Import QEMU upstream snapshot d2e570c

Upstream: https://gitlab.com/qemu-project/qemu.git

Upstream-Commit: d2e570cc0f97b936902a5b1b86b73c0f5998b475

io/channel-buffer.c

@@ -0,0 +1,253 @@
+/*
+ * QEMU I/O channels memory buffer driver
+ *
+ * Copyright (c) 2015 Red Hat, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include "qemu/osdep.h"
+#include "io/channel-buffer.h"
+#include "io/channel-watch.h"
+#include "qemu/module.h"
+#include "qemu/sockets.h"
+#include "trace.h"
+
+QIOChannelBuffer *
+qio_channel_buffer_new(size_t capacity)
+{
+    QIOChannelBuffer *ioc;
+
+    ioc = QIO_CHANNEL_BUFFER(object_new(TYPE_QIO_CHANNEL_BUFFER));
+
+    if (capacity) {
+        ioc->data = g_new0(uint8_t, capacity);
+        ioc->capacity = capacity;
+    }
+
+    return ioc;
+}
+
+
+static void qio_channel_buffer_finalize(Object *obj)
+{
+    QIOChannelBuffer *ioc = QIO_CHANNEL_BUFFER(obj);
+    g_free(ioc->data);
+    ioc->capacity = ioc->usage = ioc->offset = 0;
+}
+
+
+static ssize_t qio_channel_buffer_readv(QIOChannel *ioc,
+                                        const struct iovec *iov,
+                                        size_t niov,
+                                        int **fds,
+                                        size_t *nfds,
+                                        int flags,
+                                        Error **errp)
+{
+    QIOChannelBuffer *bioc = QIO_CHANNEL_BUFFER(ioc);
+    ssize_t ret = 0;
+    size_t i;
+
+    for (i = 0; i < niov; i++) {
+        size_t want = iov[i].iov_len;
+        if (bioc->offset >= bioc->usage) {
+            break;
+        }
+        if ((bioc->offset + want) > bioc->usage)  {
+            want = bioc->usage - bioc->offset;
+        }
+        memcpy(iov[i].iov_base, bioc->data + bioc->offset, want);
+        ret += want;
+        bioc->offset += want;
+    }
+
+    return ret;
+}
+
+static ssize_t qio_channel_buffer_writev(QIOChannel *ioc,
+                                         const struct iovec *iov,
+                                         size_t niov,
+                                         int *fds,
+                                         size_t nfds,
+                                         int flags,
+                                         Error **errp)
+{
+    QIOChannelBuffer *bioc = QIO_CHANNEL_BUFFER(ioc);
+    ssize_t ret = 0;
+    size_t i;
+    size_t towrite = 0;
+
+    for (i = 0; i < niov; i++) {
+        towrite += iov[i].iov_len;
+    }
+
+    if ((bioc->offset + towrite) > bioc->capacity) {
+        bioc->capacity = bioc->offset + towrite;
+        bioc->data = g_realloc(bioc->data, bioc->capacity);
+    }
+
+    if (bioc->offset > bioc->usage) {
+        memset(bioc->data, 0, bioc->offset - bioc->usage);
+        bioc->usage = bioc->offset;
+    }
+
+    for (i = 0; i < niov; i++) {
+        memcpy(bioc->data + bioc->usage,
+               iov[i].iov_base,
+               iov[i].iov_len);
+        bioc->usage += iov[i].iov_len;
+        bioc->offset += iov[i].iov_len;
+        ret += iov[i].iov_len;
+    }
+
+    return ret;
+}
+
+static int qio_channel_buffer_set_blocking(QIOChannel *ioc G_GNUC_UNUSED,
+                                           bool enabled G_GNUC_UNUSED,
+                                           Error **errp G_GNUC_UNUSED)
+{
+    return 0;
+}
+
+
+static off_t qio_channel_buffer_seek(QIOChannel *ioc,
+                                     off_t offset,
+                                     int whence,
+                                     Error **errp)
+{
+    QIOChannelBuffer *bioc = QIO_CHANNEL_BUFFER(ioc);
+
+    bioc->offset = offset;
+
+    return offset;
+}
+
+
+static int qio_channel_buffer_close(QIOChannel *ioc,
+                                    Error **errp)
+{
+    QIOChannelBuffer *bioc = QIO_CHANNEL_BUFFER(ioc);
+
+    g_free(bioc->data);
+    bioc->data = NULL;
+    bioc->capacity = bioc->usage = bioc->offset = 0;
+
+    return 0;
+}
+
+
+typedef struct QIOChannelBufferSource QIOChannelBufferSource;
+struct QIOChannelBufferSource {
+    GSource parent;
+    QIOChannelBuffer *bioc;
+    GIOCondition condition;
+};
+
+static gboolean
+qio_channel_buffer_source_prepare(GSource *source,
+                                  gint *timeout)
+{
+    QIOChannelBufferSource *bsource = (QIOChannelBufferSource *)source;
+
+    *timeout = -1;
+
+    return (G_IO_IN | G_IO_OUT) & bsource->condition;
+}
+
+static gboolean
+qio_channel_buffer_source_check(GSource *source)
+{
+    QIOChannelBufferSource *bsource = (QIOChannelBufferSource *)source;
+
+    return (G_IO_IN | G_IO_OUT) & bsource->condition;
+}
+
+static gboolean
+qio_channel_buffer_source_dispatch(GSource *source,
+                                   GSourceFunc callback,
+                                   gpointer user_data)
+{
+    QIOChannelFunc func = (QIOChannelFunc)callback;
+    QIOChannelBufferSource *bsource = (QIOChannelBufferSource *)source;
+
+    return (*func)(QIO_CHANNEL(bsource->bioc),
+                   ((G_IO_IN | G_IO_OUT) & bsource->condition),
+                   user_data);
+}
+
+static void
+qio_channel_buffer_source_finalize(GSource *source)
+{
+    QIOChannelBufferSource *ssource = (QIOChannelBufferSource *)source;
+
+    object_unref(OBJECT(ssource->bioc));
+}
+
+GSourceFuncs qio_channel_buffer_source_funcs = {
+    qio_channel_buffer_source_prepare,
+    qio_channel_buffer_source_check,
+    qio_channel_buffer_source_dispatch,
+    qio_channel_buffer_source_finalize
+};
+
+static GSource *qio_channel_buffer_create_watch(QIOChannel *ioc,
+                                                GIOCondition condition)
+{
+    QIOChannelBuffer *bioc = QIO_CHANNEL_BUFFER(ioc);
+    QIOChannelBufferSource *ssource;
+    GSource *source;
+
+    source = g_source_new(&qio_channel_buffer_source_funcs,
+                          sizeof(QIOChannelBufferSource));
+    ssource = (QIOChannelBufferSource *)source;
+
+    ssource->bioc = bioc;
+    object_ref(OBJECT(bioc));
+
+    ssource->condition = condition;
+
+    return source;
+}
+
+
+static void qio_channel_buffer_class_init(ObjectClass *klass,
+                                          const void *class_data G_GNUC_UNUSED)
+{
+    QIOChannelClass *ioc_klass = QIO_CHANNEL_CLASS(klass);
+
+    ioc_klass->io_writev = qio_channel_buffer_writev;
+    ioc_klass->io_readv = qio_channel_buffer_readv;
+    ioc_klass->io_set_blocking = qio_channel_buffer_set_blocking;
+    ioc_klass->io_seek = qio_channel_buffer_seek;
+    ioc_klass->io_close = qio_channel_buffer_close;
+    ioc_klass->io_create_watch = qio_channel_buffer_create_watch;
+}
+
+static const TypeInfo qio_channel_buffer_info = {
+    .parent = TYPE_QIO_CHANNEL,
+    .name = TYPE_QIO_CHANNEL_BUFFER,
+    .instance_size = sizeof(QIOChannelBuffer),
+    .instance_finalize = qio_channel_buffer_finalize,
+    .class_init = qio_channel_buffer_class_init,
+};
+
+static void qio_channel_buffer_register_types(void)
+{
+    type_register_static(&qio_channel_buffer_info);
+}
+
+type_init(qio_channel_buffer_register_types);

