Add the rt linux 4.1.3-rt3 as base

Import the rt linux 4.1.3-rt3 as OPNFV kvm base.

It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:

commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date:   Sat Jul 25 12:13:34 2015 +0200

    Prepare v4.1.3-rt3

    Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.

Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>

1 files changed, 1004 insertions, 0 deletions

diff --git a/kernel/drivers/net/hyperv/netvsc_drv.c b/kernel/drivers/net/hyperv/netvsc_drv.c
new file mode 100644
index 000000000..5993c7e2d
--- /dev/null
+++ b/kernel/drivers/net/hyperv/netvsc_drv.c
@@ -0,0 +1,1004 @@
+/*
+ * Copyright (c) 2009, Microsoft Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors:
+ *   Haiyang Zhang <haiyangz@microsoft.com>
+ *   Hank Janssen  <hjanssen@microsoft.com>
+ */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/init.h>
+#include <linux/atomic.h>
+#include <linux/module.h>
+#include <linux/highmem.h>
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/delay.h>
+#include <linux/netdevice.h>
+#include <linux/inetdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/skbuff.h>
+#include <linux/if_vlan.h>
+#include <linux/in.h>
+#include <linux/slab.h>
+#include <net/arp.h>
+#include <net/route.h>
+#include <net/sock.h>
+#include <net/pkt_sched.h>
+
+#include "hyperv_net.h"
+
+
+#define RING_SIZE_MIN 64
+static int ring_size = 128;
+module_param(ring_size, int, S_IRUGO);
+MODULE_PARM_DESC(ring_size, "Ring buffer size (# of pages)");
+
+static const u32 default_msg = NETIF_MSG_DRV | NETIF_MSG_PROBE |
+				NETIF_MSG_LINK | NETIF_MSG_IFUP |
+				NETIF_MSG_IFDOWN | NETIF_MSG_RX_ERR |
+				NETIF_MSG_TX_ERR;
+
+static int debug = -1;
+module_param(debug, int, S_IRUGO);
+MODULE_PARM_DESC(debug, "Debug level (0=none,...,16=all)");
+
+static void do_set_multicast(struct work_struct *w)
+{
+	struct net_device_context *ndevctx =
+		container_of(w, struct net_device_context, work);
+	struct netvsc_device *nvdev;
+	struct rndis_device *rdev;
+
+	nvdev = hv_get_drvdata(ndevctx->device_ctx);
+	if (nvdev == NULL || nvdev->ndev == NULL)
+		return;
+
+	rdev = nvdev->extension;
+	if (rdev == NULL)
+		return;
+
+	if (nvdev->ndev->flags & IFF_PROMISC)
+		rndis_filter_set_packet_filter(rdev,
+			NDIS_PACKET_TYPE_PROMISCUOUS);
+	else
+		rndis_filter_set_packet_filter(rdev,
+			NDIS_PACKET_TYPE_BROADCAST |
+			NDIS_PACKET_TYPE_ALL_MULTICAST |
+			NDIS_PACKET_TYPE_DIRECTED);
+}
+
+static void netvsc_set_multicast_list(struct net_device *net)
+{
+	struct net_device_context *net_device_ctx = netdev_priv(net);
+
+	schedule_work(&net_device_ctx->work);
+}
+
+static int netvsc_open(struct net_device *net)
+{
+	struct net_device_context *net_device_ctx = netdev_priv(net);
+	struct hv_device *device_obj = net_device_ctx->device_ctx;
+	struct netvsc_device *nvdev;
+	struct rndis_device *rdev;
+	int ret = 0;
+
+	netif_carrier_off(net);
+
+	/* Open up the device */
+	ret = rndis_filter_open(device_obj);
+	if (ret != 0) {
+		netdev_err(net, "unable to open device (ret %d).\n", ret);
+		return ret;
+	}
+
+	netif_tx_start_all_queues(net);
+
+	nvdev = hv_get_drvdata(device_obj);
+	rdev = nvdev->extension;
