Merge remote-tracking branch 'remotes/jasowang/tags/net-pull-request' into staging

# gpg: Signature made Tue 27 Sep 2016 11:05:56 BST
# gpg:                using RSA key 0xEF04965B398D6211
# gpg: Good signature from "Jason Wang (Jason Wang on RedHat) <jasowang@redhat.com>"
# gpg: WARNING: This key is not certified with sufficiently trusted signatures!
# gpg:          It is not certain that the signature belongs to the owner.
# Primary key fingerprint: 215D 46F4 8246 689E C77F  3562 EF04 965B 398D 6211

* remotes/jasowang/tags/net-pull-request: (27 commits)
  imx_fec: fix error in qemu_send_packet argument
  mcf_fec: fix error in qemu_send_packet argument
  net: mcf: limit buffer descriptor count
  e1000e: Fix EIAC register implementation
  e1000e: Fix spurious RX TCP ACK interrupts
  e1000e: Fix OTHER interrupts processing for MSI-X
  e1000e: Fix PBACLR implementation
  e1000e: Fix CTRL_EXT.EIAME behavior
  e1000e: Flush receive queues on link up
  e1000e: Flush all receive queues on receive enable
  net: limit allocation in nc_sendv_compat
  tap: Allow specifying a bridge
  e1000: fix buliding complaint
  docs: Add documentation for COLO-proxy
  MAINTAINERS: add maintainer for COLO-proxy
  filter-rewriter: rewrite tcp packet to keep secondary connection
  filter-rewriter: track connection and parse packet
  filter-rewriter: introduce filter-rewriter initialization
  colo-compare: add TCP, UDP, ICMP packet comparison
  colo-compare: introduce packet comparison thread
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 781 insertions, 0 deletions

diff --git a/net/colo-compare.c b/net/colo-compare.c
new file mode 100644
index 0000000000..22b1da19f5
--- /dev/null
+++ b/net/colo-compare.c
@@ -0,0 +1,781 @@
+/*
+ * COarse-grain LOck-stepping Virtual Machines for Non-stop Service (COLO)
+ * (a.k.a. Fault Tolerance or Continuous Replication)
+ *
+ * Copyright (c) 2016 HUAWEI TECHNOLOGIES CO., LTD.
+ * Copyright (c) 2016 FUJITSU LIMITED
+ * Copyright (c) 2016 Intel Corporation
+ *
+ * Author: Zhang Chen <zhangchen.fnst@cn.fujitsu.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or
+ * later.  See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/error-report.h"
+#include "trace.h"
+#include "qemu-common.h"
+#include "qapi/qmp/qerror.h"
+#include "qapi/error.h"
+#include "net/net.h"
+#include "net/eth.h"
+#include "qom/object_interfaces.h"
+#include "qemu/iov.h"
+#include "qom/object.h"
+#include "qemu/typedefs.h"
+#include "net/queue.h"
+#include "sysemu/char.h"
+#include "qemu/sockets.h"
+#include "qapi-visit.h"
+#include "net/colo.h"
+
+#define TYPE_COLO_COMPARE "colo-compare"
+#define COLO_COMPARE(obj) \
+    OBJECT_CHECK(CompareState, (obj), TYPE_COLO_COMPARE)
+
+#define COMPARE_READ_LEN_MAX NET_BUFSIZE
+#define MAX_QUEUE_SIZE 1024
+
+/* TODO: Should be configurable */
+#define REGULAR_PACKET_CHECK_MS 3000
+
+/*
+  + CompareState ++
+  |               |
+  +---------------+   +---------------+         +---------------+
+  |conn list      +--->conn           +--------->conn           |
+  +---------------+   +---------------+         +---------------+
+  |               |     |           |             |          |
+  +---------------+ +---v----+  +---v----+    +---v----+ +---v----+
+                    |primary |  |secondary    |primary | |secondary
+                    |packet  |  |packet  +    |packet  | |packet  +
+                    +--------+  +--------+    +--------+ +--------+
+                        |           |             |          |
+                    +---v----+  +---v----+    +---v----+ +---v----+
+                    |primary |  |secondary    |primary | |secondary
+                    |packet  |  |packet  +    |packet  | |packet  +
+                    +--------+  +--------+    +--------+ +--------+
+                        |           |             |          |
+                    +---v----+  +---v----+    +---v----+ +---v----+
+                    |primary |  |secondary    |primary | |secondary
+                    |packet  |  |packet  +    |packet  | |packet  +
+                    +--------+  +--------+    +--------+ +--------+
+*/
+typedef struct CompareState {
+    Object parent;
+
+    char *pri_indev;
+    char *sec_indev;
+    char *outdev;
+    CharDriverState *chr_pri_in;
+    CharDriverState *chr_sec_in;
+    CharDriverState *chr_out;
+    SocketReadState pri_rs;
+    SocketReadState sec_rs;
+
+    /* connection list: the connections belonged to this NIC could be found
+     * in this list.
