diff --git a/sys/dev/pci/pci.c b/sys/dev/pci/pci.c
--- a/sys/dev/pci/pci.c
+++ b/sys/dev/pci/pci.c
@@ -164,10 +164,18 @@
 	DEVMETHOD(bus_get_resource,	bus_generic_rl_get_resource),
 	DEVMETHOD(bus_delete_resource,	pci_delete_resource),
 	DEVMETHOD(bus_alloc_resource,	pci_alloc_resource),
+#ifdef PCI_IOV
+	DEVMETHOD(bus_adjust_resource,	pci_adjust_resource),
+#else
 	DEVMETHOD(bus_adjust_resource,	bus_generic_adjust_resource),
+#endif
 	DEVMETHOD(bus_release_resource,	pci_release_resource),
 	DEVMETHOD(bus_activate_resource, pci_activate_resource),
 	DEVMETHOD(bus_deactivate_resource, pci_deactivate_resource),
+#ifdef PCI_IOV
+	DEVMETHOD(bus_map_resource,	pci_map_resource),
+	DEVMETHOD(bus_unmap_resource,	pci_unmap_resource),
+#endif
 	DEVMETHOD(bus_child_deleted,	pci_child_deleted),
 	DEVMETHOD(bus_child_detached,	pci_child_detached),
 	DEVMETHOD(bus_child_pnpinfo,	pci_child_pnpinfo_method),
@@ -5687,14 +5695,30 @@
 	struct pci_devinfo *dinfo;
 	int error, rid, type;
 
-	error = bus_generic_activate_resource(dev, child, r);
+	dinfo = device_get_ivars(child);
+#ifdef PCI_IOV
+	if (dinfo->cfg.flags & PCICFG_VF) {
+		switch (rman_get_type(r)) {
+		/* VFs can't have I/O BARs. */
+		case SYS_RES_IOPORT:
+			error = EINVAL;
+			break;
+		case SYS_RES_MEMORY:
+			error = pci_vf_activate_mem_resource(dev, child, r);
+			break;
+		default:
+			error = bus_generic_activate_resource(dev, child, r);
+			break;
+		}
+	} else
+#endif
+		error = bus_generic_activate_resource(dev, child, r);
 	if (error)
 		return (error);
 
 	/* Enable decoding in the command register when activating BARs. */
 	if (device_get_parent(child) == dev) {
 		/* Device ROMs need their decoding explicitly enabled. */
-		dinfo = device_get_ivars(child);
 		rid = rman_get_rid(r);
 		type = rman_get_type(r);
 		if (type == SYS_RES_MEMORY && PCIR_IS_BIOS(&dinfo->cfg, rid))
@@ -5716,13 +5740,29 @@
 	struct pci_devinfo *dinfo;
 	int error, rid, type;
 
-	error = bus_generic_deactivate_resource(dev, child, r);
+	dinfo = device_get_ivars(child);
+#ifdef PCI_IOV
+	if (dinfo->cfg.flags & PCICFG_VF) {
+		switch (rman_get_type(r)) {
+		/* VFs can't have I/O BARs. */
+		case SYS_RES_IOPORT:
+			error = EINVAL;
+			break;
+		case SYS_RES_MEMORY:
+			error = pci_vf_deactivate_mem_resource(dev, child, r);
+			break;
+		default:
+			error = bus_generic_deactivate_resource(dev, child, r);
+			break;
+		}
+	} else
+#endif
+		error = bus_generic_deactivate_resource(dev, child, r);
 	if (error)
 		return (error);
 
 	/* Disable decoding for device ROMs. */
 	if (device_get_parent(child) == dev) {
-		dinfo = device_get_ivars(child);
 		rid = rman_get_rid(r);
 		type = rman_get_type(r);
 		if (type == SYS_RES_MEMORY && PCIR_IS_BIOS(&dinfo->cfg, rid))
@@ -5732,6 +5772,76 @@
 	return (0);
 }
 
