Merge branch 'netvsc-minor-fixes-and-improvements'

Stephen Hemminger says:

====================
netvsc: minor fixes and improvements

These are non-critical bug fixes, related to functionality now in net-next.
 1. delaying the automatic bring up of VF device to allow udev to change name.
 2. performance improvement
 3. handle MAC address change with VF; mostly propogate the error that VF gives.
 4. minor cleanups
 5. allow setting send/receive buffer size with ethtool.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/hyperv/hyperv_net.h

@@ -148,6 +148,8 @@ struct netvsc_device_info {
 	unsigned char mac_adr[ETH_ALEN];
 	int  ring_size;
 	u32  num_chn;
+	u32  send_sections;
+	u32  recv_sections;
 };
 
 enum rndis_device_state {
@@ -634,12 +636,12 @@ struct nvsp_message {
 #define NETVSC_SEND_BUFFER_SIZE			(1024 * 1024 * 15)   /* 15MB */
 #define NETVSC_INVALID_INDEX			-1
 
+#define NETVSC_SEND_SECTION_SIZE		6144
+#define NETVSC_RECV_SECTION_SIZE		1728
 
 #define NETVSC_RECEIVE_BUFFER_ID		0xcafe
 #define NETVSC_SEND_BUFFER_ID			0
 
-#define NETVSC_PACKET_SIZE                      4096
-
 #define VRSS_SEND_TAB_SIZE 16  /* must be power of 2 */
 #define VRSS_CHANNEL_MAX 64
 #define VRSS_CHANNEL_DEFAULT 8
@@ -678,6 +680,8 @@ struct netvsc_ethtool_stats {
 	unsigned long tx_no_space;
 	unsigned long tx_too_big;
 	unsigned long tx_busy;
+	unsigned long tx_send_full;
+	unsigned long rx_comp_busy;
 };
 
 struct netvsc_vf_pcpu_stats {
@@ -723,7 +727,7 @@ struct net_device_context {
 	/* State to manage the associated VF interface. */
 	struct net_device __rcu *vf_netdev;
 	struct netvsc_vf_pcpu_stats __percpu *vf_stats;
-	struct work_struct vf_takeover;
+	struct delayed_work vf_takeover;
 
 	/* 1: allocated, serial number is valid. 0: not allocated */
 	u32 vf_alloc;
@@ -754,14 +758,13 @@ struct netvsc_device {
 
 	/* Receive buffer allocated by us but manages by NetVSP */
 	void *recv_buf;
-	u32 recv_buf_size;
 	u32 recv_buf_gpadl_handle;
 	u32 recv_section_cnt;
+	u32 recv_section_size;
 	u32 recv_completion_cnt;
 
 	/* Send buffer allocated by us */
 	void *send_buf;
-	u32 send_buf_size;
 	u32 send_buf_gpadl_handle;
 	u32 send_section_cnt;
 	u32 send_section_size;

drivers/net/hyperv/netvsc.c

@@ -75,6 +75,10 @@ static struct netvsc_device *alloc_net_device(void)
 	atomic_set(&net_device->open_cnt, 0);
 	net_device->max_pkt = RNDIS_MAX_PKT_DEFAULT;
 	net_device->pkt_align = RNDIS_PKT_ALIGN_DEFAULT;
+
+	net_device->recv_section_size = NETVSC_RECV_SECTION_SIZE;
+	net_device->send_section_size = NETVSC_SEND_SECTION_SIZE;
+
 	init_completion(&net_device->channel_init_wait);
 	init_waitqueue_head(&net_device->subchan_open);
 
@@ -143,6 +147,7 @@ static void netvsc_destroy_buf(struct hv_device *device)
 				"revoke receive buffer to netvsp\n");
 			return;
 		}
+		net_device->recv_section_cnt = 0;
 	}
 
