drm/mediatek: Add missing IS_ERR check for ovl_adaptor platform devicegrafted

platform_device_register_data() can fail and return an ERR_PTR, but the
return value is used without checking, leading to an invalid pointer
being stored in ddp_comp[].dev and passed to component_match_add() and
mtk_ddp_comp_init(), which could result in a kernel crash.

Add an IS_ERR() check to jump to the error handling path on failure.

Fixes: 0d9eee9118b7 ("drm/mediatek: Add drm ovl_adaptor sub driver for MT8195")
Cc: stable@vger.kernel.org
Signed-off-by: Haojie Li <lihaojie@kylinos.cn>
Reviewed-by: CK Hu <ck.hu@mediatek.com>
Link: https://patchwork.kernel.org/project/linux-mediatek/patch/20260825100845.438893-1-lihaojie@kylinos.cn/
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>

13 files changed, 4149 insertions, 0 deletions

diff --git a/tools/hv/.gitignore b/tools/hv/.gitignore
new file mode 100644
index 000000000..0c5bc15d6
--- /dev/null
+++ b/tools/hv/.gitignore
@@ -0,0 +1,3 @@
+hv_fcopy_uio_daemon
+hv_kvp_daemon
+hv_vss_daemon
diff --git a/tools/hv/Build b/tools/hv/Build
new file mode 100644
index 000000000..7d1f16980
--- /dev/null
+++ b/tools/hv/Build
@@ -0,0 +1,4 @@
+hv_kvp_daemon-y += hv_kvp_daemon.o
+hv_vss_daemon-y += hv_vss_daemon.o
+hv_fcopy_uio_daemon-y += hv_fcopy_uio_daemon.o
+hv_fcopy_uio_daemon-y += vmbus_bufring.o
diff --git a/tools/hv/Makefile b/tools/hv/Makefile
new file mode 100644
index 000000000..016753f3d
--- /dev/null
+++ b/tools/hv/Makefile
@@ -0,0 +1,71 @@
+# SPDX-License-Identifier: GPL-2.0
+# Makefile for Hyper-V tools
+include ../scripts/Makefile.include
+
+ARCH ?= $(shell uname -m 2>/dev/null)
+sbindir ?= /usr/sbin
+libexecdir ?= /usr/libexec
+sharedstatedir ?= /var/lib
+
+ifeq ($(srctree),)
+srctree := $(patsubst %/,%,$(dir $(CURDIR)))
+srctree := $(patsubst %/,%,$(dir $(srctree)))
+endif
+
+# Do not use make's built-in rules
+# (this improves performance and avoids hard-to-debug behaviour);
+MAKEFLAGS += -r
+
+override CFLAGS += -O2 -Wall -g -D_GNU_SOURCE -I$(OUTPUT)include
+override CFLAGS += -Wno-address-of-packed-member
+
+ALL_TARGETS := hv_kvp_daemon hv_vss_daemon
+ifneq ($(filter x86_64 x86,$(ARCH)),)
+ALL_TARGETS += hv_fcopy_uio_daemon
+endif
+ALL_PROGRAMS := $(patsubst %,$(OUTPUT)%,$(ALL_TARGETS))
+
+ALL_SCRIPTS := hv_get_dhcp_info.sh hv_get_dns_info.sh hv_set_ifconfig.sh
+
+all: $(ALL_PROGRAMS)
+
+export srctree OUTPUT CC LD CFLAGS
+include $(srctree)/tools/build/Makefile.include
+
+HV_KVP_DAEMON_IN := $(OUTPUT)hv_kvp_daemon-in.o
+$(HV_KVP_DAEMON_IN): FORCE
+	$(Q)$(MAKE) $(build)=hv_kvp_daemon
+$(OUTPUT)hv_kvp_daemon: $(HV_KVP_DAEMON_IN)
+	$(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) $< -o $@
+
+HV_VSS_DAEMON_IN := $(OUTPUT)hv_vss_daemon-in.o
+$(HV_VSS_DAEMON_IN): FORCE
+	$(Q)$(MAKE) $(build)=hv_vss_daemon
+$(OUTPUT)hv_vss_daemon: $(HV_VSS_DAEMON_IN)
+	$(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) $< -o $@
+
+HV_FCOPY_UIO_DAEMON_IN := $(OUTPUT)hv_fcopy_uio_daemon-in.o
+$(HV_FCOPY_UIO_DAEMON_IN): FORCE
+	$(Q)$(MAKE) $(build)=hv_fcopy_uio_daemon
+$(OUTPUT)hv_fcopy_uio_daemon: $(HV_FCOPY_UIO_DAEMON_IN)
+	$(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) $< -o $@
+
+clean:
+	rm -f $(ALL_PROGRAMS)
+	find $(or $(OUTPUT),.) -name '*.o' -delete -o -name '\.*.d' -delete -o -name '\.*.cmd' -delete
+
+install: $(ALL_PROGRAMS)
+	install -d -m 755 $(DESTDIR)$(sbindir); \
+	install -d -m 755 $(DESTDIR)$(libexecdir)/hypervkvpd; \
+	install -d -m 755 $(DESTDIR)$(sharedstatedir); \
+	for program in $(ALL_PROGRAMS); do \
+		install $$program -m 755 $(DESTDIR)$(sbindir);	\
+	done; \
+	install -m 755 lsvmbus $(DESTDIR)$(sbindir); \
+	for script in $(ALL_SCRIPTS); do \
+		install $$script -m 755 $(DESTDIR)$(libexecdir)/hypervkvpd/$${script%.sh}; \
+	done
+
+FORCE:
+
+.PHONY: all install clean FORCE prepare
diff --git a/tools/hv/hv_fcopy_uio_daemon.c b/tools/hv/hv_fcopy_uio_daemon.c
new file mode 100644
index 000000000..92e8307b2
--- /dev/null
+++ b/tools/hv/hv_fcopy_uio_daemon.c
@@ -0,0 +1,559 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * An implementation of host to guest copy functionality for Linux.
+ *
+ * Copyright (C) 2023, Microsoft, Inc.
+ *
+ * Author : K. Y. Srinivasan <kys@microsoft.com>
+ * Author : Saurabh Sengar <ssengar@microsoft.com>
+ *
+ */
+
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <getopt.h>
+#include <locale.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <syslog.h>
+#include <unistd.h>
+#include <wchar.h>
+#include <sys/stat.h>
+#include <linux/hyperv.h>
+#include <linux/limits.h>
+#include "vmbus_bufring.h"
+
+#define ICMSGTYPE_NEGOTIATE	0
+#define ICMSGTYPE_FCOPY		7
+
+#define WIN8_SRV_MAJOR		1
+#define WIN8_SRV_MINOR		1
+#define WIN8_SRV_VERSION	(WIN8_SRV_MAJOR << 16 | WIN8_SRV_MINOR)
+
+#define FCOPY_DEVICE_PATH(subdir) \
+	"/sys/bus/vmbus/devices/eb765408-105f-49b6-b4aa-c123b64d17d4/" #subdir
+#define FCOPY_UIO_PATH          FCOPY_DEVICE_PATH(uio)
+#define FCOPY_CHANNELS_PATH     FCOPY_DEVICE_PATH(channels)
+
+#define FCOPY_VER_COUNT		1
+static const int fcopy_versions[] = {
+	WIN8_SRV_VERSION
+};
+
+#define FW_VER_COUNT		1
+static const int fw_versions[] = {
+	UTIL_FW_VERSION
+};
+
+static uint32_t get_ring_buffer_size(void)
+{
+	char ring_path[PATH_MAX];
+	DIR *dir;
+	struct dirent *entry;
+	struct stat st;
+	uint32_t ring_size = 0;
+	int retry_count = 0;
+
+	/* Find the channel directory */
+	dir = opendir(FCOPY_CHANNELS_PATH);
+	if (!dir) {
+		usleep(100 * 1000); /* Avoid race with kernel, wait 100ms and retry once */
+		dir = opendir(FCOPY_CHANNELS_PATH);
+		if (!dir) {
+			syslog(LOG_ERR, "Failed to open channels directory: %s", strerror(errno));
+			return 0;
+		}
+	}
+
+retry_once:
+	while ((entry = readdir(dir)) != NULL) {
+		if (entry->d_type == DT_DIR && strcmp(entry->d_name, ".") != 0 &&
+		    strcmp(entry->d_name, "..") != 0) {
+			snprintf(ring_path, sizeof(ring_path), "%s/%s/ring",
+				 FCOPY_CHANNELS_PATH, entry->d_name);
+
+			if (stat(ring_path, &st) == 0) {
+				/*
+				 * stat returns size of Tx, Rx rings combined,
+				 * so take half of it for individual ring size.
+				 */
+				ring_size = (uint32_t)st.st_size / 2;
+				syslog(LOG_INFO, "Ring buffer size from %s: %u bytes",
+				       ring_path, ring_size);
+				break;
+			}
+		}
+	}
+
+	if (!ring_size && retry_count == 0) {
+		retry_count = 1;
+		rewinddir(dir);
+		usleep(100 * 1000); /* Wait 100ms and retry once */
+		goto retry_once;
+	}
+
+	closedir(dir);
+
+	if (!ring_size)
+		syslog(LOG_ERR, "Could not determine ring size");
+
+	return ring_size;
+}
+
+static unsigned char *desc;
+
+static int target_fd;
+static char target_fname[PATH_MAX];
+static unsigned long long filesize;
+
+static int hv_fcopy_create_file(char *file_name, char *path_name, __u32 flags)
+{
+	int error = HV_E_FAIL;
+	char *q, *p;
+
+	filesize = 0;
+	p = path_name;
+	if (snprintf(target_fname, sizeof(target_fname), "%s/%s",
+		     path_name, file_name) >= sizeof(target_fname)) {
+		syslog(LOG_ERR, "target file name is too long: %s/%s", path_name, file_name);
+		goto done;
+	}
+
+	/*
+	 * Check to see if the path is already in place; if not,
+	 * create if required.
+	 */
+	while ((q = strchr(p, '/')) != NULL) {
+		if (q == p) {
+			p++;
+			continue;
+		}
+		*q = '\0';
+		if (access(path_name, F_OK)) {
+			if (flags & CREATE_PATH) {
+				if (mkdir(path_name, 0755)) {
+					syslog(LOG_ERR, "Failed to create %s",
+					       path_name);
+					goto done;
+				}
+			} else {
+				syslog(LOG_ERR, "Invalid path: %s", path_name);
+				goto done;
+			}
+		}
+		p = q + 1;
+		*q = '/';
+	}
+
+	if (!access(target_fname, F_OK)) {
+		syslog(LOG_INFO, "File: %s exists", target_fname);
+		if (!(flags & OVER_WRITE)) {
+			error = HV_ERROR_ALREADY_EXISTS;
+			goto done;
+		}
+	}
+
+	target_fd = open(target_fname,
+			 O_RDWR | O_CREAT | O_TRUNC | O_CLOEXEC, 0744);
+	if (target_fd == -1) {
+		syslog(LOG_INFO, "Open Failed: %s", strerror(errno));
+		goto done;
+	}
+
+	error = 0;
+done:
+	if (error)
+		target_fname[0] = '\0';
+	return error;
+}
+
+/* copy the data into the file */
+static int hv_copy_data(struct hv_do_fcopy *cpmsg)
+{
+	ssize_t len;
+	int ret = 0;
+
+	len = pwrite(target_fd, cpmsg->data, cpmsg->size, cpmsg->offset);
+
+	filesize += cpmsg->size;
+	if (len != cpmsg->size) {
+		switch (errno) {
+		case ENOSPC:
+			ret = HV_ERROR_DISK_FULL;
+			break;
+		default:
+			ret = HV_E_FAIL;
+			break;
+		}
+		syslog(LOG_ERR, "pwrite failed to write %llu bytes: %ld (%s)",
+		       filesize, (long)len, strerror(errno));
+	}
+
+	return ret;
+}
+
+static int hv_copy_finished(void)
+{
+	close(target_fd);
+	target_fname[0] = '\0';
+
+	return 0;
+}
+
+static void print_usage(char *argv[])
+{
+	fprintf(stderr, "Usage: %s [options]\n"
+		"Options are:\n"
+		"  -n, --no-daemon        stay in foreground, don't daemonize\n"
+		"  -h, --help             print this help\n", argv[0]);
+}
+
+static bool vmbus_prep_negotiate_resp(struct icmsg_hdr *icmsghdrp, unsigned char *buf,
+				      unsigned int buflen, const int *fw_version, int fw_vercnt,
+				const int *srv_version, int srv_vercnt,
+				int *nego_fw_version, int *nego_srv_version)
+{
+	int icframe_major, icframe_minor;
+	int icmsg_major, icmsg_minor;
+	int fw_major, fw_minor;
+	int srv_major, srv_minor;
+	int i, j;
+	bool found_match = false;
+	struct icmsg_negotiate *negop;
+
+	/* Check that there's enough space for icframe_vercnt, icmsg_vercnt */
+	if (buflen < ICMSG_HDR + offsetof(struct icmsg_negotiate, reserved)) {
+		syslog(LOG_ERR, "Invalid icmsg negotiate");
+		return false;
+	}
+
+	icmsghdrp->icmsgsize = 0x10;
+	negop = (struct icmsg_negotiate *)&buf[ICMSG_HDR];
+
+	icframe_major = negop->icframe_vercnt;
+	icframe_minor = 0;
+
+	icmsg_major = negop->icmsg_vercnt;
+	icmsg_minor = 0;
+
+	/* Validate negop packet */
+	if (icframe_major > IC_VERSION_NEGOTIATION_MAX_VER_COUNT ||
+	    icmsg_major > IC_VERSION_NEGOTIATION_MAX_VER_COUNT ||
+	    ICMSG_NEGOTIATE_PKT_SIZE(icframe_major, icmsg_major) > buflen) {
+		syslog(LOG_ERR, "Invalid icmsg negotiate - icframe_major: %u, icmsg_major: %u\n",
+		       icframe_major, icmsg_major);
+		goto fw_error;
+	}
+
+	/*
+	 * Select the framework version number we will
+	 * support.
+	 */
+
+	for (i = 0; i < fw_vercnt; i++) {
+		fw_major = (fw_version[i] >> 16);
+		fw_minor = (fw_version[i] & 0xFFFF);
+
+		for (j = 0; j < negop->icframe_vercnt; j++) {
+			if (negop->icversion_data[j].major == fw_major &&
+			    negop->icversion_data[j].minor == fw_minor) {
+				icframe_major = negop->icversion_data[j].major;
+				icframe_minor = negop->icversion_data[j].minor;
+				found_match = true;
+				break;
+			}
+		}
+
+		if (found_match)
+			break;
+	}
+
+	if (!found_match)
+		goto fw_error;
+
+	found_match = false;
+
+	for (i = 0; i < srv_vercnt; i++) {
+		srv_major = (srv_version[i] >> 16);
+		srv_minor = (srv_version[i] & 0xFFFF);
+
+		for (j = negop->icframe_vercnt;
+			(j < negop->icframe_vercnt + negop->icmsg_vercnt);
+			j++) {
+			if (negop->icversion_data[j].major == srv_major &&
+			    negop->icversion_data[j].minor == srv_minor) {
+				icmsg_major = negop->icversion_data[j].major;
+				icmsg_minor = negop->icversion_data[j].minor;
+				found_match = true;
+				break;
+			}
+		}
+
+		if (found_match)
+			break;
+	}
+
+	/*
+	 * Respond with the framework and service
+	 * version numbers we can support.
+	 */
+fw_error:
+	if (!found_match) {
+		negop->icframe_vercnt = 0;
+		negop->icmsg_vercnt = 0;
+	} else {
+		negop->icframe_vercnt = 1;
+		negop->icmsg_vercnt = 1;
+	}
+
+	if (nego_fw_version)
+		*nego_fw_version = (icframe_major << 16) | icframe_minor;
+
+	if (nego_srv_version)
+		*nego_srv_version = (icmsg_major << 16) | icmsg_minor;
+
+	negop->icversion_data[0].major = icframe_major;
+	negop->icversion_data[0].minor = icframe_minor;
+	negop->icversion_data[1].major = icmsg_major;
+	negop->icversion_data[1].minor = icmsg_minor;
+
+	return found_match;
+}
+
+static void wcstoutf8(char *dest, const __u16 *src, size_t dest_size)
+{
+	size_t len = 0;
+
+	while (len < dest_size && *src) {
+		if (src[len] < 0x80)
+			dest[len++] = (char)(*src++);
+		else
+			dest[len++] = 'X';
+	}
+
+	dest[len] = '\0';
+}
+
+static int hv_fcopy_start(struct hv_start_fcopy *smsg_in)
+{
+	/*
+	 * file_name and path_name should have same length with appropriate
+	 * member of hv_start_fcopy.
+	 */
+	char file_name[W_MAX_PATH], path_name[W_MAX_PATH];
+
+	setlocale(LC_ALL, "en_US.utf8");
+	wcstoutf8(file_name, smsg_in->file_name, W_MAX_PATH - 1);
+	wcstoutf8(path_name, smsg_in->path_name, W_MAX_PATH - 1);
+
+	return hv_fcopy_create_file(file_name, path_name, smsg_in->copy_flags);
+}
+
+static int hv_fcopy_send_data(struct hv_fcopy_hdr *fcopy_msg, int recvlen)
+{
+	int operation = fcopy_msg->operation;
+
+	/*
+	 * The  strings sent from the host are encoded in
+	 * utf16; convert it to utf8 strings.
+	 * The host assures us that the utf16 strings will not exceed
+	 * the max lengths specified. We will however, reserve room
+	 * for the string terminating character - in the utf16s_utf8s()
+	 * function we limit the size of the buffer where the converted
+	 * string is placed to W_MAX_PATH -1 to guarantee
+	 * that the strings can be properly terminated!