+	if (!rdev->link_state)
+		netif_carrier_on(net);
+
+	return ret;
+}
+
+static int netvsc_close(struct net_device *net)
+{
+	struct net_device_context *net_device_ctx = netdev_priv(net);
+	struct hv_device *device_obj = net_device_ctx->device_ctx;
+	int ret;
+
+	netif_tx_disable(net);
+
+	/* Make sure netvsc_set_multicast_list doesn't re-enable filter! */
+	cancel_work_sync(&net_device_ctx->work);
+	ret = rndis_filter_close(device_obj);
+	if (ret != 0)
+		netdev_err(net, "unable to close device (ret %d).\n", ret);
+
+	return ret;
+}
+
+static void *init_ppi_data(struct rndis_message *msg, u32 ppi_size,
+				int pkt_type)
+{
+	struct rndis_packet *rndis_pkt;
+	struct rndis_per_packet_info *ppi;
+
+	rndis_pkt = &msg->msg.pkt;
+	rndis_pkt->data_offset += ppi_size;
+
+	ppi = (struct rndis_per_packet_info *)((void *)rndis_pkt +
+		rndis_pkt->per_pkt_info_offset + rndis_pkt->per_pkt_info_len);
+
+	ppi->size = ppi_size;
+	ppi->type = pkt_type;
+	ppi->ppi_offset = sizeof(struct rndis_per_packet_info);
+
+	rndis_pkt->per_pkt_info_len += ppi_size;
+
+	return ppi;
+}
+
+union sub_key {
+	u64 k;
+	struct {
+		u8 pad[3];
+		u8 kb;
+		u32 ka;
+	};
+};
+
+/* Toeplitz hash function
+ * data: network byte order
+ * return: host byte order
+ */
+static u32 comp_hash(u8 *key, int klen, void *data, int dlen)
+{
+	union sub_key subk;
+	int k_next = 4;
+	u8 dt;
+	int i, j;
+	u32 ret = 0;
+
+	subk.k = 0;
+	subk.ka = ntohl(*(u32 *)key);
+
+	for (i = 0; i < dlen; i++) {
+		subk.kb = key[k_next];
+		k_next = (k_next + 1) % klen;
+		dt = ((u8 *)data)[i];
+		for (j = 0; j < 8; j++) {
+			if (dt & 0x80)
+				ret ^= subk.ka;
+			dt <<= 1;
+			subk.k <<= 1;
+		}
+	}
+
+	return ret;
+}
+
+static bool netvsc_set_hash(u32 *hash, struct sk_buff *skb)
+{
+	struct flow_keys flow;
+	int data_len;
+
+	if (!skb_flow_dissect(skb, &flow) ||
+	    !(flow.n_proto == htons(ETH_P_IP) ||
+	      flow.n_proto == htons(ETH_P_IPV6)))
+		return false;
+
+	if (flow.ip_proto == IPPROTO_TCP)
+		data_len = 12;
+	else
+		data_len = 8;
+
+	*hash = comp_hash(netvsc_hash_key, HASH_KEYLEN, &flow, data_len);
+
+	return true;
+}
+
+static u16 netvsc_select_queue(struct net_device *ndev, struct sk_buff *skb,
+			void *accel_priv, select_queue_fallback_t fallback)
+{
+	struct net_device_context *net_device_ctx = netdev_priv(ndev);
+	struct hv_device *hdev =  net_device_ctx->device_ctx;
+	struct netvsc_device *nvsc_dev = hv_get_drvdata(hdev);
+	u32 hash;
+	u16 q_idx = 0;
+
+	if (nvsc_dev == NULL || ndev->real_num_tx_queues <= 1)
+		return 0;
+
+	if (netvsc_set_hash(&hash, skb)) {
+		q_idx = nvsc_dev->send_table[hash % VRSS_SEND_TAB_SIZE] %
+			ndev->real_num_tx_queues;
+		skb_set_hash(skb, hash, PKT_HASH_TYPE_L3);
+	}
+
+	return q_idx;
+}
+
+void netvsc_xmit_completion(void *context)
+{
+	struct hv_netvsc_packet *packet = (struct hv_netvsc_packet *)context;
+	struct sk_buff *skb = (struct sk_buff *)
+		(unsigned long)packet->send_completion_tid;
+
+	if (skb)
+		dev_kfree_skb_any(skb);
+}
+
+static u32 fill_pg_buf(struct page *page, u32 offset, u32 len,
+			struct hv_page_buffer *pb)
+{
+	int j = 0;
+
+	/* Deal with compund pages by ignoring unused part
+	 * of the page.