io/channel-command.c

@@ -0,0 +1,390 @@
+/*
+ * QEMU I/O channels external command driver
+ *
+ * Copyright (c) 2015 Red Hat, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include "qemu/osdep.h"
+#include "io/channel-command.h"
+#include "io/channel-util.h"
+#include "io/channel-watch.h"
+#include "qapi/error.h"
+#include "qemu/module.h"
+#include "qemu/sockets.h"
+#include "trace.h"
+
+/**
+ * qio_channel_command_new_pid:
+ * @writefd: the FD connected to the command's stdin
+ * @readfd: the FD connected to the command's stdout
+ * @pid: the PID/HANDLE of the running child command
+ * @errp: pointer to a NULL-initialized error object
+ *
+ * Create a channel for performing I/O with the
+ * previously spawned command identified by @pid.
+ * The two file descriptors provide the connection
+ * to command's stdio streams, either one or which
+ * may be -1 to indicate that stream is not open.
+ *
+ * The channel will take ownership of the process
+ * @pid and will kill it when closing the channel.
+ * Similarly it will take responsibility for
+ * closing the file descriptors @writefd and @readfd.
+ *
+ * Returns: the command channel object, or NULL on error
+ */
+static QIOChannelCommand *
+qio_channel_command_new_pid(int writefd,
+                            int readfd,
+                            GPid pid)
+{
+    QIOChannelCommand *ioc;
+
+    ioc = QIO_CHANNEL_COMMAND(object_new(TYPE_QIO_CHANNEL_COMMAND));
+
+    ioc->readfd = readfd;
+    ioc->writefd = writefd;
+    ioc->pid = pid;
+
+    trace_qio_channel_command_new_pid(ioc, writefd, readfd,
+#ifdef WIN32
+                                      GetProcessId(pid)
+#else
+                                      pid
+#endif
+        );
+    return ioc;
+}
+
+QIOChannelCommand *
+qio_channel_command_new_spawn(const char *const argv[],
+                              int flags,
+                              Error **errp)
+{
+    g_autoptr(GError) err = NULL;
+    GPid pid = 0;
+    GSpawnFlags gflags = G_SPAWN_CLOEXEC_PIPES | G_SPAWN_DO_NOT_REAP_CHILD;
+    int stdinfd = -1, stdoutfd = -1;
+
+    flags = flags & O_ACCMODE;
+    gflags |= flags == O_WRONLY ? G_SPAWN_STDOUT_TO_DEV_NULL : 0;
+
+    if (!g_spawn_async_with_pipes(NULL, (char **)argv, NULL, gflags, NULL, NULL,
+                                  &pid,
+                                  flags == O_RDONLY ? NULL : &stdinfd,
+                                  flags == O_WRONLY ? NULL : &stdoutfd,
+                                  NULL, &err)) {
+        error_setg(errp, "%s", err->message);
+        return NULL;
+    }
+
+    return qio_channel_command_new_pid(stdinfd, stdoutfd, pid);
+}
+
+#ifndef WIN32
+static int qio_channel_command_abort(QIOChannelCommand *ioc,
+                                     Error **errp)
+{
+    pid_t ret;
+    int status;
+    int step = 0;
+
+    /* See if intermediate process has exited; if not, try a nice
+     * SIGTERM followed by a more severe SIGKILL.
+     */
+ rewait:
+    trace_qio_channel_command_abort(ioc, ioc->pid);
+    ret = waitpid(ioc->pid, &status, WNOHANG);
+    trace_qio_channel_command_wait(ioc, ioc->pid, ret, status);
+    if (ret == (pid_t)-1) {
+        if (errno == EINTR) {
+            goto rewait;
+        } else {
+            error_setg_errno(errp, errno,
+                             "Cannot wait on pid %llu",
+                             (unsigned long long)ioc->pid);
+            return -1;
+        }
+    } else if (ret == 0) {
+        if (step == 0) {
+            kill(ioc->pid, SIGTERM);
+        } else if (step == 1) {
+            kill(ioc->pid, SIGKILL);
+        } else {
+            error_setg(errp,
+                       "Process %llu refused to die",
+                       (unsigned long long)ioc->pid);
+            return -1;
+        }
+        step++;
+        usleep(10 * 1000);
+        goto rewait;
+    }
+
+    return 0;
+}
+#else
+static int qio_channel_command_abort(QIOChannelCommand *ioc,
+                                     Error **errp)
+{
+    DWORD ret;
+
+    TerminateProcess(ioc->pid, 0);
+    ret = WaitForSingleObject(ioc->pid, 1000);
+    if (ret != WAIT_OBJECT_0) {
+        error_setg(errp,
+                   "Process %llu refused to die",
+                   (unsigned long long)GetProcessId(ioc->pid));
+        return -1;
+    }
+
+    return 0;
+}
+#endif /* ! WIN32 */
+
+
+static void qio_channel_command_init(Object *obj)
+{
+    QIOChannelCommand *ioc = QIO_CHANNEL_COMMAND(obj);
+    ioc->readfd = -1;
+    ioc->writefd = -1;
+    ioc->pid = 0;
+}
+
+static void qio_channel_command_finalize(Object *obj)
+{
+    QIOChannelCommand *ioc = QIO_CHANNEL_COMMAND(obj);
+    if (ioc->readfd != -1) {
+        close(ioc->readfd);
+    }
+    if (ioc->writefd != -1 &&
+        ioc->writefd != ioc->readfd) {
+        close(ioc->writefd);
+    }
+    ioc->writefd = ioc->readfd = -1;
+    if (ioc->pid > 0) {
+        qio_channel_command_abort(ioc, NULL);
+        g_spawn_close_pid(ioc->pid);
+    }
+}
+
+#ifdef WIN32
+static bool win32_fd_poll(int fd, gushort events)
+{
+    GPollFD pfd = { .fd = _get_osfhandle(fd), .events = events };
+    int res;
+
+    do {
+        res = g_poll(&pfd, 1, 0);
+    } while (res < 0 && errno == EINTR);
+    if (res == 0) {
+        return false;
+    }
+
+    return true;
+}
+#endif
+
+static ssize_t qio_channel_command_readv(QIOChannel *ioc,
+                                         const struct iovec *iov,
+                                         size_t niov,
+                                         int **fds,
+                                         size_t *nfds,
+                                         int flags,
+                                         Error **errp)
+{
+    QIOChannelCommand *cioc = QIO_CHANNEL_COMMAND(ioc);
+    ssize_t ret;
+
+#ifdef WIN32
+    if (!cioc->blocking && !win32_fd_poll(cioc->readfd, G_IO_IN)) {
+        return QIO_CHANNEL_ERR_BLOCK;
+    }
+#endif
+
+ retry:
+    ret = readv(cioc->readfd, iov, niov);
+    if (ret < 0) {
+        if (errno == EAGAIN) {
+            return QIO_CHANNEL_ERR_BLOCK;
+        }
+        if (errno == EINTR) {
+            goto retry;
+        }
+
+        error_setg_errno(errp, errno,
+                         "Unable to read from command");
+        return -1;
+    }
+
+    return ret;
+}
+
+static ssize_t qio_channel_command_writev(QIOChannel *ioc,
+                                          const struct iovec *iov,
+                                          size_t niov,
+                                          int *fds,
+                                          size_t nfds,
+                                          int flags,
+                                          Error **errp)
+{
+    QIOChannelCommand *cioc = QIO_CHANNEL_COMMAND(ioc);
+    ssize_t ret;
+
+#ifdef WIN32
+    if (!cioc->blocking && !win32_fd_poll(cioc->writefd, G_IO_OUT)) {
+        return QIO_CHANNEL_ERR_BLOCK;
+    }
+#endif
+
+ retry:
+    ret = writev(cioc->writefd, iov, niov);
+    if (ret <= 0) {
+        if (errno == EAGAIN) {
+            return QIO_CHANNEL_ERR_BLOCK;
+        }
+        if (errno == EINTR) {
+            goto retry;
+        }
+        error_setg_errno(errp, errno, "%s",
+                         "Unable to write to command");
+        return -1;
+    }
+    return ret;
+}
+
+static int qio_channel_command_set_blocking(QIOChannel *ioc,
+                                            bool enabled,
+                                            Error **errp)
+{
+    QIOChannelCommand *cioc = QIO_CHANNEL_COMMAND(ioc);
+
+#ifdef WIN32
+    cioc->blocking = enabled;
+#else
+
+    if (cioc->writefd >= 0 &&
+        !qemu_set_blocking(cioc->writefd, enabled, errp)) {
+        return -1;
+    }
+    if (cioc->readfd >= 0 &&
+        !qemu_set_blocking(cioc->readfd, enabled, errp)) {
+        return -1;
+    }
+#endif
+    return 0;
+}
+
+
+static int qio_channel_command_close(QIOChannel *ioc,
+                                     Error **errp)
+{
+    QIOChannelCommand *cioc = QIO_CHANNEL_COMMAND(ioc);
+    int rv = 0;
+#ifndef WIN32
+    pid_t wp;
+#endif
+
+    /* We close FDs before killing, because that
+     * gives a better chance of clean shutdown
+     */
+    if (cioc->readfd != -1 &&
+        close(cioc->readfd) < 0) {
+        rv = -1;
+    }
+    if (cioc->writefd != -1 &&
+        cioc->writefd != cioc->readfd &&
+        close(cioc->writefd) < 0) {
+        rv = -1;
+    }
+    cioc->writefd = cioc->readfd = -1;
+
+#ifndef WIN32
+    do {
+        wp = waitpid(cioc->pid, NULL, 0);
+    } while (wp == (pid_t)-1 && errno == EINTR);
+    if (wp == (pid_t)-1) {
+        error_setg_errno(errp, errno, "Failed to wait for pid %llu",
+                         (unsigned long long)cioc->pid);
+        return -1;
+    }
+#else
+    WaitForSingleObject(cioc->pid, INFINITE);
+#endif
+
+    if (rv < 0) {
+        error_setg_errno(errp, errno, "%s",
+                         "Unable to close command");
+    }
+    return rv;
+}
+
+
+static void qio_channel_command_set_aio_fd_handler(QIOChannel *ioc,
+                                                   AioContext *read_ctx,
+                                                   IOHandler *io_read,
+                                                   AioContext *write_ctx,
+                                                   IOHandler *io_write,
+                                                   void *opaque)
+{
+    QIOChannelCommand *cioc = QIO_CHANNEL_COMMAND(ioc);
+
+    qio_channel_util_set_aio_fd_handler(cioc->readfd, read_ctx, io_read,
+                                        cioc->writefd, write_ctx, io_write,
+                                        opaque);
+}
+
+
+static GSource *qio_channel_command_create_watch(QIOChannel *ioc,
+                                                 GIOCondition condition)
+{
+    QIOChannelCommand *cioc = QIO_CHANNEL_COMMAND(ioc);
+    return qio_channel_create_fd_pair_watch(ioc,
+                                            cioc->readfd,
+                                            cioc->writefd,
+                                            condition);
+}
+
+
+static void qio_channel_command_class_init(ObjectClass *klass,
+                                           const void *class_data G_GNUC_UNUSED)
+{
+    QIOChannelClass *ioc_klass = QIO_CHANNEL_CLASS(klass);
+
+    ioc_klass->io_writev = qio_channel_command_writev;
+    ioc_klass->io_readv = qio_channel_command_readv;
+    ioc_klass->io_set_blocking = qio_channel_command_set_blocking;
+    ioc_klass->io_close = qio_channel_command_close;
+    ioc_klass->io_create_watch = qio_channel_command_create_watch;
+    ioc_klass->io_set_aio_fd_handler = qio_channel_command_set_aio_fd_handler;
+}
+
+static const TypeInfo qio_channel_command_info = {
+    .parent = TYPE_QIO_CHANNEL,
+    .name = TYPE_QIO_CHANNEL_COMMAND,
+    .instance_size = sizeof(QIOChannelCommand),
+    .instance_init = qio_channel_command_init,
+    .instance_finalize = qio_channel_command_finalize,
+    .class_init = qio_channel_command_class_init,
+};
+
+static void qio_channel_command_register_types(void)
+{
+    type_register_static(&qio_channel_command_info);
+}
+
+type_init(qio_channel_command_register_types);

io/channel-file.c

@@ -0,0 +1,323 @@
+/*
+ * QEMU I/O channels files driver
+ *
+ * Copyright (c) 2015 Red Hat, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include "qemu/osdep.h"
+#include "io/channel-file.h"
+#include "io/channel-util.h"
+#include "io/channel-watch.h"
+#include "qapi/error.h"
+#include "qemu/module.h"
+#include "qemu/sockets.h"
+#include "trace.h"
+
+QIOChannelFile *
+qio_channel_file_new_fd(int fd)
+{
+    QIOChannelFile *ioc;
+
+    ioc = QIO_CHANNEL_FILE(object_new(TYPE_QIO_CHANNEL_FILE));
+
+    ioc->fd = fd;
+
+    if (lseek(fd, 0, SEEK_CUR) != (off_t)-1) {
+        qio_channel_set_feature(QIO_CHANNEL(ioc), QIO_CHANNEL_FEATURE_SEEKABLE);
+    }
+
+    trace_qio_channel_file_new_fd(ioc, fd);
+
+    return ioc;
+}
+
+QIOChannelFile *
+qio_channel_file_new_dupfd(int fd, Error **errp)
+{
+    int newfd = dup(fd);
+
+    if (newfd < 0) {
+        error_setg_errno(errp, errno, "Could not dup FD %d", fd);
+        return NULL;
+    }
+
+    return qio_channel_file_new_fd(newfd);
+}
+
+QIOChannelFile *
+qio_channel_file_new_path(const char *path,
+                          int flags,
+                          mode_t mode,
+                          Error **errp)
+{
+    QIOChannelFile *ioc;
+
+    ioc = QIO_CHANNEL_FILE(object_new(TYPE_QIO_CHANNEL_FILE));
+
+    if (flags & O_CREAT) {
+        ioc->fd = qemu_create(path, flags & ~O_CREAT, mode, errp);
+    } else {
+        ioc->fd = qemu_open(path, flags, errp);
+    }
+    if (ioc->fd < 0) {
+        object_unref(OBJECT(ioc));
+        return NULL;
+    }
+
+    if (lseek(ioc->fd, 0, SEEK_CUR) != (off_t)-1) {
+        qio_channel_set_feature(QIO_CHANNEL(ioc), QIO_CHANNEL_FEATURE_SEEKABLE);
+    }
+
+    trace_qio_channel_file_new_path(ioc, path, flags, mode, ioc->fd);
+
+    return ioc;
+}
+
+
+static void qio_channel_file_init(Object *obj)
+{
+    QIOChannelFile *ioc = QIO_CHANNEL_FILE(obj);
+    ioc->fd = -1;
+}
+
+static void qio_channel_file_finalize(Object *obj)
+{
+    QIOChannelFile *ioc = QIO_CHANNEL_FILE(obj);
+    if (ioc->fd != -1) {
+        qemu_close(ioc->fd);
+        ioc->fd = -1;
+    }
+}
+
+
+static ssize_t qio_channel_file_readv(QIOChannel *ioc,
+                                      const struct iovec *iov,
+                                      size_t niov,
+                                      int **fds,
+                                      size_t *nfds,
+                                      int flags,
+                                      Error **errp)
+{
+    QIOChannelFile *fioc = QIO_CHANNEL_FILE(ioc);
+    ssize_t ret;
+
+ retry:
+    ret = readv(fioc->fd, iov, niov);
+    if (ret < 0) {
+        if (errno == EAGAIN) {
+            return QIO_CHANNEL_ERR_BLOCK;
+        }
+        if (errno == EINTR) {
+            goto retry;
+        }
+
+        error_setg_errno(errp, errno,
+                         "Unable to read from file");
+        return -1;
+    }
+
+    return ret;
+}
+
+static ssize_t qio_channel_file_writev(QIOChannel *ioc,
+                                       const struct iovec *iov,
+                                       size_t niov,
+                                       int *fds,
+                                       size_t nfds,
+                                       int flags,
+                                       Error **errp)
+{
+    QIOChannelFile *fioc = QIO_CHANNEL_FILE(ioc);
+    ssize_t ret;
+
+ retry:
+    ret = writev(fioc->fd, iov, niov);
+    if (ret <= 0) {
+        if (errno == EAGAIN) {
+            return QIO_CHANNEL_ERR_BLOCK;
+        }
+        if (errno == EINTR) {
+            goto retry;
+        }
+        error_setg_errno(errp, errno,
+                         "Unable to write to file");
+        return -1;
+    }
+    return ret;
+}
+
+#ifdef CONFIG_PREADV
+static ssize_t qio_channel_file_preadv(QIOChannel *ioc,
+                                       const struct iovec *iov,
+                                       size_t niov,
+                                       off_t offset,
+                                       Error **errp)
+{
+    QIOChannelFile *fioc = QIO_CHANNEL_FILE(ioc);
+    ssize_t ret;
+
+ retry:
+    ret = preadv(fioc->fd, iov, niov, offset);
+    if (ret < 0) {
+        if (errno == EAGAIN) {
+            return QIO_CHANNEL_ERR_BLOCK;
+        }
+        if (errno == EINTR) {
+            goto retry;
+        }
+
+        error_setg_errno(errp, errno, "Unable to read from file");
+        return -1;
+    }
+
+    return ret;
+}
+
+static ssize_t qio_channel_file_pwritev(QIOChannel *ioc,
+                                        const struct iovec *iov,
+                                        size_t niov,
+                                        off_t offset,
+                                        Error **errp)
+{
+    QIOChannelFile *fioc = QIO_CHANNEL_FILE(ioc);
+    ssize_t ret;
+
+ retry:
+    ret = pwritev(fioc->fd, iov, niov, offset);
+    if (ret <= 0) {
+        if (errno == EAGAIN) {
+            return QIO_CHANNEL_ERR_BLOCK;
+        }
+        if (errno == EINTR) {
+            goto retry;
+        }
+        error_setg_errno(errp, errno, "Unable to write to file");
+        return -1;
+    }
+    return ret;
+}
+#endif /* CONFIG_PREADV */
+
+static int qio_channel_file_set_blocking(QIOChannel *ioc,
+                                         bool enabled,
+                                         Error **errp)
+{
+#ifdef WIN32
+    /* not implemented */
+    error_setg_errno(errp, errno, "Failed to set FD nonblocking");
+    return -1;
+#else
+    QIOChannelFile *fioc = QIO_CHANNEL_FILE(ioc);
+
+    if (!qemu_set_blocking(fioc->fd, enabled, errp)) {
+        return -1;
+    }
+    return 0;
+#endif
+}
+
+
+static off_t qio_channel_file_seek(QIOChannel *ioc,
+                                   off_t offset,
+                                   int whence,
+                                   Error **errp)
+{
+    QIOChannelFile *fioc = QIO_CHANNEL_FILE(ioc);
+    off_t ret;
+
+    ret = lseek(fioc->fd, offset, whence);
+    if (ret == (off_t)-1) {
+        error_setg_errno(errp, errno,
+                         "Unable to seek to offset %lld whence %d in file",
+                         (long long int)offset, whence);
+        return -1;
+    }
+    return ret;
+}
+
+
+static int qio_channel_file_close(QIOChannel *ioc,
+                                  Error **errp)
+{
+    QIOChannelFile *fioc = QIO_CHANNEL_FILE(ioc);
+
+    if (qemu_close(fioc->fd) < 0) {
+        error_setg_errno(errp, errno,
+                         "Unable to close file");
+        return -1;
+    }
+    fioc->fd = -1;
+    return 0;
+}
+
+
+static void qio_channel_file_set_aio_fd_handler(QIOChannel *ioc,
+                                                AioContext *read_ctx,
+                                                IOHandler *io_read,
+                                                AioContext *write_ctx,
+                                                IOHandler *io_write,
+                                                void *opaque)
+{
+    QIOChannelFile *fioc = QIO_CHANNEL_FILE(ioc);
+
+    qio_channel_util_set_aio_fd_handler(fioc->fd, read_ctx, io_read,
+                                        fioc->fd, write_ctx, io_write,
+                                        opaque);
+}
+
+static GSource *qio_channel_file_create_watch(QIOChannel *ioc,
+                                              GIOCondition condition)
+{
+    QIOChannelFile *fioc = QIO_CHANNEL_FILE(ioc);
+    return qio_channel_create_fd_watch(ioc,
+                                       fioc->fd,
+                                       condition);
+}
+
+static void qio_channel_file_class_init(ObjectClass *klass,
+                                        const void *class_data G_GNUC_UNUSED)
+{
+    QIOChannelClass *ioc_klass = QIO_CHANNEL_CLASS(klass);
+
+    ioc_klass->io_writev = qio_channel_file_writev;
+    ioc_klass->io_readv = qio_channel_file_readv;
+    ioc_klass->io_set_blocking = qio_channel_file_set_blocking;
+#ifdef CONFIG_PREADV
+    ioc_klass->io_pwritev = qio_channel_file_pwritev;
+    ioc_klass->io_preadv = qio_channel_file_preadv;
+#endif
+    ioc_klass->io_seek = qio_channel_file_seek;
+    ioc_klass->io_close = qio_channel_file_close;
+    ioc_klass->io_create_watch = qio_channel_file_create_watch;
+    ioc_klass->io_set_aio_fd_handler = qio_channel_file_set_aio_fd_handler;
+}
+
+static const TypeInfo qio_channel_file_info = {
+    .parent = TYPE_QIO_CHANNEL,
+    .name = TYPE_QIO_CHANNEL_FILE,
+    .instance_size = sizeof(QIOChannelFile),
+    .instance_init = qio_channel_file_init,
+    .instance_finalize = qio_channel_file_finalize,
+    .class_init = qio_channel_file_class_init,
+};
+
+static void qio_channel_file_register_types(void)
+{
+    type_register_static(&qio_channel_file_info);
+}
+
+type_init(qio_channel_file_register_types);

