If it hasn’t had a tune up lately then I’d suggest starting there, maybe the smoke os carbon built up on the spark plugs or in your intake/exhaust. I’d change the spark plugs and then drive it a bit, don’t be afraid to run it a little hard. There’s no issue with running the hell out of a vehicle from time to time, the dealership I worked at last made sure to suggest that to all customers, not that they’re any authority, but I know from personal experience it won’t hurt anything as long as your motor is mechanically sound.
Second option, if it has smoke when it starts up or when you get down on the accelerator a bit harder than normal then it may be the inevitable wear associated with high mileage from old valve seals or worn piston rings, etc. That’s nothing to worry about either, if it “burns” oil, meaning it must be added between changes then that may be the issue. If so, just keep it checked and full of oil and it’ll go on for many years, I’ve had vehicles that were so reliable and just ideal, but they needed a quart of oil on a regular basis, or maybe a half a quart, whatever the case may be it’s all good as long as you keep oil in it! See the message below please and best of luck friend!