 	/* Teardown the gpadl on the vsp end */
@@ -173,7 +178,7 @@ static void netvsc_destroy_buf(struct hv_device *device)
 	 * NVSP_MSG1_TYPE_SEND_SEND_BUF msg) therefore, we need
 	 * to send a revoke msg here
 	 */
-	if (net_device->send_section_size) {
+	if (net_device->send_section_cnt) {
 		/* Send the revoke receive buffer */
 		revoke_packet = &net_device->revoke_packet;
 		memset(revoke_packet, 0, sizeof(struct nvsp_message));
@@ -205,6 +210,7 @@ static void netvsc_destroy_buf(struct hv_device *device)
 				   "revoke send buffer to netvsp\n");
 			return;
 		}
+		net_device->send_section_cnt = 0;
 	}
 	/* Teardown the gpadl on the vsp end */
 	if (net_device->send_buf_gpadl_handle) {
@@ -244,25 +250,25 @@ int netvsc_alloc_recv_comp_ring(struct netvsc_device *net_device, u32 q_idx)
 }
 
 static int netvsc_init_buf(struct hv_device *device,
-			   struct netvsc_device *net_device)
+			   struct netvsc_device *net_device,
+			   const struct netvsc_device_info *device_info)
 {
-	int ret = 0;
-	struct nvsp_message *init_packet;
 	struct nvsp_1_message_send_receive_buffer_complete *resp;
-	struct net_device *ndev;
+	struct net_device *ndev = hv_get_drvdata(device);
+	struct nvsp_message *init_packet;
+	unsigned int buf_size;
 	size_t map_words;
-	int node;
-
-	ndev = hv_get_drvdata(device);
+	int ret = 0;
 
-	node = cpu_to_node(device->channel->target_cpu);
-	net_device->recv_buf = vzalloc_node(net_device->recv_buf_size, node);
-	if (!net_device->recv_buf)
-		net_device->recv_buf = vzalloc(net_device->recv_buf_size);
+	/* Get receive buffer area. */
+	buf_size = device_info->recv_sections * net_device->recv_section_size;
+	buf_size = roundup(buf_size, PAGE_SIZE);
 
+	net_device->recv_buf = vzalloc(buf_size);
 	if (!net_device->recv_buf) {
-		netdev_err(ndev, "unable to allocate receive "
-			"buffer of size %d\n", net_device->recv_buf_size);
+		netdev_err(ndev,
+			   "unable to allocate receive buffer of size %u\n",
+			   buf_size);
 		ret = -ENOMEM;
 		goto cleanup;
 	}
@@ -273,7 +279,7 @@ static int netvsc_init_buf(struct hv_device *device,
 	 * than the channel to establish the gpadl handle.
 	 */
 	ret = vmbus_establish_gpadl(device->channel, net_device->recv_buf,
-				    net_device->recv_buf_size,
+				    buf_size,
 				    &net_device->recv_buf_gpadl_handle);
 	if (ret != 0) {
 		netdev_err(ndev,
@@ -319,33 +325,31 @@ static int netvsc_init_buf(struct hv_device *device,
 		   resp->num_sections, resp->sections[0].sub_alloc_size,
 		   resp->sections[0].num_sub_allocs);
 
-	net_device->recv_section_cnt = resp->num_sections;
-
-	/*
-	 * For 1st release, there should only be 1 section that represents the
-	 * entire receive buffer
-	 */
-	if (net_device->recv_section_cnt != 1 ||
-	    resp->sections[0].offset != 0) {
+	/* There should only be one section for the entire receive buffer */
+	if (resp->num_sections != 1 || resp->sections[0].offset != 0) {
 		ret = -EINVAL;
 		goto cleanup;
 	}
 
+	net_device->recv_section_size = resp->sections[0].sub_alloc_size;
+	net_device->recv_section_cnt = resp->sections[0].num_sub_allocs;
+
 	/* Setup receive completion ring */
 	net_device->recv_completion_cnt
-		= round_up(resp->sections[0].num_sub_allocs + 1,
+		= round_up(net_device->recv_section_cnt + 1,
 			   PAGE_SIZE / sizeof(u64));
 	ret = netvsc_alloc_recv_comp_ring(net_device, 0);
 	if (ret)
 		goto cleanup;
 
 	/* Now setup the send buffer. */
-	net_device->send_buf = vzalloc_node(net_device->send_buf_size, node);
-	if (!net_device->send_buf)
-		net_device->send_buf = vzalloc(net_device->send_buf_size);
+	buf_size = device_info->send_sections * net_device->send_section_size;
+	buf_size = round_up(buf_size, PAGE_SIZE);
+
+	net_device->send_buf = vzalloc(buf_size);
 	if (!net_device->send_buf) {
-		netdev_err(ndev, "unable to allocate send "
-			   "buffer of size %d\n", net_device->send_buf_size);
+		netdev_err(ndev, "unable to allocate send buffer of size %u\n",
+			   buf_size);
 		ret = -ENOMEM;
 		goto cleanup;
 	}
@@ -355,7 +359,7 @@ static int netvsc_init_buf(struct hv_device *device,
 	 * than the channel to establish the gpadl handle.
 	 */
 	ret = vmbus_establish_gpadl(device->channel, net_device->send_buf,
-				    net_device->send_buf_size,
+				    buf_size,
 				    &net_device->send_buf_gpadl_handle);
 	if (ret != 0) {
 		netdev_err(ndev,
@@ -400,10 +404,8 @@ static int netvsc_init_buf(struct hv_device *device,
 	net_device->send_section_size = init_packet->msg.
 				v1_msg.send_send_buf_complete.section_size;
 
