Re: [PATCH v2 00/15] qdev: Add JSON -device

[Michael S. Tsirkin]

On Fri, Oct 08, 2021 at 03:34:27PM +0200, Kevin Wolf wrote:
> It's still a long way until we'll have QAPIfied devices, but there are
> some improvements that we can already make now to make the future switch
> easier.
> 
> One important part of this is having code paths without QemuOpts, which
> we want to get rid of and replace with the keyval parser in the long
> run. This series adds support for JSON syntax to -device, which bypasses
> QemuOpts.
> 
> While we're not using QAPI yet, devices are based on QOM, so we already
> do have type checks and an implied schema. JSON syntax supported now can
> be supported by QAPI later and regarding command line compatibility,
> actually switching to it becomes an implementation detail this way (of
> course, it will still add valuable user-visible features like
> introspection and documentation).
> 
> Apart from making things more future proof, this also immediately adds
> a way to do non-scalar properties on the command line. nvme could have
> used list support recently, and the lack of it in -device led to some
> rather unnatural solution in the first version (doing the relationship
> between a device and objects backwards) and loss of features in the
> following. With this series, using a list as a device property should be
> possible without any weird tricks.
> 
> Unfortunately, even QMP device_add goes through QemuOpts before this
> series, which destroys any type safety QOM provides and also can't
> support non-scalar properties. This is a bug, but it turns out that
> libvirt actually relies on it and passes only strings for everything.
> So this series still leaves device_add alone until libvirt is fixed.


Reviewed-by: Michael S. Tsirkin <mst@redhat.com>

I assume you are merging this?

> v2:
> - Drop type safe QMP device_add because libvirt gets it wrong, too
> - More network patches to eliminate dependencies on the legacy QemuOpts
>   data structures which would not contain all devices any more after
>   this series. Fix some bugs there as a side effect.
> - Remove an unnecessary use of ERRP_GUARD()
> - Replaced error handling patch for qdev_set_id() with Damien's
> - Drop the deprecation patch until libvirt uses the new JSON syntax
> 
> Damien Hedde (1):
>   softmmu/qdev-monitor: add error handling in qdev_set_id
> 
> Kevin Wolf (14):
>   net: Introduce NetClientInfo.check_peer_type()
>   net/vhost-user: Fix device compatibility check
>   net/vhost-vdpa: Fix device compatibility check
>   qom: Reduce use of error_propagate()
>   iotests/245: Fix type for iothread property
>   iotests/051: Fix typo
>   qdev: Avoid using string visitor for properties
>   qdev: Make DeviceState.id independent of QemuOpts
>   qemu-option: Allow deleting opts during qemu_opts_foreach()
>   qdev: Add Error parameter to hide_device() callbacks
>   virtio-net: Store failover primary opts pointer locally
>   virtio-net: Avoid QemuOpts in failover_find_primary_device()
>   qdev: Base object creation on QDict rather than QemuOpts
>   vl: Enable JSON syntax for -device
> 
>  qapi/qdev.json                      | 15 +++--
>  include/hw/qdev-core.h              | 15 +++--
>  include/hw/virtio/virtio-net.h      |  2 +
>  include/monitor/qdev.h              | 27 +++++++-
>  include/net/net.h                   |  2 +
>  hw/arm/virt.c                       |  2 +-
>  hw/core/qdev-properties-system.c    |  6 ++
>  hw/core/qdev.c                      | 11 +++-
>  hw/net/virtio-net.c                 | 85 ++++++++++++-------------
>  hw/pci-bridge/pci_expander_bridge.c |  2 +-
>  hw/ppc/e500.c                       |  2 +-
>  hw/vfio/pci.c                       |  4 +-
>  hw/xen/xen-legacy-backend.c         |  3 +-
>  net/vhost-user.c                    | 41 ++++--------
>  net/vhost-vdpa.c                    | 37 ++++-------
>  qom/object.c                        |  7 +-
>  qom/object_interfaces.c             | 19 ++----
>  softmmu/qdev-monitor.c              | 99 +++++++++++++++++++----------
>  softmmu/vl.c                        | 63 ++++++++++++++++--
>  util/qemu-option.c                  |  4 +-
>  tests/qemu-iotests/051              |  2 +-
>  tests/qemu-iotests/051.pc.out       |  4 +-
>  tests/qemu-iotests/245              |  4 +-
>  23 files changed, 278 insertions(+), 178 deletions(-)
> 
> -- 
> 2.31.1