2011/1/29 Darko Petrović <darko.b.petro...@gmail.com>: > Could you please tell me if it is possible to use a block driver that > completely avoids the guest kernel and copies block data directly to/from > the given buffer in the guest userspace? > If yes, how to activate it? If not... why not? :)
Inside the guest, open files using the O_DIRECT flag. This tells the guest kernel to avoid the page cache when possible, enabling zero-copy. You need to use aligned memory buffers and perform I/O in multiples of the block size. See the open(2) man page for details. Make sure you really want to do this, most applications don't. Stefan -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
