diff --git a/usr.sbin/bhyve/pci_ahci.c b/usr.sbin/bhyve/pci_ahci.c
--- a/usr.sbin/bhyve/pci_ahci.c
+++ b/usr.sbin/bhyve/pci_ahci.c
@@ -126,6 +126,7 @@
 	STAILQ_ENTRY(ahci_ioreq) io_flist;
 	TAILQ_ENTRY(ahci_ioreq) io_blist;
 	uint8_t *cfis;
+	uint8_t *dsm;
 	uint32_t len;
 	uint32_t done;
 	int slot;
@@ -213,6 +214,8 @@
 };
 #define	ahci_ctx(sc)	((sc)->asc_pi->pi_vmctx)
 
+static void ahci_handle_next_trim(struct ahci_port *p, int slot, uint8_t *cfis,
+    uint8_t *buf, uint32_t len, uint32_t done);
 static void ahci_handle_port(struct ahci_port *p);
 
 static inline void lba_to_msf(uint8_t *buf, int lba)
@@ -812,18 +815,14 @@
 }
 
 static void
-ahci_handle_dsm_trim(struct ahci_port *p, int slot, uint8_t *cfis, uint32_t done)
+ahci_handle_dsm_trim(struct ahci_port *p, int slot, uint8_t *cfis)
 {
-	struct ahci_ioreq *aior;
-	struct blockif_req *breq;
-	uint8_t *entry;
-	uint64_t elba;
-	uint32_t len, elen;
-	int err, first, ncq;
-	uint8_t buf[512];
-	unsigned int written;
+	uint32_t len;
+	int ncq;
+	uint8_t *buf;
+	unsigned int nread;
 
-	first = (done == 0);
+	buf = NULL;
 	if (cfis[2] == ATA_DATA_SET_MANAGEMENT) {
 		len = (uint16_t)cfis[13] << 8 | cfis[12];
 		len *= 512;
@@ -833,39 +832,84 @@
 		len *= 512;
 		ncq = 1;
 	}
-	written = read_prdt(p, slot, cfis, buf, sizeof(buf));
-	memset(buf + written, 0, sizeof(buf) - written);
 
-next:
-	if (done >= sizeof(buf) - 8)
-		return;
-	entry = &buf[done];
-	elba = ((uint64_t)entry[5] << 40) |
-		((uint64_t)entry[4] << 32) |
-		((uint64_t)entry[3] << 24) |
-		((uint64_t)entry[2] << 16) |
-		((uint64_t)entry[1] << 8) |
-		entry[0];
-	elen = (uint16_t)entry[7] << 8 | entry[6];
-	done += 8;
-	if (elen == 0) {
-		if (done >= len) {
-			if (ncq) {
-				if (first)
-					ahci_write_fis_d2h_ncq(p, slot);
-				ahci_write_fis_sdb(p, slot, cfis,
-				    ATA_S_READY | ATA_S_DSC);
-			} else {
-				ahci_write_fis_d2h(p, slot, cfis,
-				    ATA_S_READY | ATA_S_DSC);
-			}
+	/* Support for only a single block is advertised via IDENTIFY. */
+	if (len > 512) {
+		goto invalid_command;
+	}
+
+	buf = malloc(len);
+	nread = read_prdt(p, slot, cfis, buf, len);
+	if (nread != len) {
+		goto invalid_command;
+	}
+	ahci_handle_next_trim(p, slot, cfis, buf, len, 0);
+	return;
+
+invalid_command:
+	free(buf);
+	if (ncq) {
+		ahci_write_fis_d2h_ncq(p, slot);
+		ahci_write_fis_sdb(p, slot, cfis,
+		    (ATA_E_ABORT << 8) | ATA_S_READY | ATA_S_ERROR);
+	} else {
+		ahci_write_fis_d2h(p, slot, cfis,
+		    (ATA_E_ABORT << 8) | ATA_S_READY | ATA_S_ERROR);
+	}
+}
+
+static void
+ahci_handle_next_trim(struct ahci_port *p, int slot, uint8_t *cfis,
+    uint8_t *buf, uint32_t len, uint32_t done)
+{
+	struct ahci_ioreq *aior;
+	struct blockif_req *breq;
+	uint8_t *entry;
+	uint64_t elba;
+	uint32_t elen;
+	int err;
+	bool first, ncq;
+
+	first = (done == 0);
+	if (cfis[2] == ATA_DATA_SET_MANAGEMENT) {
+		ncq = false;
+	} else { /* ATA_SEND_FPDMA_QUEUED */
+		ncq = true;
+	}
+
+	/* Find the next range to TRIM. */
+	while (done < len) {
+		entry = &buf[done];
+		elba = ((uint64_t)entry[5] << 40) |
+		    ((uint64_t)entry[4] << 32) |
+		    ((uint64_t)entry[3] << 24) |
+		    ((uint64_t)entry[2] << 16) |
+		    ((uint64_t)entry[1] << 8) |
+		    entry[0];
+		elen = (uint16_t)entry[7] << 8 | entry[6];
+		done += 8;
+		if (elen != 0)
+			break;
+	}
+
+	/* All remaining ranges were empty. */
+	if (done == len) {
+		free(buf);
+		if (ncq) {
+			if (first)
+				ahci_write_fis_d2h_ncq(p, slot);
+			ahci_write_fis_sdb(p, slot, cfis,
+			    ATA_S_READY | ATA_S_DSC);
+		} else {
+			ahci_write_fis_d2h(p, slot, cfis,
+			    ATA_S_READY | ATA_S_DSC);
+		}
+		if (!first) {
 			p->pending &= ~(1 << slot);
 			ahci_check_stopped(p);
-			if (!first)
-				ahci_handle_port(p);
-			return;
+			ahci_handle_port(p);
 		}
-		goto next;
+		return;
 	}
 
