KVM: PPC: Override host vmx/vsx/dfp only when information known

[qemu.git] / target-ppc / kvm.c

diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c
index a090d79ad4eb2e4e7707e02a4e2ebf6e7e77c080..f3d0861a111e3fefd0f2d51b1161c263432b6309 100644 (file)
--- a/target-ppc/kvm.c
+++ b/target-ppc/kvm.c
@@ -912,9 +912,15 @@ const ppc_def_t *kvmppc_host_cpu_def(void)
 
     /* Now fix up the spec with information we can query from the host */
 
-    alter_insns(&spec->insns_flags, PPC_ALTIVEC, vmx > 0);
-    alter_insns(&spec->insns_flags2, PPC2_VSX, vmx > 1);
-    alter_insns(&spec->insns_flags2, PPC2_DFP, dfp);
+    if (vmx != -1) {
+        /* Only override when we know what the host supports */
+        alter_insns(&spec->insns_flags, PPC_ALTIVEC, vmx > 0);
+        alter_insns(&spec->insns_flags2, PPC2_VSX, vmx > 1);
+    }
+    if (dfp != -1) {
+        /* Only override when we know what the host supports */
+        alter_insns(&spec->insns_flags2, PPC2_DFP, dfp);
+    }
 
     return spec;
 }