On Fri, Jun 18, 2021 at 2:35 AM Stefano Garzarella [off-list ref] wrote:

On Wed, Jun 09, 2021 at 11:24:52PM +0000, Jiang Wang wrote:

quoted

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.

Hi Stefano,

Sure. I will rebase and add dynamic handling of DGRAM. I run checkpatch.pl
at some point but I will make sure to run it again before submitting. Thanks.

Regards,

Jiang

Thanks,
Stefano