Re: [PATCH RFC net-next v2 0/3] vsock: add support for sockmap

[Stefano Garzarella]

Hi Bobby,
sorry for my late reply, but I have been offline these days.
I came back a few days ago and had to work off some accumulated work :-)

On Mon, Jan 30, 2023 at 08:35:11PM -0800, Bobby Eshleman wrote:
> Add support for sockmap to vsock.
>
> We're testing usage of vsock as a way to redirect guest-local UDS requests to
> the host and this patch series greatly improves the performance of such a
> setup.
>
> Compared to copying packets via userspace, this improves throughput by 121% in
> basic testing.
>
> Tested as follows.
>
> Setup: guest unix dgram sender -> guest vsock redirector -> host vsock server
> Threads: 1
> Payload: 64k
> No sockmap:
> - 76.3 MB/s
> - The guest vsock redirector was
>  "socat VSOCK-CONNECT:2:1234 UNIX-RECV:/path/to/sock"
> Using sockmap (this patch):
> - 168.8 MB/s (+121%)
> - The guest redirector was a simple sockmap echo server,
>  redirecting unix ingress to vsock 2:1234 egress.
> - Same sender and server programs
>
> *Note: these numbers are from RFC v1
>
> Only the virtio transport has been tested. The loopback transport was used in
> writing bpf/selftests, but not thoroughly tested otherwise.
>
> This series requires the skb patch.
>
> Changes in v2:
> - vsock/bpf: rename vsock_dgram_* -> vsock_*
> - vsock/bpf: change sk_psock_{get,put} and {lock,release}_sock() order to
> 	     minimize slock hold time
> - vsock/bpf: use "new style" wait
> - vsock/bpf: fix bug in wait log
> - vsock/bpf: add check that recvmsg sk_type is one dgram, seqpacket, or stream.
> 	     Return error if not one of the three.
> - virtio/vsock: comment __skb_recv_datagram() usage
> - virtio/vsock: do not init copied in read_skb()
> - vsock/bpf: add ifdef guard around struct proto in dgram_recvmsg()
> - selftests/bpf: add vsock loopback config for aarch64
> - selftests/bpf: add vsock loopback config for s390x
> - selftests/bpf: remove vsock device from vmtest.sh qemu machine
> - selftests/bpf: remove CONFIG_VIRTIO_VSOCKETS=y from config.x86_64
> - vsock/bpf: move transport-related (e.g., if (!vsk->transport)) checks out of
> 	     fast path

The series looks in a good shape.
I left some small comments on the first patch, but I think the next
version could be without RFC, so we can receive some feedbacks from
net/bpf maintainers.

Great job!

Thanks,
Stefano