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

[Michal Luczaj <mhal@rbox.co>]

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 :)