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

Stefano Garzarella
2025-12-23T13:20:49Z

On Tue, Dec 23, 2025 at 12:10:25PM +0100, Michal Luczaj wrote:
>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

aaa, right, the server is failing, sorry ;-)

Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
>
>I have no idea what's going on :)
>

In my suite, I'm checking the client, and if the last test fails only on
the server, I'm missing it. I'd fix my suite, and maybe also vsock_test
adding another sync point.

Thanks,
Stefano