[Qemu-devel] Re: Planning for 0.13

[Michael S. Tsirkin]

On Wed, Jan 06, 2010 at 08:48:16PM +0100, Paolo Bonzini wrote:
> On 01/06/2010 04:10 PM, Anthony Liguori wrote:
>> We have ones that require read/write, ones that require send/recv, and
>> ones that require vhost interaction.  Really, the first two are the same
>> but the distinction is necessary for Windows.
>
> Not necessarily, you can open sockets on Windows so that they support  
> read/write.  Just create it with
>
>   fh = WSASocket (domain, type, protocol, NULL, 0, 0);
>
> instead of socket.  Since Windows already has enough problems passing  
> file descriptors to processes, imposing the above on an external  
> management interface is not a huge chore.
>
> Paolo

For linux read/write often isn't a good idea :)
E.g. for packet sockets you really need to use sendmsg and set msg_name
with the proper protocol.  You also must use recvmsg and set MSG_TRUNC
otherwise packets can get truncatred silently.

-- 
MST