+	 */
+	page += (offset >> PAGE_SHIFT);
+	offset &= ~PAGE_MASK;
+
+	while (len > 0) {
+		unsigned long bytes;
+
+		bytes = PAGE_SIZE - offset;
+		if (bytes > len)
+			bytes = len;
+		pb[j].pfn = page_to_pfn(page);
+		pb[j].offset = offset;
+		pb[j].len = bytes;
+
+		offset += bytes;
+		len -= bytes;
+
+		if (offset == PAGE_SIZE && len) {
+			page++;
+			offset = 0;
+			j++;
+		}
+	}
+
+	return j + 1;
+}
+
+static u32 init_page_array(void *hdr, u32 len, struct sk_buff *skb,
+			   struct hv_netvsc_packet *packet)
+{
+	struct hv_page_buffer *pb = packet->page_buf;
+	u32 slots_used = 0;
+	char *data = skb->data;
+	int frags = skb_shinfo(skb)->nr_frags;
+	int i;
+
+	/* The packet is laid out thus:
+	 * 1. hdr: RNDIS header and PPI
+	 * 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]);
+
+	packet->rmsg_size = len;
+	packet->rmsg_pgcnt = slots_used;
+
+	slots_used += fill_pg_buf(virt_to_page(data),
+				offset_in_page(data),
+				skb_headlen(skb), &pb[slots_used]);
+
+	for (i = 0; i < frags; i++) {
+		skb_frag_t *frag = skb_shinfo(skb)->frags + i;
+
+		slots_used += fill_pg_buf(skb_frag_page(frag),
+					frag->page_offset,
+					skb_frag_size(frag), &pb[slots_used]);
+	}
+	return slots_used;
+}
+
+static int count_skb_frag_slots(struct sk_buff *skb)
+{
+	int i, frags = skb_shinfo(skb)->nr_frags;
+	int pages = 0;
+
+	for (i = 0; i < frags; i++) {
+		skb_frag_t *frag = skb_shinfo(skb)->frags + i;
+		unsigned long size = skb_frag_size(frag);
+		unsigned long offset = frag->page_offset;
+
+		/* Skip unused frames from start of page */
+		offset &= ~PAGE_MASK;
+		pages += PFN_UP(offset + size);
+	}
+	return pages;
+}
+
+static int netvsc_get_slots(struct sk_buff *skb)
+{
+	char *data = skb->data;
+	unsigned int offset = offset_in_page(data);
+	unsigned int len = skb_headlen(skb);
+	int slots;
+	int frag_slots;
+
+	slots = DIV_ROUND_UP(offset + len, PAGE_SIZE);
+	frag_slots = count_skb_frag_slots(skb);
+	return slots + frag_slots;
+}
+
+static u32 get_net_transport_info(struct sk_buff *skb, u32 *trans_off)
+{
+	u32 ret_val = TRANSPORT_INFO_NOT_IP;
+
+	if ((eth_hdr(skb)->h_proto != htons(ETH_P_IP)) &&
+		(eth_hdr(skb)->h_proto != htons(ETH_P_IPV6))) {
+		goto not_ip;
+	}
+
+	*trans_off = skb_transport_offset(skb);
+
+	if ((eth_hdr(skb)->h_proto == htons(ETH_P_IP))) {
+		struct iphdr *iphdr = ip_hdr(skb);
+
+		if (iphdr->protocol == IPPROTO_TCP)
+			ret_val = TRANSPORT_INFO_IPV4_TCP;
+		else if (iphdr->protocol == IPPROTO_UDP)
+			ret_val = TRANSPORT_INFO_IPV4_UDP;
+	} else {
+		if (ipv6_hdr(skb)->nexthdr == IPPROTO_TCP)
+			ret_val = TRANSPORT_INFO_IPV6_TCP;
+		else if (ipv6_hdr(skb)->nexthdr == IPPROTO_UDP)
+			ret_val = TRANSPORT_INFO_IPV6_UDP;
+	}
+
+not_ip:
+	return ret_val;
+}
+
+static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net)
+{
+	struct net_device_context *net_device_ctx = netdev_priv(net);
+	struct hv_netvsc_packet *packet = NULL;
+	int ret;
+	unsigned int num_data_pgs;
+	struct rndis_message *rndis_msg;
+	struct rndis_packet *rndis_pkt;
+	u32 rndis_msg_size;
+	bool isvlan;
+	bool linear = false;
+	struct rndis_per_packet_info *ppi;
+	struct ndis_tcp_ip_checksum_info *csum_info;
+	struct ndis_tcp_lso_info *lso_info;
+	int  hdr_offset;
+	u32 net_trans_info;
+	u32 hash;
+	u32 skb_length;
+	u32 pkt_sz;
+	struct hv_page_buffer page_buf[MAX_PAGE_BUFFER_COUNT];
+
+
+	/* We will atmost need two pages to describe the rndis
+	 * header. We can only transmit MAX_PAGE_BUFFER_COUNT number
+	 * of pages in a single packet. If skb is scattered around
+	 * more pages we try linearizing it.