-	/* Section count is simply the size divided by the section size.
-	 */
-	net_device->send_section_cnt =
-		net_device->send_buf_size / net_device->send_section_size;
+	/* Section count is simply the size divided by the section size. */
+	net_device->send_section_cnt = buf_size / net_device->send_section_size;
 
 	netdev_dbg(ndev, "Send section size: %d, Section count:%d\n",
 		   net_device->send_section_size, net_device->send_section_cnt);
@@ -481,7 +483,8 @@ static int negotiate_nvsp_ver(struct hv_device *device,
 }
 
 static int netvsc_connect_vsp(struct hv_device *device,
-			      struct netvsc_device *net_device)
+			      struct netvsc_device *net_device,
+			      const struct netvsc_device_info *device_info)
 {
 	const u32 ver_list[] = {
 		NVSP_PROTOCOL_VERSION_1, NVSP_PROTOCOL_VERSION_2,
@@ -531,14 +534,8 @@ static int netvsc_connect_vsp(struct hv_device *device,
 	if (ret != 0)
 		goto cleanup;
 
-	/* Post the big receive buffer to NetVSP */
-	if (net_device->nvsp_version <= NVSP_PROTOCOL_VERSION_2)
-		net_device->recv_buf_size = NETVSC_RECEIVE_BUFFER_SIZE_LEGACY;
-	else
-		net_device->recv_buf_size = NETVSC_RECEIVE_BUFFER_SIZE;
-	net_device->send_buf_size = NETVSC_SEND_BUFFER_SIZE;
 
-	ret = netvsc_init_buf(device, net_device);
+	ret = netvsc_init_buf(device, net_device, device_info);
 
 cleanup:
 	return ret;
@@ -886,7 +883,9 @@ int netvsc_send(struct net_device_context *ndev_ctx,
 	} else if (pktlen + net_device->pkt_align <
 		   net_device->send_section_size) {
 		section_index = netvsc_get_next_send_section(net_device);
-		if (section_index != NETVSC_INVALID_INDEX) {
+		if (unlikely(section_index == NETVSC_INVALID_INDEX)) {
+			++ndev_ctx->eth_stats.tx_send_full;
+		} else {
 			move_pkt_msd(&msd_send, &msd_skb, msdp);
 			msd_len = 0;
 		}
@@ -952,9 +951,10 @@ int netvsc_send(struct net_device_context *ndev_ctx,
 }
 
 /* Send pending recv completions */
-static int send_recv_completions(struct netvsc_channel *nvchan)
+static int send_recv_completions(struct net_device *ndev,
+				 struct netvsc_device *nvdev,
+				 struct netvsc_channel *nvchan)
 {
-	struct netvsc_device *nvdev = nvchan->net_device;
 	struct multi_recv_comp *mrc = &nvchan->mrc;
 	struct recv_comp_msg {
 		struct nvsp_message_header hdr;
@@ -972,8 +972,12 @@ static int send_recv_completions(struct netvsc_channel *nvchan)
 		msg.status = rcd->status;
 		ret = vmbus_sendpacket(nvchan->channel, &msg, sizeof(msg),
 				       rcd->tid, VM_PKT_COMP, 0);
-		if (unlikely(ret))
+		if (unlikely(ret)) {
+			struct net_device_context *ndev_ctx = netdev_priv(ndev);
+
+			++ndev_ctx->eth_stats.rx_comp_busy;
 			return ret;
+		}
 
 		if (++mrc->first == nvdev->recv_completion_cnt)
 			mrc->first = 0;
@@ -1014,7 +1018,7 @@ static void enq_receive_complete(struct net_device *ndev,
 	recv_comp_slot_avail(nvdev, mrc, &filled, &avail);
 
 	if (unlikely(filled > NAPI_POLL_WEIGHT)) {
-		send_recv_completions(nvchan);
+		send_recv_completions(ndev, nvdev, nvchan);
 		recv_comp_slot_avail(nvdev, mrc, &filled, &avail);
 	}
 
