lguest: documentation update

Went through the documentation doing typo and content fixes.  This
patch contains only comment and whitespace changes.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

diff --git a/include/linux/lguest.h b/include/linux/lguest.h
index 8beb291..175e63f 100644
--- a/include/linux/lguest.h
+++ b/include/linux/lguest.h
@@ -12,8 +12,8 @@
 #define LG_CLOCK_MAX_DELTA	ULONG_MAX
 
 /*G:032 The second method of communicating with the Host is to via "struct
- * lguest_data".  The Guest's very first hypercall is to tell the Host where
- * this is, and then the Guest and Host both publish information in it. :*/
+ * lguest_data".  Once the Guest's initialization hypercall tells the Host where
+ * this is, the Guest and Host both publish information in it. :*/
 struct lguest_data
 {
 	/* 512 == enabled (same as eflags in normal hardware).  The Guest
diff --git a/include/linux/lguest_launcher.h b/include/linux/lguest_launcher.h
index c41fd48..697104d 100644
--- a/include/linux/lguest_launcher.h
+++ b/include/linux/lguest_launcher.h
@@ -10,7 +10,11 @@
  * real devices (think of the damage it could do!) we provide virtual devices.
  * We could emulate a PCI bus with various devices on it, but that is a fairly
  * complex burden for the Host and suboptimal for the Guest, so we have our own
- * "lguest" bus and simple drivers.
+ * simple lguest bus and we use "virtio" drivers.  These drivers need a set of
+ * routines from us which will actually do the virtual I/O, but they handle all
+ * the net/block/console stuff themselves.  This means that if we want to add
+ * a new device, we simply need to write a new virtio driver and create support
+ * for it in the Launcher: this code won't need to change.
  *
  * Devices are described by a simplified ID, a status byte, and some "config"
  * bytes which describe this device's configuration.  This is placed by the