+	 */
+
+	switch (operation) {
+	case START_FILE_COPY:
+		return hv_fcopy_start((struct hv_start_fcopy *)fcopy_msg);
+	case WRITE_TO_FILE:
+		return hv_copy_data((struct hv_do_fcopy *)fcopy_msg);
+	case COMPLETE_FCOPY:
+		return hv_copy_finished();
+	}
+
+	return HV_E_FAIL;
+}
+
+/* process the packet recv from host */
+static int fcopy_pkt_process(struct vmbus_br *txbr)
+{
+	int ret, offset, pktlen;
+	int fcopy_srv_version;
+	const struct vmbus_chanpkt_hdr *pkt;
+	struct hv_fcopy_hdr *fcopy_msg;
+	struct icmsg_hdr *icmsghdr;
+
+	pkt = (const struct vmbus_chanpkt_hdr *)desc;
+	offset = pkt->hlen << 3;
+	pktlen = (pkt->tlen << 3) - offset;
+	icmsghdr = (struct icmsg_hdr *)&desc[offset + sizeof(struct vmbuspipe_hdr)];
+	icmsghdr->status = HV_E_FAIL;
+
+	if (icmsghdr->icmsgtype == ICMSGTYPE_NEGOTIATE) {
+		if (vmbus_prep_negotiate_resp(icmsghdr, desc + offset, pktlen, fw_versions,
+					      FW_VER_COUNT, fcopy_versions, FCOPY_VER_COUNT,
+					      NULL, &fcopy_srv_version)) {
+			syslog(LOG_INFO, "FCopy IC version %d.%d",
+			       fcopy_srv_version >> 16, fcopy_srv_version & 0xFFFF);
+			icmsghdr->status = 0;
+		}
+	} else if (icmsghdr->icmsgtype == ICMSGTYPE_FCOPY) {
+		/* Ensure recvlen is big enough to contain hv_fcopy_hdr */
+		if (pktlen < ICMSG_HDR + sizeof(struct hv_fcopy_hdr)) {
+			syslog(LOG_ERR, "Invalid Fcopy hdr. Packet length too small: %u",
+			       pktlen);
+			return -ENOBUFS;
+		}
+
+		fcopy_msg = (struct hv_fcopy_hdr *)&desc[offset + ICMSG_HDR];
+		icmsghdr->status = hv_fcopy_send_data(fcopy_msg, pktlen);
+	}
+
+	icmsghdr->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE;
+	ret = rte_vmbus_chan_send(txbr, 0x6, desc + offset, pktlen, 0);
+	if (ret) {
+		syslog(LOG_ERR, "Write to ringbuffer failed err: %d", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void fcopy_get_first_folder(char *path, char *chan_no)
+{
+	DIR *dir = opendir(path);
+	struct dirent *entry;
+
+	if (!dir) {
+		syslog(LOG_ERR, "Failed to open directory (errno=%s).\n", strerror(errno));
+		return;
+	}
+
+	while ((entry = readdir(dir)) != NULL) {
+		if (entry->d_type == DT_DIR && strcmp(entry->d_name, ".") != 0 &&
+		    strcmp(entry->d_name, "..") != 0) {
+			strcpy(chan_no, entry->d_name);
+			break;
+		}
+	}
+
+	closedir(dir);
+}
+
+int main(int argc, char *argv[])
+{
+	int fcopy_fd = -1, tmp = 1;
+	int daemonize = 1, long_index = 0, opt, ret = -EINVAL;
+	struct vmbus_br txbr, rxbr;
+	void *ring;
+	uint32_t ring_size, len;
+	char uio_name[NAME_MAX] = {0};
+	char uio_dev_path[PATH_MAX] = {0};
+
+	static struct option long_options[] = {
+		{"help",	no_argument,	   0,  'h' },
+		{"no-daemon",	no_argument,	   0,  'n' },
+		{0,		0,		   0,  0   }
+	};
+
+	while ((opt = getopt_long(argc, argv, "hn", long_options,
+				  &long_index)) != -1) {
+		switch (opt) {
+		case 'n':
+			daemonize = 0;
+			break;
+		case 'h':
+		default:
+			print_usage(argv);
+			goto exit;
+		}
+	}
+
+	if (daemonize && daemon(1, 0)) {
+		syslog(LOG_ERR, "daemon() failed; error: %s", strerror(errno));
+		goto exit;
+	}
+
+	openlog("HV_UIO_FCOPY", 0, LOG_USER);
+	syslog(LOG_INFO, "starting; pid is:%d", getpid());
+
+	ring_size = get_ring_buffer_size();
+	if (!ring_size) {
+		ret = -ENODEV;
+		goto exit;
+	}
+
+	desc = malloc(ring_size * sizeof(unsigned char));
+	if (!desc) {
+		syslog(LOG_ERR, "malloc failed for desc buffer");
+		ret = -ENOMEM;
+		goto exit;
+	}
+
+	fcopy_get_first_folder(FCOPY_UIO_PATH, uio_name);
+	snprintf(uio_dev_path, sizeof(uio_dev_path), "/dev/%s", uio_name);
+	fcopy_fd = open(uio_dev_path, O_RDWR);
+
+	if (fcopy_fd < 0) {
+		syslog(LOG_ERR, "open %s failed; error: %d %s",
+		       uio_dev_path, errno, strerror(errno));
+		ret = fcopy_fd;
+		goto free_desc;
+	}
+
+	ring = vmbus_uio_map(&fcopy_fd, ring_size);
+	if (!ring) {
+		ret = errno;
+		syslog(LOG_ERR, "mmap ringbuffer failed; error: %d %s", ret, strerror(ret));
+		goto close;
+	}
+	vmbus_br_setup(&txbr, ring, ring_size);
+	vmbus_br_setup(&rxbr, (char *)ring + ring_size, ring_size);
+
+	rxbr.vbr->imask = 0;
+
+	while (1) {
+		/*
+		 * In this loop we process fcopy messages after the
+		 * handshake is complete.
+		 */
+		ret = pread(fcopy_fd, &tmp, sizeof(int), 0);
+		if (ret < 0) {
+			if (errno == EINTR || errno == EAGAIN)
+				continue;
+			syslog(LOG_ERR, "pread failed: %s", strerror(errno));
+			goto close;
+		}
+
+		len = ring_size;
+		ret = rte_vmbus_chan_recv_raw(&rxbr, desc, &len);
+		if (unlikely(ret <= 0)) {
+			/* This indicates a failure to communicate (or worse) */
+			syslog(LOG_ERR, "VMBus channel recv error: %d", ret);
+		} else {
+			ret = fcopy_pkt_process(&txbr);
+			if (ret < 0)
+				goto close;
+
+			/* Signal host */
+			if ((write(fcopy_fd, &tmp, sizeof(int))) != sizeof(int)) {
+				ret = errno;
+				syslog(LOG_ERR, "Signal to host failed: %s\n", strerror(ret));
+				goto close;
+			}
+		}
+	}
+close:
+	close(fcopy_fd);
+free_desc:
+	free(desc);
+exit:
+	return ret;
+}
diff --git a/tools/hv/hv_get_dhcp_info.sh b/tools/hv/hv_get_dhcp_info.sh
new file mode 100755
index 000000000..2f2a3c7df
--- /dev/null
+++ b/tools/hv/hv_get_dhcp_info.sh
@@ -0,0 +1,29 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+# This example script retrieves the DHCP state of a given interface.
+# In the interest of keeping the KVP daemon code free of distro specific
+# information; the kvp daemon code invokes this external script to gather
+# DHCP setting for the specific interface.
+#
+# Input: Name of the interface
+#
+# Output: The script prints the string "Enabled" to stdout to indicate
+#	that DHCP is enabled on the interface. If DHCP is not enabled,
+#	the script prints the string "Disabled" to stdout.
+#
+# Each Distro is expected to implement this script in a distro specific
+# fashion. For instance, on Distros that ship with Network Manager enabled,
+# this script can be based on the Network Manager APIs for retrieving DHCP
+# information.
+
+if_file="/etc/sysconfig/network-scripts/ifcfg-"$1
+
+dhcp=$(grep "dhcp" $if_file 2>/dev/null)
+
+if [ "$dhcp" != "" ];
+then
+echo "Enabled"
+else
+echo "Disabled"
+fi
diff --git a/tools/hv/hv_get_dns_info.sh b/tools/hv/hv_get_dns_info.sh
new file mode 100755
index 000000000..268521234
--- /dev/null
+++ b/tools/hv/hv_get_dns_info.sh
@@ -0,0 +1,13 @@
+#!/bin/sh
+
+# This example script parses /etc/resolv.conf to retrive DNS information.
+# In the interest of keeping the KVP daemon code free of distro specific
+# information; the kvp daemon code invokes this external script to gather
+# DNS information.
+# This script is expected to print the nameserver values to stdout.
+# Each Distro is expected to implement this script in a distro specific
+# fashion. For instance on Distros that ship with Network Manager enabled,
+# this script can be based on the Network Manager APIs for retrieving DNS
+# entries.
+
+exec awk '/^nameserver/ { print $2 }' /etc/resolv.conf 2>/dev/null
diff --git a/tools/hv/hv_kvp_daemon.c b/tools/hv/hv_kvp_daemon.c
new file mode 100644
index 000000000..1f64c680b
--- /dev/null
+++ b/tools/hv/hv_kvp_daemon.c
@@ -0,0 +1,2059 @@
+/*
+ * An implementation of key value pair (KVP) functionality for Linux.
+ *
+ *
+ * Copyright (C) 2010, Novell, Inc.
+ * Author : K. Y. Srinivasan <ksrinivasan@novell.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ * NON INFRINGEMENT.  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, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+
+#include <sys/poll.h>
+#include <sys/utsname.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <ctype.h>
+#include <errno.h>
+#include <arpa/inet.h>
+#include <linux/hyperv.h>
+#include <ifaddrs.h>
+#include <netdb.h>
+#include <syslog.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <dirent.h>
+#include <net/if.h>
+#include <limits.h>
+#include <getopt.h>
+
+/*
+ * KVP protocol: The user mode component first registers with the
+ * kernel component. Subsequently, the kernel component requests, data
+ * for the specified keys. In response to this message the user mode component
+ * fills in the value corresponding to the specified key. We overload the
+ * sequence field in the cn_msg header to define our KVP message types.
+ *
+ * We use this infrastructure for also supporting queries from user mode
+ * application for state that may be maintained in the KVP kernel component.
+ *
+ */
+
+
+enum key_index {
+	FullyQualifiedDomainName = 0,
+	IntegrationServicesVersion, /*This key is serviced in the kernel*/
+	NetworkAddressIPv4,
+	NetworkAddressIPv6,
+	OSBuildNumber,
+	OSName,
+	OSMajorVersion,
+	OSMinorVersion,
+	OSVersion,
+	ProcessorArchitecture
+};
+
+
+enum {
+	IPADDR = 0,
+	NETMASK,
+	GATEWAY,
+	DNS
+};
+
+enum {
+	IPV4 = 1,
+	IPV6,
+	IP_TYPE_MAX
+};
+
+static int in_hand_shake;
+static int debug;
+
+static char *os_name = "";
+static char *os_major = "";
+static char *os_minor = "";
+static char *processor_arch;
+static char *os_build;
+static char *os_version;
+static char *lic_version = "Unknown version";
+static char full_domain_name[HV_KVP_EXCHANGE_MAX_VALUE_SIZE];
+static struct utsname uts_buf;
+
+/*
+ * The location of the interface configuration file.
+ */
+
+#define KVP_CONFIG_LOC	"/var/lib/hyperv"
+
+#ifndef KVP_SCRIPTS_PATH
+#define KVP_SCRIPTS_PATH "/usr/libexec/hypervkvpd/"
+#endif
+
+#define KVP_NET_DIR "/sys/class/net/"
+
+#define MAX_FILE_NAME 100
+#define ENTRIES_PER_BLOCK 50
+/*
+ * Change this entry if the number of addresses increases in future
+ */
+#define MAX_IP_ENTRIES 64
+#define OUTSTR_BUF_SIZE ((INET6_ADDRSTRLEN + 1) * MAX_IP_ENTRIES)
+
+struct kvp_record {
+	char key[HV_KVP_EXCHANGE_MAX_KEY_SIZE];
+	char value[HV_KVP_EXCHANGE_MAX_VALUE_SIZE];
+};
+
+struct kvp_file_state {
+	int fd;
+	int num_blocks;
+	struct kvp_record *records;
+	int num_records;
+	char fname[MAX_FILE_NAME];
+};
+
+static struct kvp_file_state kvp_file_info[KVP_POOL_COUNT];
+
+static void kvp_acquire_lock(int pool)
+{
+	struct flock fl = {F_WRLCK, SEEK_SET, 0, 0, 0};
+	fl.l_pid = getpid();
+
+	if (fcntl(kvp_file_info[pool].fd, F_SETLKW, &fl) == -1) {
+		syslog(LOG_ERR, "Failed to acquire the lock pool: %d; error: %d %s", pool,
+				errno, strerror(errno));
+		exit(EXIT_FAILURE);
+	}
+}
+
+static void kvp_release_lock(int pool)
+{
+	struct flock fl = {F_UNLCK, SEEK_SET, 0, 0, 0};
+	fl.l_pid = getpid();
+
+	if (fcntl(kvp_file_info[pool].fd, F_SETLK, &fl) == -1) {
+		syslog(LOG_ERR, "Failed to release the lock pool: %d; error: %d %s", pool,
+				errno, strerror(errno));
+		exit(EXIT_FAILURE);
+	}
+}
+
+static void kvp_update_file(int pool)
+{
+	FILE *filep;
+
+	/*
+	 * We are going to write our in-memory registry out to
+	 * disk; acquire the lock first.
+	 */
+	kvp_acquire_lock(pool);
+
+	filep = fopen(kvp_file_info[pool].fname, "we");
+	if (!filep) {
+		syslog(LOG_ERR, "Failed to open file, pool: %d; error: %d %s", pool,
+				errno, strerror(errno));
+		kvp_release_lock(pool);
+		exit(EXIT_FAILURE);
+	}
+
+	fwrite(kvp_file_info[pool].records, sizeof(struct kvp_record),
+				kvp_file_info[pool].num_records, filep);
+
+	if (ferror(filep) || fclose(filep)) {
+		kvp_release_lock(pool);
+		syslog(LOG_ERR, "Failed to write file, pool: %d", pool);
+		exit(EXIT_FAILURE);
+	}
+
+	kvp_release_lock(pool);
+}
+
+static void kvp_dump_initial_pools(int pool)
+{
+	int i;
+
+	syslog(LOG_DEBUG, "===Start dumping the contents of pool %d ===\n",
+	       pool);
+
+	for (i = 0; i < kvp_file_info[pool].num_records; i++)
+		syslog(LOG_DEBUG, "pool: %d, %d/%d key=%s val=%s\n",
+		       pool, i + 1, kvp_file_info[pool].num_records,
+		       kvp_file_info[pool].records[i].key,
+		       kvp_file_info[pool].records[i].value);
+}
+
+static void kvp_update_mem_state(int pool)
+{
+	FILE *filep;
+	size_t records_read = 0;
+	struct kvp_record *record = kvp_file_info[pool].records;
+	struct kvp_record *readp;
+	int num_blocks = kvp_file_info[pool].num_blocks;
+	int alloc_unit = sizeof(struct kvp_record) * ENTRIES_PER_BLOCK;
+
+	kvp_acquire_lock(pool);
+
+	filep = fopen(kvp_file_info[pool].fname, "re");
+	if (!filep) {
+		syslog(LOG_ERR, "Failed to open file, pool: %d; error: %d %s", pool,
+				errno, strerror(errno));
+		kvp_release_lock(pool);
+		exit(EXIT_FAILURE);
+	}
+	for (;;) {
+		readp = &record[records_read];
+		records_read += fread(readp, sizeof(struct kvp_record),
+				ENTRIES_PER_BLOCK * num_blocks - records_read,
+				filep);
+
+		if (ferror(filep)) {
+			syslog(LOG_ERR,
+				"Failed to read file, pool: %d; error: %d %s",
+				 pool, errno, strerror(errno));
+			kvp_release_lock(pool);
+			exit(EXIT_FAILURE);
+		}
+
+		if (!feof(filep)) {
+			/*
+			 * We have more data to read.
+			 */
+			num_blocks++;
+			record = realloc(record, alloc_unit * num_blocks);
+
+			if (record == NULL) {
+				syslog(LOG_ERR, "malloc failed");
+				kvp_release_lock(pool);
+				exit(EXIT_FAILURE);
+			}
+			continue;
+		}
+		break;
+	}
+
+	kvp_file_info[pool].num_blocks = num_blocks;
+	kvp_file_info[pool].records = record;
+	kvp_file_info[pool].num_records = records_read;
+
+	fclose(filep);
+	kvp_release_lock(pool);
+}
+
+static int kvp_file_init(void)
+{
+	int  fd;
+	char *fname;
+	int i;
+	int alloc_unit = sizeof(struct kvp_record) * ENTRIES_PER_BLOCK;
+
+	if (access(KVP_CONFIG_LOC, F_OK)) {
+		if (mkdir(KVP_CONFIG_LOC, 0755 /* rwxr-xr-x */)) {
+			syslog(LOG_ERR, "Failed to create '%s'; error: %d %s", KVP_CONFIG_LOC,
+					errno, strerror(errno));
+			exit(EXIT_FAILURE);
+		}
+	}
+
+	for (i = 0; i < KVP_POOL_COUNT; i++) {
+		fname = kvp_file_info[i].fname;
+		sprintf(fname, "%s/.kvp_pool_%d", KVP_CONFIG_LOC, i);
+		fd = open(fname, O_RDWR | O_CREAT | O_CLOEXEC, 0644 /* rw-r--r-- */);
+
+		if (fd == -1)
+			return 1;
+
+		kvp_file_info[i].fd = fd;
+		kvp_file_info[i].num_blocks = 1;
+		kvp_file_info[i].records = malloc(alloc_unit);
+		if (kvp_file_info[i].records == NULL)
+			return 1;
+		kvp_file_info[i].num_records = 0;
+		kvp_update_mem_state(i);
+		if (debug)
+			kvp_dump_initial_pools(i);
+	}
+
+	return 0;
+}
+
+static int kvp_key_delete(int pool, const __u8 *key, int key_size)
+{
+	int i;
+	int j, k;
+	int num_records;
+	struct kvp_record *record;
+
+	/*
+	 * First update the in-memory state.