+     * element type: Connection
+     */
+    GQueue conn_list;
+    /* hashtable to save connection */
+    GHashTable *connection_track_table;
+    /* compare thread, a thread for each NIC */
+    QemuThread thread;
+    /* Timer used on the primary to find packets that are never matched */
+    QEMUTimer *timer;
+    QemuMutex timer_check_lock;
+} CompareState;
+
+typedef struct CompareClass {
+    ObjectClass parent_class;
+} CompareClass;
+
+typedef struct CompareChardevProps {
+    bool is_socket;
+} CompareChardevProps;
+
+enum {
+    PRIMARY_IN = 0,
+    SECONDARY_IN,
+};
+
+static int compare_chr_send(CharDriverState *out,
+                            const uint8_t *buf,
+                            uint32_t size);
+
+/*
+ * Return 0 on success, if return -1 means the pkt
+ * is unsupported(arp and ipv6) and will be sent later
+ */
+static int packet_enqueue(CompareState *s, int mode)
+{
+    ConnectionKey key;
+    Packet *pkt = NULL;
+    Connection *conn;
+
+    if (mode == PRIMARY_IN) {
+        pkt = packet_new(s->pri_rs.buf, s->pri_rs.packet_len);
+    } else {
+        pkt = packet_new(s->sec_rs.buf, s->sec_rs.packet_len);
+    }
+
+    if (parse_packet_early(pkt)) {
+        packet_destroy(pkt, NULL);
+        pkt = NULL;
+        return -1;
+    }
+    fill_connection_key(pkt, &key);
+
+    conn = connection_get(s->connection_track_table,
+                          &key,
+                          &s->conn_list);
+
+    if (!conn->processing) {
+        g_queue_push_tail(&s->conn_list, conn);
+        conn->processing = true;
+    }
+
+    if (mode == PRIMARY_IN) {
+        if (g_queue_get_length(&conn->primary_list) <=
+                               MAX_QUEUE_SIZE) {
+            g_queue_push_tail(&conn->primary_list, pkt);
+        } else {
+            error_report("colo compare primary queue size too big,"
+                         "drop packet");
+        }
+    } else {
+        if (g_queue_get_length(&conn->secondary_list) <=
+                               MAX_QUEUE_SIZE) {
+            g_queue_push_tail(&conn->secondary_list, pkt);
+        } else {
+            error_report("colo compare secondary queue size too big,"
+                         "drop packet");
+        }
+    }
+
+    return 0;
+}
+
+/*
+ * The IP packets sent by primary and secondary
+ * will be compared in here
+ * TODO support ip fragment, Out-Of-Order
+ * return:    0  means packet same
+ *            > 0 || < 0 means packet different
+ */
+static int colo_packet_compare(Packet *ppkt, Packet *spkt)
+{
+    trace_colo_compare_ip_info(ppkt->size, inet_ntoa(ppkt->ip->ip_src),
+                               inet_ntoa(ppkt->ip->ip_dst), spkt->size,
+                               inet_ntoa(spkt->ip->ip_src),
+                               inet_ntoa(spkt->ip->ip_dst));
+
+    if (ppkt->size == spkt->size) {
+        return memcmp(ppkt->data, spkt->data, spkt->size);
+    } else {
+        return -1;
+    }
+}
+
+/*
+ * Called from the compare thread on the primary
+ * for compare tcp packet
+ * compare_tcp copied from Dr. David Alan Gilbert's branch
+ */
+static int colo_packet_compare_tcp(Packet *spkt, Packet *ppkt)
+{
+    struct tcphdr *ptcp, *stcp;
+    int res;
+    char *sdebug, *ddebug;
+
+    trace_colo_compare_main("compare tcp");
+    if (ppkt->size != spkt->size) {
+        if (trace_event_get_state(TRACE_COLO_COMPARE_MISCOMPARE)) {
+            trace_colo_compare_main("pkt size not same");
+        }
+        return -1;
+    }
+
+    ptcp = (struct tcphdr *)ppkt->transport_header;
+    stcp = (struct tcphdr *)spkt->transport_header;
+
+    /*
+     * The 'identification' field in the IP header is *very* random
+     * it almost never matches.  Fudge this by ignoring differences in
+     * unfragmented packets; they'll normally sort themselves out if different
+     * anyway, and it should recover at the TCP level.
