Re: [PATCH net 2/2] vsock/test: Test setting SO_ZEROCOPY on accept()ed socket

Michal Luczaj
2025-12-23T11:10:42Z

On 12/23/25 11:27, Stefano Garzarella wrote:
> On Tue, Dec 23, 2025 at 10:15:29AM +0100, Michal Luczaj wrote:
>> Make sure setsockopt(SOL_SOCKET, SO_ZEROCOPY) on an accept()ed socket is
>> handled by vsock's implementation.
>>
>> Signed-off-by: Michal Luczaj <mhal@rbox.co>
>> ---
>> tools/testing/vsock/vsock_test.c | 33 +++++++++++++++++++++++++++++++++
>> 1 file changed, 33 insertions(+)
>>
>> diff --git a/tools/testing/vsock/vsock_test.c b/tools/testing/vsock/vsock_test.c
>> index 9e1250790f33..8ec8f0844e22 100644
>> --- a/tools/testing/vsock/vsock_test.c
>> +++ b/tools/testing/vsock/vsock_test.c
>> @@ -2192,6 +2192,34 @@ static void test_stream_nolinger_server(const struct test_opts *opts)
>> close(fd);
>> }
>>
>> +static void test_stream_accepted_setsockopt_client(const struct test_opts *opts)
>> +{
>> + int fd;
>> +
>> + fd = vsock_stream_connect(opts->peer_cid, opts->peer_port);
>> + if (fd < 0) {
>> + perror("connect");
>> + exit(EXIT_FAILURE);
>> + }
>> +
>> + vsock_wait_remote_close(fd);
>> + close(fd);
>> +}
>> +
>> +static void test_stream_accepted_setsockopt_server(const struct test_opts *opts)
>> +{
>> + int fd;
>> +
>> + fd = vsock_stream_accept(VMADDR_CID_ANY, opts->peer_port, NULL);
>> + if (fd < 0) {
>> + perror("accept");
>> + exit(EXIT_FAILURE);
>> + }
>> +
>> + enable_so_zerocopy_check(fd);
>
> This test is passing on my env also without the patch applied.
>
> Is that expected?

Oh, no, definitely not. It fails for me:
36 - SOCK_STREAM accept()ed socket custom setsockopt()...36 - SOCK_STREAM
accept()ed socket custom setsockopt()...setsockopt err: Operation not
supported (95)
setsockopt SO_ZEROCOPY val 1

I have no idea what's going on :)