+	 */
+	kvp_update_mem_state(pool);
+
+	num_records = kvp_file_info[pool].num_records;
+	record = kvp_file_info[pool].records;
+
+	for (i = 0; i < num_records; i++) {
+		if (memcmp(key, record[i].key, key_size))
+			continue;
+		/*
+		 * Found a match; just move the remaining
+		 * entries up.
+		 */
+		if (debug)
+			syslog(LOG_DEBUG, "%s: deleting the KVP: pool=%d key=%s val=%s",
+			       __func__, pool, record[i].key, record[i].value);
+		if (i == (num_records - 1)) {
+			kvp_file_info[pool].num_records--;
+			kvp_update_file(pool);
+			return 0;
+		}
+
+		j = i;
+		k = j + 1;
+		for (; k < num_records; k++) {
+			strcpy(record[j].key, record[k].key);
+			strcpy(record[j].value, record[k].value);
+			j++;
+		}
+
+		kvp_file_info[pool].num_records--;
+		kvp_update_file(pool);
+		return 0;
+	}
+
+	if (debug)
+		syslog(LOG_DEBUG, "%s: could not delete KVP: pool=%d key=%s. Record not found",
+		       __func__, pool, key);
+
+	return 1;
+}
+
+static int kvp_key_add_or_modify(int pool, const __u8 *key, int key_size,
+				 const __u8 *value, int value_size)
+{
+	struct kvp_record *record;
+	int num_records;
+	int num_blocks;
+	int i;
+
+	if (debug)
+		syslog(LOG_DEBUG, "%s: got a KVP: pool=%d key=%s val=%s",
+		       __func__, pool, key, value);
+
+	if ((key_size > HV_KVP_EXCHANGE_MAX_KEY_SIZE) ||
+		(value_size > HV_KVP_EXCHANGE_MAX_VALUE_SIZE)) {
+		syslog(LOG_ERR, "%s: Too long key or value: key=%s, val=%s",
+		       __func__, key, value);
+
+		if (debug)
+			syslog(LOG_DEBUG, "%s: Too long key or value: pool=%d, key=%s, val=%s",
+			       __func__, pool, key, value);
+		return 1;
+	}
+
+	/*
+	 * First update the in-memory state.
+	 */
+	kvp_update_mem_state(pool);
+
+	num_records = kvp_file_info[pool].num_records;
+	record = kvp_file_info[pool].records;
+	num_blocks = kvp_file_info[pool].num_blocks;
+
+	for (i = 0; i < num_records; i++) {
+		if (memcmp(key, record[i].key, key_size))
+			continue;
+		/*
+		 * Found a match; just update the value -
+		 * this is the modify case.
+		 */
+		memcpy(record[i].value, value, value_size);
+		kvp_update_file(pool);
+		if (debug)
+			syslog(LOG_DEBUG, "%s: updated: pool=%d key=%s val=%s",
+			       __func__, pool, key, value);
+		return 0;
+	}
+
+	/*
+	 * Need to add a new entry;
+	 */
+	if (num_records == (ENTRIES_PER_BLOCK * num_blocks)) {
+		/* Need to allocate a larger array for reg entries. */
+		record = realloc(record, sizeof(struct kvp_record) *
+			 ENTRIES_PER_BLOCK * (num_blocks + 1));
+
+		if (!record) {
+			syslog(LOG_ERR, "%s: Memory alloc failure", __func__);
+			return 1;
+		}
+		kvp_file_info[pool].num_blocks++;
+
+	}
+	memcpy(record[i].value, value, value_size);
+	memcpy(record[i].key, key, key_size);
+	kvp_file_info[pool].records = record;
+	kvp_file_info[pool].num_records++;
+
+	if (debug)
+		syslog(LOG_DEBUG, "%s: added: pool=%d key=%s val=%s",
+		       __func__, pool, key, value);
+
+	kvp_update_file(pool);
+	return 0;
+}
+
+static int kvp_get_value(int pool, const __u8 *key, int key_size, __u8 *value,
+			int value_size)
+{
+	int i;
+	int num_records;
+	struct kvp_record *record;
+
+	if ((key_size > HV_KVP_EXCHANGE_MAX_KEY_SIZE) ||
+		(value_size > HV_KVP_EXCHANGE_MAX_VALUE_SIZE))
+		return 1;
+
+	/*
+	 * First update the in-memory state.
+	 */
+	kvp_update_mem_state(pool);
+
+	num_records = kvp_file_info[pool].num_records;
+	record = kvp_file_info[pool].records;
+
+	for (i = 0; i < num_records; i++) {
+		if (memcmp(key, record[i].key, key_size))
+			continue;
+		/*
+		 * Found a match; just copy the value out.
+		 */
+		memcpy(value, record[i].value, value_size);
+		return 0;
+	}
+
+	return 1;
+}
+
+static int kvp_pool_enumerate(int pool, int index, __u8 *key, int key_size,
+				__u8 *value, int value_size)
+{
+	struct kvp_record *record;
+
+	/*
+	 * First update our in-memory database.
+	 */
+	kvp_update_mem_state(pool);
+	record = kvp_file_info[pool].records;
+
+	if (index >= kvp_file_info[pool].num_records) {
+		return 1;
+	}
+
+	memcpy(key, record[index].key, key_size);
+	memcpy(value, record[index].value, value_size);
+	return 0;
+}
+
+
+void kvp_get_os_info(void)
+{
+	FILE	*file;
+	char	*p, buf[512];
+
+	uname(&uts_buf);
+	os_version = uts_buf.release;
+	os_build = strdup(uts_buf.release);
+
+	os_name = uts_buf.sysname;
+	processor_arch = uts_buf.machine;
+
+	/*
+	 * The current windows host (win7) expects the build
+	 * string to be of the form: x.y.z
+	 * Strip additional information we may have.
+	 */
+	p = strchr(os_version, '-');
+	if (p)
+		*p = '\0';
+
+	/*
+	 * Parse the /etc/os-release file if present:
+	 * https://www.freedesktop.org/software/systemd/man/os-release.html
+	 */
+	file = fopen("/etc/os-release", "r");
+	if (file != NULL) {
+		while (fgets(buf, sizeof(buf), file)) {
+			char *value, *q;
+
+			/* Ignore comments */
+			if (buf[0] == '#')
+				continue;
+
+			/* Split into name=value */
+			p = strchr(buf, '=');
+			if (!p)
+				continue;
+			*p++ = 0;
+
+			/* Remove quotes and newline; un-escape */
+			value = p;
+			q = p;
+			while (*p) {
+				if (*p == '\\') {
+					++p;
+					if (!*p)
+						break;
+					*q++ = *p++;
+				} else if (*p == '\'' || *p == '"' ||
+					   *p == '\n') {
+					++p;
+				} else {
+					*q++ = *p++;
+				}
+			}
+			*q = 0;
+
+			if (!strcmp(buf, "NAME")) {
+				p = strdup(value);
+				if (!p)
+					break;
+				os_name = p;
+			} else if (!strcmp(buf, "VERSION_ID")) {
+				p = strdup(value);
+				if (!p)
+					break;
+				os_major = p;
+			}
+		}
+		fclose(file);
+		return;
+	}
+
+	/* Fallback for older RH/SUSE releases */
+	file = fopen("/etc/SuSE-release", "r");
+	if (file != NULL)
+		goto kvp_osinfo_found;
+	file  = fopen("/etc/redhat-release", "r");
+	if (file != NULL)
+		goto kvp_osinfo_found;
+
+	/*
+	 * We don't have information about the os.
+	 */
+	return;
+
+kvp_osinfo_found:
+	/* up to three lines */
+	p = fgets(buf, sizeof(buf), file);
+	if (p) {
+		p = strchr(buf, '\n');
+		if (p)
+			*p = '\0';
+		p = strdup(buf);
+		if (!p)
+			goto done;
+		os_name = p;
+
+		/* second line */
+		p = fgets(buf, sizeof(buf), file);
+		if (p) {
+			p = strchr(buf, '\n');
+			if (p)
+				*p = '\0';
+			p = strdup(buf);
+			if (!p)
+				goto done;
+			os_major = p;
+
+			/* third line */
+			p = fgets(buf, sizeof(buf), file);
+			if (p)  {
+				p = strchr(buf, '\n');
+				if (p)
+					*p = '\0';
+				p = strdup(buf);
+				if (p)
+					os_minor = p;
+			}
+		}
+	}
+
+done:
+	fclose(file);
+	return;
+}
+
+
+
+/*
+ * Retrieve an interface name corresponding to the specified guid.
+ * If there is a match, the function returns a pointer
+ * to the interface name and if not, a NULL is returned.
+ * If a match is found, the caller is responsible for
+ * freeing the memory.
+ */
+
+static char *kvp_get_if_name(char *guid)
+{
+	DIR *dir;
+	struct dirent *entry;
+	FILE    *file;
+	char    *p, *x;
+	char    *if_name = NULL;
+	char    buf[256];
+	char dev_id[PATH_MAX];
+
+	dir = opendir(KVP_NET_DIR);
+	if (dir == NULL)
+		return NULL;
+
+	while ((entry = readdir(dir)) != NULL) {
+		/*
+		 * Set the state for the next pass.
+		 */
+		snprintf(dev_id, sizeof(dev_id), "%s%s/device/device_id",
+			 KVP_NET_DIR, entry->d_name);
+
+		file = fopen(dev_id, "r");
+		if (file == NULL)
+			continue;
+
+		p = fgets(buf, sizeof(buf), file);
+		if (p) {
+			x = strchr(p, '\n');
+			if (x)
+				*x = '\0';
+
+			if (!strcmp(p, guid)) {
+				/*
+				 * Found the guid match; return the interface
+				 * name. The caller will free the memory.
+				 */
+				if_name = strdup(entry->d_name);
+				fclose(file);
+				break;
+			}
+		}
+		fclose(file);
+	}
+
+	closedir(dir);
+	return if_name;
+}
+
+/*
+ * Retrieve the MAC address given the interface name.
+ */
+
+static char *kvp_if_name_to_mac(char *if_name)
+{
+	FILE    *file;
+	char    *p, *x;
+	char    buf[256];
+	char addr_file[PATH_MAX];
+	unsigned int i;
+	char *mac_addr = NULL;
+
+	snprintf(addr_file, sizeof(addr_file), "%s%s%s", KVP_NET_DIR,
+		 if_name, "/address");
+
+	file = fopen(addr_file, "r");
+	if (file == NULL)
+		return NULL;
+
+	p = fgets(buf, sizeof(buf), file);
+	if (p) {
+		x = strchr(p, '\n');
+		if (x)
+			*x = '\0';
+		for (i = 0; i < strlen(p); i++)
+			p[i] = toupper(p[i]);
+		mac_addr = strdup(p);
+	}
+
+	fclose(file);
+	return mac_addr;
+}
+
+static void kvp_process_ipconfig_file(char *cmd,
+					char *config_buf, unsigned int len,
+					int element_size, int offset)
+{
+	char buf[256];
+	char *p;
+	char *x;
+	FILE *file;
+
+	/*
+	 * First execute the command.
+	 */
+	file = popen(cmd, "r");
+	if (file == NULL)
+		return;
+
+	if (offset == 0)
+		memset(config_buf, 0, len);
+	while ((p = fgets(buf, sizeof(buf), file)) != NULL) {
+		if (len < strlen(config_buf) + element_size + 1)
+			break;
+
+		x = strchr(p, '\n');
+		if (x)
+			*x = '\0';
+
+		strcat(config_buf, p);
+		strcat(config_buf, ";");
+	}
+	pclose(file);
+}
+
+static bool kvp_verify_ip_address(const void *address_string)
+{
+	char verify_buf[sizeof(struct in6_addr)];
+
+	if (inet_pton(AF_INET, address_string, verify_buf) == 1)
+		return true;
+	if (inet_pton(AF_INET6, address_string, verify_buf) == 1)
+		return true;
+	return false;
+}
+
+static void kvp_extract_routes(const char *line, void **output, size_t *remaining)
+{
+	static const char needle[] = "via ";
+	const char *match, *haystack = line;
+
+	while ((match = strstr(haystack, needle))) {
+		const char *address, *next_char;
+
+		/* Address starts after needle. */
+		address = match + strlen(needle);
+
+		/* The char following address is a space or end of line. */
+		next_char = strpbrk(address, " \t\\");
+		if (!next_char)
+			next_char = address + strlen(address) + 1;
+
+		/* Enough room for address and semicolon. */
+		if (*remaining >= (next_char - address) + 1) {
+			memcpy(*output, address, next_char - address);
+			/* Terminate string for verification. */
+			memcpy(*output + (next_char - address), "", 1);
+			if (kvp_verify_ip_address(*output)) {
+				/* Advance output buffer. */
+				*output += next_char - address;
+				*remaining -= next_char - address;
+
+				/* Each address needs a trailing semicolon. */
+				memcpy(*output, ";", 1);
+				*output += 1;
+				*remaining -= 1;
+			}
+		}
+		haystack = next_char;
+	}
+}
+
+static void kvp_get_gateway(void *buffer, size_t buffer_len)
+{
+	static const char needle[] = "default ";
+	FILE *f;
+	void *output = buffer;
+	char *line = NULL;
+	size_t alloc_size = 0, remaining = buffer_len - 1;
+	ssize_t num_chars;
+
+	/* Show route information in a single line, for each address family */
+	f = popen("ip --oneline -4 route show;ip --oneline -6 route show", "r");
+	if (!f) {
+		/* Convert buffer into C-String. */
+		memcpy(output, "", 1);
+		return;
+	}
+	while ((num_chars = getline(&line, &alloc_size, f)) > 0) {
+		/* Skip short lines. */
+		if (num_chars <= strlen(needle))
+			continue;
+		/* Skip lines without default route. */
+		if (memcmp(line, needle, strlen(needle)))
+			continue;
+		/* Remove trailing newline to simplify further parsing. */
+		if (line[num_chars - 1] == '\n')
+			line[num_chars - 1] = '\0';
+		/* Search routes after match. */
+		kvp_extract_routes(line + strlen(needle), &output, &remaining);
+	}
+	/* Convert buffer into C-String. */
+	memcpy(output, "", 1);
+	free(line);
+	pclose(f);
+}
+
+static void kvp_get_ipconfig_info(char *if_name,
+				 struct hv_kvp_ipaddr_value *buffer)
+{
+	char cmd[512];
+	char dhcp_info[128];
+	char *p;
+	FILE *file;
+
+	kvp_get_gateway(buffer->gate_way, sizeof(buffer->gate_way));
+
+	/*
+	 * Gather the DNS state.
+	 * Since there is no standard way to get this information
+	 * across various distributions of interest; we just invoke
+	 * an external script that needs to be ported across distros
+	 * of interest.
+	 *
+	 * Following is the expected format of the information from the script:
+	 *
+	 * ipaddr1 (nameserver1)
+	 * ipaddr2 (nameserver2)
+	 * .
+	 * .
+	 */
+
+	sprintf(cmd, "exec %s %s", KVP_SCRIPTS_PATH "hv_get_dns_info", if_name);
+
+	/*
+	 * Execute the command to gather DNS info.
+	 */
+	kvp_process_ipconfig_file(cmd, (char *)buffer->dns_addr,
+				(MAX_IP_ADDR_SIZE * 2), INET_ADDRSTRLEN, 0);
+
+	/*
+	 * Gather the DHCP state.
+	 * We will gather this state by invoking an external script.
+	 * The parameter to the script is the interface name.
+	 * Here is the expected output:
+	 *
+	 * Enabled: DHCP enabled.
+	 */
+
+	sprintf(cmd, "exec %s %s", KVP_SCRIPTS_PATH "hv_get_dhcp_info", if_name);
+
+	file = popen(cmd, "r");
+	if (file == NULL)
+		return;
+
+	p = fgets(dhcp_info, sizeof(dhcp_info), file);
+	if (p == NULL) {
+		pclose(file);
+		return;
+	}
+
+	if (!strncmp(p, "Enabled", 7))
+		buffer->dhcp_enabled = 1;
+	else
+		buffer->dhcp_enabled = 0;
+
+	pclose(file);
+}
+
+
+static unsigned int hweight32(unsigned int *w)
+{
+	unsigned int res = *w - ((*w >> 1) & 0x55555555);
+	res = (res & 0x33333333) + ((res >> 2) & 0x33333333);
+	res = (res + (res >> 4)) & 0x0F0F0F0F;
+	res = res + (res >> 8);
+	return (res + (res >> 16)) & 0x000000FF;
+}
+
+static int kvp_process_ip_address(void *addrp,
+				int family, char *buffer,
+				int length,  int *offset)
+{
+	struct sockaddr_in *addr;
+	struct sockaddr_in6 *addr6;
+	int addr_length;
+	char tmp[50];
+	const char *str;
+
+	if (family == AF_INET) {
+		addr = addrp;
+		str = inet_ntop(family, &addr->sin_addr, tmp, 50);
+		addr_length = INET_ADDRSTRLEN;
+	} else {
+		addr6 = addrp;
+		str = inet_ntop(family, &addr6->sin6_addr.s6_addr, tmp, 50);
+		addr_length = INET6_ADDRSTRLEN;
+	}
+
+	if ((length - *offset) < addr_length + 2)
+		return HV_E_FAIL;
+	if (str == NULL) {
+		strcpy(buffer, "inet_ntop failed\n");
+		return HV_E_FAIL;
+	}
+	if (*offset == 0)
+		strcpy(buffer, tmp);
+	else {
+		strcat(buffer, ";");
+		strcat(buffer, tmp);
+	}
+
+	*offset += strlen(str) + 1;
+
+	return 0;
+}
+
+static int
+kvp_get_ip_info(int family, char *if_name, int op,
+		 void  *out_buffer, unsigned int length)
+{
+	struct ifaddrs *ifap;
+	struct ifaddrs *curp;
+	int offset = 0;
+	int sn_offset = 0;
+	int error = 0;
+	char *buffer;
+	struct hv_kvp_ipaddr_value *ip_buffer = NULL;
+	char cidr_mask[5]; /* /xyz */
+	int weight;
+	int i;
+	unsigned int *w;
+	char *sn_str;
+	struct sockaddr_in6 *addr6;
+
+	if (op == KVP_OP_ENUMERATE) {
+		buffer = out_buffer;
+	} else {
+		ip_buffer = out_buffer;
+		buffer = (char *)ip_buffer->ip_addr;
+		ip_buffer->addr_family = 0;
+	}
+	/*
+	 * On entry into this function, the buffer is capable of holding the
+	 * maximum key value.