+     * An alternative would be to get both the primary and secondary to rewrite
+     * somehow; but that would need some sync traffic to sync the state
+     */
+    if (ntohs(ppkt->ip->ip_off) & IP_DF) {
+        spkt->ip->ip_id = ppkt->ip->ip_id;
+        /* and the sum will be different if the IDs were different */
+        spkt->ip->ip_sum = ppkt->ip->ip_sum;
+    }
+
+    res = memcmp(ppkt->data + ETH_HLEN, spkt->data + ETH_HLEN,
+                (spkt->size - ETH_HLEN));
+
+    if (res != 0 && trace_event_get_state(TRACE_COLO_COMPARE_MISCOMPARE)) {
+        sdebug = strdup(inet_ntoa(ppkt->ip->ip_src));
+        ddebug = strdup(inet_ntoa(ppkt->ip->ip_dst));
+        fprintf(stderr, "%s: src/dst: %s/%s p: seq/ack=%u/%u"
+                " s: seq/ack=%u/%u res=%d flags=%x/%x\n",
+                __func__, sdebug, ddebug,
+                (unsigned int)ntohl(ptcp->th_seq),
+                (unsigned int)ntohl(ptcp->th_ack),
+                (unsigned int)ntohl(stcp->th_seq),
+                (unsigned int)ntohl(stcp->th_ack),
+                res, ptcp->th_flags, stcp->th_flags);
+
+        fprintf(stderr, "Primary len = %d\n", ppkt->size);
+        qemu_hexdump((char *)ppkt->data, stderr, "colo-compare", ppkt->size);
+        fprintf(stderr, "Secondary len = %d\n", spkt->size);
+        qemu_hexdump((char *)spkt->data, stderr, "colo-compare", spkt->size);
+
+        g_free(sdebug);
+        g_free(ddebug);
+    }
+
+    return res;
+}
+
+/*
+ * Called from the compare thread on the primary
+ * for compare udp packet
+ */
+static int colo_packet_compare_udp(Packet *spkt, Packet *ppkt)
+{
+    int ret;
+
+    trace_colo_compare_main("compare udp");
+    ret = colo_packet_compare(ppkt, spkt);
+
+    if (ret) {
+        trace_colo_compare_udp_miscompare("primary pkt size", ppkt->size);
+        qemu_hexdump((char *)ppkt->data, stderr, "colo-compare", ppkt->size);
+        trace_colo_compare_udp_miscompare("Secondary pkt size", spkt->size);
+        qemu_hexdump((char *)spkt->data, stderr, "colo-compare", spkt->size);
+    }
+
+    return ret;
+}
+
+/*
+ * Called from the compare thread on the primary
+ * for compare icmp packet
+ */
+static int colo_packet_compare_icmp(Packet *spkt, Packet *ppkt)
+{
+    int network_length;
+
+    trace_colo_compare_main("compare icmp");
+    network_length = ppkt->ip->ip_hl * 4;
+    if (ppkt->size != spkt->size ||
+        ppkt->size < network_length + ETH_HLEN) {
+        return -1;
+    }
+
+    if (colo_packet_compare(ppkt, spkt)) {
+        trace_colo_compare_icmp_miscompare("primary pkt size",
+                                           ppkt->size);
+        qemu_hexdump((char *)ppkt->data, stderr, "colo-compare",
+                     ppkt->size);
+        trace_colo_compare_icmp_miscompare("Secondary pkt size",
+                                           spkt->size);
+        qemu_hexdump((char *)spkt->data, stderr, "colo-compare",
+                     spkt->size);
+        return -1;
+    } else {
+        return 0;
+    }
+}
+
+/*
+ * Called from the compare thread on the primary
+ * for compare other packet
+ */
+static int colo_packet_compare_other(Packet *spkt, Packet *ppkt)
+{
+    trace_colo_compare_main("compare other");
+    trace_colo_compare_ip_info(ppkt->size, inet_ntoa(ppkt->ip->ip_src),
