Index: sys/cam/ata/ata_da.c
===================================================================
--- sys/cam/ata/ata_da.c
+++ sys/cam/ata/ata_da.c
@@ -2414,6 +2414,8 @@
 					ata_ncq_cmd(ataio, ATA_WRITE_FPDMA_QUEUED,
 					    lba, count);
 				}
+				if (bp->bio_flags & BIO_HIPRIO)
+					ataio->cmd.sector_count_exp = 0x80;
 			} else if ((softc->flags & ADA_FLAG_CAN_48BIT) &&
 			    (lba + count >= ATA_MAX_28BIT_LBA ||
 			    count > 256)) {
Index: sys/cam/cam_ccb.h
===================================================================
--- sys/cam/cam_ccb.h
+++ sys/cam/cam_ccb.h
@@ -758,6 +758,7 @@
 	 * from scsi_message.h.
 	 */
 #define		CAM_TAG_ACTION_NONE	0x00
+	uint8_t	   priority;		/* Command priority for SIMPLE tag */
 	u_int	   tag_id;		/* tag id from initator (target mode) */
 	u_int	   init_id;		/* initiator id of who selected */
 #if defined(BUF_TRACKING) || defined(FULL_BUF_TRACKING)
@@ -805,6 +806,7 @@
 	u_int8_t   cdb_len;		/* Number of bytes for the CDB */
 	u_int8_t   tag_action;		/* What to do for tag queueing */
 	u_int8_t   sense_len;		/* Number of bytes of Sense Data */
+	uint8_t	   priority;		/* Command priority for SIMPLE tag */
 	u_int      tag_id;		/* tag id from initator (target mode) */
 	u_int      init_id;		/* initiator id of who selected */
 	struct     scsi_sense_data sense_data;
@@ -1392,6 +1394,7 @@
 	csio->sense_len = sense_len;
 	csio->cdb_len = cdb_len;
 	csio->tag_action = tag_action;
+	csio->priority = 0;
 #if defined(BUF_TRACKING) || defined(FULL_BUF_TRACKING)
 	csio->bio = NULL;
 #endif
@@ -1414,6 +1417,7 @@
 	csio->dxfer_len = dxfer_len;
 	csio->scsi_status = scsi_status;
 	csio->tag_action = tag_action;
+	csio->priority = 0;
 	csio->tag_id = tag_id;
 	csio->init_id = init_id;
 }
Index: sys/cam/scsi/scsi_cd.c
===================================================================
--- sys/cam/scsi/scsi_cd.c
+++ sys/cam/scsi/scsi_cd.c
@@ -961,6 +961,8 @@
 				start_ccb->csio.cdb_io.cdb_bytes[11] = 0;
 				start_ccb->csio.cdb_len = 12;
 			}
+			if (bp->bio_flags & BIO_HIPRIO)
+				start_ccb->csio.priority = 1;
 			start_ccb->ccb_h.ccb_state = CD_CCB_BUFFER_IO;
 
 			LIST_INSERT_HEAD(&softc->pending_ccbs,
Index: sys/cam/scsi/scsi_da.c
===================================================================
--- sys/cam/scsi/scsi_da.c
+++ sys/cam/scsi/scsi_da.c
@@ -3457,6 +3457,8 @@
 			xpt_release_ccb(start_ccb);
 			return;
 		}
+		if (bp->bio_flags & BIO_HIPRIO)
+			start_ccb->csio.priority = 1;
 		start_ccb->ccb_h.ccb_state = DA_CCB_BUFFER_IO;
 		start_ccb->ccb_h.flags |= CAM_UNLOCKED;
 		start_ccb->ccb_h.softtimeout = sbttotv(da_default_softtimeout);
Index: sys/contrib/openzfs/module/os/freebsd/zfs/vdev_geom.c
===================================================================
--- sys/contrib/openzfs/module/os/freebsd/zfs/vdev_geom.c
+++ sys/contrib/openzfs/module/os/freebsd/zfs/vdev_geom.c
@@ -1132,6 +1132,9 @@
 			bp->bio_data =
 			    abd_borrow_buf_copy(zio->io_abd, zio->io_size);
 		}
+		if (zio->io_priority == ZIO_PRIORITY_SYNC_READ ||
+		    zio->io_priority == ZIO_PRIORITY_SYNC_WRITE)
+			bp->bio_flags |= BIO_HIPRIO;
 		break;
 	case ZIO_TYPE_TRIM:
 		bp->bio_cmd = BIO_DELETE;
Index: sys/dev/iscsi/iscsi.c
===================================================================
--- sys/dev/iscsi/iscsi.c
+++ sys/dev/iscsi/iscsi.c
@@ -2299,6 +2299,11 @@
 	} else
 		bhssc->bhssc_flags |= BHSSC_FLAGS_ATTR_UNTAGGED;
 
