scftorture: Count single_rpc offline failures in statistics outputgrafted

scf_torture_stats_print() aggregates each invoker thread's counters
into a local scf_statistics structure before printing, but the
n_single_rpc_ofl field is missing from the aggregation loop.  As a
result, the "single_rpc_ofl" value printed in the statistics line is
always zero, even when smp_call_function_single() invocations for the
RPC test have failed due to offline CPUs and been counted by the
invoker threads.

Add the missing accumulation so that the printed value reflects the
actual counts.

Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
Signed-off-by: Paul E. McKenney <paulmck@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()