Add qemu 2.4.0

Change-Id: Ic99cbad4b61f8b127b7dc74d04576c0bcbaaf4f5
Signed-off-by: Yang Zhang <yang.z.zhang@intel.com>

1 files changed, 930 insertions, 0 deletions

diff --git a/qemu/net/tap.c b/qemu/net/tap.c
new file mode 100644
index 000000000..bd01590e8
--- /dev/null
+++ b/qemu/net/tap.c
@@ -0,0 +1,930 @@
+/*
+ * QEMU System Emulator
+ *
+ * Copyright (c) 2003-2008 Fabrice Bellard
+ * Copyright (c) 2009 Red Hat, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "tap_int.h"
+
+#include "config-host.h"
+
+#include <sys/ioctl.h>
+#include <sys/stat.h>
+#include <sys/wait.h>
+#include <sys/socket.h>
+#include <net/if.h>
+
+#include "net/net.h"
+#include "clients.h"
+#include "monitor/monitor.h"
+#include "sysemu/sysemu.h"
+#include "qemu-common.h"
+#include "qemu/error-report.h"
+
+#include "net/tap.h"
+
+#include "net/vhost_net.h"
+
+typedef struct TAPState {
+    NetClientState nc;
+    int fd;
+    char down_script[1024];
+    char down_script_arg[128];
+    uint8_t buf[NET_BUFSIZE];
+    bool read_poll;
+    bool write_poll;
+    bool using_vnet_hdr;
+    bool has_ufo;
+    bool enabled;
+    VHostNetState *vhost_net;
+    unsigned host_vnet_hdr_len;
+} TAPState;
+
+static void launch_script(const char *setup_script, const char *ifname,
+                          int fd, Error **errp);
+
+static void tap_send(void *opaque);
+static void tap_writable(void *opaque);
+
+static void tap_update_fd_handler(TAPState *s)
+{
+    qemu_set_fd_handler(s->fd,
+                        s->read_poll && s->enabled ? tap_send : NULL,
+                        s->write_poll && s->enabled ? tap_writable : NULL,
+                        s);
+}
+
+static void tap_read_poll(TAPState *s, bool enable)
+{
+    s->read_poll = enable;
+    tap_update_fd_handler(s);
+}
+
+static void tap_write_poll(TAPState *s, bool enable)
+{
+    s->write_poll = enable;
+    tap_update_fd_handler(s);
+}
+
+static void tap_writable(void *opaque)
+{
+    TAPState *s = opaque;
+
+    tap_write_poll(s, false);
+
+    qemu_flush_queued_packets(&s->nc);
+}
+
+static ssize_t tap_write_packet(TAPState *s, const struct iovec *iov, int iovcnt)
+{
+    ssize_t len;
+
+    do {
+        len = writev(s->fd, iov, iovcnt);
+    } while (len == -1 && errno == EINTR);
+
+    if (len == -1 && errno == EAGAIN) {
+        tap_write_poll(s, true);
+        return 0;
+    }
+
+    return len;
+}
+
+static ssize_t tap_receive_iov(NetClientState *nc, const struct iovec *iov,
+                               int iovcnt)
+{
+    TAPState *s = DO_UPCAST(TAPState, nc, nc);
+    const struct iovec *iovp = iov;
+    struct iovec iov_copy[iovcnt + 1];
+    struct virtio_net_hdr_mrg_rxbuf hdr = { };
+
+    if (s->host_vnet_hdr_len && !s->using_vnet_hdr) {
+        iov_copy[0].iov_base = &hdr;
+        iov_copy[0].iov_len =  s->host_vnet_hdr_len;
+        memcpy(&iov_copy[1], iov, iovcnt * sizeof(*iov));
+        iovp = iov_copy;
+        iovcnt++;
+    }
+
+    return tap_write_packet(s, iovp, iovcnt);
+}
+
+static ssize_t tap_receive_raw(NetClientState *nc, const uint8_t *buf, size_t size)
+{
+    TAPState *s = DO_UPCAST(TAPState, nc, nc);
+    struct iovec iov[2];
