hv: inject invalid opcode if decode instruction fails

We inject invalid opcode if instruction decode fails.

We don't support many instruction. If new type guest hit
the invalid opcode and it's necessary to emulate that
instruction, we could add new instruction then.

Signed-off-by: Yin Fengwei <fengwei.yin@intel.com>
Reviewed-by: Jason Chen CJ <jason.cj.chen@intel.com>
Acked-by: Anthony Xu <anthony.xu@intel.com>

hypervisor/arch/x86/guest/instr_emul.c

@@ -2287,7 +2287,8 @@ int decode_instruction(struct vcpu *vcpu)
 	if (retval != 0) {
 		pr_err("decode instruction failed @ 0x%016llx:",
 			vcpu_get_rip(vcpu));
-		return -EINVAL;
+		vcpu_inject_ud(vcpu);
+		return -EFAULT;
 	}
 
 	return  emul_ctxt->vie.opsize;