Restore guest CR after exit timing calculation

No instruction which can change Condition Register (CR) should be executed after
Guest CR is loaded. So the guest CR is restored after the Exit Timing in
lightweight_exit executes cmpw, which can clobber CR.
Signed-off-by: NBharat Bhushan <bharat.bhushan@freescale.com>
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

arch/powerpc/kvm/bookehv_interrupts.S

@@ -580,7 +580,6 @@ lightweight_exit:
 	mtlr	r3
 	mtxer	r5
 	mtctr	r6
-	mtcr	r7
 	mtsrr0	r8
 	mtsrr1	r9
 
@@ -588,14 +587,20 @@ lightweight_exit:
 	/* save enter time */
 1:
 	mfspr	r6, SPRN_TBRU
-	mfspr	r7, SPRN_TBRL
+	mfspr	r9, SPRN_TBRL
 	mfspr	r8, SPRN_TBRU
 	cmpw	r8, r6
-	PPC_STL	r7, VCPU_TIMING_LAST_ENTER_TBL(r4)
+	PPC_STL	r9, VCPU_TIMING_LAST_ENTER_TBL(r4)
 	bne	1b
 	PPC_STL	r8, VCPU_TIMING_LAST_ENTER_TBU(r4)
 #endif
 
+	/*
+	 * Don't execute any instruction which can change CR after
+	 * below instruction.
+	 */
+	mtcr	r7
+
 	/* Finish loading guest volatiles and jump to guest. */
 	PPC_LL	r5, VCPU_GPR(r5)(r4)
 	PPC_LL	r6, VCPU_GPR(r6)(r4)