The Command Set Identifier has no "NVM" in its name.

+static inline bool nvmet_cc_css_check(u8 cc_css)
+{
+	switch (cc_css <<= NVME_CC_CSS_SHIFT) {
+	case NVME_CC_CSS_NVM:
+		return true;
+	default:
+		return false;
+	}
+}

This hunk looks misplaced, it isn't very useful on its own, but
should go together with the multiple command set support.