+#ifdef PCI_IOV
+int
+pci_adjust_resource(device_t dev, device_t child, struct resource *r,
+    rman_res_t start, rman_res_t end)
+{
+	struct pci_devinfo *dinfo;
+
+	dinfo = device_get_ivars(child);
+	if (dinfo->cfg.flags & PCICFG_VF) {
+		switch (rman_get_type(r)) {
+		/* VFs can't have I/O BARs. */
+		case SYS_RES_IOPORT:
+			return (EINVAL);
+		case SYS_RES_MEMORY:
+			return (pci_vf_adjust_mem_resource(dev, child, r,
+			    start, end));
+		}
+
+		/* Fall through for other types of resource allocations. */
+	}
+
+	return (bus_generic_adjust_resource(dev, child, r, start, end));
+}
+
+int
+pci_map_resource(device_t dev, device_t child, struct resource *r,
+    struct resource_map_request *argsp, struct resource_map *map)
+{
+	struct pci_devinfo *dinfo;
+
+	dinfo = device_get_ivars(child);
+	if (dinfo->cfg.flags & PCICFG_VF) {
+		switch (rman_get_type(r)) {
+		/* VFs can't have I/O BARs. */
+		case SYS_RES_IOPORT:
+			return (EINVAL);
+		case SYS_RES_MEMORY:
+			return (pci_vf_map_mem_resource(dev, child, r, argsp,
+			    map));
+		}
+
+		/* Fall through for other types of resource allocations. */
+	}
+
+	return (bus_generic_map_resource(dev, child, r, argsp, map));
+}
+
+int
+pci_unmap_resource(device_t dev, device_t child, struct resource *r,
+    struct resource_map *map)
+{
+	struct pci_devinfo *dinfo;
+
+	dinfo = device_get_ivars(child);
+	if (dinfo->cfg.flags & PCICFG_VF) {
+		switch (rman_get_type(r)) {
+		/* VFs can't have I/O BARs. */
+		case SYS_RES_IOPORT:
+			return (EINVAL);
+		case SYS_RES_MEMORY:
+			return (pci_vf_unmap_mem_resource(dev, child, r, map));
+		}
+
+		/* Fall through for other types of resource allocations. */
+	}
+
+	return (bus_generic_unmap_resource(dev, child, r, map));
+}
+#endif
+
 void
 pci_child_deleted(device_t dev, device_t child)
 {
diff --git a/sys/dev/pci/pci_iov.c b/sys/dev/pci/pci_iov.c
--- a/sys/dev/pci/pci_iov.c
+++ b/sys/dev/pci/pci_iov.c
@@ -1070,6 +1070,12 @@
 
 	dinfo = device_get_ivars(child);
 
+	KASSERT(rman_get_type(r) == SYS_RES_MEMORY,
+	    ("%s: invalid resource %p", __func__, r));
+	KASSERT(rman_is_region_manager(r, &dinfo->cfg.iov->rman),
+	    ("%s: rman %p doesn't match for resource %p", __func__,
+	    &dinfo->cfg.iov->rman, r));
+
 	if (rman_get_flags(r) & RF_ACTIVE) {
 		error = bus_deactivate_resource(child, r);
 		if (error != 0)
@@ -1086,3 +1092,147 @@
 
