[PATCH V6 1/2] KVM: PPC: BOOK3S: Always use the saved DAR value

[Aneesh Kumar K.V]

Although it's optional, IBM POWER cpus always had DAR value set on
alignment interrupt. So don't try to compute these values.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar at linux.vnet.ibm.com>
---
Changes from V5:
* Split the patch to two and also update commit message

 arch/powerpc/kvm/book3s_emulate.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/arch/powerpc/kvm/book3s_emulate.c b/arch/powerpc/kvm/book3s_emulate.c
index 99d40f8977e8..5d0f71663b99 100644
--- a/arch/powerpc/kvm/book3s_emulate.c
+++ b/arch/powerpc/kvm/book3s_emulate.c
@@ -611,6 +611,12 @@ u32 kvmppc_alignment_dsisr(struct kvm_vcpu *vcpu, unsigned int inst)
 
 ulong kvmppc_alignment_dar(struct kvm_vcpu *vcpu, unsigned int inst)
 {
+#ifdef CONFIG_PPC_BOOK3S_64
+	/*
+	 * Linux's fix_alignment() assumes that DAR is valid, so can we
+	 */
+	return vcpu->arch.fault_dar;
+#else
 	ulong dar = 0;
 	ulong ra = get_ra(inst);
 	ulong rb = get_rb(inst);
@@ -635,4 +641,5 @@ ulong kvmppc_alignment_dar(struct kvm_vcpu *vcpu, unsigned int inst)
 	}
 
 	return dar;
+#endif
 }
-- 
1.9.1