Re: [RFC v1 0/6] virtio/vsock: introduce SOCK_DGRAM support

[Stefano Garzarella]

On Wed, Jun 09, 2021 at 11:24:52PM +0000, Jiang Wang wrote:
> This patchset implements support of SOCK_DGRAM for virtio
> transport.
>
> Datagram sockets are connectionless and unreliable. To avoid unfair contention
> with stream and other sockets, add two more virtqueues and
> a new feature bit to indicate if those two new queues exist or not.
>
> Dgram does not use the existing credit update mechanism for
> stream sockets. When sending from the guest/driver, sending packets
> synchronously, so the sender will get an error when the virtqueue is full.
> When sending from the host/device, send packets asynchronously
> because the descriptor memory belongs to the corresponding QEMU
> process.
>
> The virtio spec patch is here:
> https://www.spinics.net/lists/linux-virtualization/msg50027.html
>
> For those who prefer git repo, here is the link for the linux kernel：
> https://github.com/Jiang1155/linux/tree/vsock-dgram-v1
>
> qemu patch link:
> https://github.com/Jiang1155/qemu/tree/vsock-dgram-v1
>
>
> To do:
> 1. use skb when receiving packets
> 2. support multiple transport
> 3. support mergeable rx buffer

Jiang, I'll do a fast review, but I think is better to rebase on 
net-next since SEQPACKET support is now merged.

Please also run ./scripts/checkpatch.pl, there are a lot of issues.

I'll leave some simple comments in the patches, but I prefer to do a 
deep review after the rebase and the dynamic handling of DGRAM.

Thanks,
Stefano