@@ -1191,17 +1195,13 @@ int netvsc_poll(struct napi_struct *napi, int budget)
 		nvchan->desc = hv_pkt_iter_next(channel, nvchan->desc);
 	}
 
-	/* if ring is empty, signal host */
-	if (!nvchan->desc)
-		hv_pkt_iter_close(channel);
-
 	/* If send of pending receive completions suceeded
 	 *   and did not exhaust NAPI budget this time
 	 *   and not doing busy poll
 	 * then re-enable host interrupts
 	 *     and reschedule if ring is not empty.
 	 */
-	if (send_recv_completions(nvchan) == 0 &&
+	if (send_recv_completions(ndev, net_device, nvchan) == 0 &&
 	    work_done < budget &&
 	    napi_complete_done(napi, work_done) &&
 	    hv_end_read(&channel->inbound)) {
@@ -1300,7 +1300,7 @@ struct netvsc_device *netvsc_device_add(struct hv_device *device,
 	rcu_assign_pointer(net_device_ctx->nvdev, net_device);
 
 	/* Connect with the NetVsp */
-	ret = netvsc_connect_vsp(device, net_device);
+	ret = netvsc_connect_vsp(device, net_device, device_info);
 	if (ret != 0) {
 		netdev_err(ndev,
 			"unable to connect to NetVSP - %d\n", ret);

drivers/net/hyperv/netvsc_drv.c

@@ -46,7 +46,13 @@
 #include "hyperv_net.h"
 
 #define RING_SIZE_MIN		64
+#define NETVSC_MIN_TX_SECTIONS	10
+#define NETVSC_DEFAULT_TX	192	/* ~1M */
+#define NETVSC_MIN_RX_SECTIONS	10	/* ~64K */
+#define NETVSC_DEFAULT_RX	2048	/* ~4M */
+
 #define LINKCHANGE_INT (2 * HZ)
+#define VF_TAKEOVER_INT (HZ / 10)
 
 static int ring_size = 128;
 module_param(ring_size, int, S_IRUGO);
@@ -332,7 +338,6 @@ static u32 init_page_array(void *hdr, u32 len, struct sk_buff *skb,
 	 * 2. skb linear data
 	 * 3. skb fragment data
 	 */
-	if (hdr != NULL)
 	slots_used += fill_pg_buf(virt_to_page(hdr),
 				  offset_in_page(hdr),
 				  len, &pb[slots_used]);
@@ -523,8 +528,8 @@ static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net)
 		rndis_msg_size += NDIS_VLAN_PPI_SIZE;
 		ppi = init_ppi_data(rndis_msg, NDIS_VLAN_PPI_SIZE,
 				    IEEE_8021Q_INFO);
-		vlan = (struct ndis_pkt_8021q_info *)((void *)ppi +
-						ppi->ppi_offset);
+
+		vlan = (void *)ppi + ppi->ppi_offset;
 		vlan->vlanid = skb->vlan_tci & VLAN_VID_MASK;
 		vlan->pri = (skb->vlan_tci & VLAN_PRIO_MASK) >>
 				VLAN_PRIO_SHIFT;
@@ -537,8 +542,7 @@ static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net)
 		ppi = init_ppi_data(rndis_msg, NDIS_LSO_PPI_SIZE,
 				    TCP_LARGESEND_PKTINFO);
 
-		lso_info = (struct ndis_tcp_lso_info *)((void *)ppi +
-							ppi->ppi_offset);
+		lso_info = (void *)ppi + ppi->ppi_offset;
 
 		lso_info->lso_v2_transmit.type = NDIS_TCP_LARGE_SEND_OFFLOAD_V2_TYPE;
 		if (skb->protocol == htons(ETH_P_IP)) {
@@ -625,6 +629,7 @@ static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net)
 	++net_device_ctx->eth_stats.tx_no_memory;
 	goto drop;
 }
+
 /*
  * netvsc_linkstatus_callback - Link up/down notification
  */
@@ -648,8 +653,8 @@ void netvsc_linkstatus_callback(struct hv_device *device_obj,
 	if (indicate->status == RNDIS_STATUS_LINK_SPEED_CHANGE) {
 		u32 speed;
 
