lguest: map_switcher_in_guest() per-vcpu

The switcher needs to be mapped per-vcpu, because different vcpus
will potentially have different page tables (they don't have to,
because threads will share the same).

So our first step is the make the function receive a vcpu struct

Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
diff --git a/drivers/lguest/page_tables.c b/drivers/lguest/page_tables.c
index fffabb3..17d3329 100644
--- a/drivers/lguest/page_tables.c
+++ b/drivers/lguest/page_tables.c
@@ -634,8 +634,9 @@
  * Guest (and not the pages for other CPUs).  We have the appropriate PTE pages
  * for each CPU already set up, we just need to hook them in now we know which
  * Guest is about to run on this CPU. */
-void map_switcher_in_guest(struct lguest *lg, struct lguest_pages *pages)
+void map_switcher_in_guest(struct lg_cpu *cpu, struct lguest_pages *pages)
 {
+	struct lguest *lg = cpu->lg;
 	pte_t *switcher_pte_page = __get_cpu_var(switcher_pte_pages);
 	pgd_t switcher_pgd;
 	pte_t regs_pte;