KVM: PPC: Save/Restore CR over vcpu_run

On PPC, CR2-CR4 are nonvolatile, thus have to be saved across function calls.
We didn't respect that for any architecture until Paul spotted it in his
patch for Book3S-HV. This patch saves/restores CR for all KVM capable PPC hosts.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/kvm/book3s_interrupts.S b/arch/powerpc/kvm/book3s_interrupts.S
index 0a8515a..3e35383 100644
--- a/arch/powerpc/kvm/book3s_interrupts.S
+++ b/arch/powerpc/kvm/book3s_interrupts.S
@@ -84,6 +84,10 @@
 	/* Save non-volatile registers (r14 - r31) */
 	SAVE_NVGPRS(r1)
 
+	/* Save CR */
+	mfcr	r14
+	stw	r14, _CCR(r1)
+
 	/* Save LR */
 	PPC_STL	r0, _LINK(r1)
 
@@ -165,6 +169,9 @@
 	PPC_LL	r4, _LINK(r1)
 	mtlr	r4
 
+	lwz	r14, _CCR(r1)
+	mtcr	r14
+
 	/* Restore non-volatile host registers (r14 - r31) */
 	REST_NVGPRS(r1)