+	 */
+
+check_size:
+	skb_length = skb->len;
+	num_data_pgs = netvsc_get_slots(skb) + 2;
+	if (num_data_pgs > MAX_PAGE_BUFFER_COUNT && linear) {
+		net_alert_ratelimited("packet too big: %u pages (%u bytes)\n",
+				      num_data_pgs, skb->len);
+		ret = -EFAULT;
+		goto drop;
+	} else if (num_data_pgs > MAX_PAGE_BUFFER_COUNT) {
+		if (skb_linearize(skb)) {
+			net_alert_ratelimited("failed to linearize skb\n");
+			ret = -ENOMEM;
+			goto drop;
+		}
+		linear = true;
+		goto check_size;
+	}
+
+	pkt_sz = sizeof(struct hv_netvsc_packet) + RNDIS_AND_PPI_SIZE;
+
+	ret = skb_cow_head(skb, pkt_sz);
+	if (ret) {
+		netdev_err(net, "unable to alloc hv_netvsc_packet\n");
+		ret = -ENOMEM;
+		goto drop;
+	}
+	/* Use the headroom for building up the packet */
+	packet = (struct hv_netvsc_packet *)skb->head;
+
+	packet->status = 0;
+	packet->xmit_more = skb->xmit_more;
+
+	packet->vlan_tci = skb->vlan_tci;
+	packet->page_buf = page_buf;
+
+	packet->q_idx = skb_get_queue_mapping(skb);
+
+	packet->is_data_pkt = true;
+	packet->total_data_buflen = skb->len;
+
+	packet->rndis_msg = (struct rndis_message *)((unsigned long)packet +
+				sizeof(struct hv_netvsc_packet));
+
+	memset(packet->rndis_msg, 0, RNDIS_AND_PPI_SIZE);
+
+	/* Set the completion routine */
+	packet->send_completion = netvsc_xmit_completion;
+	packet->send_completion_ctx = packet;
+	packet->send_completion_tid = (unsigned long)skb;
+
+	isvlan = packet->vlan_tci & VLAN_TAG_PRESENT;
+
+	/* Add the rndis header */
+	rndis_msg = packet->rndis_msg;
+	rndis_msg->ndis_msg_type = RNDIS_MSG_PACKET;
+	rndis_msg->msg_len = packet->total_data_buflen;
+	rndis_pkt = &rndis_msg->msg.pkt;
+	rndis_pkt->data_offset = sizeof(struct rndis_packet);
+	rndis_pkt->data_len = packet->total_data_buflen;
+	rndis_pkt->per_pkt_info_offset = sizeof(struct rndis_packet);
+
+	rndis_msg_size = RNDIS_MESSAGE_SIZE(struct rndis_packet);
+
+	hash = skb_get_hash_raw(skb);
+	if (hash != 0 && net->real_num_tx_queues > 1) {
+		rndis_msg_size += NDIS_HASH_PPI_SIZE;
+		ppi = init_ppi_data(rndis_msg, NDIS_HASH_PPI_SIZE,
+				    NBL_HASH_VALUE);
+		*(u32 *)((void *)ppi + ppi->ppi_offset) = hash;
+	}
+
+	if (isvlan) {
+		struct ndis_pkt_8021q_info *vlan;
+
+		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->vlanid = packet->vlan_tci & VLAN_VID_MASK;
+		vlan->pri = (packet->vlan_tci & VLAN_PRIO_MASK) >>
+				VLAN_PRIO_SHIFT;
+	}
+
+	net_trans_info = get_net_transport_info(skb, &hdr_offset);
+	if (net_trans_info == TRANSPORT_INFO_NOT_IP)
+		goto do_send;
+
+	/*
+	 * Setup the sendside checksum offload only if this is not a
+	 * GSO packet.
