[PATCH -V2] POWERPC: BOOK3S: KVM: Use the saved dsisr and dar values on book3s 64

[Aneesh Kumar K.V]

From: "Aneesh Kumar K.V" <aneesh.kumar at linux.vnet.ibm.com>

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>
---
 arch/powerpc/kvm/book3s_emulate.c | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/arch/powerpc/kvm/book3s_emulate.c b/arch/powerpc/kvm/book3s_emulate.c
index 502a47ac4453..d8e2d079483d 100644
--- a/arch/powerpc/kvm/book3s_emulate.c
+++ b/arch/powerpc/kvm/book3s_emulate.c
@@ -599,6 +599,19 @@ unprivileged:
 
 u32 kvmppc_alignment_dsisr(struct kvm_vcpu *vcpu, unsigned int inst)
 {
+#ifdef CONFIG_PPC_BOOK3S_64
+	return vcpu->arch.fault_dsisr;
+#else
+	/*
+	 * Mac OS X has some applications - namely the Finder - that require
+	 * alignment interrupts to work properly. So we need to implement them.
+
+	 * But the spec for 970 and 750 also looks different. While 750 requires
+	 * the DSISR and DAR fields to reflect some instruction bits (DSISR) and
+	 * the fault address (DAR), the 970 declares this as an optional feature.
+	 * So we need to reconstruct DSISR and DAR manually.
+	 */
+
 	u32 dsisr = 0;
 
 	/*
@@ -637,10 +650,24 @@ u32 kvmppc_alignment_dsisr(struct kvm_vcpu *vcpu, unsigned int inst)
 	dsisr |= (inst >> 16) & 0x03ff; /* bits 22:31 */
 
 	return dsisr;
+#endif
 }
 
 ulong kvmppc_alignment_dar(struct kvm_vcpu *vcpu, unsigned int inst)
 {
+#ifdef CONFIG_PPC_BOOK3S_64
+	return vcpu->arch.fault_dar;
+#else
+	/*
+	 * Mac OS X has some applications - namely the Finder - that require
+	 * alignment interrupts to work properly. So we need to implement them.
+
+	 * But the spec for 970 and 750 also looks different. While 750 requires
+	 * the DSISR and DAR fields to reflect some instruction bits (DSISR) and
+	 * the fault address (DAR), the 970 declares this as an optional feature.
+	 * So we need to reconstruct DSISR and DAR manually.
+	 */
+
 	ulong dar = 0;
 	ulong ra = get_ra(inst);
 	ulong rb = get_rb(inst);
@@ -665,4 +692,5 @@ ulong kvmppc_alignment_dar(struct kvm_vcpu *vcpu, unsigned int inst)
 	}
 
 	return dar;
+#endif
 }
-- 
1.8.3.2