+                               inet_ntoa(ppkt->ip->ip_dst), spkt->size,
+                               inet_ntoa(spkt->ip->ip_src),
+                               inet_ntoa(spkt->ip->ip_dst));
+    return colo_packet_compare(ppkt, spkt);
+}
+
+static int colo_old_packet_check_one(Packet *pkt, int64_t *check_time)
+{
+    int64_t now = qemu_clock_get_ms(QEMU_CLOCK_HOST);
+
+    if ((now - pkt->creation_ms) > (*check_time)) {
+        trace_colo_old_packet_check_found(pkt->creation_ms);
+        return 0;
+    } else {
+        return 1;
+    }
+}
+
+static void colo_old_packet_check_one_conn(void *opaque,
+                                           void *user_data)
+{
+    Connection *conn = opaque;
+    GList *result = NULL;
+    int64_t check_time = REGULAR_PACKET_CHECK_MS;
+
+    result = g_queue_find_custom(&conn->primary_list,
+                                 &check_time,
+                                 (GCompareFunc)colo_old_packet_check_one);
+
+    if (result) {
+        /* do checkpoint will flush old packet */
+        /* TODO: colo_notify_checkpoint();*/
+    }
+}
+
+/*
+ * Look for old packets that the secondary hasn't matched,
+ * if we have some then we have to checkpoint to wake
+ * the secondary up.
+ */
+static void colo_old_packet_check(void *opaque)
+{
+    CompareState *s = opaque;
+
+    g_queue_foreach(&s->conn_list, colo_old_packet_check_one_conn, NULL);
+}
+
+/*
+ * Called from the compare thread on the primary
+ * for compare connection
+ */
+static void colo_compare_connection(void *opaque, void *user_data)
+{
+    CompareState *s = user_data;
+    Connection *conn = opaque;
+    Packet *pkt = NULL;
+    GList *result = NULL;
+    int ret;
+
+    while (!g_queue_is_empty(&conn->primary_list) &&
+           !g_queue_is_empty(&conn->secondary_list)) {
+        qemu_mutex_lock(&s->timer_check_lock);
+        pkt = g_queue_pop_tail(&conn->primary_list);
+        qemu_mutex_unlock(&s->timer_check_lock);
+        switch (conn->ip_proto) {
+        case IPPROTO_TCP:
+            result = g_queue_find_custom(&conn->secondary_list,
+                     pkt, (GCompareFunc)colo_packet_compare_tcp);
+            break;
+        case IPPROTO_UDP:
+            result = g_queue_find_custom(&conn->secondary_list,
+                     pkt, (GCompareFunc)colo_packet_compare_udp);
+            break;
+        case IPPROTO_ICMP:
+            result = g_queue_find_custom(&conn->secondary_list,
+                     pkt, (GCompareFunc)colo_packet_compare_icmp);
+            break;
+        default:
+            result = g_queue_find_custom(&conn->secondary_list,
+                     pkt, (GCompareFunc)colo_packet_compare_other);
+            break;
+        }
+
+        if (result) {
+            ret = compare_chr_send(s->chr_out, pkt->data, pkt->size);
+            if (ret < 0) {
+                error_report("colo_send_primary_packet failed");
+            }
+            trace_colo_compare_main("packet same and release packet");
+            g_queue_remove(&conn->secondary_list, result->data);
+            packet_destroy(pkt, NULL);
+        } else {
+            /*
+             * If one packet arrive late, the secondary_list or
+             * primary_list will be empty, so we can't compare it
+             * until next comparison.