+	 */
+	if (skb_is_gso(skb))
+		goto do_lso;
+
+	if ((skb->ip_summed == CHECKSUM_NONE) ||
+	    (skb->ip_summed == CHECKSUM_UNNECESSARY))
+		goto do_send;
+
+	rndis_msg_size += NDIS_CSUM_PPI_SIZE;
+	ppi = init_ppi_data(rndis_msg, NDIS_CSUM_PPI_SIZE,
+			    TCPIP_CHKSUM_PKTINFO);
+
+	csum_info = (struct ndis_tcp_ip_checksum_info *)((void *)ppi +
+			ppi->ppi_offset);
+
+	if (net_trans_info & (INFO_IPV4 << 16))
+		csum_info->transmit.is_ipv4 = 1;
+	else
+		csum_info->transmit.is_ipv6 = 1;
+
+	if (net_trans_info & INFO_TCP) {
+		csum_info->transmit.tcp_checksum = 1;
+		csum_info->transmit.tcp_header_offset = hdr_offset;
+	} else if (net_trans_info & INFO_UDP) {
+		/* UDP checksum offload is not supported on ws2008r2.
+		 * Furthermore, on ws2012 and ws2012r2, there are some
+		 * issues with udp checksum offload from Linux guests.
+		 * (these are host issues).
+		 * For now compute the checksum here.
+		 */
+		struct udphdr *uh;
+		u16 udp_len;
+
+		ret = skb_cow_head(skb, 0);
+		if (ret)
+			goto drop;
+
+		uh = udp_hdr(skb);
+		udp_len = ntohs(uh->len);
+		uh->check = 0;
+		uh->check = csum_tcpudp_magic(ip_hdr(skb)->saddr,
+					      ip_hdr(skb)->daddr,
+					      udp_len, IPPROTO_UDP,
+					      csum_partial(uh, udp_len, 0));
+		if (uh->check == 0)
+			uh->check = CSUM_MANGLED_0;
+
+		csum_info->transmit.udp_checksum = 0;
+	}
+	goto do_send;
+
+do_lso:
+	rndis_msg_size += NDIS_LSO_PPI_SIZE;
+	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->lso_v2_transmit.type = NDIS_TCP_LARGE_SEND_OFFLOAD_V2_TYPE;
+	if (net_trans_info & (INFO_IPV4 << 16)) {
+		lso_info->lso_v2_transmit.ip_version =
+			NDIS_TCP_LARGE_SEND_OFFLOAD_IPV4;
+		ip_hdr(skb)->tot_len = 0;
+		ip_hdr(skb)->check = 0;
+		tcp_hdr(skb)->check =
+		~csum_tcpudp_magic(ip_hdr(skb)->saddr,
+				   ip_hdr(skb)->daddr, 0, IPPROTO_TCP, 0);
+	} else {
+		lso_info->lso_v2_transmit.ip_version =
+			NDIS_TCP_LARGE_SEND_OFFLOAD_IPV6;
+		ipv6_hdr(skb)->payload_len = 0;
+		tcp_hdr(skb)->check =
+		~csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
+				&ipv6_hdr(skb)->daddr, 0, IPPROTO_TCP, 0);
+	}
+	lso_info->lso_v2_transmit.tcp_header_offset = hdr_offset;
+	lso_info->lso_v2_transmit.mss = skb_shinfo(skb)->gso_size;
+
+do_send:
+	/* Start filling in the page buffers with the rndis hdr */
+	rndis_msg->msg_len += rndis_msg_size;
+	packet->total_data_buflen = rndis_msg->msg_len;
+	packet->page_buf_cnt = init_page_array(rndis_msg, rndis_msg_size,
+					       skb, packet);
+
+	ret = netvsc_send(net_device_ctx->device_ctx, packet);
+
+drop:
+	if (ret == 0) {
+		net->stats.tx_bytes += skb_length;
+		net->stats.tx_packets++;
+	} else {
+		if (ret != -EAGAIN) {
+			dev_kfree_skb_any(skb);
+			net->stats.tx_dropped++;
+		}
+	}
+
+	return (ret == -EAGAIN) ? NETDEV_TX_BUSY : NETDEV_TX_OK;
+}
+
+/*
+ * netvsc_linkstatus_callback - Link up/down notification
+ */
+void netvsc_linkstatus_callback(struct hv_device *device_obj,
+				struct rndis_message *resp)
+{
+	struct rndis_indicate_status *indicate = &resp->msg.indicate_status;
+	struct net_device *net;
+	struct net_device_context *ndev_ctx;
+	struct netvsc_device *net_device;
+	struct rndis_device *rdev;
+
+	net_device = hv_get_drvdata(device_obj);
+	rdev = net_device->extension;
+
+	switch (indicate->status) {
+	case RNDIS_STATUS_MEDIA_CONNECT:
+		rdev->link_state = false;
+		break;
+	case RNDIS_STATUS_MEDIA_DISCONNECT:
+		rdev->link_state = true;
+		break;
+	case RNDIS_STATUS_NETWORK_CHANGE:
+		rdev->link_change = true;
+		break;
+	default:
+		return;
+	}
+
+	net = net_device->ndev;
+
+	if (!net || net->reg_state != NETREG_REGISTERED)
+		return;
+
+	ndev_ctx = netdev_priv(net);
+	if (!rdev->link_state) {
+		schedule_delayed_work(&ndev_ctx->dwork, 0);
+		schedule_delayed_work(&ndev_ctx->dwork, msecs_to_jiffies(20));
+	} else {
+		schedule_delayed_work(&ndev_ctx->dwork, 0);
+	}
+}
+
+/*
+ * netvsc_recv_callback -  Callback when we receive a packet from the
+ * "wire" on the specified device.
