Re: [Qemu-devel] [PATCH v4 10/23] json: Define new QMP message for pvrdma

[Markus Armbruster <armbru@redhat.com>]

The subsystem tag in the commit message's title should be "qapi: " not
"json: ".

Yuval Shaia <yuval.shaia@oracle.com> writes:

> pvrdma requires that the same GID attached to it will be attached to the
> backend device in the host.
>
> A new QMP messages is defined so pvrdma device can broadcast any change
> made to its GID table. This event is captured by libvirt which in turn
> will update the GID table in the backend device.
>
> Signed-off-by: Yuval Shaia <yuval.shaia@oracle.com>
> Reviewed-by: Marcel Apfelbaum <marcel.apfelbaum@gmail.com>
> ---
>  MAINTAINERS           |  1 +
>  Makefile              |  3 ++-
>  Makefile.objs         |  4 ++++
>  qapi/qapi-schema.json |  1 +
>  qapi/rdma.json        | 38 ++++++++++++++++++++++++++++++++++++++
>  5 files changed, 46 insertions(+), 1 deletion(-)
>  create mode 100644 qapi/rdma.json
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index e087d58ac6..a149f68a8f 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -2232,6 +2232,7 @@ F: hw/rdma/*
>  F: hw/rdma/vmw/*
>  F: docs/pvrdma.txt
>  F: contrib/rdmacm-mux/*
> +F: qapi/rdma.json
>  
>  Build and test automation
>  -------------------------
> diff --git a/Makefile b/Makefile
> index 94072776ff..db4ce60ee5 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -599,7 +599,8 @@ qapi-modules = $(SRC_PATH)/qapi/qapi-schema.json $(SRC_PATH)/qapi/common.json \
>                 $(SRC_PATH)/qapi/tpm.json \
>                 $(SRC_PATH)/qapi/trace.json \
>                 $(SRC_PATH)/qapi/transaction.json \
> -               $(SRC_PATH)/qapi/ui.json
> +               $(SRC_PATH)/qapi/ui.json \
> +               $(SRC_PATH)/qapi/rdma.json

Please insert between net.json and rocker.json to maintain alphabetical
order.

>  qapi/qapi-builtin-types.c qapi/qapi-builtin-types.h \
>  qapi/qapi-types.c qapi/qapi-types.h \
> diff --git a/Makefile.objs b/Makefile.objs
> index cc7df3ad80..76d8028f2f 100644
> --- a/Makefile.objs
> +++ b/Makefile.objs
> @@ -21,6 +21,7 @@ util-obj-y += qapi/qapi-types-tpm.o
>  util-obj-y += qapi/qapi-types-trace.o
>  util-obj-y += qapi/qapi-types-transaction.o
>  util-obj-y += qapi/qapi-types-ui.o
> +util-obj-y += qapi/qapi-types-rdma.o
>  util-obj-y += qapi/qapi-builtin-visit.o
>  util-obj-y += qapi/qapi-visit.o
>  util-obj-y += qapi/qapi-visit-block-core.o
> @@ -40,6 +41,7 @@ util-obj-y += qapi/qapi-visit-tpm.o
>  util-obj-y += qapi/qapi-visit-trace.o
>  util-obj-y += qapi/qapi-visit-transaction.o
>  util-obj-y += qapi/qapi-visit-ui.o
> +util-obj-y += qapi/qapi-visit-rdma.o
>  util-obj-y += qapi/qapi-events.o
>  util-obj-y += qapi/qapi-events-block-core.o
>  util-obj-y += qapi/qapi-events-block.o
> @@ -58,6 +60,7 @@ util-obj-y += qapi/qapi-events-tpm.o
>  util-obj-y += qapi/qapi-events-trace.o
>  util-obj-y += qapi/qapi-events-transaction.o
>  util-obj-y += qapi/qapi-events-ui.o
> +util-obj-y += qapi/qapi-events-rdma.o
>  util-obj-y += qapi/qapi-introspect.o
>  
>  chardev-obj-y = chardev/
> @@ -155,6 +158,7 @@ common-obj-y += qapi/qapi-commands-tpm.o
>  common-obj-y += qapi/qapi-commands-trace.o
>  common-obj-y += qapi/qapi-commands-transaction.o
>  common-obj-y += qapi/qapi-commands-ui.o
> +common-obj-y += qapi/qapi-commands-rdma.o
>  common-obj-y += qapi/qapi-introspect.o
>  common-obj-y += qmp.o hmp.o
>  endif

This is incomplete, and it conflicts with Eric Blake's "[PATCH v3] qapi:
Reduce Makefile boilerplate".  I recommend to base on Eric's patch,
because that'll let you add the new rdma.json much more easily.

> diff --git a/qapi/qapi-schema.json b/qapi/qapi-schema.json
> index 65b6dc2f6f..a650d80f83 100644
> --- a/qapi/qapi-schema.json
> +++ b/qapi/qapi-schema.json
> @@ -94,3 +94,4 @@
>  { 'include': 'trace.json' }
>  { 'include': 'introspect.json' }
>  { 'include': 'misc.json' }
> +{ 'include': 'rdma.json' }

This makes the "RDMA device" section appear last in the QEMU QMP
reference manual, since they appear in include order there.

    $ grep -h @section bld-x86/qapi/qapi-doc.texi 
    @section Introduction
    @section Stability Considerations
    @section Common data types
    @section Socket data types
    @section VM run state
    @section Cryptography
    @section Block devices
    @section Character devices
    @section Net devices
    @section Rocker switch device
    @section TPM (trusted platform module) devices
    @section Remote desktop
    @section Input
    @section Migration
    @section Transactions
    @section Tracing
    @section QMP introspection
    @section Miscellanea
    @section RDMA device

It should go next to the other "device" sections, shouldn't it?

> diff --git a/qapi/rdma.json b/qapi/rdma.json
> new file mode 100644
> index 0000000000..804c68ab36
> --- /dev/null
> +++ b/qapi/rdma.json
> @@ -0,0 +1,38 @@
> +# -*- Mode: Python -*-
> +#
> +
> +##
> +# = RDMA device
> +##
> +
> +##
> +# @RDMA_GID_STATUS_CHANGED:
> +#
> +# Emitted when guest driver adds/deletes GID to/from device
> +#
> +# @netdev: RoCE Network Device name - char *
> +#
> +# @gid-status: Add or delete indication - bool
> +#
> +# @subnet-prefix: Subnet Prefix - uint64
> +#
> +# @interface-id : Interface ID - uint64
> +#
> +# Since: 3.2
> +#
> +# Example:
> +#
> +# <- {"timestamp": {"seconds": 1541579657, "microseconds": 986760},
> +#     "event": "RDMA_GID_STATUS_CHANGED",
> +#     "data":
> +#         {"netdev": "bridge0",
> +#         "interface-id": 15880512517475447892,
> +#         "gid-status": true,
> +#         "subnet-prefix": 33022}}
> +#
> +##
> +{ 'event': 'RDMA_GID_STATUS_CHANGED',
> +  'data': { 'netdev'        : 'str',
> +            'gid-status'    : 'bool',
> +            'subnet-prefix' : 'uint64',
> +            'interface-id'  : 'uint64' } }

Schema looks okay from a QAPI perspective (I know next to nothing about
RDMA).