhost.h                 | 132 ++++-
>  {hw => include/hw}/virtio/virtio-pci.h    |   0
>  subprojects/libvhost-user/libvhost-user.h |   9 +
>  contrib/vhost-user-blk/vhost-user-blk.c   |   6 +-
>  hw/scsi/vhost-user-scsi.c                 |   1 +
>  hw/virtio/vhost-scsi-pci.c                |   2 +-
>  hw/virtio/vhost-user-blk-pci.c            |   2 +-
>  hw/virtio/vhost-user-fs-pci.c             |   2 +-
>  hw/virtio/vhost-user-i2c-pci.c            |   2 +-
>  hw/virtio/vhost-user-input-pci.c          |   2 +-
>  hw/virtio/vhost-user-rng-pci.c            |   2 +-
>  hw/virtio/vhost-user-scsi-pci.c           |   2 +-
>  hw/virtio/vhost-user-vsock-pci.c          |   2 +-
>  hw/virtio/vhost-user.c                    | 133 ++++--
>  hw/virtio/vhost-vsock-pci.c               |   2 +-
>  hw/virtio/virtio-9p-pci.c                 |   2 +-
>  hw/virtio/virtio-balloon-pci.c            |   2 +-
>  hw/virtio/virtio-blk-pci.c                |   2 +-
>  hw/virtio/virtio-input-host-pci.c         |   2 +-
>  hw/virtio/virtio-input-pci.c              |   2 +-
>  hw/virtio/virtio-iommu-pci.c              |   2 +-
>  hw/virtio/virtio-net-pci.c                |   2 +-
>  hw/virtio/virtio-pci.c                    |   5 +-
>  hw/virtio/virtio-rng-pci.c                |   2 +-
>  hw/virtio/virtio-scsi-pci.c               |   2 +-
>  hw/virtio/virtio-serial-pci.c             |   2 +-
>  subprojects/libvhost-user/libvhost-user.c |   2 +-
>  contrib/vhost-user-blk/meson.build        |   3 +-
>  hw/virtio/trace-events                    |  10 +-
>  35 files changed, 831 insertions(+), 333 deletions(-)
>  create mode 100644 docs/devel/virtio-backends.rst
>  rename {hw => include/hw}/virtio/virtio-pci.h (100%)
> 
> -- 
> 2.30.2