+ */
+int netvsc_recv_callback(struct hv_device *device_obj,
+				struct hv_netvsc_packet *packet,
+				struct ndis_tcp_ip_checksum_info *csum_info)
+{
+	struct net_device *net;
+	struct sk_buff *skb;
+
+	net = ((struct netvsc_device *)hv_get_drvdata(device_obj))->ndev;
+	if (!net || net->reg_state != NETREG_REGISTERED) {
+		packet->status = NVSP_STAT_FAIL;
+		return 0;
+	}
+
+	/* Allocate a skb - TODO direct I/O to pages? */
+	skb = netdev_alloc_skb_ip_align(net, packet->total_data_buflen);
+	if (unlikely(!skb)) {
+		++net->stats.rx_dropped;
+		packet->status = NVSP_STAT_FAIL;
+		return 0;
+	}
+
+	/*
+	 * Copy to skb. This copy is needed here since the memory pointed by
+	 * hv_netvsc_packet cannot be deallocated
+	 */
+	memcpy(skb_put(skb, packet->total_data_buflen), packet->data,
+		packet->total_data_buflen);
+
+	skb->protocol = eth_type_trans(skb, net);
+	if (csum_info) {
+		/* We only look at the IP checksum here.
+		 * Should we be dropping the packet if checksum
+		 * failed? How do we deal with other checksums - TCP/UDP?
+		 */
+		if (csum_info->receive.ip_checksum_succeeded)
+			skb->ip_summed = CHECKSUM_UNNECESSARY;
+		else
+			skb->ip_summed = CHECKSUM_NONE;
+	}
+
+	if (packet->vlan_tci & VLAN_TAG_PRESENT)
+		__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q),
+				       packet->vlan_tci);
+
+	skb_record_rx_queue(skb, packet->channel->
+			    offermsg.offer.sub_channel_index);
+
+	net->stats.rx_packets++;
+	net->stats.rx_bytes += packet->total_data_buflen;
+
+	/*
+	 * Pass the skb back up. Network stack will deallocate the skb when it
+	 * is done.
+	 * TODO - use NAPI?
+	 */
+	netif_rx(skb);
+
+	return 0;
+}
+
+static void netvsc_get_drvinfo(struct net_device *net,
+			       struct ethtool_drvinfo *info)
+{
+	strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver));
+	strlcpy(info->fw_version, "N/A", sizeof(info->fw_version));
+}
+
+static void netvsc_get_channels(struct net_device *net,
+				struct ethtool_channels *channel)
+{
+	struct net_device_context *net_device_ctx = netdev_priv(net);
+	struct hv_device *dev = net_device_ctx->device_ctx;
+	struct netvsc_device *nvdev = hv_get_drvdata(dev);
+
+	if (nvdev) {
+		channel->max_combined	= nvdev->max_chn;
+		channel->combined_count = nvdev->num_chn;
+	}
+}
+
+static int netvsc_change_mtu(struct net_device *ndev, int mtu)
+{
+	struct net_device_context *ndevctx = netdev_priv(ndev);
+	struct hv_device *hdev =  ndevctx->device_ctx;
+	struct netvsc_device *nvdev = hv_get_drvdata(hdev);
+	struct netvsc_device_info device_info;
+	int limit = ETH_DATA_LEN;
+
+	if (nvdev == NULL || nvdev->destroy)
+		return -ENODEV;
+
+	if (nvdev->nvsp_version >= NVSP_PROTOCOL_VERSION_2)
+		limit = NETVSC_MTU - ETH_HLEN;
+
+	/* Hyper-V hosts don't support MTU < ETH_DATA_LEN (1500) */
+	if (mtu < ETH_DATA_LEN || mtu > limit)
+		return -EINVAL;
+
+	nvdev->start_remove = true;
+	cancel_work_sync(&ndevctx->work);
+	netif_tx_disable(ndev);
+	rndis_filter_device_remove(hdev);
+
+	ndev->mtu = mtu;
+
+	ndevctx->device_ctx = hdev;
+	hv_set_drvdata(hdev, ndev);
+	device_info.ring_size = ring_size;
+	rndis_filter_device_add(hdev, &device_info);
+	netif_tx_wake_all_queues(ndev);
+
+	return 0;
+}
+
+
+static int netvsc_set_mac_addr(struct net_device *ndev, void *p)
+{
+	struct net_device_context *ndevctx = netdev_priv(ndev);
+	struct hv_device *hdev =  ndevctx->device_ctx;
+	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)
+		return err;
+
+	err = rndis_filter_set_device_mac(hdev, 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;
+	}
+
+	return err;
+}
+
+#ifdef CONFIG_NET_POLL_CONTROLLER
+static void netvsc_poll_controller(struct net_device *net)
+{
+	/* As netvsc_start_xmit() works synchronous we don't have to
+	 * trigger anything here.
