Re: [libvirt] [PATCH] Add migration APIs for libxl driver

2012/3/15 Jim Fehlig <jfehlig(a)suse.com <mailto:jfehlig@suse.com>> > + /* Create socket connection to receive migration data */ > + if (!uri_in) { > + hostname = virGetHostname(dconn); > + if (hostname == NULL) > + goto cleanup; > + > + port = libxlFindFreeMigPort(driver, LIBXL_MIGRATION_MIN_PORT); > I think you should reserve the port in libxlFindFreeMigPort(), similar to libxlNextFreeVncPort(). In fact, you could probably generalize libxlNextFreeVncPort(), e.g. libxlNextFreePort(virBitmapPtr bitmap, int start_port, int stop_port) and use it to find available VNC and migration ports. There is some difference to handle Migration ports and VNC ports: VNC port always find a free port from VNC ports range and use it, but migration port could be pointed by user or if not pointed find a free port to use it. There are two places need to set bitmap maybe: 1. The port pointed by user could be a port in default migration ports range, we should set bitmap so that next time finding free port could avoid that port.

2. No port pointed by user, then find a free migration port from default migration ports range, and set bitmap. Besides, with port pointed, we need to create socket and bind to the port too. libxlFindFreeVNCPort creates socket and binds port and set bitmap in the function, if FindFreeMigPort also does that, then to user pointed port, we need to do same work again.