Re: [PATCH net-next v3 1/3] vsock: Add support for SIOCINQ ioctl

[Stefano Garzarella]

On Sun, Jun 22, 2025 at 09:59:10PM +0800, Xuewei Niu wrote:
> > ACCin hyper-v maintainers and list since I have a question about hyperv
> > transport.
> >
> > On Tue, Jun 17, 2025 at 12:53:44PM +0800, Xuewei Niu wrote:
> > >Add support for SIOCINQ ioctl, indicating the length of bytes unread in the
> > >socket. The value is obtained from `vsock_stream_has_data()`.
> > >
> > >Signed-off-by: Xuewei Niu <niuxuewei.nxw@xxxxxxxxxxxx>
> > >---
> > > net/vmw_vsock/af_vsock.c | 22 ++++++++++++++++++++++
> > > 1 file changed, 22 insertions(+)
> > >
> > >diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
> > >index 2e7a3034e965..bae6b89bb5fb 100644
> > >--- a/net/vmw_vsock/af_vsock.c
> > >+++ b/net/vmw_vsock/af_vsock.c
> > >@@ -1389,6 +1389,28 @@ static int vsock_do_ioctl(struct socket *sock, unsigned int cmd,
> > > 	vsk = vsock_sk(sk);
> > >
> > > 	switch (cmd) {
> > >+	case SIOCINQ: {
> > >+		ssize_t n_bytes;
> > >+
> > >+		if (!vsk->transport) {
> > >+			ret = -EOPNOTSUPP;
> > >+			break;
> > >+		}
> > >+
> > >+		if (sock_type_connectible(sk->sk_type) &&
> > >+		    sk->sk_state == TCP_LISTEN) {
> > >+			ret = -EINVAL;
> > >+			break;
> > >+		}
> > >+
> > >+		n_bytes = vsock_stream_has_data(vsk);
> >
> > Now looks better to me, I just checked transports: vmci and virtio/vhost
> > returns what we want, but for hyperv we have:
> >
> > 	static s64 hvs_stream_has_data(struct vsock_sock *vsk)
> > 	{
> > 		struct hvsock *hvs = vsk->trans;
> > 		s64 ret;
> >
> > 		if (hvs->recv_data_len > 0)
> > 			return 1;
> >
> > @Hyper-v maintainers: do you know why we don't return `recv_data_len`?
> > Do you think we can do that to support this new feature?
>
> Hi Hyper-v maintainers, could you please take a look at this?
>
> Hi Stefano, if no response, can I fix this issue in the next version?

Yep, but let's wait a little bit more.

In that case, please do it in a separate patch (same series is fine) 
that we can easily revert/fix if they will find issues later.

Thanks,
Stefano

> Thanks,
> Xuewei
>
> > Thanks,
> > Stefano
> >
> > >+		if (n_bytes < 0) {
> > >+			ret = n_bytes;
> > >+			break;
> > >+		}
> > >+		ret = put_user(n_bytes, arg);
> > >+		break;
> > >+	}
> > > 	case SIOCOUTQ: {
> > > 		ssize_t n_bytes;
> > >
> > >--
> > >2.34.1
> > >