On Tue, Oct 15, 2024 at 09:54:38PM +0200, Stefano Brivio wrote:[Still partial review][snip]+ if (peek_offset_cap) + already_sent = 0; + + iov_vu[0].iov_base = tcp_buf_discard; + iov_vu[0].iov_len = already_sent;I think I had a similar comment to a previous revision. Now, I haven't tested this (yet) on a kernel with support for SO_PEEK_OFF on TCP, but I think this should eventually follow the same logic as the (updated) tcp_buf_data_from_sock(): we should use tcp_buf_discard only if (!peek_offset_cap). It's fine to always initialise VIRTQUEUE_MAX_SIZE iov_vu items, starting from 1, for simplicity. But I'm not sure if it's safe to pass a zero iov_len if (peek_offset_cap).I'll test that (unless you already did) -- if it works, we can fix this up later as well.I believe I tested it at some point, and I think we're already using it somewhere. -- David Gibson (he or they) | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you, not the other way | around. http://www.ozlabs.org/~dgibson