io/channel-null.c

@@ -0,0 +1,239 @@
+/*
+ * QEMU I/O channels null driver
+ *
+ * Copyright (c) 2022 Red Hat, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include "qemu/osdep.h"
+#include "io/channel-null.h"
+#include "io/channel-watch.h"
+#include "qapi/error.h"
+#include "trace.h"
+#include "qemu/iov.h"
+
+typedef struct QIOChannelNullSource QIOChannelNullSource;
+struct QIOChannelNullSource {
+    GSource parent;
+    QIOChannel *ioc;
+    GIOCondition condition;
+};
+
+
+QIOChannelNull *
+qio_channel_null_new(void)
+{
+    QIOChannelNull *ioc;
+
+    ioc = QIO_CHANNEL_NULL(object_new(TYPE_QIO_CHANNEL_NULL));
+
+    trace_qio_channel_null_new(ioc);
+
+    return ioc;
+}
+
+
+static void
+qio_channel_null_init(Object *obj)
+{
+    QIOChannelNull *ioc = QIO_CHANNEL_NULL(obj);
+    ioc->closed = false;
+}
+
+
+static ssize_t
+qio_channel_null_readv(QIOChannel *ioc,
+                       const struct iovec *iov,
+                       size_t niov,
+                       int **fds G_GNUC_UNUSED,
+                       size_t *nfds G_GNUC_UNUSED,
+                       int flags,
+                       Error **errp)
+{
+    QIOChannelNull *nioc = QIO_CHANNEL_NULL(ioc);
+
+    if (nioc->closed) {
+        error_setg_errno(errp, EINVAL,
+                         "Channel is closed");
+        return -1;
+    }
+
+    return 0;
+}
+
+
+static ssize_t
+qio_channel_null_writev(QIOChannel *ioc,
+                        const struct iovec *iov,
+                        size_t niov,
+                        int *fds G_GNUC_UNUSED,
+                        size_t nfds G_GNUC_UNUSED,
+                        int flags G_GNUC_UNUSED,
+                        Error **errp)
+{
+    QIOChannelNull *nioc = QIO_CHANNEL_NULL(ioc);
+
+    if (nioc->closed) {
+        error_setg_errno(errp, EINVAL,
+                         "Channel is closed");
+        return -1;
+    }
+
+    return iov_size(iov, niov);
+}
+
+
+static int
+qio_channel_null_set_blocking(QIOChannel *ioc G_GNUC_UNUSED,
+                              bool enabled G_GNUC_UNUSED,
+                              Error **errp G_GNUC_UNUSED)
+{
+    return 0;
+}
+
+
+static off_t
+qio_channel_null_seek(QIOChannel *ioc G_GNUC_UNUSED,
+                      off_t offset G_GNUC_UNUSED,
+                      int whence G_GNUC_UNUSED,
+                      Error **errp G_GNUC_UNUSED)
+{
+    return 0;
+}
+
+
+static int
+qio_channel_null_close(QIOChannel *ioc,
+                       Error **errp G_GNUC_UNUSED)
+{
+    QIOChannelNull *nioc = QIO_CHANNEL_NULL(ioc);
+
+    nioc->closed = true;
+    return 0;
+}
+
+
+static void
+qio_channel_null_set_aio_fd_handler(QIOChannel *ioc G_GNUC_UNUSED,
+                                    AioContext *read_ctx G_GNUC_UNUSED,
+                                    IOHandler *io_read G_GNUC_UNUSED,
+                                    AioContext *write_ctx G_GNUC_UNUSED,
+                                    IOHandler *io_write G_GNUC_UNUSED,
+                                    void *opaque G_GNUC_UNUSED)
+{
+}
+
+
+static gboolean
+qio_channel_null_source_prepare(GSource *source G_GNUC_UNUSED,
+                                gint *timeout)
+{
+    *timeout = -1;
+
+    return TRUE;
+}
+
+
+static gboolean
+qio_channel_null_source_check(GSource *source G_GNUC_UNUSED)
+{
+    return TRUE;
+}
+
+
+static gboolean
+qio_channel_null_source_dispatch(GSource *source,
+                                 GSourceFunc callback,
+                                 gpointer user_data)
+{
+    QIOChannelFunc func = (QIOChannelFunc)callback;
+    QIOChannelNullSource *ssource = (QIOChannelNullSource *)source;
+
+    return (*func)(ssource->ioc,
+                   ssource->condition,
+                   user_data);
+}
+
+
+static void
+qio_channel_null_source_finalize(GSource *source)
+{
+    QIOChannelNullSource *ssource = (QIOChannelNullSource *)source;
+
+    object_unref(OBJECT(ssource->ioc));
+}
+
+
+GSourceFuncs qio_channel_null_source_funcs = {
+    qio_channel_null_source_prepare,
+    qio_channel_null_source_check,
+    qio_channel_null_source_dispatch,
+    qio_channel_null_source_finalize
+};
+
+
+static GSource *
+qio_channel_null_create_watch(QIOChannel *ioc,
+                              GIOCondition condition)
+{
+    GSource *source;
+    QIOChannelNullSource *ssource;
+
+    source = g_source_new(&qio_channel_null_source_funcs,
+                          sizeof(QIOChannelNullSource));
+    ssource = (QIOChannelNullSource *)source;
+
+    ssource->ioc = ioc;
+    object_ref(OBJECT(ioc));
+
+    ssource->condition = condition;
+
+    return source;
+}
+
+
+static void
+qio_channel_null_class_init(ObjectClass *klass,
+                            const void *class_data G_GNUC_UNUSED)
+{
+    QIOChannelClass *ioc_klass = QIO_CHANNEL_CLASS(klass);
+
+    ioc_klass->io_writev = qio_channel_null_writev;
+    ioc_klass->io_readv = qio_channel_null_readv;
+    ioc_klass->io_set_blocking = qio_channel_null_set_blocking;
+    ioc_klass->io_seek = qio_channel_null_seek;
+    ioc_klass->io_close = qio_channel_null_close;
+    ioc_klass->io_create_watch = qio_channel_null_create_watch;
+    ioc_klass->io_set_aio_fd_handler = qio_channel_null_set_aio_fd_handler;
+}
+
+
+static const TypeInfo qio_channel_null_info = {
+    .parent = TYPE_QIO_CHANNEL,
+    .name = TYPE_QIO_CHANNEL_NULL,
+    .instance_size = sizeof(QIOChannelNull),
+    .instance_init = qio_channel_null_init,
+    .class_init = qio_channel_null_class_init,
+};
+
+
+static void
+qio_channel_null_register_types(void)
+{
+    type_register_static(&qio_channel_null_info);
+}
+
+type_init(qio_channel_null_register_types);

