In a saucepan over medium-high heat, combine sugar and water; stir until sugar has dissolved. Bring to a simmer; cook for 2 minutes. Remove from heat, add vodka, lime juice and salt; let it cool completely.
Place kiwi fruits in a jar of a blender and process until fairly liquefy. Pour in the simple syrup mixture and process for 30 seconds. Pour mixture in a large measuring cup, cover with cling film and transfer to the refrigerator to chill, about 3 hours.
Churn kiwi mixture in ice cream maker according to manufacturer’s instructions (about 12 minutes). Scoop sorbet into an ice cream container and transfer to the freezer for 4 hours to firm up. When serving, serve sorbet in bowl and place a slice of kiwi. Makes 4 cups.