+    int iovcnt = 0;
+    struct virtio_net_hdr_mrg_rxbuf hdr = { };
+
+    if (s->host_vnet_hdr_len) {
+        iov[iovcnt].iov_base = &hdr;
+        iov[iovcnt].iov_len  = s->host_vnet_hdr_len;
+        iovcnt++;
+    }
+
+    iov[iovcnt].iov_base = (char *)buf;
+    iov[iovcnt].iov_len  = size;
+    iovcnt++;
+
+    return tap_write_packet(s, iov, iovcnt);
+}
+
+static ssize_t tap_receive(NetClientState *nc, const uint8_t *buf, size_t size)
+{
+    TAPState *s = DO_UPCAST(TAPState, nc, nc);
+    struct iovec iov[1];
+
+    if (s->host_vnet_hdr_len && !s->using_vnet_hdr) {
+        return tap_receive_raw(nc, buf, size);
+    }
+
+    iov[0].iov_base = (char *)buf;
+    iov[0].iov_len  = size;
+
+    return tap_write_packet(s, iov, 1);
+}
+
+#ifndef __sun__
+ssize_t tap_read_packet(int tapfd, uint8_t *buf, int maxlen)
+{
+    return read(tapfd, buf, maxlen);
+}
+#endif
+
+static void tap_send_completed(NetClientState *nc, ssize_t len)
+{
+    TAPState *s = DO_UPCAST(TAPState, nc, nc);
+    tap_read_poll(s, true);
+}
+
+static void tap_send(void *opaque)
+{
+    TAPState *s = opaque;
+    int size;
+    int packets = 0;
+
+    while (true) {
+        uint8_t *buf = s->buf;
+
+        size = tap_read_packet(s->fd, s->buf, sizeof(s->buf));
+        if (size <= 0) {
+            break;
+        }
+
+        if (s->host_vnet_hdr_len && !s->using_vnet_hdr) {
+            buf  += s->host_vnet_hdr_len;
+            size -= s->host_vnet_hdr_len;
+        }
+
+        size = qemu_send_packet_async(&s->nc, buf, size, tap_send_completed);
+        if (size == 0) {
+            tap_read_poll(s, false);
+            break;
+        } else if (size < 0) {
+            break;
+        }
+
+        /*
+         * When the host keeps receiving more packets while tap_send() is
+         * running we can hog the QEMU global mutex.  Limit the number of
+         * packets that are processed per tap_send() callback to prevent
+         * stalling the guest.
+         */
+        packets++;
+        if (packets >= 50) {
+            break;
+        }
+    }
+}
+
+static bool tap_has_ufo(NetClientState *nc)
+{
+    TAPState *s = DO_UPCAST(TAPState, nc, nc);
+
+    assert(nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP);
+
+    return s->has_ufo;
+}
+
+static bool tap_has_vnet_hdr(NetClientState *nc)
+{
+    TAPState *s = DO_UPCAST(TAPState, nc, nc);
+
+    assert(nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP);
+
+    return !!s->host_vnet_hdr_len;
+}
+
+static bool tap_has_vnet_hdr_len(NetClientState *nc, int len)
+{
+    TAPState *s = DO_UPCAST(TAPState, nc, nc);
+
+    assert(nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP);
+
+    return !!tap_probe_vnet_hdr_len(s->fd, len);
+}
+
+static void tap_set_vnet_hdr_len(NetClientState *nc, int len)
+{
+    TAPState *s = DO_UPCAST(TAPState, nc, nc);
+
+    assert(nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP);
+    assert(len == sizeof(struct virtio_net_hdr_mrg_rxbuf) ||
+           len == sizeof(struct virtio_net_hdr));
+
+    tap_fd_set_vnet_hdr_len(s->fd, len);
+    s->host_vnet_hdr_len = len;
+}
+
+static void tap_using_vnet_hdr(NetClientState *nc, bool using_vnet_hdr)
