SMP and timer interrupts

kernel/amd64/mm.c

@@ -24,6 +24,10 @@ static uintptr_t amd64_current_cr3 (void) {
   return cr3;
 }
 
+void amd64_load_kernel_cr3 (void) {
+  __asm__ volatile ("movq %0, %%cr3" ::"r"(kernel_pd.cr3_paddr) : "memory");
+}
+
 static struct pg_index amd64_mm_page_index (uint64_t vaddr) {
   struct pg_index ret;