s390/nmi: s390: New low level handling for machine check happening in guest

Add the logic to check if the machine check happens when the guest is
running. If yes, set the exit reason -EINTR in the machine check's
interrupt handler. Refactor s390_do_machine_check to avoid panicing
the host for some kinds of machine checks which happen
when guest is running.
Reinject the instruction processing damage's machine checks including
Delayed Access Exception instead of damaging the host if it happens
in the guest because it could be caused by improper update on TLB entry
or other software case and impacts the guest only.

Signed-off-by: QingFeng Hao <haoqf@linux.vnet.ibm.com>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

arch/s390/kernel/entry.S

@@ -225,6 +225,7 @@ ENTRY(sie64a)
 	jnz	.Lsie_skip
 	TSTMSK	__LC_CPU_FLAGS,_CIF_FPU
 	jo	.Lsie_skip			# exit if fp/vx regs changed
+.Lsie_entry:
 	sie	0(%r14)
 .Lsie_skip:
 	ni	__SIE_PROG0C+3(%r14),0xfe	# no longer in SIE
@@ -1102,7 +1103,13 @@ cleanup_critical:
 	.quad	.Lsie_done
 
 .Lcleanup_sie:
-	lg	%r9,__SF_EMPTY(%r15)		# get control block pointer
+	cghi    %r11,__LC_SAVE_AREA_ASYNC 	#Is this in normal interrupt?
+	je      1f
+	slg     %r9,BASED(.Lsie_crit_mcck_start)
+	clg     %r9,BASED(.Lsie_crit_mcck_length)
+	jh      1f
+	oi      __LC_CPU_FLAGS+7, _CIF_MCCK_GUEST
+1:	lg	%r9,__SF_EMPTY(%r15)		# get control block pointer
 	ni	__SIE_PROG0C+3(%r9),0xfe	# no longer in SIE
 	lctlg	%c1,%c1,__LC_USER_ASCE		# load primary asce
 	larl	%r9,sie_exit			# skip forward to sie_exit
@@ -1274,6 +1281,10 @@ cleanup_critical:
 	.quad	.Lsie_gmap
 .Lsie_critical_length:
 	.quad	.Lsie_done - .Lsie_gmap
+.Lsie_crit_mcck_start:
+	.quad   .Lsie_entry
+.Lsie_crit_mcck_length:
+	.quad   .Lsie_skip - .Lsie_entry
 #endif
 
 	.section .rodata, "a"