io/channel-tls.c

@@ -0,0 +1,650 @@
+/*
+ * QEMU I/O channels TLS driver
+ *
+ * Copyright (c) 2015 Red Hat, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include "qemu/osdep.h"
+#include "qapi/error.h"
+#include "qemu/module.h"
+#include "io/channel-tls.h"
+#include "trace.h"
+#include "qemu/atomic.h"
+
+
+static ssize_t qio_channel_tls_write_handler(const void *buf,
+                                             size_t len,
+                                             void *opaque,
+                                             Error **errp)
+{
+    QIOChannelTLS *tioc = QIO_CHANNEL_TLS(opaque);
+    ssize_t ret;
+
+    ret = qio_channel_write(tioc->master, buf, len, errp);
+    if (ret == QIO_CHANNEL_ERR_BLOCK) {
+        return QCRYPTO_TLS_SESSION_ERR_BLOCK;
+    } else if (ret < 0) {
+        return -1;
+    }
+    return ret;
+}
+
+static ssize_t qio_channel_tls_read_handler(void *buf,
+                                            size_t len,
+                                            void *opaque,
+                                            Error **errp)
+{
+    QIOChannelTLS *tioc = QIO_CHANNEL_TLS(opaque);
+    ssize_t ret;
+
+    ret = qio_channel_read(tioc->master, buf, len, errp);
+    if (ret == QIO_CHANNEL_ERR_BLOCK) {
+        return QCRYPTO_TLS_SESSION_ERR_BLOCK;
+    } else if (ret < 0) {
+        return -1;
+    }
+    return ret;
+}
+
+
+QIOChannelTLS *
+qio_channel_tls_new_server(QIOChannel *master,
+                           QCryptoTLSCreds *creds,
+                           const char *aclname,
+                           Error **errp)
+{
+    QIOChannelTLS *tioc;
+    QIOChannel *ioc;
+
+    tioc = QIO_CHANNEL_TLS(object_new(TYPE_QIO_CHANNEL_TLS));
+    ioc = QIO_CHANNEL(tioc);
+
+    tioc->master = master;
+    ioc->follow_coroutine_ctx = master->follow_coroutine_ctx;
+    if (qio_channel_has_feature(master, QIO_CHANNEL_FEATURE_SHUTDOWN)) {
+        qio_channel_set_feature(ioc, QIO_CHANNEL_FEATURE_SHUTDOWN);
+    }
+    object_ref(OBJECT(master));
+
+    tioc->session = qcrypto_tls_session_new(
+        creds,
+        NULL,
+        aclname,
+        QCRYPTO_TLS_CREDS_ENDPOINT_SERVER,
+        errp);
+    if (!tioc->session) {
+        goto error;
+    }
+
+    qcrypto_tls_session_set_callbacks(
+        tioc->session,
+        qio_channel_tls_write_handler,
+        qio_channel_tls_read_handler,
+        tioc);
+
+    trace_qio_channel_tls_new_server(tioc, master, creds, aclname);
+    return tioc;
+
+ error:
+    object_unref(OBJECT(tioc));
+    return NULL;
+}
+
+QIOChannelTLS *
+qio_channel_tls_new_client(QIOChannel *master,
+                           QCryptoTLSCreds *creds,
+                           const char *hostname,
+                           Error **errp)
+{
+    QIOChannelTLS *tioc;
+    QIOChannel *ioc;
+
+    tioc = QIO_CHANNEL_TLS(object_new(TYPE_QIO_CHANNEL_TLS));
+    ioc = QIO_CHANNEL(tioc);
+
+    tioc->master = master;
+    ioc->follow_coroutine_ctx = master->follow_coroutine_ctx;
+    if (qio_channel_has_feature(master, QIO_CHANNEL_FEATURE_SHUTDOWN)) {
+        qio_channel_set_feature(ioc, QIO_CHANNEL_FEATURE_SHUTDOWN);
+    }
+    object_ref(OBJECT(master));
+
+    tioc->session = qcrypto_tls_session_new(
+        creds,
+        hostname,
+        NULL,
+        QCRYPTO_TLS_CREDS_ENDPOINT_CLIENT,
+        errp);
+    if (!tioc->session) {
+        goto error;
+    }
+
+    qcrypto_tls_session_set_callbacks(
+        tioc->session,
+        qio_channel_tls_write_handler,
+        qio_channel_tls_read_handler,
+        tioc);
+
+    trace_qio_channel_tls_new_client(tioc, master, creds, hostname);
+    return tioc;
+
+ error:
+    object_unref(OBJECT(tioc));
+    return NULL;
+}
+
+struct QIOChannelTLSData {
+    QIOTask *task;
+    GMainContext *context;
+};
+typedef struct QIOChannelTLSData QIOChannelTLSData;
+
+static void qio_channel_tls_io_data_free(gpointer user_data)
+{
+    QIOChannelTLSData *data = user_data;
+    /*
+     * Usually 'task' will be NULL since the GSource
+     * callback will either complete the task or pass
+     * it on to a new GSource. We'll see a non-NULL
+     * task here only if the GSource was released before
+     * its callback triggers
+     */
+    if (data->task) {
+        qio_task_free(data->task);
+    }
+    if (data->context) {
+        g_main_context_unref(data->context);
+    }
+    g_free(data);
+}
+
+static gboolean qio_channel_tls_handshake_io(QIOChannel *ioc,
+                                             GIOCondition condition,
+                                             gpointer user_data);
+
+static gboolean qio_channel_tls_handshake_task(QIOChannelTLS *ioc,
+                                               QIOTask *task,
+                                               GMainContext *context)
+{
+    Error *err = NULL;
+    int status;
+
+    status = qcrypto_tls_session_handshake(ioc->session, &err);
+
+    if (status < 0) {
+        trace_qio_channel_tls_handshake_fail(ioc);
+        qio_task_set_error(task, err);
+        qio_task_complete(task);
+        return TRUE;
+    }
+
+    if (status == QCRYPTO_TLS_HANDSHAKE_COMPLETE) {
+        trace_qio_channel_tls_handshake_complete(ioc);
+        if (qcrypto_tls_session_check_credentials(ioc->session,
+                                                  &err) < 0) {
+            trace_qio_channel_tls_credentials_deny(ioc);
+            qio_task_set_error(task, err);
+        } else {
+            trace_qio_channel_tls_credentials_allow(ioc);
+        }
+        qio_task_complete(task);
+        return TRUE;
+    } else {
+        GIOCondition condition;
+        QIOChannelTLSData *data = g_new0(typeof(*data), 1);
+
+        data->task = task;
+        data->context = context;
+
+        if (context) {
+            g_main_context_ref(context);
+        }
+
+        if (status == QCRYPTO_TLS_HANDSHAKE_SENDING) {
+            condition = G_IO_OUT;
+        } else {
+            condition = G_IO_IN;
+        }
+
+        trace_qio_channel_tls_handshake_pending(ioc, status);
+        ioc->hs_ioc_tag =
+            qio_channel_add_watch_full(ioc->master,
+                                       condition,
+                                       qio_channel_tls_handshake_io,
+                                       data,
+                                       qio_channel_tls_io_data_free,
+                                       context);
+        return FALSE;
+    }
+}
+
+
+static gboolean qio_channel_tls_handshake_io(QIOChannel *ioc,
+                                             GIOCondition condition,
+                                             gpointer user_data)
+{
+    QIOChannelTLSData *data = user_data;
+    QIOTask *task = data->task;
+    GMainContext *context = data->context;
+    QIOChannelTLS *tioc = QIO_CHANNEL_TLS(
+        qio_task_get_source(task));
+
+    tioc->hs_ioc_tag = 0;
+    if (!qio_channel_tls_handshake_task(tioc, task, context)) {
+        /* task is kept by new GSource so must not be released yet */
+        data->task = NULL;
+    }
+
+    return FALSE;
+}
+
+void qio_channel_tls_handshake(QIOChannelTLS *ioc,
+                               QIOTaskFunc func,
+                               gpointer opaque,
+                               GDestroyNotify destroy,
+                               GMainContext *context)
+{
+    QIOTask *task;
+
+    if (qio_channel_has_feature(QIO_CHANNEL(ioc),
+                                QIO_CHANNEL_FEATURE_CONCURRENT_IO)) {
+        qcrypto_tls_session_require_thread_safety(ioc->session);
+    }
+
+    task = qio_task_new(OBJECT(ioc),
+                        func, opaque, destroy);
+
+    trace_qio_channel_tls_handshake_start(ioc);
+    if (qio_channel_tls_handshake_task(ioc, task, context)) {
+        qio_task_free(task);
+    }
+}
+
+static gboolean qio_channel_tls_bye_io(QIOChannel *ioc, GIOCondition condition,
+                                       gpointer user_data);
+
+static gboolean qio_channel_tls_bye_task(QIOChannelTLS *ioc, QIOTask *task,
+                                         GMainContext *context)
+{
+    GIOCondition condition;
+    QIOChannelTLSData *data;
+    int status;
+    Error *err = NULL;
+
+    status = qcrypto_tls_session_bye(ioc->session, &err);
+
+    if (status < 0) {
+        trace_qio_channel_tls_bye_fail(ioc);
+        qio_task_set_error(task, err);
+        qio_task_complete(task);
+        return TRUE;
+    }
+
+    if (status == QCRYPTO_TLS_BYE_COMPLETE) {
+        qio_task_complete(task);
+        return TRUE;
+    }
+
+    data = g_new0(typeof(*data), 1);
+    data->task = task;
+    data->context = context;
+
+    if (context) {
+        g_main_context_ref(context);
+    }
+
+    if (status == QCRYPTO_TLS_BYE_SENDING) {
+        condition = G_IO_OUT;
+    } else {
+        condition = G_IO_IN;
+    }
+
+    trace_qio_channel_tls_bye_pending(ioc, status);
+    ioc->bye_ioc_tag = qio_channel_add_watch_full(ioc->master, condition,
+                                                  qio_channel_tls_bye_io,
+                                                  data,
+                                                  qio_channel_tls_io_data_free,
+                                                  context);
+    return FALSE;
+}
+
+
+static gboolean qio_channel_tls_bye_io(QIOChannel *ioc, GIOCondition condition,
+                                       gpointer user_data)
+{
+    QIOChannelTLSData *data = user_data;
+    QIOTask *task = data->task;
+    GMainContext *context = data->context;
+    QIOChannelTLS *tioc = QIO_CHANNEL_TLS(qio_task_get_source(task));
+
+    tioc->bye_ioc_tag = 0;
+    if (!qio_channel_tls_bye_task(tioc, task, context)) {
+        /* task is kept by new GSource so must not be released yet */
+        data->task = NULL;
+    }
+
+    return FALSE;
+}
+
+static void propagate_error(QIOTask *task, gpointer opaque)
+{
+    qio_task_propagate_error(task, opaque);
+}
+
+void qio_channel_tls_bye(QIOChannelTLS *ioc, Error **errp)
+{
+    QIOTask *task;
+
+    task = qio_task_new(OBJECT(ioc), propagate_error, errp, NULL);
+
+    trace_qio_channel_tls_bye_start(ioc);
+    if (qio_channel_tls_bye_task(ioc, task, NULL)) {
+        qio_task_free(task);
+    }
+}
+
+static void qio_channel_tls_init(Object *obj G_GNUC_UNUSED)
+{
+}
+
+
+static void qio_channel_tls_finalize(Object *obj)
+{
+    QIOChannelTLS *ioc = QIO_CHANNEL_TLS(obj);
+
+    if (ioc->hs_ioc_tag) {
+        trace_qio_channel_tls_handshake_cancel(ioc);
+        g_clear_handle_id(&ioc->hs_ioc_tag, g_source_remove);
+    }
+
+    if (ioc->bye_ioc_tag) {
+        trace_qio_channel_tls_bye_cancel(ioc);
+        g_clear_handle_id(&ioc->bye_ioc_tag, g_source_remove);
+    }
+
+    object_unref(OBJECT(ioc->master));
+    qcrypto_tls_session_free(ioc->session);
+}
+
+static bool
+qio_channel_tls_allow_premature_termination(QIOChannelTLS *tioc, int flags)
+{
+    if (flags & QIO_CHANNEL_READ_FLAG_RELAXED_EOF) {
+        return true;
+    }
+
+    if (qatomic_read(&tioc->shutdown) & QIO_CHANNEL_SHUTDOWN_READ) {
+        return true;
+    }
+
+    return false;
+}
+
+static ssize_t qio_channel_tls_readv(QIOChannel *ioc,
+                                     const struct iovec *iov,
+                                     size_t niov,
+                                     int **fds,
+                                     size_t *nfds,
+                                     int flags,
+                                     Error **errp)
+{
+    ERRP_GUARD();
+    QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc);
+    size_t i;
+    ssize_t got = 0;
+
+    for (i = 0 ; i < niov ; i++) {
+        ssize_t ret = qcrypto_tls_session_read(
+            tioc->session,
+            iov[i].iov_base,
+            iov[i].iov_len,
+            errp);
+        if (ret == QCRYPTO_TLS_SESSION_ERR_BLOCK) {
+            if (got) {
+                return got;
+            } else {
+                return QIO_CHANNEL_ERR_BLOCK;
+            }
+        } else if (ret < 0) {
+            if (ret == QCRYPTO_TLS_SESSION_PREMATURE_TERMINATION &&
+                qio_channel_tls_allow_premature_termination(tioc, flags)) {
+                error_free(*errp);
+                *errp = NULL;
+                return got;
+            }
+            return -1;
+        }
+        got += ret;
+        if (ret < iov[i].iov_len) {
+            break;
+        }
+    }
+    return got;
+}
+
+
+static ssize_t qio_channel_tls_writev(QIOChannel *ioc,
+                                      const struct iovec *iov,
+                                      size_t niov,
+                                      int *fds,
+                                      size_t nfds,
+                                      int flags,
+                                      Error **errp)
+{
+    QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc);
+    size_t i;
+    ssize_t done = 0;
+
+    for (i = 0 ; i < niov ; i++) {
+        ssize_t ret = qcrypto_tls_session_write(tioc->session,
+                                                iov[i].iov_base,
+                                                iov[i].iov_len,
+                                                errp);
+        if (ret == QCRYPTO_TLS_SESSION_ERR_BLOCK) {
+            if (done) {
+                return done;
+            } else {
+                return QIO_CHANNEL_ERR_BLOCK;
+            }
+        } else if (ret < 0) {
+            return -1;
+        }
+        done += ret;
+        if (ret < iov[i].iov_len) {
+            break;
+        }
+    }
+    return done;
+}
+
+static int qio_channel_tls_set_blocking(QIOChannel *ioc,
+                                        bool enabled,
+                                        Error **errp)
+{
+    QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc);
+
+    return qio_channel_set_blocking(tioc->master, enabled, errp) ? 0 : -1;
+}
+
+static void qio_channel_tls_set_delay(QIOChannel *ioc,
+                                      bool enabled)
+{
+    QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc);
+
+    qio_channel_set_delay(tioc->master, enabled);
+}
+
+static void qio_channel_tls_set_cork(QIOChannel *ioc,
+                                     bool enabled)
+{
+    QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc);
+
+    qio_channel_set_cork(tioc->master, enabled);
+}
+
+static int qio_channel_tls_shutdown(QIOChannel *ioc,
+                                    QIOChannelShutdown how,
+                                    Error **errp)
+{
+    QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc);
+
+    qatomic_or(&tioc->shutdown, how);
+
+    return qio_channel_shutdown(tioc->master, how, errp);
+}
+
+static int qio_channel_tls_close(QIOChannel *ioc,
+                                 Error **errp)
+{
+    QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc);
+
+    if (tioc->hs_ioc_tag) {
+        trace_qio_channel_tls_handshake_cancel(ioc);
+        g_clear_handle_id(&tioc->hs_ioc_tag, g_source_remove);
+    }
+
+    if (tioc->bye_ioc_tag) {
+        trace_qio_channel_tls_bye_cancel(ioc);
+        g_clear_handle_id(&tioc->bye_ioc_tag, g_source_remove);
+    }
+
+    return qio_channel_close(tioc->master, errp);
+}
+
+static void qio_channel_tls_set_aio_fd_handler(QIOChannel *ioc,
+                                               AioContext *read_ctx,
+                                               IOHandler *io_read,
+                                               AioContext *write_ctx,
+                                               IOHandler *io_write,
+                                               void *opaque)
+{
+    QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc);
+
+    qio_channel_set_aio_fd_handler(tioc->master, read_ctx, io_read,
+            write_ctx, io_write, opaque);
+}
+
+typedef struct QIOChannelTLSSource QIOChannelTLSSource;
+struct QIOChannelTLSSource {
+    GSource parent;
+    QIOChannelTLS *tioc;
+};
+
+static gboolean
+qio_channel_tls_source_check(GSource *source)
+{
+    QIOChannelTLSSource *tsource = (QIOChannelTLSSource *)source;
+
+    return qcrypto_tls_session_check_pending(tsource->tioc->session) > 0;
+}
+
+static gboolean
+qio_channel_tls_source_prepare(GSource *source, gint *timeout)
+{
+    *timeout = -1;
+    return qio_channel_tls_source_check(source);
+}
+
+static gboolean
+qio_channel_tls_source_dispatch(GSource *source, GSourceFunc callback,
+                                gpointer user_data)
+{
+    return G_SOURCE_CONTINUE;
+}
+
+static void
+qio_channel_tls_source_finalize(GSource *source)
+{
+    QIOChannelTLSSource *tsource = (QIOChannelTLSSource *)source;
+
+    object_unref(OBJECT(tsource->tioc));
+}
+
+static GSourceFuncs qio_channel_tls_source_funcs = {
+    qio_channel_tls_source_prepare,
+    qio_channel_tls_source_check,
+    qio_channel_tls_source_dispatch,
+    qio_channel_tls_source_finalize
+};
+
+static void
+qio_channel_tls_read_watch(QIOChannelTLS *tioc, GSource *source)
+{
+    GSource *child;
+    QIOChannelTLSSource *tlssource;
+
+    child = g_source_new(&qio_channel_tls_source_funcs,
+                          sizeof(QIOChannelTLSSource));
+    tlssource = (QIOChannelTLSSource *)child;
+
+    tlssource->tioc = tioc;
+    object_ref(OBJECT(tioc));
+
+    g_source_add_child_source(source, child);
+    g_source_unref(child);
+}
+
+static GSource *qio_channel_tls_create_watch(QIOChannel *ioc,
+                                             GIOCondition condition)
+{
+    QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc);
+    GSource *source = qio_channel_create_watch(tioc->master, condition);
+
+    if (condition & G_IO_IN) {
+        qio_channel_tls_read_watch(tioc, source);
+    }
+
+    return source;
+}
+
+QCryptoTLSSession *
+qio_channel_tls_get_session(QIOChannelTLS *ioc)
+{
+    return ioc->session;
+}
+
+static void qio_channel_tls_class_init(ObjectClass *klass,
+                                       const void *class_data G_GNUC_UNUSED)
+{
+    QIOChannelClass *ioc_klass = QIO_CHANNEL_CLASS(klass);
+
+    ioc_klass->io_writev = qio_channel_tls_writev;
+    ioc_klass->io_readv = qio_channel_tls_readv;
+    ioc_klass->io_set_blocking = qio_channel_tls_set_blocking;
+    ioc_klass->io_set_delay = qio_channel_tls_set_delay;
+    ioc_klass->io_set_cork = qio_channel_tls_set_cork;
+    ioc_klass->io_close = qio_channel_tls_close;
+    ioc_klass->io_shutdown = qio_channel_tls_shutdown;
+    ioc_klass->io_create_watch = qio_channel_tls_create_watch;
+    ioc_klass->io_set_aio_fd_handler = qio_channel_tls_set_aio_fd_handler;
+}
+
+static const TypeInfo qio_channel_tls_info = {
+    .parent = TYPE_QIO_CHANNEL,
+    .name = TYPE_QIO_CHANNEL_TLS,
+    .instance_size = sizeof(QIOChannelTLS),
+    .instance_init = qio_channel_tls_init,
+    .instance_finalize = qio_channel_tls_finalize,
+    .class_init = qio_channel_tls_class_init,
+};
+
+static void qio_channel_tls_register_types(void)
+{
+    type_register_static(&qio_channel_tls_info);
+}
+
+type_init(qio_channel_tls_register_types);

