Index: sys/dev/nvme/nvme_ahci.c
===================================================================
--- sys/dev/nvme/nvme_ahci.c
+++ sys/dev/nvme/nvme_ahci.c
@@ -104,7 +104,15 @@
 	}
 	ctrlr->tag = (void *)0x1;
 
-	return nvme_attach(dev);
+	/*
+	 * We're attached via this funky mechanism. Flag the controller so that
+	 * it avoids things that can't work when we do that.
+	 */
+	ctrlr->quirks |= QUIRK_AHCI;
+
+	ret = nvme_attach(dev);
+	if (ret != 0)
+		goto bad;
 bad:
 	if (ctrlr->resource != NULL) {
 		bus_release_resource(dev, SYS_RES_MEMORY,
Index: sys/dev/nvme/nvme_private.h
===================================================================
--- sys/dev/nvme/nvme_private.h
+++ sys/dev/nvme/nvme_private.h
@@ -241,6 +241,7 @@
 #define	QUIRK_DELAY_B4_CHK_RDY	1		/* Can't touch MMIO on disable */
 #define	QUIRK_DISABLE_TIMEOUT	2		/* Disable broken completion timeout feature */
 #define	QUIRK_INTEL_ALIGNMENT	4		/* Pre NVMe 1.3 performance alignment */
+#define QUIRK_AHCI		8		/* Attached via AHCI redirect */
 
 	bus_space_tag_t		bus_tag;
 	bus_space_handle_t	bus_handle;