 	return (rman_release_resource(r));
 }
+
+int
+pci_vf_activate_mem_resource(device_t dev, device_t child, struct resource *r)
+{
+#ifdef INVARIANTS
+	struct pci_devinfo *dinfo = device_get_ivars(child);
+#endif
+	struct resource_map map;
+	int error;
+
+	KASSERT(rman_get_type(r) == SYS_RES_MEMORY,
+	    ("%s: invalid resource %p", __func__, r));
+	KASSERT(rman_is_region_manager(r, &dinfo->cfg.iov->rman),
+	    ("%s: rman %p doesn't match for resource %p", __func__,
+	    &dinfo->cfg.iov->rman, r));
+
+	error = rman_activate_resource(r);
+	if (error != 0)
+		return (error);
+
+	if ((rman_get_flags(r) & RF_UNMAPPED) == 0) {
+		error = BUS_MAP_RESOURCE(dev, child, r, NULL, &map);
+		if (error != 0) {
+			rman_deactivate_resource(r);
+			return (error);
+		}
+
+		rman_set_mapping(r, &map);
+	}
+	return (0);
+}
+
+int
+pci_vf_deactivate_mem_resource(device_t dev, device_t child, struct resource *r)
+{
+#ifdef INVARIANTS
+	struct pci_devinfo *dinfo = device_get_ivars(child);
+#endif
+	struct resource_map map;
+	int error;
+
+	KASSERT(rman_get_type(r) == SYS_RES_MEMORY,
+	    ("%s: invalid resource %p", __func__, r));
+	KASSERT(rman_is_region_manager(r, &dinfo->cfg.iov->rman),
+	    ("%s: rman %p doesn't match for resource %p", __func__,
+	    &dinfo->cfg.iov->rman, r));
+
+	error = rman_deactivate_resource(r);
+	if (error != 0)
+		return (error);
+
+	if ((rman_get_flags(r) & RF_UNMAPPED) == 0) {
+		rman_get_mapping(r, &map);
+		BUS_UNMAP_RESOURCE(dev, child, r, &map);
+	}
+	return (0);
+}
+
+int
+pci_vf_adjust_mem_resource(device_t dev, device_t child, struct resource *r,
+    rman_res_t start, rman_res_t end)
+{
+#ifdef INVARIANTS
+	struct pci_devinfo *dinfo = device_get_ivars(child);
+#endif
+
+	KASSERT(rman_get_type(r) == SYS_RES_MEMORY,
+	    ("%s: invalid resource %p", __func__, r));
+	KASSERT(rman_is_region_manager(r, &dinfo->cfg.iov->rman),
+	    ("%s: rman %p doesn't match for resource %p", __func__,
+	    &dinfo->cfg.iov->rman, r));
+
+	return (rman_adjust_resource(r, start, end));
+}
+
+static struct resource *
+pci_vf_find_parent_resource(struct pcicfg_iov *iov, struct resource *r)
+{
+	struct resource *pres;
+
+	for (u_int i = 0; i <= PCIR_MAX_BAR_0; i++) {
+		pres = iov->iov_bar[i].res;
+		if (pres != NULL) {
+			if (rman_get_start(pres) <= rman_get_start(r) &&
+			    rman_get_end(pres) >= rman_get_end(r))
+				return (pres);
+		}
+	}
+	return (NULL);
+}
+
+int
+pci_vf_map_mem_resource(device_t dev, device_t child, struct resource *r,
+    struct resource_map_request *argsp, struct resource_map *map)
+{
+	struct pci_devinfo *dinfo = device_get_ivars(child);
+	struct pcicfg_iov *iov = dinfo->cfg.iov;
+	struct resource_map_request args;
+	struct resource *pres;
+	rman_res_t length, start;
+	int error;
+
+	KASSERT(rman_get_type(r) == SYS_RES_MEMORY,
+	    ("%s: invalid resource %p", __func__, r));
+	KASSERT(rman_is_region_manager(r, &iov->rman),
+	    ("%s: rman %p doesn't match for resource %p", __func__,
+	    &dinfo->cfg.iov->rman, r));
+
+	/* Resources must be active to be mapped. */
+	if (!(rman_get_flags(r) & RF_ACTIVE))
+		return (ENXIO);
+
+	resource_init_map_request(&args);
+	error = resource_validate_map_request(r, argsp, &args, &start, &length);
+	if (error)
+		return (error);
+
+	pres = pci_vf_find_parent_resource(dinfo->cfg.iov, r);
+	if (pres == NULL)
+		return (ENOENT);
+
+	args.offset = start - rman_get_start(pres);
+	args.length = length;
+	return (bus_generic_map_resource(dev, iov->iov_pf, pres, &args, map));
+}
+
+int
+pci_vf_unmap_mem_resource(device_t dev, device_t child, struct resource *r,
+    struct resource_map *map)
+{
+	struct pci_devinfo *dinfo = device_get_ivars(child);
+	struct pcicfg_iov *iov = dinfo->cfg.iov;
+
+	KASSERT(rman_get_type(r) == SYS_RES_MEMORY,
+	    ("%s: invalid resource %p", __func__, r));
+	KASSERT(rman_is_region_manager(r, &iov->rman),
+	    ("%s: rman %p doesn't match for resource %p", __func__,
+	    &dinfo->cfg.iov->rman, r));
+
+	r = pci_vf_find_parent_resource(iov, r);
+	if (r == NULL)
+		return (ENOENT);
+	return (bus_generic_unmap_resource(dev, iov->iov_pf, r, map));
+}
diff --git a/sys/dev/pci/pci_private.h b/sys/dev/pci/pci_private.h
--- a/sys/dev/pci/pci_private.h
+++ b/sys/dev/pci/pci_private.h
@@ -65,9 +65,16 @@
 bus_get_resource_list_t	pci_get_resource_list;
 bus_delete_resource_t	pci_delete_resource;
 bus_alloc_resource_t	pci_alloc_resource;
+#ifdef PCI_IOV
+bus_adjust_resource_t	pci_adjust_resource;
+#endif
 bus_release_resource_t	pci_release_resource;
 bus_activate_resource_t	pci_activate_resource;
 bus_deactivate_resource_t pci_deactivate_resource;
+#ifdef PCI_IOV
+bus_map_resource_t	pci_map_resource;
+bus_unmap_resource_t	pci_unmap_resource;
+#endif
 bus_child_deleted_t	pci_child_deleted;
 bus_child_detached_t	pci_child_detached;
 bus_child_pnpinfo_t	pci_child_pnpinfo_method;
@@ -158,4 +165,16 @@
 		    rman_res_t count, u_int flags);
 int		pci_vf_release_mem_resource(device_t dev, device_t child,
 		    struct resource *r);
+int		pci_vf_activate_mem_resource(device_t dev, device_t child,
+		    struct resource *r);
+int		pci_vf_deactivate_mem_resource(device_t dev, device_t child,
+		    struct resource *r);
+int		pci_vf_adjust_mem_resource(device_t dev, device_t child,
+		    struct resource *r, rman_res_t start, rman_res_t end);
+int		pci_vf_map_mem_resource(device_t dev, device_t child,
+		    struct resource *r, struct resource_map_request *argsp,
+		    struct resource_map *map);
+int		pci_vf_unmap_mem_resource(device_t dev, device_t child,
+		    struct resource *r, struct resource_map *map);
+
 #endif /* _PCI_PRIVATE_H_ */