io/channel-util.c

@@ -0,0 +1,62 @@
+/*
+ * QEMU I/O channels utility APIs
+ *
+ * Copyright (c) 2016 Red Hat, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include "qemu/osdep.h"
+#include "io/channel-util.h"
+#include "io/channel-file.h"
+#include "io/channel-socket.h"
+
+
+QIOChannel *qio_channel_new_fd(int fd,
+                               Error **errp)
+{
+    QIOChannel *ioc;
+
+    if (fd_is_socket(fd)) {
+        ioc = QIO_CHANNEL(qio_channel_socket_new_fd(fd, errp));
+    } else {
+        ioc = QIO_CHANNEL(qio_channel_file_new_fd(fd));
+    }
+    return ioc;
+}
+
+
+void qio_channel_util_set_aio_fd_handler(int read_fd,
+                                         AioContext *read_ctx,
+                                         IOHandler *io_read,
+                                         int write_fd,
+                                         AioContext *write_ctx,
+                                         IOHandler *io_write,
+                                         void *opaque)
+{
+    if (read_fd == write_fd && read_ctx == write_ctx) {
+        aio_set_fd_handler(read_ctx, read_fd, io_read, io_write,
+                NULL, NULL, opaque);
+    } else {
+        if (read_ctx) {
+            aio_set_fd_handler(read_ctx, read_fd, io_read, NULL,
+                    NULL, NULL, opaque);
+        }
+        if (write_ctx) {
+            aio_set_fd_handler(write_ctx, write_fd, NULL, io_write,
+                    NULL, NULL, opaque);
+        }
+    }
+}

io/channel-watch.c

@@ -0,0 +1,347 @@
+/*
+ * QEMU I/O channels watch helper APIs
+ *
+ * Copyright (c) 2015 Red Hat, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include "qemu/osdep.h"
+#include "io/channel-watch.h"
+
+typedef struct QIOChannelFDSource QIOChannelFDSource;
+struct QIOChannelFDSource {
+    GSource parent;
+    GPollFD fd;
+    QIOChannel *ioc;
+    GIOCondition condition;
+};
+
+
+#ifdef CONFIG_WIN32
+typedef struct QIOChannelSocketSource QIOChannelSocketSource;
+struct QIOChannelSocketSource {
+    GSource parent;
+    GPollFD fd;
+    QIOChannel *ioc;
+    SOCKET socket;
+    int revents;
+    GIOCondition condition;
+};
+
+#endif
+
+
+typedef struct QIOChannelFDPairSource QIOChannelFDPairSource;
+struct QIOChannelFDPairSource {
+    GSource parent;
+    GPollFD fdread;
+    GPollFD fdwrite;
+    QIOChannel *ioc;
+    GIOCondition condition;
+};
+
+
+static gboolean
+qio_channel_fd_source_prepare(GSource *source G_GNUC_UNUSED,
+                              gint *timeout)
+{
+    *timeout = -1;
+
+    return FALSE;
+}
+
+
+static gboolean
+qio_channel_fd_source_check(GSource *source)
+{
+    QIOChannelFDSource *ssource = (QIOChannelFDSource *)source;
+
+    return ssource->fd.revents & ssource->condition;
+}
+
+
+static gboolean
+qio_channel_fd_source_dispatch(GSource *source,
+                               GSourceFunc callback,
+                               gpointer user_data)
+{
+    QIOChannelFunc func = (QIOChannelFunc)callback;
+    QIOChannelFDSource *ssource = (QIOChannelFDSource *)source;
+
+    return (*func)(ssource->ioc,
+                   ssource->fd.revents & ssource->condition,
+                   user_data);
+}
+
+
+static void
+qio_channel_fd_source_finalize(GSource *source)
+{
+    QIOChannelFDSource *ssource = (QIOChannelFDSource *)source;
+
+    object_unref(OBJECT(ssource->ioc));
+}
+
+
+#ifdef CONFIG_WIN32
+static gboolean
+qio_channel_socket_source_prepare(GSource *source G_GNUC_UNUSED,
+                                  gint *timeout)
+{
+    *timeout = -1;
+
+    return FALSE;
+}
+
+
+/*
+ * NB, this impl only works when the socket is in non-blocking
+ * mode on Win32
+ */
+static gboolean
+qio_channel_socket_source_check(GSource *source)
+{
+    static struct timeval tv0;
+    QIOChannelSocketSource *ssource = (QIOChannelSocketSource *)source;
+    fd_set rfds, wfds, xfds;
+
+    if (!ssource->condition) {
+        return 0;
+    }
+
+    FD_ZERO(&rfds);
+    FD_ZERO(&wfds);
+    FD_ZERO(&xfds);
+    if (ssource->condition & G_IO_IN) {
+        FD_SET(ssource->socket, &rfds);
+    }
+    if (ssource->condition & G_IO_OUT) {
+        FD_SET(ssource->socket, &wfds);
+    }
+    if (ssource->condition & G_IO_PRI) {
+        FD_SET(ssource->socket, &xfds);
+    }
+    ssource->revents = 0;
+    if (select(0, &rfds, &wfds, &xfds, &tv0) == 0) {
+        return 0;
+    }
+
+    if (FD_ISSET(ssource->socket, &rfds)) {
+        ssource->revents |= G_IO_IN;
+    }
+    if (FD_ISSET(ssource->socket, &wfds)) {
+        ssource->revents |= G_IO_OUT;
+    }
+    if (FD_ISSET(ssource->socket, &xfds)) {
+        ssource->revents |= G_IO_PRI;
+    }
+
+    return ssource->revents;
+}
+
+
+static gboolean
+qio_channel_socket_source_dispatch(GSource *source,
+                                   GSourceFunc callback,
+                                   gpointer user_data)
+{
+    QIOChannelFunc func = (QIOChannelFunc)callback;
+    QIOChannelSocketSource *ssource = (QIOChannelSocketSource *)source;
+
+    return (*func)(ssource->ioc, ssource->revents, user_data);
+}
+
+
+static void
+qio_channel_socket_source_finalize(GSource *source)
+{
+    QIOChannelSocketSource *ssource = (QIOChannelSocketSource *)source;
+
+    object_unref(OBJECT(ssource->ioc));
+}
+
+
+GSourceFuncs qio_channel_socket_source_funcs = {
+    qio_channel_socket_source_prepare,
+    qio_channel_socket_source_check,
+    qio_channel_socket_source_dispatch,
+    qio_channel_socket_source_finalize
+};
+#endif
+
+
+static gboolean
+qio_channel_fd_pair_source_prepare(GSource *source G_GNUC_UNUSED,
+                                   gint *timeout)
+{
+    *timeout = -1;
+
+    return FALSE;
+}
+
+
+static gboolean
+qio_channel_fd_pair_source_check(GSource *source)
+{
+    QIOChannelFDPairSource *ssource = (QIOChannelFDPairSource *)source;
+    GIOCondition poll_condition = ssource->fdread.revents |
+        ssource->fdwrite.revents;
+
+    return poll_condition & ssource->condition;
+}
+
+
+static gboolean
+qio_channel_fd_pair_source_dispatch(GSource *source,
+                                    GSourceFunc callback,
+                                    gpointer user_data)
+{
+    QIOChannelFunc func = (QIOChannelFunc)callback;
+    QIOChannelFDPairSource *ssource = (QIOChannelFDPairSource *)source;
+    GIOCondition poll_condition = ssource->fdread.revents |
+        ssource->fdwrite.revents;
+
+    return (*func)(ssource->ioc,
+                   poll_condition & ssource->condition,
+                   user_data);
+}
+
+
+static void
+qio_channel_fd_pair_source_finalize(GSource *source)
+{
+    QIOChannelFDPairSource *ssource = (QIOChannelFDPairSource *)source;
+
+    object_unref(OBJECT(ssource->ioc));
+}
+
+
+GSourceFuncs qio_channel_fd_source_funcs = {
+    qio_channel_fd_source_prepare,
+    qio_channel_fd_source_check,
+    qio_channel_fd_source_dispatch,
+    qio_channel_fd_source_finalize
+};
+
+
+GSourceFuncs qio_channel_fd_pair_source_funcs = {
+    qio_channel_fd_pair_source_prepare,
+    qio_channel_fd_pair_source_check,
+    qio_channel_fd_pair_source_dispatch,
+    qio_channel_fd_pair_source_finalize
+};
+
+
+GSource *qio_channel_create_fd_watch(QIOChannel *ioc,
+                                     int fd,
+                                     GIOCondition condition)
+{
+    GSource *source;
+    QIOChannelFDSource *ssource;
+
+    source = g_source_new(&qio_channel_fd_source_funcs,
+                          sizeof(QIOChannelFDSource));
+    ssource = (QIOChannelFDSource *)source;
+
+    ssource->ioc = ioc;
+    object_ref(OBJECT(ioc));
+
+    ssource->condition = condition;
+
+#ifdef CONFIG_WIN32
+    ssource->fd.fd = (gint64)_get_osfhandle(fd);
+#else
+    ssource->fd.fd = fd;
+#endif
+    ssource->fd.events = condition;
+
+    g_source_add_poll(source, &ssource->fd);
+
+    return source;
+}
+
+#ifdef CONFIG_WIN32
+GSource *qio_channel_create_socket_watch(QIOChannel *ioc,
+                                         int sockfd,
+                                         GIOCondition condition)
+{
+    GSource *source;
+    QIOChannelSocketSource *ssource;
+
+    qemu_socket_select_nofail(sockfd, ioc->event,
+                              FD_READ | FD_ACCEPT | FD_CLOSE |
+                              FD_CONNECT | FD_WRITE | FD_OOB);
+
+    source = g_source_new(&qio_channel_socket_source_funcs,
+                          sizeof(QIOChannelSocketSource));
+    ssource = (QIOChannelSocketSource *)source;
+
+    ssource->ioc = ioc;
+    object_ref(OBJECT(ioc));
+
+    ssource->condition = condition;
+    ssource->socket = _get_osfhandle(sockfd);
+    ssource->revents = 0;
+
+    ssource->fd.fd = (gintptr)ioc->event;
+    ssource->fd.events = G_IO_IN;
+
+    g_source_add_poll(source, &ssource->fd);
+
+    return source;
+}
+#else
+GSource *qio_channel_create_socket_watch(QIOChannel *ioc,
+                                         int socket,
+                                         GIOCondition condition)
+{
+    return qio_channel_create_fd_watch(ioc, socket, condition);
+}
+#endif
+
+GSource *qio_channel_create_fd_pair_watch(QIOChannel *ioc,
+                                          int fdread,
+                                          int fdwrite,
+                                          GIOCondition condition)
+{
+    GSource *source;
+    QIOChannelFDPairSource *ssource;
+
+    source = g_source_new(&qio_channel_fd_pair_source_funcs,
+                          sizeof(QIOChannelFDPairSource));
+    ssource = (QIOChannelFDPairSource *)source;
+
+    ssource->ioc = ioc;
+    object_ref(OBJECT(ioc));
+
+    ssource->condition = condition;
+
+#ifdef CONFIG_WIN32
+    ssource->fdread.fd = (gint64)_get_osfhandle(fdread);
+    ssource->fdwrite.fd = (gint64)_get_osfhandle(fdwrite);
+#else
+    ssource->fdread.fd = fdread;
+    ssource->fdwrite.fd = fdwrite;
+#endif
+
+    ssource->fdread.events = condition & G_IO_IN;
+    ssource->fdwrite.events = condition & G_IO_OUT;
+
+    g_source_add_poll(source, &ssource->fdread);
+    g_source_add_poll(source, &ssource->fdwrite);
+
+    return source;
+}