+{
+    TAPState *s = DO_UPCAST(TAPState, nc, nc);
+
+    assert(nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP);
+    assert(!!s->host_vnet_hdr_len == using_vnet_hdr);
+
+    s->using_vnet_hdr = using_vnet_hdr;
+}
+
+static int tap_set_vnet_le(NetClientState *nc, bool is_le)
+{
+    TAPState *s = DO_UPCAST(TAPState, nc, nc);
+
+    return tap_fd_set_vnet_le(s->fd, is_le);
+}
+
+static int tap_set_vnet_be(NetClientState *nc, bool is_be)
+{
+    TAPState *s = DO_UPCAST(TAPState, nc, nc);
+
+    return tap_fd_set_vnet_be(s->fd, is_be);
+}
+
+static void tap_set_offload(NetClientState *nc, int csum, int tso4,
+                     int tso6, int ecn, int ufo)
+{
+    TAPState *s = DO_UPCAST(TAPState, nc, nc);
+    if (s->fd < 0) {
+        return;
+    }
+
+    tap_fd_set_offload(s->fd, csum, tso4, tso6, ecn, ufo);
+}
+
+static void tap_cleanup(NetClientState *nc)
+{
+    TAPState *s = DO_UPCAST(TAPState, nc, nc);
+    Error *err = NULL;
+
+    if (s->vhost_net) {
+        vhost_net_cleanup(s->vhost_net);
+        s->vhost_net = NULL;
+    }
+
+    qemu_purge_queued_packets(nc);
+
+    if (s->down_script[0]) {
+        launch_script(s->down_script, s->down_script_arg, s->fd, &err);
+        if (err) {
+            error_report_err(err);
+        }
+    }
+
+    tap_read_poll(s, false);
+    tap_write_poll(s, false);
+    close(s->fd);
+    s->fd = -1;
+}
+
+static void tap_poll(NetClientState *nc, bool enable)
+{
+    TAPState *s = DO_UPCAST(TAPState, nc, nc);
+    tap_read_poll(s, enable);
+    tap_write_poll(s, enable);
+}
+
+int tap_get_fd(NetClientState *nc)
+{
+    TAPState *s = DO_UPCAST(TAPState, nc, nc);
+    assert(nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP);
+    return s->fd;
+}
+
+/* fd support */
+
+static NetClientInfo net_tap_info = {
+    .type = NET_CLIENT_OPTIONS_KIND_TAP,
+    .size = sizeof(TAPState),
+    .receive = tap_receive,
+    .receive_raw = tap_receive_raw,
+    .receive_iov = tap_receive_iov,
+    .poll = tap_poll,
+    .cleanup = tap_cleanup,
+    .has_ufo = tap_has_ufo,
+    .has_vnet_hdr = tap_has_vnet_hdr,
+    .has_vnet_hdr_len = tap_has_vnet_hdr_len,
+    .using_vnet_hdr = tap_using_vnet_hdr,
+    .set_offload = tap_set_offload,
+    .set_vnet_hdr_len = tap_set_vnet_hdr_len,
+    .set_vnet_le = tap_set_vnet_le,
+    .set_vnet_be = tap_set_vnet_be,
+};
+
+static TAPState *net_tap_fd_init(NetClientState *peer,
+                                 const char *model,
+                                 const char *name,
+                                 int fd,
+                                 int vnet_hdr)
+{
+    NetClientState *nc;
+    TAPState *s;
+
+    nc = qemu_new_net_client(&net_tap_info, peer, model, name);
+
+    s = DO_UPCAST(TAPState, nc, nc);
+
+    s->fd = fd;
+    s->host_vnet_hdr_len = vnet_hdr ? sizeof(struct virtio_net_hdr) : 0;
+    s->using_vnet_hdr = false;
+    s->has_ufo = tap_probe_has_ufo(s->fd);
+    s->enabled = true;
+    tap_set_offload(&s->nc, 0, 0, 0, 0, 0);
+    /*
+     * Make sure host header length is set correctly in tap:
+     * it might have been modified by another instance of qemu.