+	 */
+}
+#endif
+
+static const struct ethtool_ops ethtool_ops = {
+	.get_drvinfo	= netvsc_get_drvinfo,
+	.get_link	= ethtool_op_get_link,
+	.get_channels   = netvsc_get_channels,
+};
+
+static const struct net_device_ops device_ops = {
+	.ndo_open =			netvsc_open,
+	.ndo_stop =			netvsc_close,
+	.ndo_start_xmit =		netvsc_start_xmit,
+	.ndo_set_rx_mode =		netvsc_set_multicast_list,
+	.ndo_change_mtu =		netvsc_change_mtu,
+	.ndo_validate_addr =		eth_validate_addr,
+	.ndo_set_mac_address =		netvsc_set_mac_addr,
+	.ndo_select_queue =		netvsc_select_queue,
+#ifdef CONFIG_NET_POLL_CONTROLLER
+	.ndo_poll_controller =		netvsc_poll_controller,
+#endif
+};
+
+/*
+ * Send GARP packet to network peers after migrations.
+ * After Quick Migration, the network is not immediately operational in the
+ * current context when receiving RNDIS_STATUS_MEDIA_CONNECT event. So, add
+ * another netif_notify_peers() into a delayed work, otherwise GARP packet
+ * will not be sent after quick migration, and cause network disconnection.
+ * Also, we update the carrier status here.
+ */
+static void netvsc_link_change(struct work_struct *w)
+{
+	struct net_device_context *ndev_ctx;
+	struct net_device *net;
+	struct netvsc_device *net_device;
+	struct rndis_device *rdev;
+	bool notify, refresh = false;
+	char *argv[] = { "/etc/init.d/network", "restart", NULL };
+	char *envp[] = { "HOME=/", "PATH=/sbin:/usr/sbin:/bin:/usr/bin", NULL };
+
+	rtnl_lock();
+
+	ndev_ctx = container_of(w, struct net_device_context, dwork.work);
+	net_device = hv_get_drvdata(ndev_ctx->device_ctx);
+	rdev = net_device->extension;
+	net = net_device->ndev;
+
+	if (rdev->link_state) {
+		netif_carrier_off(net);
+		notify = false;
+	} else {
+		netif_carrier_on(net);
+		notify = true;
+		if (rdev->link_change) {
+			rdev->link_change = false;
+			refresh = true;
+		}
+	}
+
+	rtnl_unlock();
+
+	if (refresh)
+		call_usermodehelper(argv[0], argv, envp, UMH_WAIT_EXEC);
+
+	if (notify)
+		netdev_notify_peers(net);
+}
+
+
+static int netvsc_probe(struct hv_device *dev,
+			const struct hv_vmbus_device_id *dev_id)
+{
+	struct net_device *net = NULL;
+	struct net_device_context *net_device_ctx;
+	struct netvsc_device_info device_info;
+	struct netvsc_device *nvdev;
+	int ret;
+	u32 max_needed_headroom;
+
+	net = alloc_etherdev_mq(sizeof(struct net_device_context),
+				num_online_cpus());
+	if (!net)
+		return -ENOMEM;
+
+	max_needed_headroom = sizeof(struct hv_netvsc_packet) +
+			      RNDIS_AND_PPI_SIZE;
+
+	netif_carrier_off(net);
+
+	net_device_ctx = netdev_priv(net);
+	net_device_ctx->device_ctx = dev;
+	net_device_ctx->msg_enable = netif_msg_init(debug, default_msg);
+	if (netif_msg_probe(net_device_ctx))
+		netdev_dbg(net, "netvsc msg_enable: %d\n",
+			   net_device_ctx->msg_enable);
+
+	hv_set_drvdata(dev, net);
+	INIT_DELAYED_WORK(&net_device_ctx->dwork, netvsc_link_change);
+	INIT_WORK(&net_device_ctx->work, do_set_multicast);
+
+	net->netdev_ops = &device_ops;
+
+	net->hw_features = NETIF_F_RXCSUM | NETIF_F_SG | NETIF_F_IP_CSUM |
+				NETIF_F_TSO;
+	net->features = NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_SG | NETIF_F_RXCSUM |
+			NETIF_F_IP_CSUM | NETIF_F_TSO;
+
+	net->ethtool_ops = &ethtool_ops;
+	SET_NETDEV_DEV(net, &dev->device);
+
+	/*
+	 * Request additional head room in the skb.