+             */
+            trace_colo_compare_main("packet different");
+            qemu_mutex_lock(&s->timer_check_lock);
+            g_queue_push_tail(&conn->primary_list, pkt);
+            qemu_mutex_unlock(&s->timer_check_lock);
+            /* TODO: colo_notify_checkpoint();*/
+            break;
+        }
+    }
+}
+
+static int compare_chr_send(CharDriverState *out,
+                            const uint8_t *buf,
+                            uint32_t size)
+{
+    int ret = 0;
+    uint32_t len = htonl(size);
+
+    if (!size) {
+        return 0;
+    }
+
+    ret = qemu_chr_fe_write_all(out, (uint8_t *)&len, sizeof(len));
+    if (ret != sizeof(len)) {
+        goto err;
+    }
+
+    ret = qemu_chr_fe_write_all(out, (uint8_t *)buf, size);
+    if (ret != size) {
+        goto err;
+    }
+
+    return 0;
+
+err:
+    return ret < 0 ? ret : -EIO;
+}
+
+static int compare_chr_can_read(void *opaque)
+{
+    return COMPARE_READ_LEN_MAX;
+}
+
+/*
+ * Called from the main thread on the primary for packets
+ * arriving over the socket from the primary.
+ */
+static void compare_pri_chr_in(void *opaque, const uint8_t *buf, int size)
+{
+    CompareState *s = COLO_COMPARE(opaque);
+    int ret;
+
+    ret = net_fill_rstate(&s->pri_rs, buf, size);
+    if (ret == -1) {
+        qemu_chr_add_handlers(s->chr_pri_in, NULL, NULL, NULL, NULL);
+        error_report("colo-compare primary_in error");
+    }
+}
+
+/*
+ * Called from the main thread on the primary for packets
+ * arriving over the socket from the secondary.
+ */
+static void compare_sec_chr_in(void *opaque, const uint8_t *buf, int size)
+{
+    CompareState *s = COLO_COMPARE(opaque);
+    int ret;
+
+    ret = net_fill_rstate(&s->sec_rs, buf, size);
+    if (ret == -1) {
+        qemu_chr_add_handlers(s->chr_sec_in, NULL, NULL, NULL, NULL);
+        error_report("colo-compare secondary_in error");
+    }
+}
+
+static void *colo_compare_thread(void *opaque)
+{
+    GMainContext *worker_context;
+    GMainLoop *compare_loop;
+    CompareState *s = opaque;
+
+    worker_context = g_main_context_new();
+
+    qemu_chr_add_handlers_full(s->chr_pri_in, compare_chr_can_read,
+                          compare_pri_chr_in, NULL, s, worker_context);
+    qemu_chr_add_handlers_full(s->chr_sec_in, compare_chr_can_read,
+                          compare_sec_chr_in, NULL, s, worker_context);
+
+    compare_loop = g_main_loop_new(worker_context, FALSE);
+
+    g_main_loop_run(compare_loop);
+
+    g_main_loop_unref(compare_loop);
+    g_main_context_unref(worker_context);
+    return NULL;
+}
+
+static char *compare_get_pri_indev(Object *obj, Error **errp)
+{
+    CompareState *s = COLO_COMPARE(obj);
+
+    return g_strdup(s->pri_indev);
+}
+
+static void compare_set_pri_indev(Object *obj, const char *value, Error **errp)
+{
+    CompareState *s = COLO_COMPARE(obj);
+
+    g_free(s->pri_indev);
+    s->pri_indev = g_strdup(value);
+}
+
+static char *compare_get_sec_indev(Object *obj, Error **errp)
+{
+    CompareState *s = COLO_COMPARE(obj);
+
+    return g_strdup(s->sec_indev);
+}
+
+static void compare_set_sec_indev(Object *obj, const char *value, Error **errp)
+{
+    CompareState *s = COLO_COMPARE(obj);
+
+    g_free(s->sec_indev);
+    s->sec_indev = g_strdup(value);
+}
+
+static char *compare_get_outdev(Object *obj, Error **errp)