+	 */
+
+	if (getifaddrs(&ifap)) {
+		strcpy(buffer, "getifaddrs failed\n");
+		return HV_E_FAIL;
+	}
+
+	curp = ifap;
+	while (curp != NULL) {
+		if (curp->ifa_addr == NULL) {
+			curp = curp->ifa_next;
+			continue;
+		}
+
+		if ((if_name != NULL) &&
+			(strncmp(curp->ifa_name, if_name, strlen(if_name)))) {
+			/*
+			 * We want info about a specific interface;
+			 * just continue.
+			 */
+			curp = curp->ifa_next;
+			continue;
+		}
+
+		/*
+		 * We only support two address families: AF_INET and AF_INET6.
+		 * If a family value of 0 is specified, we collect both
+		 * supported address families; if not we gather info on
+		 * the specified address family.
+		 */
+		if ((((family != 0) &&
+			 (curp->ifa_addr->sa_family != family))) ||
+			 (curp->ifa_flags & IFF_LOOPBACK)) {
+			curp = curp->ifa_next;
+			continue;
+		}
+		if ((curp->ifa_addr->sa_family != AF_INET) &&
+			(curp->ifa_addr->sa_family != AF_INET6)) {
+			curp = curp->ifa_next;
+			continue;
+		}
+
+		if (op == KVP_OP_GET_IP_INFO) {
+			/*
+			 * Gather info other than the IP address.
+			 * IP address info will be gathered later.
+			 */
+			if (curp->ifa_addr->sa_family == AF_INET) {
+				ip_buffer->addr_family |= ADDR_FAMILY_IPV4;
+				/*
+				 * Get subnet info.
+				 */
+				error = kvp_process_ip_address(
+							     curp->ifa_netmask,
+							     AF_INET,
+							     (char *)
+							     ip_buffer->sub_net,
+							     length,
+							     &sn_offset);
+				if (error)
+					goto gather_ipaddr;
+			} else {
+				ip_buffer->addr_family |= ADDR_FAMILY_IPV6;
+
+				/*
+				 * Get subnet info in CIDR format.
+				 */
+				weight = 0;
+				sn_str = (char *)ip_buffer->sub_net;
+				addr6 = (struct sockaddr_in6 *)
+					curp->ifa_netmask;
+				w = addr6->sin6_addr.s6_addr32;
+
+				for (i = 0; i < 4; i++)
+					weight += hweight32(&w[i]);
+
+				sprintf(cidr_mask, "/%d", weight);
+				if (length < sn_offset + strlen(cidr_mask) + 1)
+					goto gather_ipaddr;
+
+				if (sn_offset == 0)
+					strcpy(sn_str, cidr_mask);
+				else {
+					strcat((char *)ip_buffer->sub_net, ";");
+					strcat(sn_str, cidr_mask);
+				}
+				sn_offset += strlen(sn_str) + 1;
+			}
+
+			/*
+			 * Collect other ip related configuration info.
+			 */
+
+			kvp_get_ipconfig_info(if_name, ip_buffer);
+		}
+
+gather_ipaddr:
+		error = kvp_process_ip_address(curp->ifa_addr,
+						curp->ifa_addr->sa_family,
+						buffer,
+						length, &offset);
+		if (error)
+			goto getaddr_done;
+
+		curp = curp->ifa_next;
+	}
+
+getaddr_done:
+	freeifaddrs(ifap);
+	return error;
+}
+
+/*
+ * Retrieve the IP given the MAC address.
+ */
+static int kvp_mac_to_ip(struct hv_kvp_ipaddr_value *kvp_ip_val)
+{
+	char *mac = (char *)kvp_ip_val->adapter_id;
+	DIR *dir;
+	struct dirent *entry;
+	FILE    *file;
+	char    *p, *x;
+	char    *if_name = NULL;
+	char    buf[256];
+	char dev_id[PATH_MAX];
+	unsigned int i;
+	int error = HV_E_FAIL;
+
+	dir = opendir(KVP_NET_DIR);
+	if (dir == NULL)
+		return HV_E_FAIL;
+
+	while ((entry = readdir(dir)) != NULL) {
+		/*
+		 * Set the state for the next pass.
+		 */
+		snprintf(dev_id, sizeof(dev_id), "%s%s/address", KVP_NET_DIR,
+			 entry->d_name);
+
+		file = fopen(dev_id, "r");
+		if (file == NULL)
+			continue;
+
+		p = fgets(buf, sizeof(buf), file);
+		fclose(file);
+		if (!p)
+			continue;
+
+		x = strchr(p, '\n');
+		if (x)
+			*x = '\0';
+
+		for (i = 0; i < strlen(p); i++)
+			p[i] = toupper(p[i]);
+
+		if (strcmp(p, mac))
+			continue;
+
+		/*
+		 * Found the MAC match.
+		 * A NIC (e.g. VF) matching the MAC, but without IP, is skipped.
+		 */
+		if_name = entry->d_name;
+		if (!if_name)
+			continue;
+
+		error = kvp_get_ip_info(0, if_name, KVP_OP_GET_IP_INFO,
+					kvp_ip_val, MAX_IP_ADDR_SIZE * 2);
+
+		if (!error && strlen((char *)kvp_ip_val->ip_addr))
+			break;
+	}
+
+	closedir(dir);
+	return error;
+}
+
+static int expand_ipv6(char *addr, int type)
+{
+	int ret;
+	struct in6_addr v6_addr;
+
+	ret = inet_pton(AF_INET6, addr, &v6_addr);
+
+	if (ret != 1) {
+		if (type == NETMASK)
+			return 1;
+		return 0;
+	}
+
+	sprintf(addr, "%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:"
+		"%02x%02x:%02x%02x:%02x%02x",
+		(int)v6_addr.s6_addr[0], (int)v6_addr.s6_addr[1],
+		(int)v6_addr.s6_addr[2], (int)v6_addr.s6_addr[3],
+		(int)v6_addr.s6_addr[4], (int)v6_addr.s6_addr[5],
+		(int)v6_addr.s6_addr[6], (int)v6_addr.s6_addr[7],
+		(int)v6_addr.s6_addr[8], (int)v6_addr.s6_addr[9],
+		(int)v6_addr.s6_addr[10], (int)v6_addr.s6_addr[11],
+		(int)v6_addr.s6_addr[12], (int)v6_addr.s6_addr[13],
+		(int)v6_addr.s6_addr[14], (int)v6_addr.s6_addr[15]);
+
+	return 1;
+
+}
+
+static int is_ipv4(char *addr)
+{
+	int ret;
+	struct in_addr ipv4_addr;
+
+	ret = inet_pton(AF_INET, addr, &ipv4_addr);
+
+	if (ret == 1)
+		return 1;
+	return 0;
+}
+
+static int parse_ip_val_buffer(char *in_buf, int *offset,
+				char *out_buf, int out_len)
+{
+	char *x;
+	char *start;
+
+	/*
+	 * in_buf has sequence of characters that are separated by
+	 * the character ';'. The last sequence does not have the
+	 * terminating ";" character.
+	 */
+	start = in_buf + *offset;
+
+	x = strchr(start, ';');
+	if (x)
+		*x = 0;
+	else
+		x = start + strlen(start);
+
+	if (strlen(start) != 0) {
+		int i = 0;
+		/*
+		 * Get rid of leading spaces.
+		 */
+		while (start[i] == ' ')
+			i++;
+
+		if ((x - start) <= out_len) {
+			strcpy(out_buf, (start + i));
+			*offset += (x - start) + 1;
+			return 1;
+		}
+	}
+	return 0;
+}
+
+static int kvp_write_file(FILE *f, char *s1, char *s2, char *s3)
+{
+	int ret;
+
+	ret = fprintf(f, "%s%s%s%s\n", s1, s2, "=", s3);
+
+	if (ret < 0)
+		return HV_E_FAIL;
+
+	return 0;
+}
+
+
+static int process_ip_string(FILE *f, char *ip_string, int type)
+{
+	int error = 0;
+	char addr[INET6_ADDRSTRLEN];
+	int i = 0;
+	int j = 0;
+	char str[256];
+	char sub_str[13];
+	int offset = 0;
+
+	memset(addr, 0, sizeof(addr));
+
+	while (parse_ip_val_buffer(ip_string, &offset, addr,
+					(MAX_IP_ADDR_SIZE * 2))) {
+
+		sub_str[0] = 0;
+		if (is_ipv4(addr)) {
+			switch (type) {
+			case IPADDR:
+				snprintf(str, sizeof(str), "%s", "IPADDR");
+				break;
+			case NETMASK:
+				snprintf(str, sizeof(str), "%s", "NETMASK");
+				break;
+			case GATEWAY:
+				snprintf(str, sizeof(str), "%s", "GATEWAY");
+				break;
+			case DNS:
+				snprintf(str, sizeof(str), "%s", "DNS");
+				break;
+			}
+
+			if (type == DNS) {
+				snprintf(sub_str, sizeof(sub_str), "%d", ++i);
+			} else if (type == GATEWAY && i == 0) {
+				++i;
+			} else {
+				snprintf(sub_str, sizeof(sub_str), "%d", i++);
+			}
+
+
+		} else if (expand_ipv6(addr, type)) {
+			switch (type) {
+			case IPADDR:
+				snprintf(str, sizeof(str), "%s", "IPV6ADDR");
+				break;
+			case NETMASK:
+				snprintf(str, sizeof(str), "%s", "IPV6NETMASK");
+				break;
+			case GATEWAY:
+				snprintf(str, sizeof(str), "%s",
+					"IPV6_DEFAULTGW");
+				break;
+			case DNS:
+				snprintf(str, sizeof(str), "%s",  "DNS");
+				break;
+			}
+
+			if (type == DNS) {
+				snprintf(sub_str, sizeof(sub_str), "%d", ++i);
+			} else if (j == 0) {
+				++j;
+			} else {
+				snprintf(sub_str, sizeof(sub_str), "_%d", j++);
+			}
+		} else {
+			return  HV_INVALIDARG;
+		}
+
+		error = kvp_write_file(f, str, sub_str, addr);
+		if (error)
+			return error;
+		memset(addr, 0, sizeof(addr));
+	}
+
+	return 0;
+}
+
+int ip_version_check(const char *input_addr)
+{
+	struct in6_addr addr;
+
+	if (inet_pton(AF_INET, input_addr, &addr))
+		return IPV4;
+	else if (inet_pton(AF_INET6, input_addr, &addr))
+		return IPV6;
+
+	return -EINVAL;
+}
+
+/*
+ * Only IPv4 subnet strings needs to be converted to plen
+ * For IPv6 the subnet is already privided in plen format
+ */
+static int kvp_subnet_to_plen(char *subnet_addr_str)
+{
+	int plen = 0;
+	struct in_addr subnet_addr4;
+
+	/*
+	 * Convert subnet address to binary representation
+	 */
+	if (inet_pton(AF_INET, subnet_addr_str, &subnet_addr4) == 1) {
+		uint32_t subnet_mask = ntohl(subnet_addr4.s_addr);
+
+		while (subnet_mask & 0x80000000) {
+			plen++;
+			subnet_mask <<= 1;
+		}
+	} else {
+		return -1;
+	}
+
+	return plen;
+}
+
+static int process_dns_gateway_nm(FILE *f, char *ip_string, int type,
+				  int ip_sec)
+{
+	char addr[INET6_ADDRSTRLEN], *output_str;
+	int ip_offset = 0, error = 0, ip_ver;
+	char *param_name;
+
+	if (type == DNS)
+		param_name = "dns";
+	else if (type == GATEWAY)
+		param_name = "gateway";
+	else
+		return -EINVAL;
+
+	output_str = (char *)calloc(OUTSTR_BUF_SIZE, sizeof(char));
+	if (!output_str)
+		return -ENOMEM;
+
+	while (1) {
+		memset(addr, 0, sizeof(addr));
+
+		if (!parse_ip_val_buffer(ip_string, &ip_offset, addr,
+					 (MAX_IP_ADDR_SIZE * 2)))
+			break;
+
+		ip_ver = ip_version_check(addr);
+		if (ip_ver < 0)
+			continue;
+
+		if ((ip_ver == IPV4 && ip_sec == IPV4) ||
+		    (ip_ver == IPV6 && ip_sec == IPV6)) {
+			/*
+			 * do a bound check to avoid out-of bound writes
+			 */
+			if ((OUTSTR_BUF_SIZE - strlen(output_str)) >
+			    (strlen(addr) + 1)) {
+				strncat(output_str, addr,
+					OUTSTR_BUF_SIZE -
+					strlen(output_str) - 1);
+				strncat(output_str, ",",
+					OUTSTR_BUF_SIZE -
+					strlen(output_str) - 1);
+			}
+		} else {
+			continue;
+		}
+	}
+
+	if (strlen(output_str)) {
+		/*
+		 * This is to get rid of that extra comma character
+		 * in the end of the string
+		 */
+		output_str[strlen(output_str) - 1] = '\0';
+		error = fprintf(f, "%s=%s\n", param_name, output_str);
+	}
+
+	free(output_str);
+	return error;
+}
+
+static int process_ip_string_nm(FILE *f, char *ip_string, char *subnet,
+				int ip_sec)
+{
+	char addr[INET6_ADDRSTRLEN];
+	char subnet_addr[INET6_ADDRSTRLEN];
+	int error = 0, i = 0;
+	int ip_offset = 0, subnet_offset = 0;
+	int plen, ip_ver;
+
+	memset(addr, 0, sizeof(addr));
+	memset(subnet_addr, 0, sizeof(subnet_addr));
+
+	while (parse_ip_val_buffer(ip_string, &ip_offset, addr,
+				   (MAX_IP_ADDR_SIZE * 2)) &&
+				   parse_ip_val_buffer(subnet,
+						       &subnet_offset,
+						       subnet_addr,
+						       (MAX_IP_ADDR_SIZE *
+							2))) {
+		ip_ver = ip_version_check(addr);
+		if (ip_ver < 0)
+			continue;
+
+		if (ip_ver == IPV4 && ip_sec == IPV4)
+			plen = kvp_subnet_to_plen((char *)subnet_addr);
+		else if (ip_ver == IPV6 && ip_sec == IPV6)
+			plen = atoi(subnet_addr);
+		else
+			continue;
+
+		if (plen < 0)
+			return plen;
+
+		error = fprintf(f, "address%d=%s/%d\n", ++i, (char *)addr,
+				plen);
+		if (error < 0)
+			return error;
+
+		memset(addr, 0, sizeof(addr));
+		memset(subnet_addr, 0, sizeof(subnet_addr));
+	}
+
+	return error;
+}
+
+static int kvp_set_ip_info(char *if_name, struct hv_kvp_ipaddr_value *new_val)
+{
+	int error = 0, ip_ver;
+	char if_filename[PATH_MAX];
+	char nm_filename[PATH_MAX];
+	FILE *ifcfg_file, *nmfile;
+	char cmd[PATH_MAX];
+	char *mac_addr;
+	int str_len;
+
+	/*
+	 * Set the configuration for the specified interface with
+	 * the information provided. Since there is no standard
+	 * way to configure an interface, we will have an external
+	 * script that does the job of configuring the interface and
+	 * flushing the configuration.
+	 *
+	 * The parameters passed to this external script are:
+	 * 1. A configuration file that has the specified configuration.
+	 *
+	 * We will embed the name of the interface in the configuration
+	 * file: ifcfg-ethx (where ethx is the interface name).
+	 *
+	 * The information provided here may be more than what is needed
+	 * in a given distro to configure the interface and so are free
+	 * ignore information that may not be relevant.
+	 *
+	 * Here is the ifcfg format of the ip configuration file:
+	 *
+	 * HWADDR=macaddr
+	 * DEVICE=interface name
+	 * BOOTPROTO=<protocol> (where <protocol> is "dhcp" if DHCP is configured
+	 *                       or "none" if no boot-time protocol should be used)
+	 *
+	 * IPADDR0=ipaddr1
+	 * IPADDR1=ipaddr2
+	 * IPADDRx=ipaddry (where y = x + 1)
+	 *
+	 * NETMASK0=netmask1
+	 * NETMASKx=netmasky (where y = x + 1)
+	 *
+	 * GATEWAY=ipaddr1
+	 * GATEWAYx=ipaddry (where y = x + 1)
+	 *
+	 * DNSx=ipaddrx (where first DNS address is tagged as DNS1 etc)
+	 *
+	 * IPV6 addresses will be tagged as IPV6ADDR, IPV6 gateway will be
+	 * tagged as IPV6_DEFAULTGW and IPV6 NETMASK will be tagged as
+	 * IPV6NETMASK.
