Re: [RFC PATCH 4/5] vsock: seqpacket_allow adapts to multi-devices

[Stefano Garzarella <sgarzare@xxxxxxxxxx>]

On Fri, May 17, 2024 at 10:46:06PM GMT, Xuewei Niu wrote:
> Adds a new argument, named "src_cid", to let them know which `virtio_vsock`
> to be selected.
>
> Signed-off-by: Xuewei Niu <niuxuewei.nxw@xxxxxxxxxxxx>
> ---
> include/net/af_vsock.h           |  2 +-
> net/vmw_vsock/af_vsock.c         | 15 +++++++++++++--
> net/vmw_vsock/virtio_transport.c |  4 ++--
> net/vmw_vsock/vsock_loopback.c   |  4 ++--
> 4 files changed, 18 insertions(+), 7 deletions(-)

Same for this.

> diff --git a/include/net/af_vsock.h b/include/net/af_vsock.h
> index 0151296a0bc5..25f7dc3d602d 100644
> --- a/include/net/af_vsock.h
> +++ b/include/net/af_vsock.h
> @@ -143,7 +143,7 @@ struct vsock_transport {
> 				     int flags);
> 	int (*seqpacket_enqueue)(struct vsock_sock *vsk, struct msghdr *msg,
> 				 size_t len);
> -	bool (*seqpacket_allow)(u32 remote_cid);
> +	bool (*seqpacket_allow)(u32 src_cid, u32 remote_cid);
> 	u32 (*seqpacket_has_data)(struct vsock_sock *vsk);
>
> 	/* Notification. */
> diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
> index da06ddc940cd..3b34be802bf2 100644
> --- a/net/vmw_vsock/af_vsock.c
> +++ b/net/vmw_vsock/af_vsock.c
> @@ -470,10 +470,12 @@ int vsock_assign_transport(struct vsock_sock *vsk, struct vsock_sock *psk)
> {
> 	const struct vsock_transport *new_transport;
> 	struct sock *sk = sk_vsock(vsk);
> -	unsigned int remote_cid = vsk->remote_addr.svm_cid;
> +	unsigned int src_cid, remote_cid;
> 	__u8 remote_flags;
> 	int ret;
>
> +	remote_cid = vsk->remote_addr.svm_cid;
> +
> 	/* If the packet is coming with the source and destination CIDs higher
> 	 * than VMADDR_CID_HOST, then a vsock channel where all the packets are
> 	 * forwarded to the host should be established. Then the host will
> @@ -527,8 +529,17 @@ int vsock_assign_transport(struct vsock_sock *vsk, struct vsock_sock *psk)
> 		return -ENODEV;
>
> 	if (sk->sk_type == SOCK_SEQPACKET) {
> +		if (vsk->local_addr.svm_cid == VMADDR_CID_ANY) {
> +			if (new_transport->get_default_cid)
> +				src_cid = new_transport->get_default_cid();
> +			else
> +				src_cid = new_transport->get_local_cid();
> +		} else {
> +			src_cid = vsk->local_addr.svm_cid;
> +		}
> +
> 		if (!new_transport->seqpacket_allow ||
> -		    !new_transport->seqpacket_allow(remote_cid)) {
> +		    !new_transport->seqpacket_allow(src_cid, remote_cid)) {
> 			module_put(new_transport->module);
> 			return -ESOCKTNOSUPPORT;
> 		}
> diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c
> index 998b22e5ce36..0bddcbd906a2 100644
> --- a/net/vmw_vsock/virtio_transport.c
> +++ b/net/vmw_vsock/virtio_transport.c
> @@ -615,14 +615,14 @@ static struct virtio_transport virtio_transport = {
> 	.can_msgzerocopy = virtio_transport_can_msgzerocopy,
> };
>
> -static bool virtio_transport_seqpacket_allow(u32 remote_cid)
> +static bool virtio_transport_seqpacket_allow(u32 src_cid, u32 remote_cid)
> {
> 	struct virtio_vsock *vsock;
> 	bool seqpacket_allow;
>
> 	seqpacket_allow = false;
> 	rcu_read_lock();
> -	vsock = rcu_dereference(the_virtio_vsock);
> +	vsock = virtio_transport_get_virtio_vsock(src_cid);
> 	if (vsock)
> 		seqpacket_allow = vsock->seqpacket_allow;
> 	rcu_read_unlock();
> diff --git a/net/vmw_vsock/vsock_loopback.c b/net/vmw_vsock/vsock_loopback.c
> index 6dea6119f5b2..b94358f5bb2c 100644
> --- a/net/vmw_vsock/vsock_loopback.c
> +++ b/net/vmw_vsock/vsock_loopback.c
> @@ -46,7 +46,7 @@ static int vsock_loopback_cancel_pkt(struct vsock_sock *vsk)
> 	return 0;
> }
>
> -static bool vsock_loopback_seqpacket_allow(u32 remote_cid);
> +static bool vsock_loopback_seqpacket_allow(u32 src_cid, u32 remote_cid);
> static bool vsock_loopback_msgzerocopy_allow(void)
> {
> 	return true;
> @@ -104,7 +104,7 @@ static struct virtio_transport loopback_transport = {
> 	.send_pkt = vsock_loopback_send_pkt,
> };
>
> -static bool vsock_loopback_seqpacket_allow(u32 remote_cid)
> +static bool vsock_loopback_seqpacket_allow(u32 src_cid, u32 remote_cid)
> {
> 	return true;
> }
> --
> 2.34.1