-		speed = *(u32 *)((void *)indicate + indicate->
-				 status_buf_offset) / 10000;
+		speed = *(u32 *)((void *)indicate
+				 + indicate->status_buf_offset) / 10000;
 		ndev_ctx->speed = speed;
 		return;
 	}
@@ -831,11 +836,13 @@ static int netvsc_set_channels(struct net_device *net,
 	if (was_opened)
 		rndis_filter_close(nvdev);
 
-	rndis_filter_device_remove(dev, nvdev);
-
 	memset(&device_info, 0, sizeof(device_info));
 	device_info.num_chn = count;
 	device_info.ring_size = ring_size;
+	device_info.send_sections = nvdev->send_section_cnt;
+	device_info.recv_sections = nvdev->recv_section_cnt;
+
+	rndis_filter_device_remove(dev, nvdev);
 
 	nvdev = rndis_filter_device_add(dev, &device_info);
 	if (!IS_ERR(nvdev)) {
@@ -844,7 +851,13 @@ static int netvsc_set_channels(struct net_device *net,
 	} else {
 		ret = PTR_ERR(nvdev);
 		device_info.num_chn = orig;
-		rndis_filter_device_add(dev, &device_info);
+		nvdev = rndis_filter_device_add(dev, &device_info);
+
+		if (IS_ERR(nvdev)) {
+			netdev_err(net, "restoring channel setting failed: %ld\n",
+				   PTR_ERR(nvdev));
+			return ret;
+		}
 	}
 
 	if (was_opened)
@@ -941,6 +954,8 @@ static int netvsc_change_mtu(struct net_device *ndev, int mtu)
 	memset(&device_info, 0, sizeof(device_info));
 	device_info.ring_size = ring_size;
 	device_info.num_chn = nvdev->num_chn;
+	device_info.send_sections = nvdev->send_section_cnt;
+	device_info.recv_sections = nvdev->recv_section_cnt;
 
 	rndis_filter_device_remove(hdev, nvdev);
 
@@ -952,10 +967,16 @@ static int netvsc_change_mtu(struct net_device *ndev, int mtu)
 
 		/* Attempt rollback to original MTU */
 		ndev->mtu = orig_mtu;
-		rndis_filter_device_add(hdev, &device_info);
+		nvdev = rndis_filter_device_add(hdev, &device_info);
 
 		if (vf_netdev)
 			dev_set_mtu(vf_netdev, orig_mtu);
+
+		if (IS_ERR(nvdev)) {
+			netdev_err(ndev, "restoring mtu failed: %ld\n",
+				   PTR_ERR(nvdev));
+			return ret;
+		}
 	}
 
 	if (was_opened)
@@ -1052,27 +1073,31 @@ static void netvsc_get_stats64(struct net_device *net,
 static int netvsc_set_mac_addr(struct net_device *ndev, void *p)
 {
 	struct net_device_context *ndc = netdev_priv(ndev);
+	struct net_device *vf_netdev = rtnl_dereference(ndc->vf_netdev);
 	struct netvsc_device *nvdev = rtnl_dereference(ndc->nvdev);
 	struct sockaddr *addr = p;
-	char save_adr[ETH_ALEN];
-	unsigned char save_aatype;
 	int err;
 
-	memcpy(save_adr, ndev->dev_addr, ETH_ALEN);
-	save_aatype = ndev->addr_assign_type;
-
-	err = eth_mac_addr(ndev, p);
-	if (err != 0)
+	err = eth_prepare_mac_addr_change(ndev, p);
+	if (err)
 		return err;
 
 	if (!nvdev)
 		return -ENODEV;
 
+	if (vf_netdev) {
+		err = dev_set_mac_address(vf_netdev, addr);
+		if (err)
+			return err;
+	}
+
 	err = rndis_filter_set_device_mac(nvdev, addr->sa_data);
-	if (err != 0) {
-		/* roll back to saved MAC */
-		memcpy(ndev->dev_addr, save_adr, ETH_ALEN);
-		ndev->addr_assign_type = save_aatype;
+	if (!err) {
+		eth_commit_mac_addr_change(ndev, p);
+	} else if (vf_netdev) {
+		/* rollback change on VF */
+		memcpy(addr->sa_data, ndev->dev_addr, ETH_ALEN);
+		dev_set_mac_address(vf_netdev, addr);
 	}
 