io/channel.c

@@ -0,0 +1,952 @@
+/*
+ * QEMU I/O channels
+ *
+ * Copyright (c) 2015 Red Hat, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/aio-wait.h"
+#include "io/channel.h"
+#include "qapi/error.h"
+#include "qemu/main-loop.h"
+#include "qemu/module.h"
+#include "qemu/iov.h"
+
+bool qio_channel_has_feature(QIOChannel *ioc,
+                             QIOChannelFeature feature)
+{
+    return ioc->features & (1 << feature);
+}
+
+
+void qio_channel_set_feature(QIOChannel *ioc,
+                             QIOChannelFeature feature)
+{
+    ioc->features |= (1 << feature);
+}
+
+
+void qio_channel_set_name(QIOChannel *ioc,
+                          const char *name)
+{
+    g_free(ioc->name);
+    ioc->name = g_strdup(name);
+}
+
+
+ssize_t qio_channel_readv_full(QIOChannel *ioc,
+                               const struct iovec *iov,
+                               size_t niov,
+                               int **fds,
+                               size_t *nfds,
+                               int flags,
+                               Error **errp)
+{
+    QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc);
+
+    if ((fds || nfds) &&
+        !qio_channel_has_feature(ioc, QIO_CHANNEL_FEATURE_FD_PASS)) {
+        error_setg_errno(errp, EINVAL,
+                         "Channel does not support file descriptor passing");
+        return -1;
+    }
+
+    if ((flags & QIO_CHANNEL_READ_FLAG_MSG_PEEK) &&
+        !qio_channel_has_feature(ioc, QIO_CHANNEL_FEATURE_READ_MSG_PEEK)) {
+        error_setg_errno(errp, EINVAL,
+                         "Channel does not support peek read");
+        return -1;
+    }
+
+    return klass->io_readv(ioc, iov, niov, fds, nfds, flags, errp);
+}
+
+
+ssize_t qio_channel_writev_full(QIOChannel *ioc,
+                                const struct iovec *iov,
+                                size_t niov,
+                                int *fds,
+                                size_t nfds,
+                                int flags,
+                                Error **errp)
+{
+    QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc);
+
+    if (fds || nfds) {
+        if (!qio_channel_has_feature(ioc, QIO_CHANNEL_FEATURE_FD_PASS)) {
+            error_setg_errno(errp, EINVAL,
+                             "Channel does not support file descriptor passing");
+            return -1;
+        }
+        if (flags & QIO_CHANNEL_WRITE_FLAG_ZERO_COPY) {
+            error_setg_errno(errp, EINVAL,
+                             "Zero Copy does not support file descriptor passing");
+            return -1;
+        }
+    }
+
+    if ((flags & QIO_CHANNEL_WRITE_FLAG_ZERO_COPY) &&
+        !qio_channel_has_feature(ioc, QIO_CHANNEL_FEATURE_WRITE_ZERO_COPY)) {
+        error_setg_errno(errp, EINVAL,
+                         "Requested Zero Copy feature is not available");
+        return -1;
+    }
+
+    return klass->io_writev(ioc, iov, niov, fds, nfds, flags, errp);
+}
+
+
+int coroutine_mixed_fn qio_channel_readv_all_eof(QIOChannel *ioc,
+                                                 const struct iovec *iov,
+                                                 size_t niov,
+                                                 Error **errp)
+{
+    return qio_channel_readv_full_all_eof(ioc, iov, niov, NULL, NULL, 0,
+                                          errp);
+}
+
+int coroutine_mixed_fn qio_channel_readv_all(QIOChannel *ioc,
+                                             const struct iovec *iov,
+                                             size_t niov,
+                                             Error **errp)
+{
+    return qio_channel_readv_full_all(ioc, iov, niov, NULL, NULL, errp);
+}
+
+int coroutine_mixed_fn qio_channel_readv_full_all_eof(QIOChannel *ioc,
+                                                      const struct iovec *iov,
+                                                      size_t niov,
+                                                      int **fds, size_t *nfds,
+                                                      int flags,
+                                                      Error **errp)
+{
+    int ret = -1;
+    struct iovec *local_iov = g_new(struct iovec, niov);
+    struct iovec *local_iov_head = local_iov;
+    unsigned int nlocal_iov = niov;
+    int **local_fds = fds;
+    size_t *local_nfds = nfds;
+    bool partial = false;
+
+    if (nfds) {
+        *nfds = 0;
+    }
+
+    if (fds) {
+        *fds = NULL;
+    }
+
+    nlocal_iov = iov_copy(local_iov, nlocal_iov,
+                          iov, niov,
+                          0, iov_size(iov, niov));
+
+    while ((nlocal_iov > 0) || local_fds) {
+        ssize_t len;
+        len = qio_channel_readv_full(ioc, local_iov, nlocal_iov, local_fds,
+                                     local_nfds, flags, errp);
+        if (len == QIO_CHANNEL_ERR_BLOCK) {
+            qio_channel_wait_cond(ioc, G_IO_IN);
+            continue;
+        }
+
+        if (len == 0) {
+            if (local_nfds && *local_nfds) {
+                /*
+                 * Got some FDs, but no data yet. This isn't an EOF
+                 * scenario (yet), so carry on to try to read data
+                 * on next loop iteration
+                 */
+                goto next_iter;
+            } else if (!partial) {
+                /* No fds and no data - EOF before any data read */
+                ret = 0;
+                goto cleanup;
+            } else {
+                len = -1;
+                error_setg(errp,
+                           "Unexpected end-of-file before all data were read");
+                /* Fallthrough into len < 0 handling */
+            }
+        }
+
+        if (len < 0) {
+            /* Close any FDs we previously received */
+            if (nfds && fds) {
+                size_t i;
+                for (i = 0; i < (*nfds); i++) {
+                    close((*fds)[i]);
+                }
+                g_free(*fds);
+                *fds = NULL;
+                *nfds = 0;
+            }
+            goto cleanup;
+        }
+
+        if (nlocal_iov) {
+            iov_discard_front(&local_iov, &nlocal_iov, len);
+        }
+
+next_iter:
+        partial = true;
+        local_fds = NULL;
+        local_nfds = NULL;
+    }
+
+    ret = 1;
+
+ cleanup:
+    g_free(local_iov_head);
+    return ret;
+}
+
+int coroutine_mixed_fn qio_channel_readv_full_all(QIOChannel *ioc,
+                                                  const struct iovec *iov,
+                                                  size_t niov,
+                                                  int **fds, size_t *nfds,
+                                                  Error **errp)
+{
+    int ret = qio_channel_readv_full_all_eof(ioc, iov, niov, fds, nfds, 0,
+                                             errp);
+
+    if (ret == 0) {
+        error_setg(errp, "Unexpected end-of-file before all data were read");
+        return -1;
+    }
+    if (ret == 1) {
+        return 0;
+    }
+
+    return ret;
+}
+
+int coroutine_mixed_fn qio_channel_writev_all(QIOChannel *ioc,
+                                              const struct iovec *iov,
+                                              size_t niov,
+                                              Error **errp)
+{
+    return qio_channel_writev_full_all(ioc, iov, niov, NULL, 0, 0, errp);
+}
+
+int coroutine_mixed_fn qio_channel_writev_full_all(QIOChannel *ioc,
+                                                   const struct iovec *iov,
+                                                   size_t niov,
+                                                   int *fds, size_t nfds,
+                                                   int flags, Error **errp)
+{
+    int ret = -1;
+    struct iovec *local_iov = g_new(struct iovec, niov);
+    struct iovec *local_iov_head = local_iov;
+    unsigned int nlocal_iov = niov;
+
+    nlocal_iov = iov_copy(local_iov, nlocal_iov,
+                          iov, niov,
+                          0, iov_size(iov, niov));
+
+    while (nlocal_iov > 0) {
+        ssize_t len;
+
+        len = qio_channel_writev_full(ioc, local_iov, nlocal_iov, fds,
+                                            nfds, flags, errp);
+
+        if (len == QIO_CHANNEL_ERR_BLOCK) {
+            qio_channel_wait_cond(ioc, G_IO_OUT);
+            continue;
+        }
+        if (len < 0) {
+            goto cleanup;
+        }
+
+        iov_discard_front(&local_iov, &nlocal_iov, len);
+
+        fds = NULL;
+        nfds = 0;
+    }
+
+    ret = 0;
+ cleanup:
+    g_free(local_iov_head);
+    return ret;
+}
+
+ssize_t qio_channel_readv(QIOChannel *ioc,
+                          const struct iovec *iov,
+                          size_t niov,
+                          Error **errp)
+{
+    return qio_channel_readv_full(ioc, iov, niov, NULL, NULL, 0, errp);
+}
+
+
+ssize_t qio_channel_writev(QIOChannel *ioc,
+                           const struct iovec *iov,
+                           size_t niov,
+                           Error **errp)
+{
+    return qio_channel_writev_full(ioc, iov, niov, NULL, 0, 0, errp);
+}
+
+
+ssize_t qio_channel_read(QIOChannel *ioc,
+                         void *buf,
+                         size_t buflen,
+                         Error **errp)
+{
+    struct iovec iov = { .iov_base = buf, .iov_len = buflen };
+    return qio_channel_readv_full(ioc, &iov, 1, NULL, NULL, 0, errp);
+}
+
+
+ssize_t qio_channel_write(QIOChannel *ioc,
+                          const void *buf,
+                          size_t buflen,
+                          Error **errp)
+{
+    struct iovec iov = { .iov_base = (char *)buf, .iov_len = buflen };
+    return qio_channel_writev_full(ioc, &iov, 1, NULL, 0, 0, errp);
+}
+
+
+int coroutine_mixed_fn qio_channel_read_all_eof(QIOChannel *ioc,
+                                                void *buf,
+                                                size_t buflen,
+                                                Error **errp)
+{
+    struct iovec iov = { .iov_base = buf, .iov_len = buflen };
+    return qio_channel_readv_all_eof(ioc, &iov, 1, errp);
+}
+
+
+int coroutine_mixed_fn qio_channel_read_all(QIOChannel *ioc,
+                                            void *buf,
+                                            size_t buflen,
+                                            Error **errp)
+{
+    struct iovec iov = { .iov_base = buf, .iov_len = buflen };
+    return qio_channel_readv_all(ioc, &iov, 1, errp);
+}
+
+
+int coroutine_mixed_fn qio_channel_write_all(QIOChannel *ioc,
+                                             const void *buf,
+                                             size_t buflen,
+                                             Error **errp)
+{
+    struct iovec iov = { .iov_base = (char *)buf, .iov_len = buflen };
+    return qio_channel_writev_all(ioc, &iov, 1, errp);
+}
+
+
+bool qio_channel_set_blocking(QIOChannel *ioc,
+                              bool enabled,
+                              Error **errp)
+{
+    QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc);
+    return klass->io_set_blocking(ioc, enabled, errp) == 0;
+}
+
+
+void qio_channel_set_follow_coroutine_ctx(QIOChannel *ioc, bool enabled)
+{
+    ioc->follow_coroutine_ctx = enabled;
+}
+
+
+int qio_channel_close(QIOChannel *ioc,
+                      Error **errp)
+{
+    QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc);
+    return klass->io_close(ioc, errp);
+}
+
+
+GSource *qio_channel_create_watch(QIOChannel *ioc,
+                                  GIOCondition condition)
+{
+    QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc);
+    GSource *ret = klass->io_create_watch(ioc, condition);
+
+    if (ioc->name) {
+        g_source_set_name(ret, ioc->name);
+    }
+
+    return ret;
+}
+
+
+void qio_channel_set_aio_fd_handler(QIOChannel *ioc,
+                                    AioContext *read_ctx,
+                                    IOHandler *io_read,
+                                    AioContext *write_ctx,
+                                    IOHandler *io_write,
+                                    void *opaque)
+{
+    QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc);
+
+    klass->io_set_aio_fd_handler(ioc, read_ctx, io_read, write_ctx, io_write,
+            opaque);
+}
+
+guint qio_channel_add_watch_full(QIOChannel *ioc,
+                                 GIOCondition condition,
+                                 QIOChannelFunc func,
+                                 gpointer user_data,
+                                 GDestroyNotify notify,
+                                 GMainContext *context)
+{
+    GSource *source;
+    guint id;
+
+    source = qio_channel_create_watch(ioc, condition);
+
+    g_source_set_callback(source, (GSourceFunc)func, user_data, notify);
+
+    id = g_source_attach(source, context);
+    g_source_unref(source);
+
+    return id;
+}
+
+guint qio_channel_add_watch(QIOChannel *ioc,
+                            GIOCondition condition,
+                            QIOChannelFunc func,
+                            gpointer user_data,
+                            GDestroyNotify notify)
+{
+    return qio_channel_add_watch_full(ioc, condition, func,
+                                      user_data, notify, NULL);
+}
+
+GSource *qio_channel_add_watch_source(QIOChannel *ioc,
+                                      GIOCondition condition,
+                                      QIOChannelFunc func,
+                                      gpointer user_data,
+                                      GDestroyNotify notify,
+                                      GMainContext *context)
+{
+    GSource *source;
+    guint id;
+
+    id = qio_channel_add_watch_full(ioc, condition, func,
+                                    user_data, notify, context);
+    source = g_main_context_find_source_by_id(context, id);
+    g_source_ref(source);
+    return source;
+}
+
+
+ssize_t qio_channel_pwritev(QIOChannel *ioc, const struct iovec *iov,
+                            size_t niov, off_t offset, Error **errp)
+{
+    QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc);
+
+    if (!klass->io_pwritev) {
+        error_setg(errp, "Channel does not support pwritev");
+        return -1;
