KVM: PPC: Teach MMIO Signedness

The guest I was trying to get to run uses the LHA and LHAU instructions.
Those instructions basically do a load, but also sign extend the result.

Since we need to fill our registers by hand when doing MMIO, we also need
to sign extend manually.

This patch implements sign extended MMIO and the LHA(U) instructions.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 14 insertions, 0 deletions

diff --git a/arch/powerpc/kvm/emulate.c b/arch/powerpc/kvm/emulate.c
index cb72a65f4ecc..11789dd33a13 100644
--- a/arch/powerpc/kvm/emulate.c
+++ b/arch/powerpc/kvm/emulate.c
@@ -62,6 +62,8 @@
 #define OP_STBU 39
 #define OP_LHZ  40
 #define OP_LHZU 41
+#define OP_LHA  42
+#define OP_LHAU 43
 #define OP_STH  44
 #define OP_STHU 45
 
@@ -450,6 +452,18 @@ int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu)
                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed);
                 break;
 
+        case OP_LHA:
+                rt = get_rt(inst);
+                emulated = kvmppc_handle_loads(run, vcpu, rt, 2, 1);
+                break;
+
+        case OP_LHAU:
+                ra = get_ra(inst);
+                rt = get_rt(inst);
+                emulated = kvmppc_handle_loads(run, vcpu, rt, 2, 1);
+                kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed);
+                break;
+
         case OP_STH:
                 rs = get_rs(inst);
                 emulated = kvmppc_handle_store(run, vcpu,