+	 *
+	 * Here is the keyfile format of the ip configuration file:
+	 *
+	 * [ethernet]
+	 * mac-address=macaddr
+	 * [connection]
+	 * interface-name=interface name
+	 *
+	 * [ipv4]
+	 * method=<protocol> (where <protocol> is "auto" if DHCP is configured
+	 *                       or "manual" if no boot-time protocol should be used)
+	 *
+	 * address1=ipaddr1/plen
+	 * address2=ipaddr2/plen
+	 *
+	 * gateway=gateway1;gateway2
+	 *
+	 * dns=dns1;dns2
+	 *
+	 * [ipv6]
+	 * address1=ipaddr1/plen
+	 * address2=ipaddr2/plen
+	 *
+	 * gateway=gateway1;gateway2
+	 *
+	 * dns=dns1;dns2
+	 *
+	 * The host can specify multiple ipv4 and ipv6 addresses to be
+	 * configured for the interface. Furthermore, the configuration
+	 * needs to be persistent. A subsequent GET call on the interface
+	 * is expected to return the configuration that is set via the SET
+	 * call.
+	 */
+
+	/*
+	 * We are populating both ifcfg and nmconnection files
+	 */
+	snprintf(if_filename, sizeof(if_filename), "%s%s%s", KVP_CONFIG_LOC,
+		 "/ifcfg-", if_name);
+
+	ifcfg_file = fopen(if_filename, "w");
+
+	if (!ifcfg_file) {
+		syslog(LOG_ERR, "Failed to open config file; error: %d %s",
+		       errno, strerror(errno));
+		return HV_E_FAIL;
+	}
+
+	snprintf(nm_filename, sizeof(nm_filename), "%s%s%s%s", KVP_CONFIG_LOC,
+		 "/", if_name, ".nmconnection");
+
+	nmfile = fopen(nm_filename, "w");
+
+	if (!nmfile) {
+		syslog(LOG_ERR, "Failed to open config file; error: %d %s",
+		       errno, strerror(errno));
+		fclose(ifcfg_file);
+		return HV_E_FAIL;
+	}
+
+	/*
+	 * First write out the MAC address.
+	 */
+
+	mac_addr = kvp_if_name_to_mac(if_name);
+	if (mac_addr == NULL) {
+		error = HV_E_FAIL;
+		goto setval_error;
+	}
+
+	error = kvp_write_file(ifcfg_file, "HWADDR", "", mac_addr);
+	if (error < 0)
+		goto setmac_error;
+
+	error = kvp_write_file(ifcfg_file, "DEVICE", "", if_name);
+	if (error < 0)
+		goto setmac_error;
+
+	error = fprintf(nmfile, "\n[connection]\n");
+	if (error < 0)
+		goto setmac_error;
+
+	error = kvp_write_file(nmfile, "interface-name", "", if_name);
+	if (error)
+		goto setmac_error;
+
+	error = fprintf(nmfile, "\n[ethernet]\n");
+	if (error < 0)
+		goto setmac_error;
+
+	error = kvp_write_file(nmfile, "mac-address", "", mac_addr);
+	if (error)
+		goto setmac_error;
+
+	free(mac_addr);
+
+	/*
+	 * The dhcp_enabled flag is only for IPv4. In the case the host only
+	 * injects an IPv6 address, the flag is true, but we still need to
+	 * proceed to parse and pass the IPv6 information to the
+	 * disto-specific script hv_set_ifconfig.
+	 */
+
+	/*
+	 * First populate the ifcfg file format
+	 */
+	if (new_val->dhcp_enabled) {
+		error = kvp_write_file(ifcfg_file, "BOOTPROTO", "", "dhcp");
+		if (error)
+			goto setval_error;
+	} else {
+		error = kvp_write_file(ifcfg_file, "BOOTPROTO", "", "none");
+		if (error)
+			goto setval_error;
+	}
+
+	error = process_ip_string(ifcfg_file, (char *)new_val->ip_addr,
+				  IPADDR);
+	if (error)
+		goto setval_error;
+
+	error = process_ip_string(ifcfg_file, (char *)new_val->sub_net,
+				  NETMASK);
+	if (error)
+		goto setval_error;
+
+	error = process_ip_string(ifcfg_file, (char *)new_val->gate_way,
+				  GATEWAY);
+	if (error)
+		goto setval_error;
+
+	error = process_ip_string(ifcfg_file, (char *)new_val->dns_addr, DNS);
+	if (error)
+		goto setval_error;
+
+	/*
+	 * Now we populate the keyfile format
+	 *
+	 * The keyfile format expects the IPv6 and IPv4 configuration in
+	 * different sections. Therefore we iterate through the list twice,
+	 * once to populate the IPv4 section and the next time for IPv6
+	 */
+	ip_ver = IPV4;
+	do {
+		if (ip_ver == IPV4) {
+			error = fprintf(nmfile, "\n[ipv4]\n");
+			if (error < 0)
+				goto setval_error;
+		} else {
+			error = fprintf(nmfile, "\n[ipv6]\n");
+			if (error < 0)
+				goto setval_error;
+		}
+
+		/*
+		 * Write the configuration for ipaddress, netmask, gateway and
+		 * name services
+		 */
+		error = process_ip_string_nm(nmfile, (char *)new_val->ip_addr,
+					     (char *)new_val->sub_net,
+					     ip_ver);
+		if (error < 0)
+			goto setval_error;
+
+		/*
+		 * As dhcp_enabled is only valid for ipv4, we do not set dhcp
+		 * methods for ipv6 based on dhcp_enabled flag.
+		 *
+		 * For ipv4, set method to manual only when dhcp_enabled is
+		 * false and specific ipv4 addresses are configured. If neither
+		 * dhcp_enabled is true and no ipv4 addresses are configured,
+		 * set method to 'disabled'.
+		 *
+		 * For ipv6, set method to manual when we configure ipv6
+		 * addresses. Otherwise set method to 'auto' so that SLAAC from
+		 * RA may be used.
+		 */
+		if (ip_ver == IPV4) {
+			if (new_val->dhcp_enabled) {
+				error = kvp_write_file(nmfile, "method", "",
+						       "auto");
+				if (error < 0)
+					goto setval_error;
+			} else if (error) {
+				error = kvp_write_file(nmfile, "method", "",
+						       "manual");
+				if (error < 0)
+					goto setval_error;
+			} else {
+				error = kvp_write_file(nmfile, "method", "",
+						       "disabled");
+				if (error < 0)
+					goto setval_error;
+			}
+		} else if (ip_ver == IPV6) {
+			if (error) {
+				error = kvp_write_file(nmfile, "method", "",
+						       "manual");
+				if (error < 0)
+					goto setval_error;
+			} else {
+				error = kvp_write_file(nmfile, "method", "",
+						       "auto");
+				if (error < 0)
+					goto setval_error;
+			}
+		}
+
+		error = process_dns_gateway_nm(nmfile,
+					       (char *)new_val->gate_way,
+					       GATEWAY, ip_ver);
+		if (error < 0)
+			goto setval_error;
+
+		error = process_dns_gateway_nm(nmfile,
+					       (char *)new_val->dns_addr, DNS,
+					       ip_ver);
+		if (error < 0)
+			goto setval_error;
+
+		ip_ver++;
+	} while (ip_ver < IP_TYPE_MAX);
+
+	fclose(nmfile);
+	fclose(ifcfg_file);
+
+	/*
+	 * Now that we have populated the configuration file,
+	 * invoke the external script to do its magic.
+	 */
+
+	str_len = snprintf(cmd, sizeof(cmd), "exec %s %s %s",
+			   KVP_SCRIPTS_PATH "hv_set_ifconfig",
+			   if_filename, nm_filename);
+	/*
+	 * This is a little overcautious, but it's necessary to suppress some
+	 * false warnings from gcc 8.0.1.
+	 */
+	if (str_len <= 0 || (unsigned int)str_len >= sizeof(cmd)) {
+		syslog(LOG_ERR, "Cmd '%s' (len=%d) may be too long",
+		       cmd, str_len);
+		return HV_E_FAIL;
+	}
+
+	if (system(cmd)) {
+		syslog(LOG_ERR, "Failed to execute cmd '%s'; error: %d %s",
+		       cmd, errno, strerror(errno));
+		return HV_E_FAIL;
+	}
+	return 0;
+setmac_error:
+	free(mac_addr);
+setval_error:
+	syslog(LOG_ERR, "Failed to write config file");
+	fclose(ifcfg_file);
+	fclose(nmfile);
+	return error;
+}
+
+
+static void
+kvp_get_domain_name(char *buffer, int length)
+{
+	struct addrinfo	hints, *info ;
+	int error = 0;
+
+	gethostname(buffer, length);
+	memset(&hints, 0, sizeof(hints));
+	hints.ai_family = AF_INET; /*Get only ipv4 addrinfo. */
+	hints.ai_socktype = SOCK_STREAM;
+	hints.ai_flags = AI_CANONNAME;
+
+	error = getaddrinfo(buffer, NULL, &hints, &info);
+	if (error != 0) {
+		snprintf(buffer, length, "getaddrinfo failed: 0x%x %s",
+			error, gai_strerror(error));
+		return;
+	}
+	snprintf(buffer, length, "%s", info->ai_canonname);
+	freeaddrinfo(info);
+}
+
+void print_usage(char *argv[])
+{
+	fprintf(stderr, "Usage: %s [options]\n"
+		"Options are:\n"
+		"  -n, --no-daemon        stay in foreground, don't daemonize\n"
+		"  -d, --debug            Enable debug logs(syslog debug by default)\n"
+		"  -h, --help             print this help\n", argv[0]);
+}
+
+int main(int argc, char *argv[])
+{
+	int kvp_fd = -1, len;
+	int error;
+	struct pollfd pfd;
+	char    *p;
+	struct hv_kvp_msg hv_msg[1];
+	char	*key_value;
+	char	*key_name;
+	int	op;
+	int	pool;
+	char	*if_name;
+	struct hv_kvp_ipaddr_value *kvp_ip_val;
+	int daemonize = 1, long_index = 0, opt;
+
+	static struct option long_options[] = {
+		{"help",	no_argument,	   0,  'h' },
+		{"no-daemon",	no_argument,	   0,  'n' },
+		{"debug",	no_argument,	   0,  'd' },
+		{0,		0,		   0,  0   }
+	};
+
+	while ((opt = getopt_long(argc, argv, "hnd", long_options,
+				  &long_index)) != -1) {
+		switch (opt) {
+		case 'n':
+			daemonize = 0;
+			break;
+		case 'h':
+			print_usage(argv);
+			exit(0);
+		case 'd':
+			debug = 1;
+			break;
+		default:
+			print_usage(argv);
+			exit(EXIT_FAILURE);
+		}
+	}
+
+	if (daemonize && daemon(1, 0))
+		return 1;
+
+	openlog("KVP", 0, LOG_USER);
+	syslog(LOG_INFO, "KVP starting; pid is:%d", getpid());
+
+	/*
+	 * Retrieve OS release information.
+	 */
+	kvp_get_os_info();
+	/*
+	 * Cache Fully Qualified Domain Name because getaddrinfo takes an
+	 * unpredictable amount of time to finish.
+	 */
+	kvp_get_domain_name(full_domain_name, sizeof(full_domain_name));
+
+	if (debug)
+		syslog(LOG_INFO, "Logging debug info in syslog(debug)");
+
+	if (kvp_file_init()) {
+		syslog(LOG_ERR, "Failed to initialize the pools");
+		exit(EXIT_FAILURE);
+	}
+
+reopen_kvp_fd:
+	if (kvp_fd != -1)
+		close(kvp_fd);
+	in_hand_shake = 1;
+	kvp_fd = open("/dev/vmbus/hv_kvp", O_RDWR | O_CLOEXEC);
+
+	if (kvp_fd < 0) {
+		syslog(LOG_ERR, "open /dev/vmbus/hv_kvp failed; error: %d %s",
+		       errno, strerror(errno));
+		exit(EXIT_FAILURE);
+	}
+
+	/*
+	 * Register ourselves with the kernel.
+	 */
+	hv_msg->kvp_hdr.operation = KVP_OP_REGISTER1;
+	len = write(kvp_fd, hv_msg, sizeof(struct hv_kvp_msg));
+	if (len != sizeof(struct hv_kvp_msg)) {
+		syslog(LOG_ERR, "registration to kernel failed; error: %d %s",
+		       errno, strerror(errno));
+		close(kvp_fd);
+		exit(EXIT_FAILURE);
+	}
+
+	pfd.fd = kvp_fd;
+
+	while (1) {
+		pfd.events = POLLIN;
+		pfd.revents = 0;
+
+		if (poll(&pfd, 1, -1) < 0) {
+			syslog(LOG_ERR, "poll failed; error: %d %s", errno, strerror(errno));
+			if (errno == EINVAL) {
+				close(kvp_fd);
+				exit(EXIT_FAILURE);
+			}
+			else
+				continue;
+		}
+
+		len = read(kvp_fd, hv_msg, sizeof(struct hv_kvp_msg));
+
+		if (len != sizeof(struct hv_kvp_msg)) {
+			syslog(LOG_ERR, "read failed; error:%d %s",
+			       errno, strerror(errno));
+			goto reopen_kvp_fd;
+		}
+
+		/*
+		 * We will use the KVP header information to pass back
+		 * the error from this daemon. So, first copy the state
+		 * and set the error code to success.
+		 */
+		op = hv_msg->kvp_hdr.operation;
+		pool = hv_msg->kvp_hdr.pool;
+		hv_msg->error = HV_S_OK;
+
+		if ((in_hand_shake) && (op == KVP_OP_REGISTER1)) {
+			/*
+			 * Driver is registering with us; stash away the version
+			 * information.
+			 */
+			in_hand_shake = 0;
+			p = (char *)hv_msg->body.kvp_register.version;
+			lic_version = malloc(strlen(p) + 1);
+			if (lic_version) {
+				strcpy(lic_version, p);
+				syslog(LOG_INFO, "KVP LIC Version: %s",
+				       lic_version);
+			} else {
+				syslog(LOG_ERR, "malloc failed");
+			}
+			continue;
+		}
+
+		switch (op) {
+		case KVP_OP_GET_IP_INFO:
+			kvp_ip_val = &hv_msg->body.kvp_ip_val;
+
+			error = kvp_mac_to_ip(kvp_ip_val);
+
+			if (error)
+				hv_msg->error = error;
+
+			break;
+
+		case KVP_OP_SET_IP_INFO:
+			kvp_ip_val = &hv_msg->body.kvp_ip_val;
+			if_name = kvp_get_if_name(
+					(char *)kvp_ip_val->adapter_id);
+			if (if_name == NULL) {
+				/*
+				 * We could not map the guid to an
+				 * interface name; return error.
+				 */
+				hv_msg->error = HV_GUID_NOTFOUND;
+				break;
+			}
+			error = kvp_set_ip_info(if_name, kvp_ip_val);
+			if (error)
+				hv_msg->error = error;
+
+			free(if_name);
+			break;
+
+		case KVP_OP_SET:
+			if (kvp_key_add_or_modify(pool,
+					hv_msg->body.kvp_set.data.key,
+					hv_msg->body.kvp_set.data.key_size,
+					hv_msg->body.kvp_set.data.value,
+					hv_msg->body.kvp_set.data.value_size))
+					hv_msg->error = HV_S_CONT;
+			break;
+
+		case KVP_OP_GET:
+			if (kvp_get_value(pool,
+					hv_msg->body.kvp_set.data.key,
+					hv_msg->body.kvp_set.data.key_size,
+					hv_msg->body.kvp_set.data.value,
+					hv_msg->body.kvp_set.data.value_size))
+					hv_msg->error = HV_S_CONT;
+			break;
+
+		case KVP_OP_DELETE:
+			if (kvp_key_delete(pool,
+					hv_msg->body.kvp_delete.key,
+					hv_msg->body.kvp_delete.key_size))
+					hv_msg->error = HV_S_CONT;
+			break;
+
+		default:
+			break;
+		}
+
+		if (op != KVP_OP_ENUMERATE)
+			goto kvp_done;
+
+		/*
+		 * If the pool is KVP_POOL_AUTO, dynamically generate
+		 * both the key and the value; if not read from the
+		 * appropriate pool.
+		 */
+		if (pool != KVP_POOL_AUTO) {
+			if (kvp_pool_enumerate(pool,
+					hv_msg->body.kvp_enum_data.index,
+					hv_msg->body.kvp_enum_data.data.key,
+					HV_KVP_EXCHANGE_MAX_KEY_SIZE,
+					hv_msg->body.kvp_enum_data.data.value,
+					HV_KVP_EXCHANGE_MAX_VALUE_SIZE))
+					hv_msg->error = HV_S_CONT;
+			goto kvp_done;
+		}
+
+		key_name = (char *)hv_msg->body.kvp_enum_data.data.key;
+		key_value = (char *)hv_msg->body.kvp_enum_data.data.value;
+
+		switch (hv_msg->body.kvp_enum_data.index) {
+		case FullyQualifiedDomainName:
+			strcpy(key_value, full_domain_name);
+			strcpy(key_name, "FullyQualifiedDomainName");
+			break;
+		case IntegrationServicesVersion:
+			strcpy(key_name, "IntegrationServicesVersion");
+			strcpy(key_value, lic_version);
+			break;
+		case NetworkAddressIPv4:
+			kvp_get_ip_info(AF_INET, NULL, KVP_OP_ENUMERATE,
+				key_value, HV_KVP_EXCHANGE_MAX_VALUE_SIZE);
+			strcpy(key_name, "NetworkAddressIPv4");
+			break;
+		case NetworkAddressIPv6:
+			kvp_get_ip_info(AF_INET6, NULL, KVP_OP_ENUMERATE,
+				key_value, HV_KVP_EXCHANGE_MAX_VALUE_SIZE);
+			strcpy(key_name, "NetworkAddressIPv6");
+			break;
+		case OSBuildNumber:
+			strcpy(key_value, os_build);
+			strcpy(key_name, "OSBuildNumber");
+			break;
+		case OSName:
+			strcpy(key_value, os_name);
+			strcpy(key_name, "OSName");
+			break;
+		case OSMajorVersion:
+			strcpy(key_value, os_major);
+			strcpy(key_name, "OSMajorVersion");
+			break;
+		case OSMinorVersion:
+			strcpy(key_value, os_minor);
+			strcpy(key_name, "OSMinorVersion");
+			break;
+		case OSVersion:
+			strcpy(key_value, os_version);
+			strcpy(key_name, "OSVersion");
+			break;
+		case ProcessorArchitecture:
+			strcpy(key_value, processor_arch);
+			strcpy(key_name, "ProcessorArchitecture");
+			break;
+		default:
+			hv_msg->error = HV_S_CONT;
+			break;
+		}
+
+		/*
+		 * Send the value back to the kernel. Note: the write() may
+		 * return an error due to hibernation; we can ignore the error
+		 * by resetting the dev file, i.e. closing and re-opening it.