+     */
+    if (tap_probe_vnet_hdr_len(s->fd, s->host_vnet_hdr_len)) {
+        tap_fd_set_vnet_hdr_len(s->fd, s->host_vnet_hdr_len);
+    }
+    tap_read_poll(s, true);
+    s->vhost_net = NULL;
+    return s;
+}
+
+static void launch_script(const char *setup_script, const char *ifname,
+                          int fd, Error **errp)
+{
+    int pid, status;
+    char *args[3];
+    char **parg;
+
+    /* try to launch network script */
+    pid = fork();
+    if (pid < 0) {
+        error_setg_errno(errp, errno, "could not launch network script %s",
+                         setup_script);
+        return;
+    }
+    if (pid == 0) {
+        int open_max = sysconf(_SC_OPEN_MAX), i;
+
+        for (i = 3; i < open_max; i++) {
+            if (i != fd) {
+                close(i);
+            }
+        }
+        parg = args;
+        *parg++ = (char *)setup_script;
+        *parg++ = (char *)ifname;
+        *parg = NULL;
+        execv(setup_script, args);
+        _exit(1);
+    } else {
+        while (waitpid(pid, &status, 0) != pid) {
+            /* loop */
+        }
+
+        if (WIFEXITED(status) && WEXITSTATUS(status) == 0) {
+            return;
+        }
+        error_setg(errp, "network script %s failed with status %d",
+                   setup_script, status);
+    }
+}
+
+static int recv_fd(int c)
+{
+    int fd;
+    uint8_t msgbuf[CMSG_SPACE(sizeof(fd))];
+    struct msghdr msg = {
+        .msg_control = msgbuf,
+        .msg_controllen = sizeof(msgbuf),
+    };
+    struct cmsghdr *cmsg;
+    struct iovec iov;
+    uint8_t req[1];
+    ssize_t len;
+
+    cmsg = CMSG_FIRSTHDR(&msg);
+    cmsg->cmsg_level = SOL_SOCKET;
+    cmsg->cmsg_type = SCM_RIGHTS;
+    cmsg->cmsg_len = CMSG_LEN(sizeof(fd));
+    msg.msg_controllen = cmsg->cmsg_len;
+
+    iov.iov_base = req;
+    iov.iov_len = sizeof(req);
+
+    msg.msg_iov = &iov;
+    msg.msg_iovlen = 1;
+
+    len = recvmsg(c, &msg, 0);
+    if (len > 0) {
+        memcpy(&fd, CMSG_DATA(cmsg), sizeof(fd));
+        return fd;
+    }
+
+    return len;
+}
+
+static int net_bridge_run_helper(const char *helper, const char *bridge,
+                                 Error **errp)
+{
+    sigset_t oldmask, mask;
+    int pid, status;
+    char *args[5];
+    char **parg;
+    int sv[2];
+
+    sigemptyset(&mask);
+    sigaddset(&mask, SIGCHLD);
+    sigprocmask(SIG_BLOCK, &mask, &oldmask);
+
+    if (socketpair(PF_UNIX, SOCK_STREAM, 0, sv) == -1) {
+        error_setg_errno(errp, errno, "socketpair() failed");
+        return -1;
+    }
+
+    /* try to launch bridge helper */
+    pid = fork();
+    if (pid < 0) {
+        error_setg_errno(errp, errno, "Can't fork bridge helper");
+        return -1;
+    }
+    if (pid == 0) {
+        int open_max = sysconf(_SC_OPEN_MAX), i;
+        char fd_buf[6+10];
+        char br_buf[6+IFNAMSIZ] = {0};
+        char helper_cmd[PATH_MAX + sizeof(fd_buf) + sizeof(br_buf) + 15];
+
+        for (i = 3; i < open_max; i++) {
+            if (i != sv[1]) {
+                close(i);
+            }
+        }
+
+        snprintf(fd_buf, sizeof(fd_buf), "%s%d", "--fd=", sv[1]);
+
+        if (strrchr(helper, ' ') || strrchr(helper, '\t')) {
+            /* assume helper is a command */
+
+            if (strstr(helper, "--br=") == NULL) {
+                snprintf(br_buf, sizeof(br_buf), "%s%s", "--br=", bridge);
+            }
+
+            snprintf(helper_cmd, sizeof(helper_cmd), "%s %s %s %s",
