On Wed, 11 Jan 2012 11:07:47 +0400 Michael Tokarev <mjt@xxxxxxxxxx> wrote: > On 11.01.2012 08:54, Stephen Hemminger wrote: > > By adding the a module alias, programs (or users) won't have to explicitly > > call modprobe. Vhost-net will always be available if built into the kernel. > > It does require assigning a permanent minor number for depmod to work. > > Choose one next to TUN since this driver is related to it. > > Why do you think a statically-allocated device number will do any good > at all? Static /dev is gone almost completely, at least on the systems > where whole virt stuff makes any sense, so you don't have pre-created > vhost-net device anymore, and hence this allocation makes no sense. > Just IMHO anyway. The statically allocated device number is required for the udev/module autoloading to work. Probably the udev infrastructure needs a consistent number to hang off of. It looks like: * driver adds MODULE_ALIAS() for devname and character device * depmod scans modules and creates modules.devname (in /lib/modules) * udev uses modules.devname to autoload the module $ /sbin/modinfo vhost_net filename: /lib/modules/3.2.0-net+/kernel/drivers/vhost/vhost_net.ko alias: devname:vhost-net alias: char-major-10-201 description: Host kernel accelerator for virtio net ... See also: https://lkml.org/lkml/2010/5/21/134 _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
