Re: [Qemu-devel] Re: virtio-serial: An interface for host-guest communication

[Amit Shah]

On (Fri) Aug 14 2009 [08:29:28], Anthony Liguori wrote:
> Amit Shah wrote:
>> On (Mon) Aug 10 2009 [11:59:31], Anthony Liguori wrote:
>>   
>>> However, as I've mentioned repeatedly, the reason I won't merge   
>>> virtio-serial is that it duplicates functionality with 
>>> virtio-console.   If the two are converged, I'm happy to merge it.  
>>> I'm not opposed to  having more functionality.
>>>     
>>
>> The guest code sort-of ends up looking like this after merging
>> virtio_console into virtio_serial. Diff is against virtio_serial in my
>> git tree, but that should be pretty close to the last submission I made
>> at
>>
>> http://patchwork.kernel.org/patch/39335/
>>
>> or the tree at
>>
>> git://git.kernel.org/pub/scm/linux/kernel/git/amit/vs-kernel.git
>>
>> I've merged bits from virtio_console.c into virtio_serial.c. If needed,
>> virtio_serial can be renamed to virtio_console. The VIRITIO_ID also
>> needs to change to that of virtio_console's.
>>
>> Similar changes are needed for userspace.
>>
>> Since there's support for only one console as of now, I've assigned port
>> #2 as the console port so that we hook into hvc when a port is found at
>> that location.
>>
>> One issue that crops up for put_chars: a copy of the buffer to be sent
>> has to be made as we don't wait for host to ack the buffer before we
>> move on.
>>
>> The biggest loss so far is Rusty's excellent comments: they will have to
>> be reworked and added for the whole of the new file.
>>
>> Is this approach acceptable?
>>   
>
> I think we want to keep virtio_console.c and definitely continue using  
> the virtio_console id.  It looks like you are still creating character  
> devices as opposed to tty devices.  Is this just an incremental step or  
> are you choosing to not do tty devices for a reason (as if so, what's  
> that reason)?

Just an incremental step. In fact, I haven't yet thought about exposing
a tty device and any problems that might come up. I'll get to doing that
too, of course.

Currently I plan to:
- finish sending connect/disconnect notifications
- finish merge of virtio-console and serial
- look at tty

                Amit