+                     helper, "--use-vnet", fd_buf, br_buf);
+
+            parg = args;
+            *parg++ = (char *)"sh";
+            *parg++ = (char *)"-c";
+            *parg++ = helper_cmd;
+            *parg++ = NULL;
+
+            execv("/bin/sh", args);
+        } else {
+            /* assume helper is just the executable path name */
+
+            snprintf(br_buf, sizeof(br_buf), "%s%s", "--br=", bridge);
+
+            parg = args;
+            *parg++ = (char *)helper;
+            *parg++ = (char *)"--use-vnet";
+            *parg++ = fd_buf;
+            *parg++ = br_buf;
+            *parg++ = NULL;
+
+            execv(helper, args);
+        }
+        _exit(1);
+
+    } else {
+        int fd;
+        int saved_errno;
+
+        close(sv[1]);
+
+        do {
+            fd = recv_fd(sv[0]);
+        } while (fd == -1 && errno == EINTR);
+        saved_errno = errno;
+
+        close(sv[0]);
+
+        while (waitpid(pid, &status, 0) != pid) {
+            /* loop */
+        }
+        sigprocmask(SIG_SETMASK, &oldmask, NULL);
+        if (fd < 0) {
+            error_setg_errno(errp, saved_errno,
+                             "failed to recv file descriptor");
+            return -1;
+        }
+        if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
+            error_setg(errp, "bridge helper failed");
+            return -1;
+        }
+        return fd;
+    }
+}
+
+int net_init_bridge(const NetClientOptions *opts, const char *name,
+                    NetClientState *peer, Error **errp)
+{
+    const NetdevBridgeOptions *bridge;
+    const char *helper, *br;
+    TAPState *s;
+    int fd, vnet_hdr;
+
+    assert(opts->kind == NET_CLIENT_OPTIONS_KIND_BRIDGE);
+    bridge = opts->bridge;
+
+    helper = bridge->has_helper ? bridge->helper : DEFAULT_BRIDGE_HELPER;
+    br     = bridge->has_br     ? bridge->br     : DEFAULT_BRIDGE_INTERFACE;
+
+    fd = net_bridge_run_helper(helper, br, errp);
+    if (fd == -1) {
+        return -1;
+    }
+
+    fcntl(fd, F_SETFL, O_NONBLOCK);
+    vnet_hdr = tap_probe_vnet_hdr(fd);
+    s = net_tap_fd_init(peer, "bridge", name, fd, vnet_hdr);
+
+    snprintf(s->nc.info_str, sizeof(s->nc.info_str), "helper=%s,br=%s", helper,
+             br);
+
+    return 0;
+}
+
+static int net_tap_init(const NetdevTapOptions *tap, int *vnet_hdr,
+                        const char *setup_script, char *ifname,
+                        size_t ifname_sz, int mq_required, Error **errp)
+{
+    Error *err = NULL;
+    int fd, vnet_hdr_required;
+
+    if (tap->has_vnet_hdr) {
+        *vnet_hdr = tap->vnet_hdr;
+        vnet_hdr_required = *vnet_hdr;
+    } else {
+        *vnet_hdr = 1;
+        vnet_hdr_required = 0;
+    }
+
+    TFR(fd = tap_open(ifname, ifname_sz, vnet_hdr, vnet_hdr_required,
+                      mq_required, errp));
+    if (fd < 0) {
+        return -1;
+    }
+
+    if (setup_script &&
+        setup_script[0] != '\0' &&
+        strcmp(setup_script, "no") != 0) {
+        launch_script(setup_script, ifname, fd, &err);
+        if (err) {
+            error_propagate(errp, err);
+            close(fd);
+            return -1;
+        }
+    }
+
+    return fd;
+}
+
+#define MAX_TAP_QUEUES 1024
+
+static void net_init_tap_one(const NetdevTapOptions *tap, NetClientState *peer,
+                             const char *model, const char *name,
+                             const char *ifname, const char *script,
