David sacrificed, wore a linen ephod and blessed the people. Was he doing a priest's work?

Here is what the chapter says. After six paces "he sacrificed an ox and a fattened calf" (6:13); "David was clothed in a linen ephod" (6:14); "David offered burnt offerings and peace offerings before the LORD" (6:17); and "he blessed the people in the name of the LORD of Armies" (6:18). The chapter names no priest or Levite, and it doesn't say whose hands made the offerings. The boy Samuel wore a linen ephod, "being a child, clothed with a linen ephod" (1 Samuel 2:18), and so did the priests of Nob, "eighty-five people who wore a linen ephod" (1 Samuel 22:18). Chronicles, telling this day, names the priests and Levites: "So the priests and the Levites sanctified themselves to bring up the ark of the LORD, the God of Israel" (1 Chronicles 15:14). It says "David had an ephod of linen on him" (1 Chronicles 15:27), and when the ark was in the tent, "they offered burnt offerings and peace offerings before God" (1 Chronicles 16:1). Kings speaks of Solomon in the same way: "The king, and all Israel with him, offered sacrifice before the LORD" (1 Kings 8:62). This chapter doesn't say whether David did any of this in a priest's place, and this answer doesn't go past these verses.