On (Tue) Jan 12 2010 [09:55:41], Anthony Liguori wrote:
> On 01/12/2010 09:49 AM, Amit Shah wrote:
>> On (Tue) Jan 12 2010 [09:46:55], Anthony Liguori wrote:
>>
>>> On 01/12/2010 09:13 AM, Amit Shah wrote:
>>>
>>>> On (Tue) Jan 12 2010 [09:00:52], Anthony Liguori wrote:
>>>>
>>>>
>>>>> On 01/12/2010 01:16 AM, Amit Shah wrote:
>>>>>
>>>>>
>>>>>> BTW I don't really want this too, I can get rid of it if everyone agrees
>>>>>> we won't support clipboard writes> 4k over vnc or if there's a better
>>>>>> idea.
>>>>>>
>>>>>>
>>>>>>
>>>>> Why bother trying to preserve message boundaries? I think that's the
>>>>> fundamental question.
>>>>>
>>>>>
>>>> For the vnc clipboard copy-paste case, I explained that in the couple of
>>>> mails before in this thread.
>>>>
>>>>
>>> It didn't make sense to me. I think the assumption has to be that the
>>> client can send corrupt data and the host has to handle it.
>>>
>> You mean if the guest kernel sends the wrong flags? Or doesn't set the
>> flags? Can you explain what scenario you're talking about?
>>
>
> It's very likely that you'll have to implement some sort of protocol on
> top of virtio-serial. It won't always just be simple strings.
Yes, virtio-serial is just meant to be a transport agnostic of whatever
data or protocols that ride over it.
> If you have a simple datagram protocol, that contains two ints and a
> string, it's going to have to be encoded like <int a><int b><int
> len><char data[len]>. You need to validate that len fits within the
> boundaries and deal with len being less than the boundary.
>
> If you've got a command protocol where the you send the guest something
> and then expect a response, you have to deal with the fact that the
> guest may never respond. Having well defined message boundaries does
> not help the general problem and it only helps in the most trivial cases.
>
> Basically, it boils down to a lot of complexity for something that isn't
> going to be helpful in most circumstances.
I don't know why you're saying virtio-serial-bus does (or needs to) do
anything of this.
Amit