+                             const char *downscript, const char *vhostfdname,
+                             int vnet_hdr, int fd, Error **errp)
+{
+    Error *err = NULL;
+    TAPState *s = net_tap_fd_init(peer, model, name, fd, vnet_hdr);
+    int vhostfd;
+
+    tap_set_sndbuf(s->fd, tap, &err);
+    if (err) {
+        error_propagate(errp, err);
+        return;
+    }
+
+    if (tap->has_fd || tap->has_fds) {
+        snprintf(s->nc.info_str, sizeof(s->nc.info_str), "fd=%d", fd);
+    } else if (tap->has_helper) {
+        snprintf(s->nc.info_str, sizeof(s->nc.info_str), "helper=%s",
+                 tap->helper);
+    } else {
+        snprintf(s->nc.info_str, sizeof(s->nc.info_str),
+                 "ifname=%s,script=%s,downscript=%s", ifname, script,
+                 downscript);
+
+        if (strcmp(downscript, "no") != 0) {
+            snprintf(s->down_script, sizeof(s->down_script), "%s", downscript);
+            snprintf(s->down_script_arg, sizeof(s->down_script_arg),
+                     "%s", ifname);
+        }
+    }
+
+    if (tap->has_vhost ? tap->vhost :
+        vhostfdname || (tap->has_vhostforce && tap->vhostforce)) {
+        VhostNetOptions options;
+
+        options.backend_type = VHOST_BACKEND_TYPE_KERNEL;
+        options.net_backend = &s->nc;
+
+        if (tap->has_vhostfd || tap->has_vhostfds) {
+            vhostfd = monitor_fd_param(cur_mon, vhostfdname, &err);
+            if (vhostfd == -1) {
+                error_propagate(errp, err);
+                return;
+            }
+        } else {
+            vhostfd = open("/dev/vhost-net", O_RDWR);
+            if (vhostfd < 0) {
+                error_setg_errno(errp, errno,
+                                 "tap: open vhost char device failed");
+                return;
+            }
+        }
+        options.opaque = (void *)(uintptr_t)vhostfd;
+
+        s->vhost_net = vhost_net_init(&options);
+        if (!s->vhost_net) {
+            error_setg(errp,
+                       "vhost-net requested but could not be initialized");
+            return;
+        }
+    } else if (tap->has_vhostfd || tap->has_vhostfds) {
+        error_setg(errp, "vhostfd= is not valid without vhost");
+    }
+}
+
+static int get_fds(char *str, char *fds[], int max)
+{
+    char *ptr = str, *this;
+    size_t len = strlen(str);
+    int i = 0;
+
+    while (i < max && ptr < str + len) {
+        this = strchr(ptr, ':');
+
+        if (this == NULL) {
+            fds[i] = g_strdup(ptr);
+        } else {
+            fds[i] = g_strndup(ptr, this - ptr);
+        }
+
+        i++;
+        if (this == NULL) {
+            break;
+        } else {
+            ptr = this + 1;
+        }
+    }
+
+    return i;
+}
+
+int net_init_tap(const NetClientOptions *opts, const char *name,
+                 NetClientState *peer, Error **errp)
+{
+    const NetdevTapOptions *tap;
+    int fd, vnet_hdr = 0, i = 0, queues;
+    /* for the no-fd, no-helper case */
+    const char *script = NULL; /* suppress wrong "uninit'd use" gcc warning */
+    const char *downscript = NULL;
+    Error *err = NULL;
+    const char *vhostfdname;
+    char ifname[128];
+
+    assert(opts->kind == NET_CLIENT_OPTIONS_KIND_TAP);
+    tap = opts->tap;
+    queues = tap->has_queues ? tap->queues : 1;
+    vhostfdname = tap->has_vhostfd ? tap->vhostfd : NULL;
+
+    /* QEMU vlans does not support multiqueue tap, in this case peer is set.
