s390/mm: remember the int code for the last gmap fault

For nested virtualization, we want to know if we are handling a protection
exception, because these can directly be forwarded to the guest without
additional checks.
Acked-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

arch/s390/include/asm/processor.h

@@ -110,6 +110,7 @@ struct thread_struct {
 	mm_segment_t mm_segment;
 	unsigned long gmap_addr;	/* address of last gmap fault. */
 	unsigned int gmap_write_flag;	/* gmap fault write indication */
+	unsigned int gmap_int_code;	/* int code of last gmap fault */
 	unsigned int gmap_pfault;	/* signal of a pending guest pfault */
 	struct per_regs per_user;	/* User specified PER registers */
 	struct per_event per_event;	/* Cause of the last PER trap */

arch/s390/mm/fault.c

@@ -419,6 +419,7 @@ static inline int do_exception(struct pt_regs *regs, int access)
 	if (gmap) {
 		current->thread.gmap_addr = address;
 		current->thread.gmap_write_flag = !!(flags & FAULT_FLAG_WRITE);
+		current->thread.gmap_int_code = regs->int_code & 0xffff;
 		address = __gmap_translate(gmap, address);
 		if (address == -EFAULT) {
 			fault = VM_FAULT_BADMAP;