[PATCH net v4 0/2] vsock/virtio: fix skb overhead accounting to preserve full buf_alloc

[Stefano Garzarella <sgarzare@redhat.com>]

Patch 1 resets the connection when we can no longer queue packets,
this prevents silent data loss, and both peers are notified.

Patch 2 increases the total budget to `buf_alloc * 2` for payload
plus skb overhead similar to how SO_RCVBUF is doubled to reserve
space for sk_buff metadata. This preserves the full buf_alloc for
payload under normal operation, while still bounding the skb queue
growth.

In the future, we plan to improve how we handle the merging of packets
to minimize overhead and avoid closing connections.

v4:
- Split the buf_alloc check to be sure the credit is still respected and
  to avoid overflow of buf_used [sashiko]
- call virtio_transport_do_close() and vsock_remove_sock() to properly
  close the connection and remove the socket from the connect table
  [sashiko]

v3: https://lore.kernel.org/netdev/20260513105417.56761-1-sgarzare@redhat.com/
- Split in 2 patches [MST]

v2: https://lore.kernel.org/netdev/20260512080737.36787-1-sgarzare@redhat.com/
- Close the connection when we can no longer queue new packets instead
  of losing data.
- No longer announce the reduced buf_alloc to avoid violating the
  spec. [MST]

v1: https://lore.kernel.org/netdev/20260508092330.69690-1-sgarzare@redhat.com/

Stefano Garzarella (2):
  vsock/virtio: reset connection on receiving queue overflow
  vsock/virtio: fix skb overhead accounting to preserve full buf_alloc

 net/vmw_vsock/virtio_transport_common.c | 29 ++++++++++++++++++++-----
 1 file changed, 23 insertions(+), 6 deletions(-)

-- 
2.54.0