> > There will be an additional problem if do this: > > Who decides which port the `runtime` should listen? > > Let the host kernel automatically assign a port using VMADDR_PORT_ANY. > It works like this: > > struct sockaddr_vm svm = { > .svm_family = AF_VSOCK, > .svm_port = VMADDR_PORT_ANY, > .svm_cid = VMADDR_CID_ANY, > }; > > int fd = socket(AF_VSOCK, SOCK_STREAM, 0); > ... > if (bind(fd, (const struct sockaddr )&svm, sizeof(svm)) < 0) { > ... > } > > socklen_t socklen = sizeof(svm); > if (getsockname(fd, (struct sockaddr *)&svm, &socklen) < 0) { > ... > } > > printf("cid %u port %u\n", svm.svm_cid, svm.svm_port); > > > Consider the worst case: > > The ports selected by two `runtime` running in parallel always conflict, > > and this case is unavoidable, even if we can reduce the possibility of > > conflicts through algorithms. > > Because we don't have a daemon that can allocate unique port to `runtime`. > > The kernel assigns unique ports and only fails if the entire port > namespace is exhausted. The port namespace is 32-bits so this is not a > real-world concern. > > Does this information clarify how the runtime can connect to the guest > agent without loops or delays?
Thank you very much. I will do as you instructed above