 	return err;
@@ -1087,6 +1112,8 @@ static const struct {
 	{ "tx_no_space",  offsetof(struct netvsc_ethtool_stats, tx_no_space) },
 	{ "tx_too_big",	  offsetof(struct netvsc_ethtool_stats, tx_too_big) },
 	{ "tx_busy",	  offsetof(struct netvsc_ethtool_stats, tx_busy) },
+	{ "tx_send_full", offsetof(struct netvsc_ethtool_stats, tx_send_full) },
+	{ "rx_comp_busy", offsetof(struct netvsc_ethtool_stats, rx_comp_busy) },
 }, vf_stats[] = {
 	{ "vf_rx_packets", offsetof(struct netvsc_vf_pcpu_stats, rx_packets) },
 	{ "vf_rx_bytes",   offsetof(struct netvsc_vf_pcpu_stats, rx_bytes) },
@@ -1335,6 +1362,104 @@ static int netvsc_set_rxfh(struct net_device *dev, const u32 *indir,
 	return rndis_filter_set_rss_param(rndis_dev, key, ndev->num_chn);
 }
 
+/* Hyper-V RNDIS protocol does not have ring in the HW sense.
+ * It does have pre-allocated receive area which is divided into sections.
+ */
+static void __netvsc_get_ringparam(struct netvsc_device *nvdev,
+				   struct ethtool_ringparam *ring)
+{
+	u32 max_buf_size;
+
+	ring->rx_pending = nvdev->recv_section_cnt;
+	ring->tx_pending = nvdev->send_section_cnt;
+
+	if (nvdev->nvsp_version <= NVSP_PROTOCOL_VERSION_2)
+		max_buf_size = NETVSC_RECEIVE_BUFFER_SIZE_LEGACY;
+	else
+		max_buf_size = NETVSC_RECEIVE_BUFFER_SIZE;
+
+	ring->rx_max_pending = max_buf_size / nvdev->recv_section_size;
+	ring->tx_max_pending = NETVSC_SEND_BUFFER_SIZE
+		/ nvdev->send_section_size;
+}
+
+static void netvsc_get_ringparam(struct net_device *ndev,
+				 struct ethtool_ringparam *ring)
+{
+	struct net_device_context *ndevctx = netdev_priv(ndev);
+	struct netvsc_device *nvdev = rtnl_dereference(ndevctx->nvdev);
+
+	if (!nvdev)
+		return;
+
+	__netvsc_get_ringparam(nvdev, ring);
+}
+
+static int netvsc_set_ringparam(struct net_device *ndev,
+				struct ethtool_ringparam *ring)
+{
+	struct net_device_context *ndevctx = netdev_priv(ndev);
+	struct netvsc_device *nvdev = rtnl_dereference(ndevctx->nvdev);
+	struct hv_device *hdev = ndevctx->device_ctx;
+	struct netvsc_device_info device_info;
+	struct ethtool_ringparam orig;
+	u32 new_tx, new_rx;
+	bool was_opened;
+	int ret = 0;
+
+	if (!nvdev || nvdev->destroy)
+		return -ENODEV;
+
+	memset(&orig, 0, sizeof(orig));
+	__netvsc_get_ringparam(nvdev, &orig);
+
+	new_tx = clamp_t(u32, ring->tx_pending,
+			 NETVSC_MIN_TX_SECTIONS, orig.tx_max_pending);
+	new_rx = clamp_t(u32, ring->rx_pending,
+			 NETVSC_MIN_RX_SECTIONS, orig.rx_max_pending);
+
+	if (new_tx == orig.tx_pending &&
+	    new_rx == orig.rx_pending)
+		return 0;	 /* no change */
+
+	memset(&device_info, 0, sizeof(device_info));
+	device_info.num_chn = nvdev->num_chn;
+	device_info.ring_size = ring_size;
+	device_info.send_sections = new_tx;
+	device_info.recv_sections = new_rx;
+
+	netif_device_detach(ndev);
+	was_opened = rndis_filter_opened(nvdev);
+	if (was_opened)
+		rndis_filter_close(nvdev);
+
+	rndis_filter_device_remove(hdev, nvdev);
+
+	nvdev = rndis_filter_device_add(hdev, &device_info);
+	if (IS_ERR(nvdev)) {
+		ret = PTR_ERR(nvdev);
+
+		device_info.send_sections = orig.tx_pending;
+		device_info.recv_sections = orig.rx_pending;
+		nvdev = rndis_filter_device_add(hdev, &device_info);
+		if (IS_ERR(nvdev)) {
+			netdev_err(ndev, "restoring ringparam failed: %ld\n",
+				   PTR_ERR(nvdev));
+			return ret;
+		}
+	}
+
+	if (was_opened)
+		rndis_filter_open(nvdev);
+	netif_device_attach(ndev);
+
+	/* We may have missed link change notifications */
+	ndevctx->last_reconfig = 0;
+	schedule_delayed_work(&ndevctx->dwork, 0);
+
+	return ret;
+}
+
 static const struct ethtool_ops ethtool_ops = {
 	.get_drvinfo	= netvsc_get_drvinfo,
 	.get_link	= ethtool_op_get_link,
@@ -1351,6 +1476,8 @@ static const struct ethtool_ops ethtool_ops = {
 	.set_rxfh	= netvsc_set_rxfh,
 	.get_link_ksettings = netvsc_get_link_ksettings,
 	.set_link_ksettings = netvsc_set_link_ksettings,
+	.get_ringparam	= netvsc_get_ringparam,
+	.set_ringparam	= netvsc_set_ringparam,
 };
 
