From 47436aa4ad054c1c7c8231618e86ebd9305308dc Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Mon, 22 Oct 2007 11:03:36 +1000 Subject: 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 --- drivers/lguest/hypercalls.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'drivers/lguest/hypercalls.c') diff --git a/drivers/lguest/hypercalls.c b/drivers/lguest/hypercalls.c index 02d0ae268267..13b5f2f813de 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) -- cgit v1.2.2