+    }
+
+    if (!qio_channel_has_feature(ioc, QIO_CHANNEL_FEATURE_SEEKABLE)) {
+        error_setg_errno(errp, EINVAL, "Requested channel is not seekable");
+        return -1;
+    }
+
+    return klass->io_pwritev(ioc, iov, niov, offset, errp);
+}
+
+ssize_t qio_channel_pwrite(QIOChannel *ioc, void *buf, size_t buflen,
+                           off_t offset, Error **errp)
+{
+    struct iovec iov = {
+        .iov_base = buf,
+        .iov_len = buflen
+    };
+
+    return qio_channel_pwritev(ioc, &iov, 1, offset, errp);
+}
+
+int coroutine_mixed_fn qio_channel_pwritev_all(QIOChannel *ioc,
+                                               const struct iovec *iov,
+                                               size_t niov,
+                                               off_t offset,
+                                               Error **errp)
+{
+    int ret = -1;
+    struct iovec *local_iov = g_new(struct iovec, niov);
+    struct iovec *local_iov_head = local_iov;
+    unsigned int nlocal_iov = niov;
+
+    nlocal_iov = iov_copy(local_iov, nlocal_iov,
+                          iov, niov,
+                          0, iov_size(iov, niov));
+
+    while (nlocal_iov > 0) {
+        ssize_t len;
+
+        len = qio_channel_pwritev(ioc, local_iov, nlocal_iov, offset, errp);
+
+        if (len == QIO_CHANNEL_ERR_BLOCK) {
+            qio_channel_wait_cond(ioc, G_IO_OUT);
+            continue;
+        }
+        if (len < 0) {
+            goto cleanup;
+        }
+
+        offset += len;
+        iov_discard_front(&local_iov, &nlocal_iov, len);
+    }
+
+    ret = 0;
+ cleanup:
+    g_free(local_iov_head);
+    return ret;
+}
+
+int coroutine_mixed_fn qio_channel_pwrite_all(QIOChannel *ioc,
+                                              const void *buf,
+                                              size_t buflen,
+                                              off_t offset,
+                                              Error **errp)
+{
+    struct iovec iov = { .iov_base = (char *)buf, .iov_len = buflen };
+    return qio_channel_pwritev_all(ioc, &iov, 1, offset, errp);
+}
+
+ssize_t qio_channel_preadv(QIOChannel *ioc, const struct iovec *iov,
+                           size_t niov, off_t offset, Error **errp)
+{
+    QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc);
+
+    if (!klass->io_preadv) {
+        error_setg(errp, "Channel does not support preadv");
+        return -1;
+    }
+
+    if (!qio_channel_has_feature(ioc, QIO_CHANNEL_FEATURE_SEEKABLE)) {
+        error_setg_errno(errp, EINVAL, "Requested channel is not seekable");
+        return -1;
+    }
+
+    return klass->io_preadv(ioc, iov, niov, offset, errp);
+}
+
+ssize_t qio_channel_pread(QIOChannel *ioc, void *buf, size_t buflen,
+                          off_t offset, Error **errp)
+{
+    struct iovec iov = {
+        .iov_base = buf,
+        .iov_len = buflen
+    };
+
+    return qio_channel_preadv(ioc, &iov, 1, offset, errp);
+}
+
+int coroutine_mixed_fn qio_channel_preadv_all_eof(QIOChannel *ioc,
+                                                  const struct iovec *iov,
+                                                  size_t niov,
+                                                  off_t offset,
+                                                  Error **errp)
+{
+    int ret = -1;
+    struct iovec *local_iov = g_new(struct iovec, niov);
+    struct iovec *local_iov_head = local_iov;
+    unsigned int nlocal_iov = niov;
+    bool partial = false;
+
+    nlocal_iov = iov_copy(local_iov, nlocal_iov,
+                          iov, niov,
+                          0, iov_size(iov, niov));
+
+    while (nlocal_iov > 0) {
+        ssize_t len;
+        len = qio_channel_preadv(ioc, local_iov, nlocal_iov, offset, errp);
+
+        if (len == QIO_CHANNEL_ERR_BLOCK) {
+            qio_channel_wait_cond(ioc, G_IO_IN);
+            continue;
+        }
+
+        if (len == 0) {
+            if (!partial) {
+                ret = 0;
+                goto cleanup;
+            }
+            error_setg(errp,
+                       "Unexpected end-of-file before all data were read");
+            goto cleanup;
+        }
+
+        if (len < 0) {
+            goto cleanup;
+        }
+
+        partial = true;
+        offset += len;
+        iov_discard_front(&local_iov, &nlocal_iov, len);
+    }
+
+    ret = 1;
+
+ cleanup:
+    g_free(local_iov_head);
+    return ret;
+}
+
+int coroutine_mixed_fn qio_channel_preadv_all(QIOChannel *ioc,
+                                              const struct iovec *iov,
+                                              size_t niov,
+                                              off_t offset,
+                                              Error **errp)
+{
+    int ret = qio_channel_preadv_all_eof(ioc, iov, niov, offset, errp);
+
+    if (ret == 0) {
+        error_setg(errp,
+                   "Unexpected end-of-file before all data were read");
+        return -1;
+    }
+    if (ret == 1) {
+        return 0;
+    }
+
+    return ret;
+}
+
+int coroutine_mixed_fn qio_channel_pread_all_eof(QIOChannel *ioc,
+                                                 void *buf,
+                                                 size_t buflen,
+                                                 off_t offset,
+                                                 Error **errp)
+{
+    struct iovec iov = { .iov_base = buf, .iov_len = buflen };
+    return qio_channel_preadv_all_eof(ioc, &iov, 1, offset, errp);
+}
+
+int coroutine_mixed_fn qio_channel_pread_all(QIOChannel *ioc,
+                                             void *buf,
+                                             size_t buflen,
+                                             off_t offset,
+                                             Error **errp)
+{
+    struct iovec iov = { .iov_base = buf, .iov_len = buflen };
+    return qio_channel_preadv_all(ioc, &iov, 1, offset, errp);
+}
+
+int qio_channel_shutdown(QIOChannel *ioc,
+                         QIOChannelShutdown how,
+                         Error **errp)
+{
+    QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc);
+
+    if (!klass->io_shutdown) {
+        error_setg(errp, "Data path shutdown not supported");
+        return -1;
+    }
+
+    return klass->io_shutdown(ioc, how, errp);
+}
+
+
+void qio_channel_set_delay(QIOChannel *ioc,
+                           bool enabled)
+{
+    QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc);
+
+    if (klass->io_set_delay) {
+        klass->io_set_delay(ioc, enabled);
+    }
+}
+
+
+void qio_channel_set_cork(QIOChannel *ioc,
+                          bool enabled)
+{
+    QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc);
+
+    if (klass->io_set_cork) {
+        klass->io_set_cork(ioc, enabled);
+    }
+}
+
+int qio_channel_get_peerpid(QIOChannel *ioc,
+                             unsigned int *pid,
+                             Error **errp)
+{
+    QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc);
+
+    if (!klass->io_peerpid) {
+        error_setg(errp, "Channel does not support peer pid");
+        return -1;
+    }
+    klass->io_peerpid(ioc, pid, errp);
+    return 0;
+}
+
+off_t qio_channel_io_seek(QIOChannel *ioc,
+                          off_t offset,
+                          int whence,
+                          Error **errp)
+{
+    QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc);
+
+    if (!klass->io_seek) {
+        error_setg(errp, "Channel does not support random access");
+        return -1;
+    }
+
+    return klass->io_seek(ioc, offset, whence, errp);
+}
+
+int qio_channel_flush(QIOChannel *ioc,
+                                Error **errp)
+{
+    QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc);
+
+    if (!klass->io_flush ||
+        !qio_channel_has_feature(ioc, QIO_CHANNEL_FEATURE_WRITE_ZERO_COPY)) {
+        return 0;
+    }
+
+    return klass->io_flush(ioc, errp);
+}
+
+
+static void qio_channel_restart_read(void *opaque)
+{
+    QIOChannel *ioc = opaque;
+    Coroutine *co = qatomic_xchg(&ioc->read_coroutine, NULL);
+
+    if (!co) {
+        return;
+    }
+
+    /* Assert that aio_co_wake() reenters the coroutine directly */
+    assert(qemu_get_current_aio_context() ==
+           qemu_coroutine_get_aio_context(co));
+    aio_co_wake(co);
+}
+
+static void qio_channel_restart_write(void *opaque)
+{
+    QIOChannel *ioc = opaque;
+    Coroutine *co = qatomic_xchg(&ioc->write_coroutine, NULL);
+
+    if (!co) {
+        return;
+    }
+
+    /* Assert that aio_co_wake() reenters the coroutine directly */
+    assert(qemu_get_current_aio_context() ==
+           qemu_coroutine_get_aio_context(co));
+    aio_co_wake(co);
+}
+
+static void coroutine_fn
+qio_channel_set_fd_handlers(QIOChannel *ioc, GIOCondition condition)
+{
+    AioContext *ctx = ioc->follow_coroutine_ctx ?
+        qemu_coroutine_get_aio_context(qemu_coroutine_self()) :
+        iohandler_get_aio_context();
+    AioContext *read_ctx = NULL;
+    IOHandler *io_read = NULL;
+    AioContext *write_ctx = NULL;
+    IOHandler *io_write = NULL;
+
+    if (condition == G_IO_IN) {
+        ioc->read_coroutine = qemu_coroutine_self();
+        ioc->read_ctx = ctx;
+        read_ctx = ctx;
+        io_read = qio_channel_restart_read;
+
+        /*
+         * Thread safety: if the other coroutine is set and its AioContext
+         * matches ours, then there is mutual exclusion between read and write
+         * because they share a single thread and it's safe to set both read
+         * and write fd handlers here. If the AioContext does not match ours,
+         * then both threads may run in parallel but there is no shared state
+         * to worry about.
+         */
+        if (ioc->write_coroutine && ioc->write_ctx == ctx) {
+            write_ctx = ctx;
+            io_write = qio_channel_restart_write;
+        }
+    } else if (condition == G_IO_OUT) {
+        ioc->write_coroutine = qemu_coroutine_self();
+        ioc->write_ctx = ctx;
+        write_ctx = ctx;
+        io_write = qio_channel_restart_write;
+        if (ioc->read_coroutine && ioc->read_ctx == ctx) {
+            read_ctx = ctx;
+            io_read = qio_channel_restart_read;
+        }
+    } else {
+        abort();
+    }
+
+    qio_channel_set_aio_fd_handler(ioc, read_ctx, io_read,
+            write_ctx, io_write, ioc);
+}
+
+static void coroutine_fn
+qio_channel_clear_fd_handlers(QIOChannel *ioc, GIOCondition condition)
+{
+    AioContext *read_ctx = NULL;
+    IOHandler *io_read = NULL;
+    AioContext *write_ctx = NULL;
+    IOHandler *io_write = NULL;
+    AioContext *ctx;
+
+    if (condition == G_IO_IN) {
+        ctx = ioc->read_ctx;
+        read_ctx = ctx;
+        io_read = NULL;
+        if (ioc->write_coroutine && ioc->write_ctx == ctx) {
+            write_ctx = ctx;
+            io_write = qio_channel_restart_write;
+        }
+    } else if (condition == G_IO_OUT) {
+        ctx = ioc->write_ctx;
+        write_ctx = ctx;
+        io_write = NULL;
+        if (ioc->read_coroutine && ioc->read_ctx == ctx) {
+            read_ctx = ctx;
+            io_read = qio_channel_restart_read;
+        }
+    } else {
+        abort();
+    }
+
+    qio_channel_set_aio_fd_handler(ioc, read_ctx, io_read,
+            write_ctx, io_write, ioc);
+}
+
+void coroutine_fn qio_channel_yield(QIOChannel *ioc,
+                                    GIOCondition condition)
+{
+    AioContext *ioc_ctx;
+
+    assert(qemu_in_coroutine());
+    ioc_ctx = qemu_coroutine_get_aio_context(qemu_coroutine_self());
+
+    if (condition == G_IO_IN) {
+        assert(!ioc->read_coroutine);
+    } else if (condition == G_IO_OUT) {
+        assert(!ioc->write_coroutine);
+    } else {
+        abort();
+    }
+    qio_channel_set_fd_handlers(ioc, condition);
+    qemu_coroutine_yield();
+    assert(in_aio_context_home_thread(ioc_ctx));
+
+    /* Allow interrupting the operation by reentering the coroutine other than
+     * through the aio_fd_handlers. */
+    if (condition == G_IO_IN) {
+        assert(ioc->read_coroutine == NULL);
+    } else if (condition == G_IO_OUT) {
+        assert(ioc->write_coroutine == NULL);
+    }
+    qio_channel_clear_fd_handlers(ioc, condition);
+}
+
+void qio_channel_wake_read(QIOChannel *ioc)
+{
+    Coroutine *co = qatomic_xchg(&ioc->read_coroutine, NULL);
+    if (co) {
+        aio_co_wake(co);
+    }
+}
+
+static gboolean qio_channel_wait_complete(QIOChannel *ioc,
+                                          GIOCondition condition,
+                                          gpointer opaque)
+{
+    GMainLoop *loop = opaque;
+
+    g_main_loop_quit(loop);
+    return FALSE;
+}
+
+
+void qio_channel_wait(QIOChannel *ioc,
+                      GIOCondition condition)
+{
+    GMainContext *ctxt = g_main_context_new();
+    GMainLoop *loop = g_main_loop_new(ctxt, TRUE);
+    GSource *source;
+
+    source = qio_channel_create_watch(ioc, condition);
+
+    g_source_set_callback(source,
+                          (GSourceFunc)qio_channel_wait_complete,
+                          loop,
+                          NULL);
+
+    g_source_attach(source, ctxt);
+
+    g_main_loop_run(loop);
+
+    g_source_unref(source);
+    g_main_loop_unref(loop);
+    g_main_context_unref(ctxt);
+}
+
+void coroutine_mixed_fn
+qio_channel_wait_cond(QIOChannel *ioc,
+                      GIOCondition condition)
+{
+    if (qemu_in_coroutine()) {
+        qio_channel_yield(ioc, condition);
+    } else {
+        qio_channel_wait(ioc, condition);
+    }
+}
+
+static void qio_channel_finalize(Object *obj)
+{
+    QIOChannel *ioc = QIO_CHANNEL(obj);
+
+    /* Must not have coroutines in qio_channel_yield() */
+    assert(!ioc->read_coroutine);
+    assert(!ioc->write_coroutine);
+
+    g_free(ioc->name);
+
+#ifdef _WIN32
+    if (ioc->event) {
+        CloseHandle(ioc->event);
+    }
+#endif
+}
+
+static const TypeInfo qio_channel_info = {
+    .parent = TYPE_OBJECT,
+    .name = TYPE_QIO_CHANNEL,
+    .instance_size = sizeof(QIOChannel),
+    .instance_finalize = qio_channel_finalize,
+    .abstract = true,
+    .class_size = sizeof(QIOChannelClass),
+};
+
+
+static void qio_channel_register_types(void)
+{
+    type_register_static(&qio_channel_info);
+}
+
+
+type_init(qio_channel_register_types);