 static const struct net_device_ops device_ops = {
@@ -1559,7 +1686,9 @@ static int netvsc_vf_join(struct net_device *vf_netdev,
 	/* set slave flag before open to prevent IPv6 addrconf */
 	vf_netdev->flags |= IFF_SLAVE;
 
-	schedule_work(&ndev_ctx->vf_takeover);
+	schedule_delayed_work(&ndev_ctx->vf_takeover, VF_TAKEOVER_INT);
+
+	call_netdevice_notifiers(NETDEV_JOIN, vf_netdev);
 
 	netdev_info(vf_netdev, "joined to %s\n", ndev->name);
 	return 0;
@@ -1575,8 +1704,6 @@ static void __netvsc_vf_setup(struct net_device *ndev,
 {
 	int ret;
 
-	call_netdevice_notifiers(NETDEV_JOIN, vf_netdev);
-
 	/* Align MTU of VF with master */
 	ret = dev_set_mtu(vf_netdev, ndev->mtu);
 	if (ret)
@@ -1597,12 +1724,12 @@ static void __netvsc_vf_setup(struct net_device *ndev,
 static void netvsc_vf_setup(struct work_struct *w)
 {
 	struct net_device_context *ndev_ctx
-		= container_of(w, struct net_device_context, vf_takeover);
+		= container_of(w, struct net_device_context, vf_takeover.work);
 	struct net_device *ndev = hv_get_drvdata(ndev_ctx->device_ctx);
 	struct net_device *vf_netdev;
 
 	if (!rtnl_trylock()) {
-		schedule_work(w);
+		schedule_delayed_work(&ndev_ctx->vf_takeover, 0);
 		return;
 	}
 
@@ -1706,7 +1833,7 @@ static int netvsc_unregister_vf(struct net_device *vf_netdev)
 		return NOTIFY_DONE;
 
 	net_device_ctx = netdev_priv(ndev);
-	cancel_work_sync(&net_device_ctx->vf_takeover);
+	cancel_delayed_work_sync(&net_device_ctx->vf_takeover);
 
 	netdev_info(ndev, "VF unregistering: %s\n", vf_netdev->name);
 
@@ -1748,7 +1875,7 @@ static int netvsc_probe(struct hv_device *dev,
 
 	spin_lock_init(&net_device_ctx->lock);
 	INIT_LIST_HEAD(&net_device_ctx->reconfig_events);
-	INIT_WORK(&net_device_ctx->vf_takeover, netvsc_vf_setup);
+	INIT_DELAYED_WORK(&net_device_ctx->vf_takeover, netvsc_vf_setup);
 
 	net_device_ctx->vf_stats
 		= netdev_alloc_pcpu_stats(struct netvsc_vf_pcpu_stats);
@@ -1766,6 +1893,8 @@ static int netvsc_probe(struct hv_device *dev,
 	memset(&device_info, 0, sizeof(device_info));
 	device_info.ring_size = ring_size;
 	device_info.num_chn = VRSS_CHANNEL_DEFAULT;
+	device_info.send_sections = NETVSC_DEFAULT_TX;
+	device_info.recv_sections = NETVSC_DEFAULT_RX;
 
 	nvdev = rndis_filter_device_add(dev, &device_info);
 	if (IS_ERR(nvdev)) {