Introduce guest mem offset, static link example launcher

[safe/jmp/linux-2.6] / drivers / lguest / lg.h

diff --git a/drivers/lguest/lg.h b/drivers/lguest/lg.h
index 3b9dc12..54f2c24 100644 (file)
--- a/drivers/lguest/lg.h
+++ b/drivers/lguest/lg.h
@@ -12,7 +12,6 @@
 #include <linux/types.h>
 #include <linux/init.h>
 #include <linux/stringify.h>
-#include <linux/binfmts.h>
 #include <linux/futex.h>
 #include <linux/lguest.h>
 #include <linux/lguest_launcher.h>
@@ -58,9 +57,18 @@ struct lguest_dma_info
        u8 interrupt;   /* 0 when not registered */
 };
 
-/* We have separate types for the guest's ptes & pgds and the shadow ptes &
- * pgds.  Since this host might use three-level pagetables and the guest and
- * shadow pagetables don't, we can't use the normal pte_t/pgd_t. */
+/*H:310 The page-table code owes a great debt of gratitude to Andi Kleen.  He
+ * reviewed the original code which used "u32" for all page table entries, and
+ * insisted that it would be far clearer with explicit typing.  I thought it
+ * was overkill, but he was right: it is much clearer than it was before.
+ *
+ * We have separate types for the Guest's ptes & pgds and the shadow ptes &
+ * pgds.  There's already a Linux type for these (pte_t and pgd_t) but they
+ * change depending on kernel config options (PAE). */
+
+/* Each entry is identical: lower 12 bits of flags and upper 20 bits for the
+ * "page frame number" (0 == first physical page, etc).  They are different
+ * types so the compiler will warn us if we mix them improperly. */
 typedef union {
        struct { unsigned flags:12, pfn:20; };
        struct { unsigned long val; } raw;
@@ -77,8 +85,12 @@ typedef union {
        struct { unsigned flags:12, pfn:20; };
        struct { unsigned long val; } raw;
 } gpte_t;
+
+/* We have two convenient macros to convert a "raw" value as handed to us by
+ * the Guest into the correct Guest PGD or PTE type. */
 #define mkgpte(_val) ((gpte_t){.raw.val = _val})
 #define mkgpgd(_val) ((gpgd_t){.raw.val = _val})
+/*:*/
 
 struct pgdir
 {
@@ -130,6 +142,9 @@ struct lguest
        struct mm_struct *mm;   /* == tsk->mm, but that becomes NULL on exit */
        u16 guestid;
        u32 pfn_limit;
+       /* This provides the offset to the base of guest-physical
+        * memory in the Launcher. */
+       void __user *mem_base;
        u32 page_offset;
        u32 cr2;
        int halted;
@@ -243,6 +258,7 @@ unsigned long get_dma_buffer(struct lguest *lg, unsigned long key,
 
 /* hypercalls.c: */
 void do_hypercalls(struct lguest *lg);
+void write_timestamp(struct lguest *lg);
 
 /*L:035
  * Let's step aside for the moment, to study one important routine that's used