On Fri, Sep 27, 2019 at 01:27:01PM +0200, Stefano Garzarella wrote: > VMCI transport provides both g2h and h2g behaviors in a single > transport. > We are able to set (or not) the g2h behavior, detecting if we > are in a VMware guest (or not), but the h2g feature is always set. > This prevents to load other h2g transports while we are in a > VMware guest. > > This patch adds a new 'transport_hg' to handle this case, reducing > the priority of transports that provide both g2h and h2g > behaviors. A transport that has g2h and h2g features, can be > bypassed by a transport that has only the h2g feature. > Since I'm enabling the VSOCK_TRANSPORT_F_G2H in the vmci_transport only when we run in a VMware guest, this patch doesn't work well if a KVM (or HyperV) guest application create an AF_VSOCK socket and no transports are loaded, because in this case the vmci_transport is loaded (MODULE_ALIAS_NETPROTO(PF_VSOCK)) and it is registered as transport_h2g. At this point, if we want to run a nested VM using vhost_transport, we can't load it. So, I can leave VSOCK_TRANSPORT_F_G2H always set in the vmci_transport and this should fix this issue. Or maybe I need to change how the registering works, e.g. handling a list of transport registered, setting priority or using the last registered transport. Any suggestion? Thanks, Stefano
