We prefer revisions be posted as new threads. Next time :)
Fails to build for me:
[334/335] Generating docs/QEMU manual with a custom command
FAILED: [code=1] docs/docs.stamp
/usr/bin/env CONFDIR=etc/qemu
/work/armbru/qemu/bld-docs/pyvenv/bin/sphinx-build -q -j auto -W
-Dkerneldoc_werror=1 -Dversion=11.0.90 -Drelease= -Ddepfile=docs/docs.d
-Ddepfile_stamp=docs/docs.stamp -b html -d
/work/armbru/qemu/bld-docs/docs/manual.p /work/armbru/qemu/docs
/work/armbru/qemu/bld-docs/docs/manual
/work/armbru/qemu/docs/system/devices/remote-i2c-master.rst: WARNING:
document isn't included in any toctree [toc.not_included]
Should you add a reference to your new .rst to
docs/system/device-emulation.rst section "Emulated Devices"?
Ilya Chichkov <[email protected]> writes:
> Add a "remote-i2c-master" device that exposes a QEMU I2C bus to the
> host system through a FUSE/CUSE character device. This lets external
> host programs and standard i2c-tools interact with I2C slaves emulated
> inside QEMU as if they were real devices attached to the host.
>
> The implementation is split into three layers:
>
> - A non-blocking finite state machine that drives the QEMU I2C
> master. It is pumped by a QEMU Bottom Half and uses virtual timers
> to yield during long transfers and to model clock stretching for
> asynchronous slaves, so the main loop is never blocked. The FSM
> walks IDLE -> ADDR -> SEND/RECV -> WAIT_STRETCH -> END -> FINISHED
> and handles NACKs (ENXIO), lost arbitration (EBUSY, with optional
> back-off and retry), stretch timeouts, and manual abort/reset.
>
> - An abstract RemoteI2CBackend QOM base class that decouples the
> internal I2C hardware state machine (the frontend) from any
> host-specific transport, exposing on_tx_complete and on_tx_error
> virtual callbacks.
>
> - A concrete remote-i2c-backend-cuse backend implementing that
> transport over CUSE. It manages the FUSE session and integrates
> its file descriptors into QEMU's main AioContext event loop,
> translates Linux I2C_RDWR, I2C_SMBUS and I2C_SLAVE ioctls into
> generic byte streams for the FSM, and formats responses back into
> Linux I2C/SMBus structures for the FUSE driver. SMBus repeated
> start is supported for atomic write-then-read operations.
>
> Example usage:
>
> -device remote-i2c-master,i2cbus=i2c-bus.0,devname=i2c-33
> -object remote-i2c-backend-cuse,id=b0,devname=i2c-33
>
> This creates /dev/i2c-33 on the host, usable with i2c-tools:
>
> i2cdetect -y -l
> i2cget -y <bus_id> <addr> <reg>
>
> Signed-off-by: Ilya Chichkov <[email protected]>
[...]
> diff --git a/qapi/qom.json b/qapi/qom.json
> index dd45ac1087..1552103a4a 100644
> --- a/qapi/qom.json
> +++ b/qapi/qom.json
> @@ -1258,6 +1258,8 @@
> 'tls-creds-psk',
> 'tls-creds-x509',
> 'tls-cipher-suites',
> + { 'name': 'remote-i2c-backend-cuse',
> + 'if': 'CONFIG_LINUX' },
> { 'name': 'x-remote-object', 'features': [ 'unstable' ] },
> { 'name': 'x-vfio-user-server', 'features': [ 'unstable' ] }
> ] }
> @@ -1334,6 +1336,8 @@
> 'tls-creds-psk': 'TlsCredsPskProperties',
> 'tls-creds-x509': 'TlsCredsX509Properties',
> 'tls-cipher-suites': 'TlsCredsProperties',
> + 'remote-i2c-backend-cuse': { 'type':
> 'RemoteI2CBackendCuseProperties',
> + 'if': 'CONFIG_LINUX' },
> 'x-remote-object': 'RemoteObjectProperties',
> 'x-vfio-user-server': 'VfioUserServerProperties'
> } }
> @@ -1377,3 +1381,27 @@
> ##
> { 'command': 'object-del', 'data': {'id': 'str'},
> 'allow-preconfig': true }
> +
> +##
> +# @RemoteI2CBackendCuseProperties:
> +#
> +# Properties for the CUSE remote I2C backend. See
> +# :doc:`/system/devices/remote-i2c-master` for usage information.
Suggest "for detailed usage information."
> +#
> +# @devname: The name of the character device node to create under /dev
> +# (e.g., 'i2c-33' creates /dev/i2c-33). The node is accessible
> +# via the standard Linux I2C device interface and usable directly
> +# with i2c-tools and the Linux i2c-dev API.
> +#
> +# @fuse-opts: Options passed verbatim to the FUSE/CUSE session at
> +# mount time, one option (or argument) per list element. For
> +# example ['-d'] enables debug tracing, and ['-o', 'allow_other']
> +# grants other users access. See the libfuse documentation for
> +# the full list of supported options.
> +#
> +# Since: 11.2
> +##
> +{ 'struct': 'RemoteI2CBackendCuseProperties',
> + 'data': { 'devname': 'str',
> + '*fuse-opts': ['str'] },
> + 'if': 'CONFIG_LINUX' }
Please add this type before its use. Put it right before
RemoteObjectProperties?
With that, QAPI schema
Acked-by: Markus Armbruster <[email protected]>
[...]
