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authorRusty Russell <rusty@rustcorp.com.au>2007-07-26 10:41:02 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-07-26 11:35:16 -0700
commitf938d2c892db0d80d144253d4a7b7083efdbedeb (patch)
tree1fbc946a9fb59827001a5d4d5224abe5e624e605 /drivers/lguest/interrupts_and_traps.c
parentdfb68689bf3e3d31dc9fb5c2bde5379a4ca9b0ec (diff)
lguest: documentation I: Preparation
The netfilter code had very good documentation: the Netfilter Hacking HOWTO. Noone ever read it. So this time I'm trying something different, using a bit of Knuthiness. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/lguest/interrupts_and_traps.c')
-rw-r--r--drivers/lguest/interrupts_and_traps.c13
1 files changed, 13 insertions, 0 deletions
diff --git a/drivers/lguest/interrupts_and_traps.c b/drivers/lguest/interrupts_and_traps.c
index bee029bb2c7..b2647974e1a 100644
--- a/drivers/lguest/interrupts_and_traps.c
+++ b/drivers/lguest/interrupts_and_traps.c
@@ -1,3 +1,16 @@
+/*P:800 Interrupts (traps) are complicated enough to earn their own file.
+ * There are three classes of interrupts:
+ *
+ * 1) Real hardware interrupts which occur while we're running the Guest,
+ * 2) Interrupts for virtual devices attached to the Guest, and
+ * 3) Traps and faults from the Guest.
+ *
+ * Real hardware interrupts must be delivered to the Host, not the Guest.
+ * Virtual interrupts must be delivered to the Guest, but we make them look
+ * just like real hardware would deliver them. Traps from the Guest can be set
+ * up to go directly back into the Guest, but sometimes the Host wants to see
+ * them first, so we also have a way of "reflecting" them into the Guest as if
+ * they had been delivered to it directly. :*/
#include <linux/uaccess.h>
#include "lg.h"