Spicy Grilled Corn Salad

Ingredients 1/2 cup fresh lime juice 1 teaspoon ground cumin 1 teaspoon chili powder 3/4 olive oil, plus more for brushing 8 ears of corn, husks and silks removed 1 1/2 cups grape tomatoes, sliced in half 1/2 cup diced onion 1 to 2 fresh jalapeno peppers, seeds removed and diced 1/4 cup chopped fresh cilantro (or parsley) 4 ounces feta cheese crumbles Salt and pepper.