+     * For -netdev, peer is always NULL. */
+    if (peer && (tap->has_queues || tap->has_fds || tap->has_vhostfds)) {
+        error_setg(errp, "Multiqueue tap cannot be used with QEMU vlans");
+        return -1;
+    }
+
+    if (tap->has_fd) {
+        if (tap->has_ifname || tap->has_script || tap->has_downscript ||
+            tap->has_vnet_hdr || tap->has_helper || tap->has_queues ||
+            tap->has_fds || tap->has_vhostfds) {
+            error_setg(errp, "ifname=, script=, downscript=, vnet_hdr=, "
+                       "helper=, queues=, fds=, and vhostfds= "
+                       "are invalid with fd=");
+            return -1;
+        }
+
+        fd = monitor_fd_param(cur_mon, tap->fd, &err);
+        if (fd == -1) {
+            error_propagate(errp, err);
+            return -1;
+        }
+
+        fcntl(fd, F_SETFL, O_NONBLOCK);
+
+        vnet_hdr = tap_probe_vnet_hdr(fd);
+
+        net_init_tap_one(tap, peer, "tap", name, NULL,
+                         script, downscript,
+                         vhostfdname, vnet_hdr, fd, &err);
+        if (err) {
+            error_propagate(errp, err);
+            return -1;
+        }
+    } else if (tap->has_fds) {
+        char *fds[MAX_TAP_QUEUES];
+        char *vhost_fds[MAX_TAP_QUEUES];
+        int nfds, nvhosts;
+
+        if (tap->has_ifname || tap->has_script || tap->has_downscript ||
+            tap->has_vnet_hdr || tap->has_helper || tap->has_queues ||
+            tap->has_vhostfd) {
+            error_setg(errp, "ifname=, script=, downscript=, vnet_hdr=, "
+                       "helper=, queues=, and vhostfd= "
+                       "are invalid with fds=");
+            return -1;
+        }
+
+        nfds = get_fds(tap->fds, fds, MAX_TAP_QUEUES);
+        if (tap->has_vhostfds) {
+            nvhosts = get_fds(tap->vhostfds, vhost_fds, MAX_TAP_QUEUES);
+            if (nfds != nvhosts) {
+                error_setg(errp, "The number of fds passed does not match "
+                           "the number of vhostfds passed");
+                return -1;
+            }
+        }
+
+        for (i = 0; i < nfds; i++) {
+            fd = monitor_fd_param(cur_mon, fds[i], &err);
+            if (fd == -1) {
+                error_propagate(errp, err);
+                return -1;
+            }
+
+            fcntl(fd, F_SETFL, O_NONBLOCK);
+
+            if (i == 0) {
+                vnet_hdr = tap_probe_vnet_hdr(fd);
+            } else if (vnet_hdr != tap_probe_vnet_hdr(fd)) {
+                error_setg(errp,
+                           "vnet_hdr not consistent across given tap fds");
+                return -1;
+            }
+
+            net_init_tap_one(tap, peer, "tap", name, ifname,
+                             script, downscript,
+                             tap->has_vhostfds ? vhost_fds[i] : NULL,
+                             vnet_hdr, fd, &err);
+            if (err) {
+                error_propagate(errp, err);
+                return -1;
+            }
+        }
+    } else if (tap->has_helper) {
+        if (tap->has_ifname || tap->has_script || tap->has_downscript ||