+	if (is->is_protocol_level >= 2) {
+		bhssc->bhssc_pri = (csio->priority << BHSSC_PRI_SHIFT) &
+		    BHSSC_PRI_MASK;
+	}
+
 	bhssc->bhssc_lun = htobe64(CAM_EXTLUN_BYTE_SWIZZLE(ccb->ccb_h.target_lun));
 	bhssc->bhssc_initiator_task_tag = initiator_task_tag;
 	bhssc->bhssc_expected_data_transfer_length = htonl(csio->dxfer_len);
Index: sys/dev/isp/isp.c
===================================================================
--- sys/dev/isp/isp.c
+++ sys/dev/isp/isp.c
@@ -4554,7 +4554,9 @@
 		} else {
 			ttype = FCP_CMND_TASK_ATTR_SIMPLE;
 		}
-		((ispreqt7_t *)reqp)->req_task_attribute = ttype;
+		((ispreqt7_t *)reqp)->req_task_attribute = ttype |
+		    ((XS_PRIORITY(xs) << FCP_CMND_PRIO_SHIFT) &
+		     FCP_CMND_PRIO_MASK);
 	} else if (IS_FC(isp)) {
 		/*
 		 * See comment in isp_intr_respq
Index: sys/dev/isp/isp_freebsd.h
===================================================================
--- sys/dev/isp/isp_freebsd.h
+++ sys/dev/isp/isp_freebsd.h
@@ -546,7 +546,8 @@
 #define	XS_TAG_TYPE(ccb)	\
 	((ccb->tag_action == MSG_SIMPLE_Q_TAG)? REQFLAG_STAG : \
 	 ((ccb->tag_action == MSG_HEAD_OF_Q_TAG)? REQFLAG_HTAG : REQFLAG_OTAG))
-		
+
+#define	XS_PRIORITY(ccb)	(ccb)->priority
 
 #define	XS_SETERR(ccb, v)	(ccb)->ccb_h.status &= ~CAM_STATUS_MASK, \
 				(ccb)->ccb_h.status |= v
Index: sys/dev/isp/isp_freebsd.c
===================================================================
--- sys/dev/isp/isp_freebsd.c
+++ sys/dev/isp/isp_freebsd.c
@@ -1917,6 +1917,8 @@
 		atiop->tag_action = 0;
 		break;
 	}
+	atiop->priority = (aep->at_cmnd.fcp_cmnd_task_attribute &
+	    FCP_CMND_PRIO_MASK) >> FCP_CMND_PRIO_SHIFT;
 	atp->orig_datalen = aep->at_cmnd.cdb_dl.sf.fcp_cmnd_dl;
 	atp->bytes_xfered = 0;
 	atp->lun = lun;
Index: sys/dev/isp/isp_stds.h
===================================================================
--- sys/dev/isp/isp_stds.h
+++ sys/dev/isp/isp_stds.h
@@ -89,6 +89,9 @@
 #define	FCP_CMND_TASK_ATTR_UNTAGGED	0x05
 #define	FCP_CMND_TASK_ATTR_MASK		0x07
 