+		 */
+kvp_done:
+		len = write(kvp_fd, hv_msg, sizeof(struct hv_kvp_msg));
+		if (len != sizeof(struct hv_kvp_msg)) {
+			syslog(LOG_ERR, "write failed; error: %d %s", errno,
+			       strerror(errno));
+			goto reopen_kvp_fd;
+		}
+	}
+
+	close(kvp_fd);
+	exit(0);
+}
diff --git a/tools/hv/hv_set_ifconfig.sh b/tools/hv/hv_set_ifconfig.sh
new file mode 100755
index 000000000..2f8baed2b
--- /dev/null
+++ b/tools/hv/hv_set_ifconfig.sh
@@ -0,0 +1,92 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+# This example script activates an interface based on the specified
+# configuration.
+#
+# In the interest of keeping the KVP daemon code free of distro specific
+# information; the kvp daemon code invokes this external script to configure
+# the interface.
+#
+# The only argument to this script is the configuration file that is to
+# be used to configure the interface.
+#
+# Each Distro is expected to implement this script in a distro specific
+# fashion. For instance, on Distros that ship with Network Manager enabled,
+# this script can be based on the Network Manager APIs for configuring the
+# interface.
+#
+# This example script is based on a RHEL environment.
+#
+# Here is the ifcfg format of the ip configuration file:
+#
+# HWADDR=macaddr
+# DEVICE=interface name
+# BOOTPROTO=<protocol> (where <protocol> is "dhcp" if DHCP is configured
+# 			or "none" if no boot-time protocol should be used)
+#
+# IPADDR0=ipaddr1
+# IPADDR1=ipaddr2
+# IPADDRx=ipaddry (where y = x + 1)
+#
+# NETMASK0=netmask1
+# NETMASKx=netmasky (where y = x + 1)
+#
+# GATEWAY=ipaddr1
+# GATEWAYx=ipaddry (where y = x + 1)
+#
+# DNSx=ipaddrx (where first DNS address is tagged as DNS1 etc)
+#
+# IPV6 addresses will be tagged as IPV6ADDR, IPV6 gateway will be
+# tagged as IPV6_DEFAULTGW and IPV6 NETMASK will be tagged as
+# IPV6NETMASK.
+#
+# Here is the keyfile format of the ip configuration file:
+#
+# [ethernet]
+# mac-address=macaddr
+# [connection]
+# interface-name=interface name
+#
+# [ipv4]
+# method=<protocol> (where <protocol> is "auto" if DHCP is configured
+#                       or "manual" if no boot-time protocol should be used)
+#
+# address1=ipaddr1/plen
+# address2=ipaddr2/plen
+#
+# gateway=gateway1;gateway2
+#
+# dns=dns1;
+#
+# [ipv6]
+# address1=ipaddr1/plen
+# address2=ipaddr2/plen
+#
+# gateway=gateway1;gateway2
+#
+# dns=dns1;dns2
+#
+# The host can specify multiple ipv4 and ipv6 addresses to be
+# configured for the interface. Furthermore, the configuration
+# needs to be persistent. A subsequent GET call on the interface
+# is expected to return the configuration that is set via the SET
+# call.
+#
+
+echo "IPV6INIT=yes" >> $1
+echo "NM_CONTROLLED=no" >> $1
+echo "PEERDNS=yes" >> $1
+echo "ONBOOT=yes" >> $1
+
+cp $1 /etc/sysconfig/network-scripts/
+
+umask 0177
+interface=$(echo $2 | awk -F - '{ print $2 }')
+filename="${2##*/}"
+
+sed '/\[connection\]/a autoconnect=true' $2 > /etc/NetworkManager/system-connections/${filename}
+
+
+/sbin/ifdown $interface 2>/dev/null
+/sbin/ifup $interface 2>/dev/null
diff --git a/tools/hv/hv_vss_daemon.c b/tools/hv/hv_vss_daemon.c
new file mode 100644
index 000000000..dd111870b
--- /dev/null
+++ b/tools/hv/hv_vss_daemon.c
@@ -0,0 +1,355 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * An implementation of the host initiated guest snapshot for Hyper-V.
+ *
+ * Copyright (C) 2013, Microsoft, Inc.
+ * Author : K. Y. Srinivasan <kys@microsoft.com>
+ */
+
+
+#include <sys/types.h>
+#include <sys/poll.h>
+#include <sys/ioctl.h>
+#include <sys/stat.h>
+#include <sys/sysmacros.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <mntent.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <ctype.h>
+#include <errno.h>
+#include <linux/fs.h>
+#include <linux/major.h>
+#include <linux/hyperv.h>
+#include <syslog.h>
+#include <getopt.h>
+#include <stdbool.h>
+#include <dirent.h>
+
+static bool fs_frozen;
+
+/* Don't use syslog() in the function since that can cause write to disk */
+static int vss_do_freeze(char *dir, unsigned int cmd)
+{
+	int ret, fd = open(dir, O_RDONLY);
+
+	if (fd < 0)
+		return 1;
+
+	ret = ioctl(fd, cmd, 0);
+
+	/*
+	 * If a partition is mounted more than once, only the first
+	 * FREEZE/THAW can succeed and the later ones will get
+	 * EBUSY/EINVAL respectively: there could be 2 cases:
+	 * 1) a user may mount the same partition to different directories
+	 *  by mistake or on purpose;
+	 * 2) The subvolume of btrfs appears to have the same partition
+	 * mounted more than once.
+	 */
+	if (ret) {
+		if ((cmd == FIFREEZE && errno == EBUSY) ||
+		    (cmd == FITHAW && errno == EINVAL)) {
+			close(fd);
+			return 0;
+		}
+	}
+
+	close(fd);
+	return !!ret;
+}
+
+static bool is_dev_loop(const char *blkname)
+{
+	char *buffer;
+	DIR *dir;
+	struct dirent *entry;
+	bool ret = false;
+
+	buffer = malloc(PATH_MAX);
+	if (!buffer) {
+		syslog(LOG_ERR, "Can't allocate memory!");
+		exit(1);
+	}
+
+	snprintf(buffer, PATH_MAX, "%s/loop", blkname);
+	if (!access(buffer, R_OK | X_OK)) {
+		ret = true;
+		goto free_buffer;
+	} else if (errno != ENOENT) {
+		syslog(LOG_ERR, "Can't access: %s; error:%d %s!",
+		       buffer, errno, strerror(errno));
+	}
+
+	snprintf(buffer, PATH_MAX, "%s/slaves", blkname);
+	dir = opendir(buffer);
+	if (!dir) {
+		if (errno != ENOENT)
+			syslog(LOG_ERR, "Can't opendir: %s; error:%d %s!",
+			       buffer, errno, strerror(errno));
+		goto free_buffer;
+	}
+
+	while ((entry = readdir(dir)) != NULL) {
+		if (strcmp(entry->d_name, ".") == 0 ||
+		    strcmp(entry->d_name, "..") == 0)
+			continue;
+
+		snprintf(buffer, PATH_MAX, "%s/slaves/%s", blkname,
+			 entry->d_name);
+		if (is_dev_loop(buffer)) {
+			ret = true;
+			break;
+		}
+	}
+	closedir(dir);
+free_buffer:
+	free(buffer);
+	return ret;
+}
+
+static int vss_operate(int operation)
+{
+	char match[] = "/dev/";
+	FILE *mounts;
+	struct mntent *ent;
+	struct stat sb;
+	char errdir[1024] = {0};
+	char blkdir[23]; /* /sys/dev/block/XXX:XXX */
+	unsigned int cmd;
+	int error = 0, root_seen = 0, save_errno = 0;
+
+	switch (operation) {
+	case VSS_OP_FREEZE:
+		cmd = FIFREEZE;
+		break;
+	case VSS_OP_THAW:
+		cmd = FITHAW;
+		break;
+	default:
+		return -1;
+	}
+
+	mounts = setmntent("/proc/mounts", "r");
+	if (mounts == NULL)
+		return -1;
+
+	while ((ent = getmntent(mounts))) {
+		if (strncmp(ent->mnt_fsname, match, strlen(match)))
+			continue;
+		if (stat(ent->mnt_fsname, &sb)) {
+			syslog(LOG_ERR, "Can't stat: %s; error:%d %s!",
+			       ent->mnt_fsname, errno, strerror(errno));
+		} else {
+			sprintf(blkdir, "/sys/dev/block/%d:%d",
+				major(sb.st_rdev), minor(sb.st_rdev));
+			if (is_dev_loop(blkdir))
+				continue;
+		}
+		if (hasmntopt(ent, MNTOPT_RO) != NULL)
+			continue;
+		if (strcmp(ent->mnt_type, "vfat") == 0)
+			continue;
+		if (strcmp(ent->mnt_dir, "/") == 0) {
+			root_seen = 1;
+			continue;
+		}
+		error |= vss_do_freeze(ent->mnt_dir, cmd);
+		if (operation == VSS_OP_FREEZE) {
+			if (error)
+				goto err;
+			fs_frozen = true;
+		}
+	}
+
+	endmntent(mounts);
+
+	if (root_seen) {
+		error |= vss_do_freeze("/", cmd);
+		if (operation == VSS_OP_FREEZE) {
+			if (error)
+				goto err;
+			fs_frozen = true;
+		}
+	}
+
+	if (operation == VSS_OP_THAW && !error)
+		fs_frozen = false;
+
+	goto out;
+err:
+	save_errno = errno;
+	if (ent) {
+		strncpy(errdir, ent->mnt_dir, sizeof(errdir)-1);
+		endmntent(mounts);
+	}
+	vss_operate(VSS_OP_THAW);
+	fs_frozen = false;
+	/* Call syslog after we thaw all filesystems */
+	if (ent)
+		syslog(LOG_ERR, "FREEZE of %s failed; error:%d %s",
+		       errdir, save_errno, strerror(save_errno));
+	else
+		syslog(LOG_ERR, "FREEZE of / failed; error:%d %s", save_errno,
+		       strerror(save_errno));
+out:
+	return error;
+}
+
+void print_usage(char *argv[])
+{
+	fprintf(stderr, "Usage: %s [options]\n"
+		"Options are:\n"
+		"  -n, --no-daemon        stay in foreground, don't daemonize\n"
+		"  -h, --help             print this help\n", argv[0]);
+}
+
+int main(int argc, char *argv[])
+{
+	int vss_fd = -1, len;
+	int error;
+	struct pollfd pfd;
+	int	op;
+	struct hv_vss_msg vss_msg[1];
+	int daemonize = 1, long_index = 0, opt;
+	int in_handshake;
+	__u32 kernel_modver;
+
+	static struct option long_options[] = {
+		{"help",	no_argument,	   0,  'h' },
+		{"no-daemon",	no_argument,	   0,  'n' },
+		{0,		0,		   0,  0   }
+	};
+
+	while ((opt = getopt_long(argc, argv, "hn", long_options,
+				  &long_index)) != -1) {
+		switch (opt) {
+		case 'n':
+			daemonize = 0;
+			break;
+		case 'h':
+			print_usage(argv);
+			exit(0);
+		default:
+			print_usage(argv);
+			exit(EXIT_FAILURE);
+		}
+	}
+
+	if (daemonize && daemon(1, 0))
+		return 1;
+
+	openlog("Hyper-V VSS", 0, LOG_USER);
+	syslog(LOG_INFO, "VSS starting; pid is:%d", getpid());
+
+reopen_vss_fd:
+	if (vss_fd != -1)
+		close(vss_fd);
+	if (fs_frozen) {
+		if (vss_operate(VSS_OP_THAW) || fs_frozen) {
+			syslog(LOG_ERR, "failed to thaw file system: err=%d",
+			       errno);
+			exit(EXIT_FAILURE);
+		}
+	}
+
+	in_handshake = 1;
+	vss_fd = open("/dev/vmbus/hv_vss", O_RDWR);
+	if (vss_fd < 0) {
+		syslog(LOG_ERR, "open /dev/vmbus/hv_vss failed; error: %d %s",
+		       errno, strerror(errno));
+		exit(EXIT_FAILURE);
+	}
+	/*
+	 * Register ourselves with the kernel.
+	 */
+	vss_msg->vss_hdr.operation = VSS_OP_REGISTER1;
+
+	len = write(vss_fd, vss_msg, sizeof(struct hv_vss_msg));
+	if (len < 0) {
+		syslog(LOG_ERR, "registration to kernel failed; error: %d %s",
+		       errno, strerror(errno));
+		close(vss_fd);
+		exit(EXIT_FAILURE);
+	}
+
+	pfd.fd = vss_fd;
+
+	while (1) {
+		pfd.events = POLLIN;
+		pfd.revents = 0;
+
+		if (poll(&pfd, 1, -1) < 0) {
+			syslog(LOG_ERR, "poll failed; error:%d %s", errno, strerror(errno));
+			if (errno == EINVAL) {
+				close(vss_fd);
+				exit(EXIT_FAILURE);
+			}
+			else
+				continue;
+		}
+
+		len = read(vss_fd, vss_msg, sizeof(struct hv_vss_msg));
+
+		if (in_handshake) {
+			if (len != sizeof(kernel_modver)) {
+				syslog(LOG_ERR, "invalid version negotiation");
+				exit(EXIT_FAILURE);
+			}
+			kernel_modver = *(__u32 *)vss_msg;
+			in_handshake = 0;
+			syslog(LOG_INFO, "VSS: kernel module version: %d",
+			       kernel_modver);
+			continue;
+		}
+
+		if (len != sizeof(struct hv_vss_msg)) {
+			syslog(LOG_ERR, "read failed; error:%d %s",
+			       errno, strerror(errno));
+			goto reopen_vss_fd;
+		}
+
+		op = vss_msg->vss_hdr.operation;
+		error =  HV_S_OK;
+
+		switch (op) {
+		case VSS_OP_FREEZE:
+		case VSS_OP_THAW:
+			error = vss_operate(op);
+			syslog(LOG_INFO, "VSS: op=%s: %s\n",
+				op == VSS_OP_FREEZE ? "FREEZE" : "THAW",
+				error ? "failed" : "succeeded");
+
+			if (error) {
+				error = HV_E_FAIL;
+				syslog(LOG_ERR, "op=%d failed!", op);
+				syslog(LOG_ERR, "report it with these files:");
+				syslog(LOG_ERR, "/etc/fstab and /proc/mounts");
+			}
+			break;
+		case VSS_OP_HOT_BACKUP:
+			syslog(LOG_INFO, "VSS: op=CHECK HOT BACKUP\n");
+			break;
+		default:
+			syslog(LOG_ERR, "Illegal op:%d\n", op);
+		}
+
+		/*
+		 * The write() may return an error due to the faked VSS_OP_THAW
+		 * message upon hibernation. Ignore the error by resetting the
+		 * dev file, i.e. closing and re-opening it.