+            tap->has_vnet_hdr || tap->has_queues || tap->has_vhostfds) {
+            error_setg(errp, "ifname=, script=, downscript=, vnet_hdr=, "
+                       "queues=, and vhostfds= are invalid with helper=");
+            return -1;
+        }
+
+        fd = net_bridge_run_helper(tap->helper, DEFAULT_BRIDGE_INTERFACE,
+                                   errp);
+        if (fd == -1) {
+            return -1;
+        }
+
+        fcntl(fd, F_SETFL, O_NONBLOCK);
+        vnet_hdr = tap_probe_vnet_hdr(fd);
+
+        net_init_tap_one(tap, peer, "bridge", name, ifname,
+                         script, downscript, vhostfdname,
+                         vnet_hdr, fd, &err);
+        if (err) {
+            error_propagate(errp, err);
+            close(fd);
+            return -1;
+        }
+    } else {
+        if (tap->has_vhostfds) {
+            error_setg(errp, "vhostfds= is invalid if fds= wasn't specified");
+            return -1;
+        }
+        script = tap->has_script ? tap->script : DEFAULT_NETWORK_SCRIPT;
+        downscript = tap->has_downscript ? tap->downscript :
+            DEFAULT_NETWORK_DOWN_SCRIPT;
+
+        if (tap->has_ifname) {
+            pstrcpy(ifname, sizeof ifname, tap->ifname);
+        } else {
+            ifname[0] = '\0';
+        }
+
+        for (i = 0; i < queues; i++) {
+            fd = net_tap_init(tap, &vnet_hdr, i >= 1 ? "no" : script,
+                              ifname, sizeof ifname, queues > 1, errp);
+            if (fd == -1) {
+                return -1;
+            }
+
+            if (queues > 1 && i == 0 && !tap->has_ifname) {
+                if (tap_fd_get_ifname(fd, ifname)) {
+                    error_setg(errp, "Fail to get ifname");
+                    close(fd);
+                    return -1;
+                }
+            }
+
+            net_init_tap_one(tap, peer, "tap", name, ifname,
+                             i >= 1 ? "no" : script,
+                             i >= 1 ? "no" : downscript,
+                             vhostfdname, vnet_hdr, fd, &err);
+            if (err) {
+                error_propagate(errp, err);
+                close(fd);
+                return -1;
+            }
+        }
+    }
+
+    return 0;
+}
+
+VHostNetState *tap_get_vhost_net(NetClientState *nc)
+{
+    TAPState *s = DO_UPCAST(TAPState, nc, nc);
+    assert(nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP);
+    return s->vhost_net;
+}
+
+int tap_enable(NetClientState *nc)
+{
+    TAPState *s = DO_UPCAST(TAPState, nc, nc);
+    int ret;
+
+    if (s->enabled) {
+        return 0;
+    } else {
+        ret = tap_fd_enable(s->fd);
+        if (ret == 0) {
+            s->enabled = true;
+            tap_update_fd_handler(s);
+        }
+        return ret;
+    }
+}
+
+int tap_disable(NetClientState *nc)
+{
+    TAPState *s = DO_UPCAST(TAPState, nc, nc);
+    int ret;
+
+    if (s->enabled == 0) {
+        return 0;
+    } else {
+        ret = tap_fd_disable(s->fd);
+        if (ret == 0) {
+            qemu_purge_queued_packets(nc);
+            s->enabled = false;
+            tap_update_fd_handler(s);
+        }
+        return ret;
+    }
+}