+#define	FCP_CMND_PRIO_MASK		0x78
+#define	FCP_CMND_PRIO_SHIFT		3
+
 #define	FCP_CMND_ADDTL_CDBLEN_SHIFT	2
 
 #define	FCP_CMND_DATA_WRITE		0x01
Index: sys/dev/isp/ispvar.h
===================================================================
--- sys/dev/isp/ispvar.h
+++ sys/dev/isp/ispvar.h
@@ -1036,6 +1036,7 @@
  *	XS_SNSASCQ(xs)		dereferences XS_SNSP to get the current stored Additional Sense Code Qualifier
  *	XS_TAG_P(xs)		predicate of whether this command should be tagged
  *	XS_TAG_TYPE(xs)		which type of tag to use
+ *	XS_PRIORITY(xs)		command priority for SIMPLE tag
  *	XS_SETERR(xs)		set error state
  *
  *		HBA_NOERROR	command has no erros
Index: sys/dev/mpr/mpr_sas.c
===================================================================
--- sys/dev/mpr/mpr_sas.c
+++ sys/dev/mpr/mpr_sas.c
@@ -1997,6 +1997,8 @@
 		mpi_control |= MPI2_SCSIIO_CONTROL_SIMPLEQ;
 		break;
 	}
+	mpi_control |= (csio->priority << MPI2_SCSIIO_CONTROL_CMDPRI_SHIFT) &
+	    MPI2_SCSIIO_CONTROL_CMDPRI_MASK;
 	mpi_control |= sc->mapping_table[csio->ccb_h.target_id].TLR_bits;
 	req->Control = htole32(mpi_control);
 
Index: sys/dev/mps/mps_sas.c
===================================================================
--- sys/dev/mps/mps_sas.c
+++ sys/dev/mps/mps_sas.c
@@ -1786,6 +1786,8 @@
 		mpi_control |= MPI2_SCSIIO_CONTROL_SIMPLEQ;
 		break;
 	}
+	mpi_control |= (csio->priority << MPI2_SCSIIO_CONTROL_TASKPRI_SHIFT) &
+	    MPI2_SCSIIO_CONTROL_TASKPRI_MASK;
 	mpi_control |= sc->mapping_table[csio->ccb_h.target_id].TLR_bits;
 	req->Control = htole32(mpi_control);
 	if (MPS_SET_LUN(req->LUN, csio->ccb_h.target_lun) != 0) {
Index: sys/geom/geom_io.c
===================================================================
--- sys/geom/geom_io.c
+++ sys/geom/geom_io.c
@@ -204,7 +204,7 @@
 		 *  Other bio flags are not suitable for cloning.
 		 */
 		bp2->bio_flags = bp->bio_flags &
-		    (BIO_ORDERED | BIO_UNMAPPED | BIO_VLIST);
+		    (BIO_ORDERED | BIO_UNMAPPED | BIO_VLIST | BIO_HIPRIO);
 		bp2->bio_length = bp->bio_length;
 		bp2->bio_offset = bp->bio_offset;
 		bp2->bio_data = bp->bio_data;
Index: sys/sys/bio.h
===================================================================
--- sys/sys/bio.h
+++ sys/sys/bio.h
@@ -67,8 +67,9 @@
 #define	BIO_UNMAPPED	0x10
 #define	BIO_TRANSIENT_MAPPING	0x20
 #define	BIO_VLIST	0x40
+#define	BIO_HIPRIO	0x80
 
-#define	PRINT_BIO_FLAGS "\20\7vlist\6transient_mapping\5unmapped" \
+#define	PRINT_BIO_FLAGS "\20\10hiprio\7vlist\6transient_mapping\5unmapped" \
 	"\4ordered\3onqueue\2done\1error"
 
 #define BIO_SPEEDUP_WRITE	0x4000	/* Resource shortage at upper layers */