+		 */
+		vss_msg->error = error;
+		len = write(vss_fd, vss_msg, sizeof(struct hv_vss_msg));
+		if (len != sizeof(struct hv_vss_msg)) {
+			syslog(LOG_ERR, "write failed; error: %d %s", errno,
+			       strerror(errno));
+			goto reopen_vss_fd;
+		}
+	}
+
+	close(vss_fd);
+	exit(0);
+}
diff --git a/tools/hv/lsvmbus b/tools/hv/lsvmbus
new file mode 100755
index 000000000..f83698f14
--- /dev/null
+++ b/tools/hv/lsvmbus
@@ -0,0 +1,112 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: GPL-2.0
+
+import os
+from optparse import OptionParser
+
+help_msg = "print verbose messages. Try -vv, -vvv for  more verbose messages"
+parser = OptionParser()
+parser.add_option(
+	"-v", "--verbose", dest="verbose", help=help_msg, action="count")
+
+(options, args) = parser.parse_args()
+
+verbose = 0
+if options.verbose is not None:
+	verbose = options.verbose
+
+vmbus_sys_path = '/sys/bus/vmbus/devices'
+if not os.path.isdir(vmbus_sys_path):
+	print("%s doesn't exist: exiting..." % vmbus_sys_path)
+	exit(-1)
+
+vmbus_dev_dict = {
+	'{0e0b6031-5213-4934-818b-38d90ced39db}': '[Operating system shutdown]',
+	'{9527e630-d0ae-497b-adce-e80ab0175caf}': '[Time Synchronization]',
+	'{57164f39-9115-4e78-ab55-382f3bd5422d}': '[Heartbeat]',
+	'{a9a0f4e7-5a45-4d96-b827-8a841e8c03e6}': '[Data Exchange]',
+	'{35fa2e29-ea23-4236-96ae-3a6ebacba440}': '[Backup (volume checkpoint)]',
+	'{34d14be3-dee4-41c8-9ae7-6b174977c192}': '[Guest services]',
+	'{525074dc-8985-46e2-8057-a307dc18a502}': '[Dynamic Memory]',
+	'{cfa8b69e-5b4a-4cc0-b98b-8ba1a1f3f95a}': 'Synthetic mouse',
+	'{f912ad6d-2b17-48ea-bd65-f927a61c7684}': 'Synthetic keyboard',
+	'{da0a7802-e377-4aac-8e77-0558eb1073f8}': 'Synthetic framebuffer adapter',
+	'{f8615163-df3e-46c5-913f-f2d2f965ed0e}': 'Synthetic network adapter',
+	'{32412632-86cb-44a2-9b5c-50d1417354f5}': 'Synthetic IDE Controller',
+	'{ba6163d9-04a1-4d29-b605-72e2ffb1dc7f}': 'Synthetic SCSI Controller',
+	'{2f9bcc4a-0069-4af3-b76b-6fd0be528cda}': 'Synthetic fiber channel adapter',
+	'{8c2eaf3d-32a7-4b09-ab99-bd1f1c86b501}': 'Synthetic RDMA adapter',
+	'{44c4f61d-4444-4400-9d52-802e27ede19f}': 'PCI Express pass-through',
+	'{276aacf4-ac15-426c-98dd-7521ad3f01fe}': '[Reserved system device]',
+	'{f8e65716-3cb3-4a06-9a60-1889c5cccab5}': '[Reserved system device]',
+	'{3375baf4-9e15-4b30-b765-67acb10d607b}': '[Reserved system device]',
+}
+
+
+def get_vmbus_dev_attr(dev_name, attr):
+	try:
+		f = open('%s/%s/%s' % (vmbus_sys_path, dev_name, attr), 'r')
+		lines = f.readlines()
+		f.close()
+	except IOError:
+		lines = []
+
+	return lines
+
+
+class VMBus_Dev:
+	pass
+
+
+vmbus_dev_list = []
+
+for f in os.listdir(vmbus_sys_path):
+	vmbus_id = get_vmbus_dev_attr(f, 'id')[0].strip()
+	class_id = get_vmbus_dev_attr(f, 'class_id')[0].strip()
+	device_id = get_vmbus_dev_attr(f, 'device_id')[0].strip()
+	dev_desc = vmbus_dev_dict.get(class_id, 'Unknown')
+
+	chn_vp_mapping = get_vmbus_dev_attr(f, 'channel_vp_mapping')
+	chn_vp_mapping = [c.strip() for c in chn_vp_mapping]
+	chn_vp_mapping = sorted(
+		chn_vp_mapping, key=lambda c: int(c.split(':')[0]))
+
+	chn_vp_mapping = [
+		'\tRel_ID=%s, target_cpu=%s' %
+		(c.split(':')[0], c.split(':')[1]) for c in chn_vp_mapping
+	]
+	d = VMBus_Dev()
+	d.sysfs_path = '%s/%s' % (vmbus_sys_path, f)
+	d.vmbus_id = vmbus_id
+	d.class_id = class_id
+	d.device_id = device_id
+	d.dev_desc = dev_desc
+	d.chn_vp_mapping = '\n'.join(chn_vp_mapping)
+	if d.chn_vp_mapping:
+		d.chn_vp_mapping += '\n'
+
+	vmbus_dev_list.append(d)
+
+
+vmbus_dev_list = sorted(vmbus_dev_list, key=lambda d: int(d.vmbus_id))
+
+format0 = '%2s: %s'
+format1 = '%2s: Class_ID = %s - %s\n%s'
+format2 = '%2s: Class_ID = %s - %s\n\tDevice_ID = %s\n\tSysfs path: %s\n%s'
+
+for d in vmbus_dev_list:
+	if verbose == 0:
+		print(('VMBUS ID ' + format0) % (d.vmbus_id, d.dev_desc))
+	elif verbose == 1:
+		print(
+			('VMBUS ID ' + format1) %
+			(d.vmbus_id, d.class_id, d.dev_desc, d.chn_vp_mapping)
+		)
+	else:
+		print(
+			('VMBUS ID ' + format2) %
+			(
+				d.vmbus_id, d.class_id, d.dev_desc,
+				d.device_id, d.sysfs_path, d.chn_vp_mapping
+			)
+		)
diff --git a/tools/hv/vmbus_bufring.c b/tools/hv/vmbus_bufring.c
new file mode 100644
index 000000000..bac32c110
--- /dev/null
+++ b/tools/hv/vmbus_bufring.c
@@ -0,0 +1,318 @@
+// SPDX-License-Identifier: BSD-3-Clause
+/*
+ * Copyright (c) 2009-2012,2016,2023 Microsoft Corp.
+ * Copyright (c) 2012 NetApp Inc.
+ * Copyright (c) 2012 Citrix Inc.
+ * All rights reserved.
+ */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <emmintrin.h>
+#include <linux/limits.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <sys/uio.h>
+#include <unistd.h>
+#include "vmbus_bufring.h"
+
+/**
+ * Compiler barrier.
+ *
+ * Guarantees that operation reordering does not occur at compile time
+ * for operations directly before and after the barrier.
+ */
+#define	rte_compiler_barrier()		({ asm volatile ("" : : : "memory"); })
+
+#define VMBUS_RQST_ERROR	0xFFFFFFFFFFFFFFFF
+#define ALIGN(val, align)	((typeof(val))((val) & (~((typeof(val))((align) - 1)))))
+
+void *vmbus_uio_map(int *fd, int size)
+{
+	void *map;
+
+	map = mmap(NULL, 2 * size, PROT_READ | PROT_WRITE, MAP_SHARED, *fd, 0);
+	if (map == MAP_FAILED)
+		return NULL;
+
+	return map;
+}
+
+/* Increase bufring index by inc with wraparound */
+static inline uint32_t vmbus_br_idxinc(uint32_t idx, uint32_t inc, uint32_t sz)
+{
+	idx += inc;
+	if (idx >= sz)
+		idx -= sz;
+
+	return idx;
+}
+
+void vmbus_br_setup(struct vmbus_br *br, void *buf, unsigned int blen)
+{
+	br->vbr = buf;
+	br->windex = br->vbr->windex;
+	br->dsize = blen - sizeof(struct vmbus_bufring);
+}
+
+static inline __always_inline void
+rte_smp_mb(void)
+{
+	asm volatile("lock addl $0, -128(%%rsp); " ::: "memory");
+}
+
+static inline int
+rte_atomic32_cmpset(volatile uint32_t *dst, uint32_t exp, uint32_t src)
+{
+	uint8_t res;
+
+	asm volatile("lock ; "
+		     "cmpxchgl %[src], %[dst];"
+		     "sete %[res];"
+		     : [res] "=a" (res),     /* output */
+		     [dst] "=m" (*dst)
+		     : [src] "r" (src),      /* input */
+		     "a" (exp),
+		     "m" (*dst)
+		     : "memory");            /* no-clobber list */
+	return res;
+}
+
+static inline uint32_t
+vmbus_txbr_copyto(const struct vmbus_br *tbr, uint32_t windex,
+		  const void *src0, uint32_t cplen)
+{
+	uint8_t *br_data = tbr->vbr->data;
+	uint32_t br_dsize = tbr->dsize;
+	const uint8_t *src = src0;
+
+	/* XXX use double mapping like Linux kernel? */
+	if (cplen > br_dsize - windex) {
+		uint32_t fraglen = br_dsize - windex;
+
+		/* Wrap-around detected */
+		memcpy(br_data + windex, src, fraglen);
+		memcpy(br_data, src + fraglen, cplen - fraglen);
+	} else {
+		memcpy(br_data + windex, src, cplen);
+	}
+
+	return vmbus_br_idxinc(windex, cplen, br_dsize);
+}
+
+/*
+ * Write scattered channel packet to TX bufring.
+ *
+ * The offset of this channel packet is written as a 64bits value
+ * immediately after this channel packet.
+ *
+ * The write goes through three stages:
+ *  1. Reserve space in ring buffer for the new data.
+ *     Writer atomically moves priv_write_index.
+ *  2. Copy the new data into the ring.
+ *  3. Update the tail of the ring (visible to host) that indicates
+ *     next read location. Writer updates write_index
+ */
+static int
+vmbus_txbr_write(struct vmbus_br *tbr, const struct iovec iov[], int iovlen)
+{
+	struct vmbus_bufring *vbr = tbr->vbr;
+	uint32_t ring_size = tbr->dsize;
+	uint32_t old_windex, next_windex, windex, total;
+	uint64_t save_windex;
+	int i;
+
+	total = 0;
+	for (i = 0; i < iovlen; i++)
+		total += iov[i].iov_len;
+	total += sizeof(save_windex);
+
+	/* Reserve space in ring */
+	do {
+		uint32_t avail;
+
+		/* Get current free location */
+		old_windex = tbr->windex;
+
+		/* Prevent compiler reordering this with calculation */
+		rte_compiler_barrier();
+
+		avail = vmbus_br_availwrite(tbr, old_windex);
+
+		/* If not enough space in ring, then tell caller. */
+		if (avail <= total)
+			return -EAGAIN;
+
+		next_windex = vmbus_br_idxinc(old_windex, total, ring_size);
+
+		/* Atomic update of next write_index for other threads */
+	} while (!rte_atomic32_cmpset(&tbr->windex, old_windex, next_windex));
+
+	/* Space from old..new is now reserved */
+	windex = old_windex;
+	for (i = 0; i < iovlen; i++)
+		windex = vmbus_txbr_copyto(tbr, windex, iov[i].iov_base, iov[i].iov_len);
+
+	/* Set the offset of the current channel packet. */
+	save_windex = ((uint64_t)old_windex) << 32;
+	windex = vmbus_txbr_copyto(tbr, windex, &save_windex,
+				   sizeof(save_windex));
+
+	/* The region reserved should match region used */
+	if (windex != next_windex)
+		return -EINVAL;
+
+	/* Ensure that data is available before updating host index */
+	rte_compiler_barrier();
+
+	/* Checkin for our reservation. wait for our turn to update host */
+	while (!rte_atomic32_cmpset(&vbr->windex, old_windex, next_windex))
+		_mm_pause();
+
+	return 0;
+}
+
+int rte_vmbus_chan_send(struct vmbus_br *txbr, uint16_t type, void *data,
+			uint32_t dlen, uint32_t flags)
+{
+	struct vmbus_chanpkt pkt;
+	unsigned int pktlen, pad_pktlen;
+	const uint32_t hlen = sizeof(pkt);
+	uint64_t pad = 0;
+	struct iovec iov[3];
+	int error;
+
+	pktlen = hlen + dlen;
+	pad_pktlen = ALIGN(pktlen, sizeof(uint64_t));
+
+	pkt.hdr.type = type;
+	pkt.hdr.flags = flags;
+	pkt.hdr.hlen = hlen >> VMBUS_CHANPKT_SIZE_SHIFT;
+	pkt.hdr.tlen = pad_pktlen >> VMBUS_CHANPKT_SIZE_SHIFT;
+	pkt.hdr.xactid = VMBUS_RQST_ERROR;
+
+	iov[0].iov_base = &pkt;
+	iov[0].iov_len = hlen;
+	iov[1].iov_base = data;
+	iov[1].iov_len = dlen;
+	iov[2].iov_base = &pad;
+	iov[2].iov_len = pad_pktlen - pktlen;
+
+	error = vmbus_txbr_write(txbr, iov, 3);
+
+	return error;
+}
+
+static inline uint32_t
+vmbus_rxbr_copyfrom(const struct vmbus_br *rbr, uint32_t rindex,
+		    void *dst0, size_t cplen)
+{
+	const uint8_t *br_data = rbr->vbr->data;
+	uint32_t br_dsize = rbr->dsize;
+	uint8_t *dst = dst0;
+
+	if (cplen > br_dsize - rindex) {
+		uint32_t fraglen = br_dsize - rindex;
+
+		/* Wrap-around detected. */
+		memcpy(dst, br_data + rindex, fraglen);
+		memcpy(dst + fraglen, br_data, cplen - fraglen);
+	} else {
+		memcpy(dst, br_data + rindex, cplen);
+	}
+
+	return vmbus_br_idxinc(rindex, cplen, br_dsize);
+}
+
+/* Copy data from receive ring but don't change index */
+static int
+vmbus_rxbr_peek(const struct vmbus_br *rbr, void *data, size_t dlen)
+{
+	uint32_t avail;
+
+	/*
+	 * The requested data and the 64bits channel packet
+	 * offset should be there at least.
+	 */
+	avail = vmbus_br_availread(rbr);
+	if (avail < dlen + sizeof(uint64_t))
+		return -EAGAIN;
+
+	vmbus_rxbr_copyfrom(rbr, rbr->vbr->rindex, data, dlen);
+	return 0;
+}
+
+/*
+ * Copy data from receive ring and change index
+ * NOTE:
+ * We assume (dlen + skip) == sizeof(channel packet).
+ */
+static int
+vmbus_rxbr_read(struct vmbus_br *rbr, void *data, size_t dlen, size_t skip)
+{
+	struct vmbus_bufring *vbr = rbr->vbr;
+	uint32_t br_dsize = rbr->dsize;
+	uint32_t rindex;
+
+	if (vmbus_br_availread(rbr) < dlen + skip + sizeof(uint64_t))
+		return -EAGAIN;
+
+	/* Record where host was when we started read (for debug) */
+	rbr->windex = rbr->vbr->windex;
+
+	/*
+	 * Copy channel packet from RX bufring.
+	 */
+	rindex = vmbus_br_idxinc(rbr->vbr->rindex, skip, br_dsize);
+	rindex = vmbus_rxbr_copyfrom(rbr, rindex, data, dlen);
+
+	/*
+	 * Discard this channel packet's 64bits offset, which is useless to us.
+	 */
+	rindex = vmbus_br_idxinc(rindex, sizeof(uint64_t), br_dsize);
+
+	/* Update the read index _after_ the channel packet is fetched.	 */
+	rte_compiler_barrier();
+
+	vbr->rindex = rindex;
+
+	return 0;
+}
+
+int rte_vmbus_chan_recv_raw(struct vmbus_br *rxbr,
+			    void *data, uint32_t *len)
+{
+	struct vmbus_chanpkt_hdr pkt;
+	uint32_t dlen, bufferlen = *len;
+	int error;
+
+	error = vmbus_rxbr_peek(rxbr, &pkt, sizeof(pkt));
+	if (error)
+		return error;
+
+	if (unlikely(pkt.hlen < VMBUS_CHANPKT_HLEN_MIN))
+		/* XXX this channel is dead actually. */
+		return -EIO;
+
+	if (unlikely(pkt.hlen > pkt.tlen))
+		return -EIO;
+
+	/* Length are in quad words */
+	dlen = pkt.tlen << VMBUS_CHANPKT_SIZE_SHIFT;
+	*len = dlen;
+
+	/* If caller buffer is not large enough */
+	if (unlikely(dlen > bufferlen))
+		return -ENOBUFS;
+
+	/* Read data and skip packet header */
+	error = vmbus_rxbr_read(rxbr, data, dlen, 0);
+	if (error)
+		return error;
+
+	/* Return the number of bytes read */
+	return dlen + sizeof(uint64_t);
+}
diff --git a/tools/hv/vmbus_bufring.h b/tools/hv/vmbus_bufring.h
new file mode 100644
index 000000000..6e7caacff
--- /dev/null
+++ b/tools/hv/vmbus_bufring.h
@@ -0,0 +1,158 @@
+/* SPDX-License-Identifier: BSD-3-Clause */
+
+#ifndef _VMBUS_BUF_H_
+#define _VMBUS_BUF_H_
+
+#include <stdbool.h>
+#include <stdint.h>
+
+#define __packed   __attribute__((__packed__))
+#define unlikely(x)	__builtin_expect(!!(x), 0)
+
+#define ICMSGHDRFLAG_TRANSACTION	1
+#define ICMSGHDRFLAG_REQUEST		2
+#define ICMSGHDRFLAG_RESPONSE		4
+
+#define IC_VERSION_NEGOTIATION_MAX_VER_COUNT 100
+#define ICMSG_HDR (sizeof(struct vmbuspipe_hdr) + sizeof(struct icmsg_hdr))
+#define ICMSG_NEGOTIATE_PKT_SIZE(icframe_vercnt, icmsg_vercnt) \
+	(ICMSG_HDR + sizeof(struct icmsg_negotiate) + \
+	 (((icframe_vercnt) + (icmsg_vercnt)) * sizeof(struct ic_version)))
+
+/*
+ * Channel packets
+ */
+
+/* Channel packet flags */
+#define VMBUS_CHANPKT_TYPE_INBAND	0x0006
+#define VMBUS_CHANPKT_TYPE_RXBUF	0x0007
+#define VMBUS_CHANPKT_TYPE_GPA		0x0009
+#define VMBUS_CHANPKT_TYPE_COMP		0x000b
+
+#define VMBUS_CHANPKT_FLAG_NONE		0
+#define VMBUS_CHANPKT_FLAG_RC		0x0001  /* report completion */
+
+#define VMBUS_CHANPKT_SIZE_SHIFT	3
+#define VMBUS_CHANPKT_SIZE_ALIGN	BIT(VMBUS_CHANPKT_SIZE_SHIFT)
+#define VMBUS_CHANPKT_HLEN_MIN		\
+	(sizeof(struct vmbus_chanpkt_hdr) >> VMBUS_CHANPKT_SIZE_SHIFT)
+
+/*
+ * Buffer ring
+ */
+struct vmbus_bufring {
+	volatile uint32_t windex;
+	volatile uint32_t rindex;
+
+	/*
+	 * Interrupt mask {0,1}
+	 *
+	 * For TX bufring, host set this to 1, when it is processing
+	 * the TX bufring, so that we can safely skip the TX event
+	 * notification to host.
+	 *
+	 * For RX bufring, once this is set to 1 by us, host will not
+	 * further dispatch interrupts to us, even if there are data
+	 * pending on the RX bufring.  This effectively disables the
+	 * interrupt of the channel to which this RX bufring is attached.
+	 */
+	volatile uint32_t imask;
+
+	/*
+	 * Win8 uses some of the reserved bits to implement
+	 * interrupt driven flow management. On the send side
+	 * we can request that the receiver interrupt the sender
+	 * when the ring transitions from being full to being able
+	 * to handle a message of size "pending_send_sz".
