Linux Virtualization - Nov 2018 - [RFC] Discuss about an new idea "Vsock over Virtio-net"

On 2018/11/30 ??8:52, Michael S. Tsirkin wrote:
>>>    If you want to compare it with
>>> something that would be TCP or QUIC.  The fundamental difference
between
>>> virtio-vsock and e.g. TCP is that TCP operates in a packet loss
environment.
>>> So they are using timers for reliability, and receiver is always
free to
>>> discard any unacked data.
>> Virtio-net knows nothing above L2, so they are totally transparent to
device
>> itself. I still don't get why not using virtio-net instead.
>>
>>
>> Thanks
> Is your question why is virtio-vsock used instead of TCP on top of IP
> on top of virtio-net?
>
>
No, my question is why not do vsock through virtio-net.

Thanks

On 2018/11/30 ??8:55, Jason Wang wrote:
>
> On 2018/11/30 ??8:52, Michael S. Tsirkin wrote:
>>>> ?? If you want to compare it with
>>>> something that would be TCP or QUIC.? The fundamental
difference
>>>> between
>>>> virtio-vsock and e.g. TCP is that TCP operates in a packet loss
>>>> environment.
>>>> So they are using timers for reliability, and receiver is
always
>>>> free to
>>>> discard any unacked data.
>>> Virtio-net knows nothing above L2, so they are totally transparent 
>>> to device
>>> itself. I still don't get why not using virtio-net instead.
>>>
>>>
>>> Thanks
>> Is your question why is virtio-vsock used instead of TCP on top of IP
>> on top of virtio-net?
>>
>>
>
> No, my question is why not do vsock through virtio-net.
>
> Thanks
>
Just to clarify, it's not about vosck over ethernet, and it's not about 
inventing new features or APIs. It's probably something like:

- Let virtio-net driver probe vsock device and do vosck specific things 
if needed to share as much codes.

- A new kind of sockfd (which is vsock based) for vhost-net for it to do 
vsock specific things (hopefully it can be transparent).

The change should be totally transparent to userspace applications.

Thanks

On Fri, Nov 30, 2018 at 08:55:17PM +0800, Jason Wang
wrote:
> 
> On 2018/11/30 ??8:52, Michael S. Tsirkin wrote:
> > > >    If you want to compare it with
> > > > something that would be TCP or QUIC.  The fundamental
difference between
> > > > virtio-vsock and e.g. TCP is that TCP operates in a packet
loss environment.
> > > > So they are using timers for reliability, and receiver is
always free to
> > > > discard any unacked data.
> > > Virtio-net knows nothing above L2, so they are totally
transparent to device
> > > itself. I still don't get why not using virtio-net instead.
> > > 
> > > 
> > > Thanks
> > Is your question why is virtio-vsock used instead of TCP on top of IP
> > on top of virtio-net?
> > 
> > 
> 
> No, my question is why not do vsock through virtio-net.
> 
> Thanks
Because apps need reliability, multiplexing and flow control and
virtio-net does not provide it.

-- 
MST

On Fri, Nov 30, 2018 at 09:10:03PM +0800, Jason Wang
wrote:
> 
> On 2018/11/30 ??8:55, Jason Wang wrote:
> > 
> > On 2018/11/30 ??8:52, Michael S. Tsirkin wrote:
> > > > > ?? If you want to compare it with
> > > > > something that would be TCP or QUIC.? The fundamental
> > > > > difference between
> > > > > virtio-vsock and e.g. TCP is that TCP operates in a
packet
> > > > > loss environment.
> > > > > So they are using timers for reliability, and receiver
is
> > > > > always free to
> > > > > discard any unacked data.
> > > > Virtio-net knows nothing above L2, so they are totally
> > > > transparent to device
> > > > itself. I still don't get why not using virtio-net
instead.
> > > > 
> > > > 
> > > > Thanks
> > > Is your question why is virtio-vsock used instead of TCP on top
of IP
> > > on top of virtio-net?
> > > 
> > > 
> > 
> > No, my question is why not do vsock through virtio-net.
> > 
> > Thanks
> > 
> 
> Just to clarify, it's not about vosck over ethernet, and it's not
about
> inventing new features or APIs. It's probably something like:
> 
> - Let virtio-net driver probe vsock device and do vosck specific things if
> needed to share as much codes.
> 
> - A new kind of sockfd (which is vsock based) for vhost-net for it to do
> vsock specific things (hopefully it can be transparent).
> 
> The change should be totally transparent to userspace applications.
> 
> Thanks
Which code is duplicated between virtio vsock and virtio net right now?

-- 
MST