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

From: Jason Wang
Date: Wed Jun 09 2021 - 21:51:15 EST

在 2021/6/10 上午7:24, Jiang Wang 写道:
This patchset implements support of SOCK_DGRAM for virtio

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

What's the use case for the datagram vsock?

The virtio spec patch is here:

Have a quick glance, I suggest to split mergeable rx buffer into an separate patch.

But I think it's time to revisit the idea of unifying the virtio-net and virtio-vsock. Otherwise we're duplicating features and bugs.


For those who prefer git repo, here is the link for the linux kernel:

qemu patch link:

To do:
1. use skb when receiving packets
2. support multiple transport
3. support mergeable rx buffer

Jiang Wang (6):
virtio/vsock: add VIRTIO_VSOCK_F_DGRAM feature bit
virtio/vsock: add support for virtio datagram
vhost/vsock: add support for vhost dgram.
vsock_test: add tests for vsock dgram
vhost/vsock: add kconfig for vhost dgram support
virtio/vsock: add sysfs for rx buf len for dgram

drivers/vhost/Kconfig | 8 +
drivers/vhost/vsock.c | 207 ++++++++--
include/linux/virtio_vsock.h | 9 +
include/net/af_vsock.h | 1 +
.../trace/events/vsock_virtio_transport_common.h | 5 +-
include/uapi/linux/virtio_vsock.h | 4 +
net/vmw_vsock/af_vsock.c | 12 +
net/vmw_vsock/virtio_transport.c | 433 ++++++++++++++++++---
net/vmw_vsock/virtio_transport_common.c | 184 ++++++++-
tools/testing/vsock/util.c | 105 +++++
tools/testing/vsock/util.h | 4 +
tools/testing/vsock/vsock_test.c | 195 ++++++++++
12 files changed, 1070 insertions(+), 97 deletions(-)