On 01/09/13 19:12, Eric Blake wrote:
> On 01/07/2013 06:55 AM, Gerd Hoffmann wrote:
>> Add support for file chardevs. Output file is mandatory, input
>> file is optional. Both file names and file descriptor passing is
>> supported.
>>
>> Signed-off-by: Gerd Hoffmann <kra...@redhat.com> ---
>> qapi-schema.json | 9 +++++- qemu-char.c | 77
>> +++++++++++++++++++++++++++++++++++++++++++++++++++++- 2 files
>> changed, 84 insertions(+), 2 deletions(-)
>>
>> diff --git a/qapi-schema.json b/qapi-schema.json index
>> e3f0d44..8904d36 100644 --- a/qapi-schema.json +++
>> b/qapi-schema.json @@ -3030,9 +3030,16 @@ # # Since: 1.4 ## +{
>> 'union': 'ChardevFileSource', 'data': { 'path' : 'str', +
>> 'fd' : 'str' } } + +{ 'type': 'ChardevFile', 'data': { '*in' :
>> 'ChardevFileSource', + 'out' :
>> 'ChardevFileSource' } } + { 'type': 'ChardevDummy', 'data': { }
>> }
>>
>> -{ 'union': 'ChardevBackend', 'data': { 'null' : 'ChardevDummy' }
>> } +{ 'union': 'ChardevBackend', 'data': { 'file' :
>> 'ChardevFile', + 'null' :
>> 'ChardevDummy' } }
>>
>> { 'command': 'chardev-add', 'data': {'id' : 'str', 'backend'
>> : 'ChardevBackend' } }
>
> An example in qmp-commands.hx would be helpful; am I correct that
> an example would be:
>
> -> { "execute" : "chardev-add", "arguments" : { "id" : "foo",
> "backend" : { "type" : "file", "data" : { "in" : { "type" : "fd",
> "data" : "namedfd" }, "out" : { "type" : "path", "data" :
> "/path/to/file" } } } } } <- { "return": {} }
>
> where namedfd was previously given via 'getfd'?
Yes.
> Do we need the complexity of supporting fd passing explicitly?
> 'getfd' is less than ideal compared to 'add-fd', and for 'add-fd',
> we would pass via "path":"/dev/fdset/nnn". That is, why do we need
> to bend over backwards to support an alternate syntax for fd
> passing in a new command, when we can already use existing commands
> to get fd passing for free?
Oh, didn't know that. Was just following what SocketAddress does and
what Paolo suggested. It isn't needed indeed.
cheers,
Gerd