+	 *
+	 * Add necessary state for this enhancement.
+	 */
+	volatile uint32_t pending_send;
+	uint32_t reserved1[12];
+
+	union {
+		struct {
+			uint32_t feat_pending_send_sz:1;
+		};
+		uint32_t value;
+	} feature_bits;
+
+	/* Pad it to rte_mem_page_size() so that data starts on page boundary */
+	uint8_t	reserved2[4028];
+
+	/*
+	 * Ring data starts here + RingDataStartOffset
+	 * !!! DO NOT place any fields below this !!!
+	 */
+	uint8_t data[];
+} __packed;
+
+struct vmbus_br {
+	struct vmbus_bufring *vbr;
+	uint32_t	dsize;
+	uint32_t	windex; /* next available location */
+};
+
+struct vmbus_chanpkt_hdr {
+	uint16_t	type;	/* VMBUS_CHANPKT_TYPE_ */
+	uint16_t	hlen;	/* header len, in 8 bytes */
+	uint16_t	tlen;	/* total len, in 8 bytes */
+	uint16_t	flags;	/* VMBUS_CHANPKT_FLAG_ */
+	uint64_t	xactid;
+} __packed;
+
+struct vmbus_chanpkt {
+	struct vmbus_chanpkt_hdr hdr;
+} __packed;
+
+struct vmbuspipe_hdr {
+	unsigned int flags;
+	unsigned int msgsize;
+} __packed;
+
+struct ic_version {
+	unsigned short major;
+	unsigned short minor;
+} __packed;
+
+struct icmsg_negotiate {
+	unsigned short icframe_vercnt;
+	unsigned short icmsg_vercnt;
+	unsigned int reserved;
+	struct ic_version icversion_data[]; /* any size array */
+} __packed;
+
+struct icmsg_hdr {
+	struct ic_version icverframe;
+	unsigned short icmsgtype;
+	struct ic_version icvermsg;
+	unsigned short icmsgsize;
+	unsigned int status;
+	unsigned char ictransaction_id;
+	unsigned char icflags;
+	unsigned char reserved[2];
+} __packed;
+
+int rte_vmbus_chan_recv_raw(struct vmbus_br *rxbr, void *data, uint32_t *len);
+int rte_vmbus_chan_send(struct vmbus_br *txbr, uint16_t type, void *data,
+			uint32_t dlen, uint32_t flags);
+void vmbus_br_setup(struct vmbus_br *br, void *buf, unsigned int blen);
+void *vmbus_uio_map(int *fd, int size);
+
+/* Amount of space available for write */
+static inline uint32_t vmbus_br_availwrite(const struct vmbus_br *br, uint32_t windex)
+{
+	uint32_t rindex = br->vbr->rindex;
+
+	if (windex >= rindex)
+		return br->dsize - (windex - rindex);
+	else
+		return rindex - windex;
+}
+
+static inline uint32_t vmbus_br_availread(const struct vmbus_br *br)
+{
+	return br->dsize - vmbus_br_availwrite(br, br->vbr->windex);
+}
+
+#endif	/* !_VMBUS_BUF_H_ */
diff --git a/tools/hv/vmbus_testing b/tools/hv/vmbus_testing
new file mode 100755
index 000000000..4467979d8
--- /dev/null
+++ b/tools/hv/vmbus_testing
@@ -0,0 +1,376 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: GPL-2.0
+#
+# Program to allow users to fuzz test Hyper-V drivers
+# by interfacing with Hyper-V debugfs attributes.
+# Current test methods available:
+#       1. delay testing
+#
+# Current file/directory structure of hyper-V debugfs:
+#       /sys/kernel/debug/hyperv/UUID
+#       /sys/kernel/debug/hyperv/UUID/<test-state filename>
+#       /sys/kernel/debug/hyperv/UUID/<test-method sub-directory>
+#
+# author: Branden Bonaby <brandonbonaby94@gmail.com>
+
+import os
+import cmd
+import argparse
+import glob
+from argparse import RawDescriptionHelpFormatter
+from argparse import RawTextHelpFormatter
+from enum import Enum
+
+# Do not change unless, you change the debugfs attributes
+# in /drivers/hv/debugfs.c. All fuzz testing
+# attributes will start with "fuzz_test".
+
+# debugfs path for hyperv must exist before proceeding
+debugfs_hyperv_path = "/sys/kernel/debug/hyperv"
+if not os.path.isdir(debugfs_hyperv_path):
+        print("{} doesn't exist/check permissions".format(debugfs_hyperv_path))
+        exit(-1)
+
+class dev_state(Enum):
+        off = 0
+        on = 1
+
+# File names, that correspond to the files created in
+# /drivers/hv/debugfs.c
+class f_names(Enum):
+        state_f = "fuzz_test_state"
+        buff_f =  "fuzz_test_buffer_interrupt_delay"
+        mess_f =  "fuzz_test_message_delay"
+
+# Both single_actions and all_actions are used
+# for error checking and to allow for some subparser
+# names to be abbreviated. Do not abbreviate the
+# test method names, as it will become less intuitive
+# as to what the user can do. If you do decide to
+# abbreviate the test method name, make sure the main
+# function reflects this change.
+
+all_actions = [
+        "disable_all",
+        "D",
+        "enable_all",
+        "view_all",
+        "V"
+]
+
+single_actions = [
+        "disable_single",
+        "d",
+        "enable_single",
+        "view_single",
+        "v"
+]
+
+def main():
+
+        file_map = recursive_file_lookup(debugfs_hyperv_path, dict())
+        args = parse_args()
+        if (not args.action):
+                print ("Error, no options selected...exiting")
+                exit(-1)
+        arg_set = { k for (k,v) in vars(args).items() if v and k != "action" }
+        arg_set.add(args.action)
+        path = args.path if "path" in arg_set else None
+        if (path and path[-1] == "/"):
+                path = path[:-1]
+        validate_args_path(path, arg_set, file_map)
+        if (path and "enable_single" in arg_set):
+            state_path = locate_state(path, file_map)
+            set_test_state(state_path, dev_state.on.value, args.quiet)
+
+        # Use subparsers as the key for different actions
+        if ("delay" in arg_set):
+                validate_delay_values(args.delay_time)
+                if (args.enable_all):
+                        set_delay_all_devices(file_map, args.delay_time,
+                                              args.quiet)
+                else:
+                        set_delay_values(path, file_map, args.delay_time,
+                                         args.quiet)
+        elif ("disable_all" in arg_set or "D" in arg_set):
+                disable_all_testing(file_map)
+        elif ("disable_single" in arg_set or "d" in arg_set):
+                disable_testing_single_device(path, file_map)
+        elif ("view_all" in arg_set or "V" in arg_set):
+                get_all_devices_test_status(file_map)
+        elif ("view_single" in arg_set or  "v" in arg_set):
+                get_device_test_values(path, file_map)
+
+# Get the state location
+def locate_state(device, file_map):
+        return file_map[device][f_names.state_f.value]
+
+# Validate delay values to make sure they are acceptable to
+# enable delays on a device
+def validate_delay_values(delay):
+
+        if (delay[0]  == -1 and delay[1] == -1):
+                print("\nError, At least 1 value must be greater than 0")
+                exit(-1)
+        for i in delay:
+                if (i < -1 or i == 0 or i > 1000):
+                        print("\nError, Values must be  equal to -1 "
+                              "or be > 0 and <= 1000")
+                        exit(-1)
+
+# Validate argument path
+def validate_args_path(path, arg_set, file_map):
+
+        if (not path and any(element in arg_set for element in single_actions)):
+                print("Error, path (-p) REQUIRED for the specified option. "
+                      "Use (-h) to check usage.")
+                exit(-1)
+        elif (path and any(item in arg_set for item in all_actions)):
+                print("Error, path (-p) NOT REQUIRED for the specified option. "
+                      "Use (-h) to check usage." )
+                exit(-1)
+        elif (path not in file_map and any(item in arg_set
+                                           for item in single_actions)):
+                print("Error, path '{}' not a valid vmbus device".format(path))
+                exit(-1)
+
+# display Testing status of single device
+def get_device_test_values(path, file_map):
+
+        for name in file_map[path]:
+                file_location = file_map[path][name]
+                print( name + " = " + str(read_test_files(file_location)))
+
+# Create a map of the vmbus devices and their associated files
+# [key=device, value = [key = filename, value = file path]]
+def recursive_file_lookup(path, file_map):
+
+        for f_path in glob.iglob(path + '**/*'):
+                if (os.path.isfile(f_path)):
+                        if (f_path.rsplit("/",2)[0] == debugfs_hyperv_path):
+                                directory = f_path.rsplit("/",1)[0]
+                        else:
+                                directory = f_path.rsplit("/",2)[0]
+                        f_name = f_path.split("/")[-1]
+                        if (file_map.get(directory)):
+                                file_map[directory].update({f_name:f_path})
+                        else:
+                                file_map[directory] = {f_name:f_path}
+                elif (os.path.isdir(f_path)):
+                        recursive_file_lookup(f_path,file_map)
+        return file_map
+
+# display Testing state of devices
+def get_all_devices_test_status(file_map):
+
+        for device in file_map:
+                if (get_test_state(locate_state(device, file_map)) == 1):
+                        print("Testing = ON for: {}"
+                              .format(device.split("/")[5]))
+                else:
+                        print("Testing = OFF for: {}"
+                              .format(device.split("/")[5]))
+
+# read the vmbus device files, path must be absolute path before calling
+def read_test_files(path):
+        try:
+                with open(path,"r") as f:
+                        file_value = f.readline().strip()
+                return int(file_value)
+
+        except IOError as e:
+                errno, strerror = e.args
+                print("I/O error({0}): {1} on file {2}"
+                      .format(errno, strerror, path))
+                exit(-1)
+        except ValueError:
+                print ("Element to int conversion error in: \n{}".format(path))
+                exit(-1)
+
+# writing to vmbus device files, path must be absolute path before calling
+def write_test_files(path, value):
+
+        try:
+                with open(path,"w") as f:
+                        f.write("{}".format(value))
+        except IOError as e:
+                errno, strerror = e.args
+                print("I/O error({0}): {1} on file {2}"
+                      .format(errno, strerror, path))
+                exit(-1)
+
+# set testing state of device
+def set_test_state(state_path, state_value, quiet):
+
+        write_test_files(state_path, state_value)
+        if (get_test_state(state_path) == 1):
+                if (not quiet):
+                        print("Testing = ON for device: {}"
+                              .format(state_path.split("/")[5]))
+        else:
+                if (not quiet):
+                        print("Testing = OFF for device: {}"
+                              .format(state_path.split("/")[5]))
+
+# get testing state of device
+def get_test_state(state_path):
+        #state == 1 - test = ON
+        #state == 0 - test = OFF
+        return  read_test_files(state_path)
+
+# write 1 - 1000 microseconds, into a single device using the
+# fuzz_test_buffer_interrupt_delay and fuzz_test_message_delay
+# debugfs attributes
+def set_delay_values(device, file_map, delay_length, quiet):
+
+        try:
+                interrupt = file_map[device][f_names.buff_f.value]
+                message = file_map[device][f_names.mess_f.value]
+
+                # delay[0]- buffer interrupt delay, delay[1]- message delay
+                if (delay_length[0] >= 0 and delay_length[0] <= 1000):
+                        write_test_files(interrupt, delay_length[0])
+                if (delay_length[1] >= 0 and delay_length[1] <= 1000):
+                        write_test_files(message, delay_length[1])
+                if (not quiet):
+                        print("Buffer delay testing = {} for: {}"
+                              .format(read_test_files(interrupt),
+                                      interrupt.split("/")[5]))
+                        print("Message delay testing = {} for: {}"
+                              .format(read_test_files(message),
+                                      message.split("/")[5]))
+        except IOError as e:
+                errno, strerror = e.args
+                print("I/O error({0}): {1} on files {2}{3}"
+                      .format(errno, strerror, interrupt, message))
+                exit(-1)
+
+# enabling delay testing on all devices
+def set_delay_all_devices(file_map, delay, quiet):
+
+        for device in (file_map):
+                set_test_state(locate_state(device, file_map),
+                               dev_state.on.value,
+                               quiet)
+                set_delay_values(device, file_map, delay, quiet)
+
+# disable all testing on a SINGLE device.
+def disable_testing_single_device(device, file_map):
+
+        for name in file_map[device]:
+                file_location = file_map[device][name]
+                write_test_files(file_location, dev_state.off.value)
+        print("ALL testing now OFF for {}".format(device.split("/")[-1]))
+
+# disable all testing on ALL devices
+def disable_all_testing(file_map):
+
+        for device in file_map:
+                disable_testing_single_device(device, file_map)
+
+def parse_args():
+        parser = argparse.ArgumentParser(prog = "vmbus_testing",usage ="\n"
+                "%(prog)s [delay]   [-h] [-e|-E] -t [-p]\n"
+                "%(prog)s [view_all       | V]      [-h]\n"
+                "%(prog)s [disable_all    | D]      [-h]\n"
+                "%(prog)s [disable_single | d]      [-h|-p]\n"
+                "%(prog)s [view_single    | v]      [-h|-p]\n"
+                "%(prog)s --version\n",
+                description = "\nUse lsvmbus to get vmbus device type "
+                "information.\n" "\nThe debugfs root path is "
+                "/sys/kernel/debug/hyperv",
+                formatter_class = RawDescriptionHelpFormatter)
+        subparsers = parser.add_subparsers(dest = "action")
+        parser.add_argument("--version", action = "version",
+                version = '%(prog)s 0.1.0')
+        parser.add_argument("-q","--quiet", action = "store_true",
+                help = "silence none important test messages."
+                       " This will only work when enabling testing"
+                       " on a device.")
+        # Use the path parser to hold the --path attribute so it can
+        # be shared between subparsers. Also do the same for the state
+        # parser, as all testing methods will use --enable_all and
+        # enable_single.
+        path_parser = argparse.ArgumentParser(add_help=False)
+        path_parser.add_argument("-p","--path", metavar = "",
+                help = "Debugfs path to a vmbus device. The path "
+                "must be the absolute path to the device.")
+        state_parser = argparse.ArgumentParser(add_help=False)
+        state_group = state_parser.add_mutually_exclusive_group(required = True)
+        state_group.add_argument("-E", "--enable_all", action = "store_const",
+                                 const = "enable_all",
+                                 help = "Enable the specified test type "
+                                 "on ALL vmbus devices.")
+        state_group.add_argument("-e", "--enable_single",
+                                 action = "store_const",
+                                 const = "enable_single",
+                                 help = "Enable the specified test type on a "
+                                 "SINGLE vmbus device.")
+        parser_delay = subparsers.add_parser("delay",
+                        parents = [state_parser, path_parser],
+                        help = "Delay the ring buffer interrupt or the "
+                        "ring buffer message reads in microseconds.",
+                        prog = "vmbus_testing",
+                        usage = "%(prog)s [-h]\n"
+                        "%(prog)s -E -t [value] [value]\n"
+                        "%(prog)s -e -t [value] [value] -p",
+                        description = "Delay the ring buffer interrupt for "
+                        "vmbus devices, or delay the ring buffer message "
+                        "reads for vmbus devices (both in microseconds). This "
+                        "is only on the host to guest channel.")
+        parser_delay.add_argument("-t", "--delay_time", metavar = "", nargs = 2,
+                        type = check_range, default =[0,0], required = (True),
+                        help = "Set [buffer] & [message] delay time. "
+                        "Value constraints: -1 == value "
+                        "or 0 < value <= 1000.\n"
+                        "Use -1 to keep the previous value for that delay "
+                        "type, or a value > 0 <= 1000 to change the delay "
+                        "time.")
+        parser_dis_all = subparsers.add_parser("disable_all",
+                        aliases = ['D'], prog = "vmbus_testing",
+                        usage = "%(prog)s [disable_all | D] -h\n"
+                        "%(prog)s [disable_all | D]\n",
+                        help = "Disable ALL testing on ALL vmbus devices.",
+                        description = "Disable ALL testing on ALL vmbus "
+                        "devices.")
+        parser_dis_single = subparsers.add_parser("disable_single",
+                        aliases = ['d'],
+                        parents = [path_parser], prog = "vmbus_testing",
+                        usage = "%(prog)s [disable_single | d] -h\n"
+                        "%(prog)s [disable_single | d] -p\n",
+                        help = "Disable ALL testing on a SINGLE vmbus device.",
+                        description = "Disable ALL testing on a SINGLE vmbus "
+                        "device.")
+        parser_view_all = subparsers.add_parser("view_all", aliases = ['V'],
+                        help = "View the test state for ALL vmbus devices.",
+                        prog = "vmbus_testing",
+                        usage = "%(prog)s [view_all | V] -h\n"
+                        "%(prog)s [view_all | V]\n",
+                        description = "This shows the test state for ALL the "
+                        "vmbus devices.")
+        parser_view_single = subparsers.add_parser("view_single",
+                        aliases = ['v'],parents = [path_parser],
+                        help = "View the test values for a SINGLE vmbus "
+                        "device.",
+                        description = "This shows the test values for a SINGLE "
+                        "vmbus device.", prog = "vmbus_testing",
+                        usage = "%(prog)s [view_single | v] -h\n"
+                        "%(prog)s [view_single | v] -p")
+
+        return  parser.parse_args()
+
+# value checking for range checking input in parser
+def check_range(arg1):
+
+        try:
+                val = int(arg1)
+        except ValueError as err:
+                raise argparse.ArgumentTypeError(str(err))
+        if val < -1 or val > 1000:
+                message = ("\n\nvalue must be -1 or  0 < value <= 1000. "
+                           "Value program received: {}\n").format(val)
+                raise argparse.ArgumentTypeError(message)
+        return val
+
+if __name__ == "__main__":
+        main()