It expresses the author’s strong feeling of missing his hometown.
Ask where the plum blossoms fall, and the wind blows all night long all over Guanshan Mountain. It comes from "Listening to the Flute on the Wall" written by the poet Gao Shi. It means asking where the "Plum Blossom Song" full of detachment floats to? It seems like plum blossoms falling all over Guanshan in the wind, euphemistically expressing the author's strong feeling of missing his hometown.
The original text of "Listening to the Flute Playing on the Fortress" is "The snow is clear and Hu Tian is returning her horses, and the moon is bright and the Qiang flute is guarding the tower." May I ask where the plum blossoms fell? The wind blew all over the mountain all night.