+	 * We will use this space to build the rndis
+	 * heaser and other state we need to maintain.
+	 */
+	net->needed_headroom = max_needed_headroom;
+
+	/* Notify the netvsc driver of the new device */
+	device_info.ring_size = ring_size;
+	ret = rndis_filter_device_add(dev, &device_info);
+	if (ret != 0) {
+		netdev_err(net, "unable to add netvsc device (ret %d)\n", ret);
+		free_netdev(net);
+		hv_set_drvdata(dev, NULL);
+		return ret;
+	}
+	memcpy(net->dev_addr, device_info.mac_adr, ETH_ALEN);
+
+	nvdev = hv_get_drvdata(dev);
+	netif_set_real_num_tx_queues(net, nvdev->num_chn);
+	netif_set_real_num_rx_queues(net, nvdev->num_chn);
+
+	ret = register_netdev(net);
+	if (ret != 0) {
+		pr_err("Unable to register netdev.\n");
+		rndis_filter_device_remove(dev);
+		free_netdev(net);
+	} else {
+		schedule_delayed_work(&net_device_ctx->dwork, 0);
+	}
+
+	return ret;
+}
+
+static int netvsc_remove(struct hv_device *dev)
+{
+	struct net_device *net;
+	struct net_device_context *ndev_ctx;
+	struct netvsc_device *net_device;
+
+	net_device = hv_get_drvdata(dev);
+	net = net_device->ndev;
+
+	if (net == NULL) {
+		dev_err(&dev->device, "No net device to remove\n");
+		return 0;
+	}
+
+	net_device->start_remove = true;
+
+	ndev_ctx = netdev_priv(net);
+	cancel_delayed_work_sync(&ndev_ctx->dwork);
+	cancel_work_sync(&ndev_ctx->work);
+
+	/* Stop outbound asap */
+	netif_tx_disable(net);
+
+	unregister_netdev(net);
+
+	/*
+	 * Call to the vsc driver to let it know that the device is being
+	 * removed
+	 */
+	rndis_filter_device_remove(dev);
+
+	free_netdev(net);
+	return 0;
+}
+
+static const struct hv_vmbus_device_id id_table[] = {
+	/* Network guid */
+	{ HV_NIC_GUID, },
+	{ },
+};
+
+MODULE_DEVICE_TABLE(vmbus, id_table);
+
+/* The one and only one */
+static struct  hv_driver netvsc_drv = {
+	.name = KBUILD_MODNAME,
+	.id_table = id_table,
+	.probe = netvsc_probe,
+	.remove = netvsc_remove,
+};
+
+static void __exit netvsc_drv_exit(void)
+{
+	vmbus_driver_unregister(&netvsc_drv);
+}
+
+static int __init netvsc_drv_init(void)
+{
+	if (ring_size < RING_SIZE_MIN) {
+		ring_size = RING_SIZE_MIN;
+		pr_info("Increased ring_size to %d (min allowed)\n",
+			ring_size);
+	}
+	return vmbus_driver_register(&netvsc_drv);
+}
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Microsoft Hyper-V network driver");
+
+module_init(netvsc_drv_init);
+module_exit(netvsc_drv_exit);