+{
+    CompareState *s = COLO_COMPARE(obj);
+
+    return g_strdup(s->outdev);
+}
+
+static void compare_set_outdev(Object *obj, const char *value, Error **errp)
+{
+    CompareState *s = COLO_COMPARE(obj);
+
+    g_free(s->outdev);
+    s->outdev = g_strdup(value);
+}
+
+static void compare_pri_rs_finalize(SocketReadState *pri_rs)
+{
+    CompareState *s = container_of(pri_rs, CompareState, pri_rs);
+
+    if (packet_enqueue(s, PRIMARY_IN)) {
+        trace_colo_compare_main("primary: unsupported packet in");
+        compare_chr_send(s->chr_out, pri_rs->buf, pri_rs->packet_len);
+    } else {
+        /* compare connection */
+        g_queue_foreach(&s->conn_list, colo_compare_connection, s);
+    }
+}
+
+static void compare_sec_rs_finalize(SocketReadState *sec_rs)
+{
+    CompareState *s = container_of(sec_rs, CompareState, sec_rs);
+
+    if (packet_enqueue(s, SECONDARY_IN)) {
+        trace_colo_compare_main("secondary: unsupported packet in");
+    } else {
+        /* compare connection */
+        g_queue_foreach(&s->conn_list, colo_compare_connection, s);
+    }
+}
+
+static int compare_chardev_opts(void *opaque,
+                                const char *name, const char *value,
+                                Error **errp)
+{
+    CompareChardevProps *props = opaque;
+
+    if (strcmp(name, "backend") == 0 &&
+        strcmp(value, "socket") == 0) {
+        props->is_socket = true;
+        return 0;
+    } else if (strcmp(name, "host") == 0 ||
+              (strcmp(name, "port") == 0) ||
+              (strcmp(name, "server") == 0) ||
+              (strcmp(name, "wait") == 0) ||
+              (strcmp(name, "path") == 0)) {
+        return 0;
+    } else {
+        error_setg(errp,
+                   "COLO-compare does not support a chardev with option %s=%s",
+                   name, value);
+        return -1;
+    }
+}
+
+/*
+ * Return 0 is success.
+ * Return 1 is failed.
+ */
+static int find_and_check_chardev(CharDriverState **chr,
+                                  char *chr_name,
+                                  Error **errp)
+{
+    CompareChardevProps props;
+
+    *chr = qemu_chr_find(chr_name);
+    if (*chr == NULL) {
+        error_setg(errp, "Device '%s' not found",
+                   chr_name);
+        return 1;
+    }
+
+    memset(&props, 0, sizeof(props));
+    if (qemu_opt_foreach((*chr)->opts, compare_chardev_opts, &props, errp)) {
+        return 1;
+    }
+
+    if (!props.is_socket) {
+        error_setg(errp, "chardev \"%s\" is not a tcp socket",
+                   chr_name);
+        return 1;
+    }
+    return 0;
+}
+
+/*
+ * Check old packet regularly so it can watch for any packets
+ * that the secondary hasn't produced equivalents of.
+ */
+static void check_old_packet_regular(void *opaque)
+{
+    CompareState *s = opaque;
+
+    timer_mod(s->timer, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) +
+              REGULAR_PACKET_CHECK_MS);
+    /* if have old packet we will notify checkpoint */
+    /*
+     * TODO: Make timer handler run in compare thread
+     * like qemu_chr_add_handlers_full.
+     */
+    qemu_mutex_lock(&s->timer_check_lock);
+    colo_old_packet_check(s);
+    qemu_mutex_unlock(&s->timer_check_lock);
+}
+
+/*
+ * Called from the main thread on the primary
+ * to setup colo-compare.
