Index: sys/net/iflib.h
===================================================================
--- sys/net/iflib.h
+++ sys/net/iflib.h
@@ -246,7 +246,7 @@
 	/* fields necessary for probe */
 	pci_vendor_info_t *isc_vendor_info;
 	char *isc_driver_version;
-/* optional function to transform the read values to match the table*/
+	/* optional function to transform the read values to match the table*/
 	void (*isc_parse_devinfo) (uint16_t *device_id, uint16_t *subvendor_id,
 				   uint16_t *subdevice_id, uint16_t *rev_id);
 	int isc_nrxd_min[8];
@@ -375,6 +375,8 @@
 if_shared_ctx_t iflib_get_sctx(if_ctx_t ctx);
 
 void iflib_set_mac(if_ctx_t ctx, uint8_t mac[ETHER_ADDR_LEN]);
+void iflib_request_reset(if_ctx_t ctx);
+uint8_t iflib_in_detach(if_ctx_t ctx);
 
 /*
  * If the driver can plug cleanly in to newbus use these
Index: sys/net/iflib.c
===================================================================
--- sys/net/iflib.c
+++ sys/net/iflib.c
@@ -101,6 +101,10 @@
 #include <x86/iommu/busdma_dmar.h>
 #endif
 
+#ifdef PCI_IOV
+#include <dev/pci/pci_iov.h>
+#endif
+
 #include <sys/bitstring.h>
 /*
  * enable accounting of every mbuf as it comes in to and goes out of
@@ -157,9 +161,9 @@
 
 struct iflib_ctx {
 	KOBJ_FIELDS;
-   /*
-   * Pointer to hardware driver's softc
-   */
+	/*
+	 * Pointer to hardware driver's softc
+	 */
 	void *ifc_softc;
 	device_t ifc_dev;
 	if_t ifc_ifp;
@@ -178,7 +182,7 @@
 	uint32_t ifc_if_flags;
 	uint32_t ifc_flags;
 	uint32_t ifc_max_fl_buf_size;
-	int ifc_in_detach;
+	uint32_t ifc_in_detach;
 
 	int ifc_link_state;
 	int ifc_link_irq;
@@ -256,7 +260,13 @@
 void
 iflib_set_detach(if_ctx_t ctx)
 {
-	ctx->ifc_in_detach = 1;
+	atomic_store_rel_32(&ctx->ifc_in_detach, 1);
+}
+
+uint8_t
+iflib_in_detach(if_ctx_t ctx)
+{
+	return (atomic_load_acq_32(&ctx->ifc_in_detach) != 0);
 }
 
 void
@@ -3857,8 +3867,9 @@
 	ctx->ifc_flags &= ~(IFC_DO_RESET|IFC_DO_WATCHDOG);
 	STATE_UNLOCK(ctx);
 
-	if ((!running & !oactive) &&
-	    !(ctx->ifc_sctx->isc_flags & IFLIB_ADMIN_ALWAYS_RUN))
+	if ((!running & !oactive) && !(ctx->ifc_sctx->isc_flags & IFLIB_ADMIN_ALWAYS_RUN))
+		return;
+	if (iflib_in_detach(ctx))
 		return;
 
 	CTX_LOCK(ctx);
@@ -3897,7 +3908,8 @@
 {
 	if_ctx_t ctx = context;
 
-	if (!(if_getdrvflags(ctx->ifc_ifp) & IFF_DRV_RUNNING))
+	if (!(if_getdrvflags(ctx->ifc_ifp) & IFF_DRV_RUNNING) &&
+	    !(ctx->ifc_sctx->isc_flags & IFLIB_ADMIN_ALWAYS_RUN))
 		return;
 
 	CTX_LOCK(ctx);
@@ -4909,9 +4921,16 @@
 		device_printf(dev,"Vlan in use, detach first\n");
 		return (EBUSY);
 	}
+#ifdef PCI_IOV
+	if (pci_iov_detach(dev)) {
+		device_printf(dev, "SR-IOV in use; detach first.\n");
+		return (EBUSY);
+	}
+#endif
+
+	iflib_set_detach(ctx);
 
 	CTX_LOCK(ctx);
-	ctx->ifc_in_detach = 1;
 	iflib_stop(ctx);
 	CTX_UNLOCK(ctx);
 
@@ -5324,7 +5343,7 @@
 			fl[j].ifl_ifdi = &rxq->ifr_ifdi[j + rxq->ifr_fl_offset];
 			fl[j].ifl_rxd_size = scctx->isc_rxd_size[j];
 		}
-        /* Allocate receive buffers for the ring*/
+		/* Allocate receive buffers for the ring */
 		if (iflib_rxsd_alloc(rxq)) {
 			device_printf(dev,
 			    "Critical Failure setting up receive buffers\n");
@@ -6388,6 +6407,15 @@
 
 }
 
+void
+iflib_request_reset(if_ctx_t ctx)
+{
+
+	STATE_LOCK(ctx);
+	ctx->ifc_flags |= IFC_DO_RESET;
+	STATE_UNLOCK(ctx);
+}
+
 #ifndef __NO_STRICT_ALIGNMENT
 static struct mbuf *
 iflib_fixup_rx(struct mbuf *m)