 	/*
@@ -878,6 +922,7 @@
 	aior->slot = slot;
 	aior->len = len;
 	aior->done = done;
+	aior->dsm = buf;
 	aior->more = (len != done);
 
 	breq = &aior->io_req;
@@ -1755,7 +1800,7 @@
 	case ATA_DATA_SET_MANAGEMENT:
 		if (cfis[11] == 0 && cfis[3] == ATA_DSM_TRIM &&
 		    cfis[13] == 0 && cfis[12] == 1) {
-			ahci_handle_dsm_trim(p, slot, cfis, 0);
+			ahci_handle_dsm_trim(p, slot, cfis);
 			break;
 		}
 		ahci_write_fis_d2h(p, slot, cfis,
@@ -1765,7 +1810,7 @@
 		if ((cfis[13] & 0x1f) == ATA_SFPDMA_DSM &&
 		    cfis[17] == 0 && cfis[16] == ATA_DSM_TRIM &&
 		    cfis[11] == 0 && cfis[3] == 1) {
-			ahci_handle_dsm_trim(p, slot, cfis, 0);
+			ahci_handle_dsm_trim(p, slot, cfis);
 			break;
 		}
 		ahci_write_fis_d2h(p, slot, cfis,
@@ -1903,12 +1948,12 @@
 	struct ahci_port *p;
 	struct pci_ahci_softc *sc;
 	uint32_t tfd;
-	uint8_t *cfis;
-	int slot, ncq, dsm;
+	uint8_t *cfis, *dsm;
+	int slot, ncq;
 
 	DPRINTF("%s %d", __func__, err);
 
-	ncq = dsm = 0;
+	ncq = 0;
 	aior = br->br_param;
 	p = aior->io_pr;
 	cfis = aior->cfis;
@@ -1920,10 +1965,8 @@
 	    cfis[2] == ATA_READ_FPDMA_QUEUED ||
 	    cfis[2] == ATA_SEND_FPDMA_QUEUED)
 		ncq = 1;
-	if (cfis[2] == ATA_DATA_SET_MANAGEMENT ||
-	    (cfis[2] == ATA_SEND_FPDMA_QUEUED &&
-	     (cfis[13] & 0x1f) == ATA_SFPDMA_DSM))
-		dsm = 1;
+	dsm = aior->dsm;
+	aior->dsm = NULL;
 
 	pthread_mutex_lock(&sc->mtx);
 
@@ -1941,8 +1984,9 @@
 		hdr->prdbc = aior->done;
 
 	if (!err && aior->more) {
-		if (dsm)
-			ahci_handle_dsm_trim(p, slot, cfis, aior->done);
+		if (dsm != NULL)
+			ahci_handle_next_trim(p, slot, cfis, dsm,
+			    aior->len, aior->done);
 		else
 			ahci_handle_rw(p, slot, cfis, aior->done);
 		goto out;
@@ -1964,6 +2008,7 @@
 
 	ahci_check_stopped(p);
 	ahci_handle_port(p);
+	free(dsm);
 out:
 	pthread_mutex_unlock(&sc->mtx);
 	DPRINTF("%s exit", __func__);