+ */
+static void colo_compare_complete(UserCreatable *uc, Error **errp)
+{
+    CompareState *s = COLO_COMPARE(uc);
+    char thread_name[64];
+    static int compare_id;
+
+    if (!s->pri_indev || !s->sec_indev || !s->outdev) {
+        error_setg(errp, "colo compare needs 'primary_in' ,"
+                   "'secondary_in','outdev' property set");
+        return;
+    } else if (!strcmp(s->pri_indev, s->outdev) ||
+               !strcmp(s->sec_indev, s->outdev) ||
+               !strcmp(s->pri_indev, s->sec_indev)) {
+        error_setg(errp, "'indev' and 'outdev' could not be same "
+                   "for compare module");
+        return;
+    }
+
+    if (find_and_check_chardev(&s->chr_pri_in, s->pri_indev, errp)) {
+        return;
+    }
+
+    if (find_and_check_chardev(&s->chr_sec_in, s->sec_indev, errp)) {
+        return;
+    }
+
+    if (find_and_check_chardev(&s->chr_out, s->outdev, errp)) {
+        return;
+    }
+
+    qemu_chr_fe_claim_no_fail(s->chr_pri_in);
+
+    qemu_chr_fe_claim_no_fail(s->chr_sec_in);
+
+    qemu_chr_fe_claim_no_fail(s->chr_out);
+
+    net_socket_rs_init(&s->pri_rs, compare_pri_rs_finalize);
+    net_socket_rs_init(&s->sec_rs, compare_sec_rs_finalize);
+
+    g_queue_init(&s->conn_list);
+    qemu_mutex_init(&s->timer_check_lock);
+
+    s->connection_track_table = g_hash_table_new_full(connection_key_hash,
+                                                      connection_key_equal,
+                                                      g_free,
+                                                      connection_destroy);
+
+    sprintf(thread_name, "colo-compare %d", compare_id);
+    qemu_thread_create(&s->thread, thread_name,
+                       colo_compare_thread, s,
+                       QEMU_THREAD_JOINABLE);
+    compare_id++;
+
+    /* A regular timer to kick any packets that the secondary doesn't match */
+    s->timer = timer_new_ms(QEMU_CLOCK_VIRTUAL, /* Only when guest runs */
+                            check_old_packet_regular, s);
+    timer_mod(s->timer, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) +
+                        REGULAR_PACKET_CHECK_MS);
+
+    return;
+}
+
+static void colo_compare_class_init(ObjectClass *oc, void *data)
+{
+    UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
+
+    ucc->complete = colo_compare_complete;
+}
+
+static void colo_compare_init(Object *obj)
+{
+    object_property_add_str(obj, "primary_in",
+                            compare_get_pri_indev, compare_set_pri_indev,
+                            NULL);
+    object_property_add_str(obj, "secondary_in",
+                            compare_get_sec_indev, compare_set_sec_indev,
+                            NULL);
+    object_property_add_str(obj, "outdev",
+                            compare_get_outdev, compare_set_outdev,
+                            NULL);
+}
+
+static void colo_compare_finalize(Object *obj)
+{
+    CompareState *s = COLO_COMPARE(obj);
+
+    if (s->chr_pri_in) {
+        qemu_chr_add_handlers(s->chr_pri_in, NULL, NULL, NULL, NULL);
+        qemu_chr_fe_release(s->chr_pri_in);
+    }
+    if (s->chr_sec_in) {
+        qemu_chr_add_handlers(s->chr_sec_in, NULL, NULL, NULL, NULL);
+        qemu_chr_fe_release(s->chr_sec_in);
+    }
+    if (s->chr_out) {
+        qemu_chr_fe_release(s->chr_out);
+    }
+
+    g_queue_free(&s->conn_list);
+
+    if (qemu_thread_is_self(&s->thread)) {
+        /* compare connection */
+        g_queue_foreach(&s->conn_list, colo_compare_connection, s);
+        qemu_thread_join(&s->thread);
+    }
+
+    if (s->timer) {
+        timer_del(s->timer);
+    }
+
+    qemu_mutex_destroy(&s->timer_check_lock);
+
+    g_free(s->pri_indev);
+    g_free(s->sec_indev);
+    g_free(s->outdev);
+}
+
+static const TypeInfo colo_compare_info = {
+    .name = TYPE_COLO_COMPARE,
+    .parent = TYPE_OBJECT,
+    .instance_size = sizeof(CompareState),
+    .instance_init = colo_compare_init,
+    .instance_finalize = colo_compare_finalize,
+    .class_size = sizeof(CompareClass),
+    .class_init = colo_compare_class_init,
+    .interfaces = (InterfaceInfo[]) {
+        { TYPE_USER_CREATABLE },
+        { }
+    }
+};
+
+static void register_types(void)
+{
+    type_register_static(&colo_compare_info);
+}
+
+type_init(register_types);