On 7/3/23 12:22 AM, Mina Almasry wrote: > tcpdump is able to access the header of these skbs which is in host > memory, but not the payload in device memory. Here is an example > session with my netcat-like test for device memory TCP: > https://pastebin.com/raw/FRjKf0kv > > tcpdump seems to work, and the length of the packets above is correct. > tcpdump -A however isn't able to print the payload of the packets: > https://pastebin.com/raw/2PcNxaZV That is my expectation. The tcpdump is just an easy example of accessing the skb page frags. skb_copy_and_csum_bits used by icmp is another example that can walk frags wanting access to device memory. You did not cause a panic or trip a WARN_ON for example with the tcpdump? Thanks for checking.
