On Wed, Oct 30, 2019 at 03:40:05PM +0000, Jorgen Hansen wrote: > > From: Stefano Garzarella [mailto:sgarzare@xxxxxxxxxx] > > > +/* Assign a transport to a socket and call the .init transport callback. > > > + * > > > + * Note: for stream socket this must be called when vsk->remote_addr > > > +is set > > > + * (e.g. during the connect() or when a connection request on a > > > +listener > > > + * socket is received). > > > + * The vsk->remote_addr is used to decide which transport to use: > > > + * - remote CID > VMADDR_CID_HOST will use host->guest transport > > > + * - remote CID <= VMADDR_CID_HOST will use guest->host transport > > > +*/ int vsock_assign_transport(struct vsock_sock *vsk, struct > > > +vsock_sock *psk) { > > > + const struct vsock_transport *new_transport; > > > + struct sock *sk = sk_vsock(vsk); > > > + > > > + switch (sk->sk_type) { > > > + case SOCK_DGRAM: > > > + new_transport = transport_dgram; > > > + break; > > > + case SOCK_STREAM: > > > + if (vsk->remote_addr.svm_cid > VMADDR_CID_HOST) > > > + new_transport = transport_h2g; > > > + else > > > + new_transport = transport_g2h; > > > > I just noticed that this break the loopback in the guest. > > As a fix, we should use 'transport_g2h' when remote_cid <= > > VMADDR_CID_HOST or remote_cid is the id of 'transport_g2h'. > > > > To do that we also need to avoid that L2 guests can have the same CID of L1. > > For vhost_vsock I can call vsock_find_cid() in vhost_vsock_set_cid() > > > > @Jorgen: for vmci we need to do the same? or it is guaranteed, since it's > > already support nested VMs, that a L2 guests cannot have the same CID as > > the L1. > > As far as I can tell, we have the same issue with the current support for nested VMs in > VMCI. If we have an L2 guest with the same CID as the L1 guest, we will always send to > the L2 guest, and we may assign an L2 guest the same CID as L1. It should be straight > forward to avoid this, though. > Yes, I think so. For the v2 I'm exposing the vsock_find_cid() to the transports, in this way I can reject requests to set the same L1 CID for L2 guests. Thanks, Stefano
