Boot with virtual == physical to get closer to native Linux.

1) This allows us to get alot closer to booting bzImages.

2) It means we don't have to know page_offset.

3) The Guest needs to modify the boot pagetables to create the
   PAGE_OFFSET mapping before jumping to C code.

4) guest_pa() walks the page tables rather than using page_offset.

5) We don't use page_offset to figure out whether to emulate: it was
   always kinda quesationable, and won't work for instructions done
   before remapping (bzImage unpacking in particular).

6) We still want the kernel address for tlb flushing: have the initial
   hypercall give us that, too.

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

1 files changed, 4 insertions, 4 deletions

diff --git a/drivers/lguest/hypercalls.c b/drivers/lguest/hypercalls.c
index 02d0ae2..13b5f2f 100644
--- a/drivers/lguest/hypercalls.c
+++ b/drivers/lguest/hypercalls.c
@@ -181,15 +181,15 @@ static void initialize(struct lguest *lg)
 	/* The Guest tells us where we're not to deliver interrupts by putting
 	 * the range of addresses into "struct lguest_data". */
 	if (get_user(lg->noirq_start, &lg->lguest_data->noirq_start)
-	    || get_user(lg->noirq_end, &lg->lguest_data->noirq_end)
-	    /* We tell the Guest that it can't use the top 4MB of virtual
-	     * addresses used by the Switcher. */
-	    || put_user(4U*1024*1024, &lg->lguest_data->reserve_mem))
+	    || get_user(lg->noirq_end, &lg->lguest_data->noirq_end))
 		kill_guest(lg, "bad guest page %p", lg->lguest_data);
 
 	/* We write the current time into the Guest's data page once now. */
 	write_timestamp(lg);
 
+	/* page_tables.c will also do some setup. */
+	page_table_guest_data_init(lg);
+
 	/* This is the one case where the above accesses might have been the
 	 * first write to a Guest page.  This may have caused a copy-on-write
 	 * fault, but the Guest might be referring to the old (read-only)