io/dns-resolver.c

@@ -0,0 +1,272 @@
+/*
+ * QEMU DNS resolver
+ *
+ * Copyright (c) 2016 Red Hat, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include "qemu/osdep.h"
+#include "io/dns-resolver.h"
+#include "qapi/clone-visitor.h"
+#include "qapi/qapi-visit-sockets.h"
+#include "qemu/sockets.h"
+#include "qapi/error.h"
+#include "qemu/cutils.h"
+#include "qemu/module.h"
+
+#ifndef AI_NUMERICSERV
+# define AI_NUMERICSERV 0
+#endif
+
+static QIODNSResolver *instance;
+static GOnce instance_init = G_ONCE_INIT;
+
+static gpointer qio_dns_resolve_init_instance(gpointer unused G_GNUC_UNUSED)
+{
+    instance = QIO_DNS_RESOLVER(object_new(TYPE_QIO_DNS_RESOLVER));
+    return NULL;
+}
+
+QIODNSResolver *qio_dns_resolver_get_instance(void)
+{
+    g_once(&instance_init, qio_dns_resolve_init_instance, NULL);
+    return instance;
+}
+
+static int qio_dns_resolver_lookup_sync_inet(QIODNSResolver *resolver,
+                                             SocketAddress *addr,
+                                             size_t *naddrs,
+                                             SocketAddress ***addrs,
+                                             Error **errp)
+{
+    struct addrinfo ai, *res, *e;
+    InetSocketAddress *iaddr = &addr->u.inet;
+    char port[33];
+    char uaddr[INET6_ADDRSTRLEN + 1];
+    char uport[33];
+    int rc;
+    Error *err = NULL;
+    size_t i;
+
+    *naddrs = 0;
+    *addrs = NULL;
+
+    memset(&ai, 0, sizeof(ai));
+    ai.ai_flags = AI_PASSIVE;
+    if (iaddr->has_numeric && iaddr->numeric) {
+        ai.ai_flags |= AI_NUMERICHOST | AI_NUMERICSERV;
+    }
+    ai.ai_family = inet_ai_family_from_address(iaddr, &err);
+    ai.ai_socktype = SOCK_STREAM;
+
+    if (err) {
+        error_propagate(errp, err);
+        return -1;
+    }
+
+    if (iaddr->host == NULL) {
+        error_setg(errp, "host not specified");
+        return -1;
+    }
+    if (iaddr->port != NULL) {
+        pstrcpy(port, sizeof(port), iaddr->port);
+    } else {
+        port[0] = '\0';
+    }
+
+    rc = getaddrinfo(strlen(iaddr->host) ? iaddr->host : NULL,
+                     strlen(port) ? port : NULL, &ai, &res);
+    if (rc != 0) {
+        error_setg(errp, "address resolution failed for %s:%s: %s",
+                   iaddr->host, port, gai_strerror(rc));
+        return -1;
+    }
+
+    for (e = res; e != NULL; e = e->ai_next) {
+        (*naddrs)++;
+    }
+
+    *addrs = g_new0(SocketAddress *, *naddrs);
+
+    /* create socket + bind */
+    for (i = 0, e = res; e != NULL; i++, e = e->ai_next) {
+        SocketAddress *newaddr = g_new0(SocketAddress, 1);
+
+        newaddr->type = SOCKET_ADDRESS_TYPE_INET;
+
+        getnameinfo((struct sockaddr *)e->ai_addr, e->ai_addrlen,
+                    uaddr, INET6_ADDRSTRLEN, uport, 32,
+                    NI_NUMERICHOST | NI_NUMERICSERV);
+
+        newaddr->u.inet = *iaddr;
+        newaddr->u.inet.host = g_strdup(uaddr),
+        newaddr->u.inet.port = g_strdup(uport),
+        newaddr->u.inet.has_numeric = true,
+        newaddr->u.inet.numeric = true,
+
+        (*addrs)[i] = newaddr;
+    }
+    freeaddrinfo(res);
+    return 0;
+}
+
+
+static int qio_dns_resolver_lookup_sync_nop(QIODNSResolver *resolver,
+                                            SocketAddress *addr,
+                                            size_t *naddrs,
+                                            SocketAddress ***addrs,
+                                            Error **errp)
+{
+    *naddrs = 1;
+    *addrs = g_new0(SocketAddress *, 1);
+    (*addrs)[0] = QAPI_CLONE(SocketAddress, addr);
+
+    return 0;
+}
+
+
+int qio_dns_resolver_lookup_sync(QIODNSResolver *resolver,
+                                 SocketAddress *addr,
+                                 size_t *naddrs,
+                                 SocketAddress ***addrs,
+                                 Error **errp)
+{
+    switch (addr->type) {
+    case SOCKET_ADDRESS_TYPE_INET:
+        return qio_dns_resolver_lookup_sync_inet(resolver,
+                                                 addr,
+                                                 naddrs,
+                                                 addrs,
+                                                 errp);
+
+    case SOCKET_ADDRESS_TYPE_UNIX:
+    case SOCKET_ADDRESS_TYPE_VSOCK:
+    case SOCKET_ADDRESS_TYPE_FD:
+        return qio_dns_resolver_lookup_sync_nop(resolver,
+                                                addr,
+                                                naddrs,
+                                                addrs,
+                                                errp);
+
+    default:
+        abort();
+    }
+}
+
+
+struct QIODNSResolverLookupData {
+    SocketAddress *addr;
+    SocketAddress **addrs;
+    size_t naddrs;
+};
+
+
+static void qio_dns_resolver_lookup_data_free(gpointer opaque)
+{
+    struct QIODNSResolverLookupData *data = opaque;
+    size_t i;
+
+    qapi_free_SocketAddress(data->addr);
+    for (i = 0; i < data->naddrs; i++) {
+        qapi_free_SocketAddress(data->addrs[i]);
+    }
+
+    g_free(data->addrs);
+    g_free(data);
+}
+
+
+static void qio_dns_resolver_lookup_worker(QIOTask *task,
+                                           gpointer opaque)
+{
+    QIODNSResolver *resolver = QIO_DNS_RESOLVER(qio_task_get_source(task));
+    struct QIODNSResolverLookupData *data = opaque;
+    Error *err = NULL;
+
+    qio_dns_resolver_lookup_sync(resolver,
+                                 data->addr,
+                                 &data->naddrs,
+                                 &data->addrs,
+                                 &err);
+    if (err) {
+        qio_task_set_error(task, err);
+    } else {
+        qio_task_set_result_pointer(task, opaque, NULL);
+    }
+
+    object_unref(OBJECT(resolver));
+}
+
+
+void qio_dns_resolver_lookup_async(QIODNSResolver *resolver,
+                                   SocketAddress *addr,
+                                   QIOTaskFunc func,
+                                   gpointer opaque,
+                                   GDestroyNotify notify)
+{
+    QIOTask *task;
+    struct QIODNSResolverLookupData *data =
+        g_new0(struct QIODNSResolverLookupData, 1);
+
+    data->addr = QAPI_CLONE(SocketAddress, addr);
+
+    task = qio_task_new(OBJECT(resolver), func, opaque, notify);
+
+    qio_task_run_in_thread(task,
+                           qio_dns_resolver_lookup_worker,
+                           data,
+                           qio_dns_resolver_lookup_data_free,
+                           NULL);
+}
+
+
+void qio_dns_resolver_lookup_result(QIODNSResolver *resolver,
+                                    QIOTask *task,
+                                    size_t *naddrs,
+                                    SocketAddress ***addrs)
+{
+    struct QIODNSResolverLookupData *data =
+        qio_task_get_result_pointer(task);
+    size_t i;
+
+    *naddrs = 0;
+    *addrs = NULL;
+    if (!data) {
+        return;
+    }
+
+    *naddrs = data->naddrs;
+    *addrs = g_new0(SocketAddress *, data->naddrs);
+    for (i = 0; i < data->naddrs; i++) {
+        (*addrs)[i] = QAPI_CLONE(SocketAddress, data->addrs[i]);
+    }
+}
+
+
+static const TypeInfo qio_dns_resolver_info = {
+    .parent = TYPE_OBJECT,
+    .name = TYPE_QIO_DNS_RESOLVER,
+    .instance_size = sizeof(QIODNSResolver),
+};
+
+
+static void qio_dns_resolver_register_types(void)
+{
+    type_register_static(&qio_dns_resolver_info);
+}
+
+
+type_init(qio_dns_resolver_register_types);

io/meson.build

@@ -0,0 +1,16 @@
+io_ss.add(genh)
+io_ss.add(files(
+  'channel-buffer.c',
+  'channel-command.c',
+  'channel-file.c',
+  'channel-null.c',
+  'channel-socket.c',
+  'channel-tls.c',
+  'channel-util.c',
+  'channel-watch.c',
+  'channel-websock.c',
+  'channel.c',
+  'dns-resolver.c',
+  'net-listener.c',
+  'task.c',
+))

io/net-listener.c

@@ -0,0 +1,483 @@
+/*
+ * QEMU network listener
+ *
+ * Copyright (c) 2016-2017 Red Hat, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include "qemu/osdep.h"
+#include "io/net-listener.h"
+#include "io/dns-resolver.h"
+#include "qapi/error.h"
+#include "qemu/module.h"
+#include "qemu/lockable.h"
+#include "qemu/main-loop.h"
+#include "trace.h"
+
+struct QIONetListenerSource {
+    QIOChannelSocket *sioc;
+    GSource *io_source;
+    QIONetListener *listener;
+};
+
+QIONetListener *qio_net_listener_new(void)
+{
+    QIONetListener *listener;
+
+    listener = QIO_NET_LISTENER(object_new(TYPE_QIO_NET_LISTENER));
+    return listener;
+}
+
+void qio_net_listener_set_name(QIONetListener *listener,
+                               const char *name)
+{
+    g_free(listener->name);
+    listener->name = g_strdup(name);
+}
+
+
+static gboolean qio_net_listener_channel_func(QIOChannel *ioc,
+                                              GIOCondition condition,
+                                              gpointer opaque)
+{
+    QIONetListener *listener = QIO_NET_LISTENER(opaque);
+    QIOChannelSocket *sioc;
+    QIONetListenerClientFunc io_func;
+    gpointer io_data;
+    GMainContext *context;
+    AioContext *aio_context;
+
+    sioc = qio_channel_socket_accept(QIO_CHANNEL_SOCKET(ioc),
+                                     NULL);
+    if (!sioc) {
+        return TRUE;
+    }
+
+    WITH_QEMU_LOCK_GUARD(&listener->lock) {
+        io_func = listener->io_func;
+        io_data = listener->io_data;
+        context = listener->context;
+        aio_context = listener->aio_context;
+    }
+
+    trace_qio_net_listener_callback(listener, io_func, context, aio_context);
+    if (io_func) {
+        io_func(listener, sioc, io_data);
+    }
+
+    object_unref(OBJECT(sioc));
+
+    return TRUE;
+}
+
+
+static void qio_net_listener_aio_func(void *opaque)
+{
+    QIONetListenerSource *data = opaque;
+
+    assert(data->io_source == NULL);
+    assert(data->listener->aio_context != NULL);
+    qio_net_listener_channel_func(QIO_CHANNEL(data->sioc), G_IO_IN,
+                                  data->listener);
+}
+
+
+int qio_net_listener_open_sync(QIONetListener *listener,
+                               SocketAddress *addr,
+                               int num,
+                               Error **errp)
+{
+    QIODNSResolver *resolver = qio_dns_resolver_get_instance();
+    SocketAddress **resaddrs;
+    size_t nresaddrs;
+    size_t i;
+    Error *err = NULL;
+    bool success = false;
+
+    if (qio_dns_resolver_lookup_sync(resolver,
+                                     addr,
+                                     &nresaddrs,
+                                     &resaddrs,
+                                     errp) < 0) {
+        return -1;
+    }
+
+    for (i = 0; i < nresaddrs; i++) {
+        QIOChannelSocket *sioc = qio_channel_socket_new();
+
+        if (qio_channel_socket_listen_sync(sioc, resaddrs[i], num,
+                                           err ? NULL : &err) == 0) {
+            success = true;
+
+            qio_net_listener_add(listener, sioc);
+        }
+
+        qapi_free_SocketAddress(resaddrs[i]);
+        object_unref(OBJECT(sioc));
+    }
+    g_free(resaddrs);
+
+    if (success) {
+        error_free(err);
+        return 0;
+    } else {
+        error_propagate(errp, err);
+        return -1;
+    }
+}
+
+/*
+ * i == 0 to set watch on entire array, non-zero to only set watch on
+ * recent additions when earlier entries are already watched.
+ *
+ * listener->lock must be held by caller.
+ */
+static void
+qio_net_listener_watch(QIONetListener *listener, size_t i, const char *caller)
+{
+    if (!listener->io_func) {
+        return;
+    }
+
+    trace_qio_net_listener_watch(listener, listener->io_func,
+                                 listener->context, listener->aio_context,
+                                 caller);
+    for ( ; i < listener->nsioc; i++) {
+        if (!listener->aio_context) {
+            /*
+             * The user passed a GMainContext with the async callback;
+             * they plan on running the default or their own g_main_loop.
+             */
+            object_ref(OBJECT(listener));
+            listener->source[i]->io_source = qio_channel_add_watch_source(
+                QIO_CHANNEL(listener->source[i]->sioc), G_IO_IN,
+                qio_net_listener_channel_func,
+                listener, (GDestroyNotify)object_unref, listener->context);
+        } else {
+            /*
+             * The user passed an AioContext.  At this point,
+             * AioContext lacks a clean way to call a notify function
+             * to release a final reference after any callback is
+             * complete.  But we asserted earlier that the async
+             * callback is changed only from the thread associated
+             * with aio_context, which means no other thread is in the
+             * middle of running the callback when we are changing the
+             * refcount on listener here.  Therefore, a single
+             * reference here is sufficient to ensure listener is not
+             * finalized during the callback.
+             */
+            assert(listener->context == NULL);
+            if (i == 0) {
+                object_ref(OBJECT(listener));
+            }
+            qio_channel_set_aio_fd_handler(
+                QIO_CHANNEL(listener->source[i]->sioc),
+                listener->aio_context, qio_net_listener_aio_func,
+                NULL, NULL, listener->source[i]);
+        }
+    }
+}
+
+/* listener->lock must be held by caller. */
+static void
+qio_net_listener_unwatch(QIONetListener *listener, const char *caller)
+{
+    size_t i;
+
+    if (!listener->io_func) {
+        return;
+    }
+
+    trace_qio_net_listener_unwatch(listener, listener->io_func,
+                                   listener->context, listener->aio_context,
+                                   caller);
+    for (i = 0; i < listener->nsioc; i++) {
+        if (!listener->aio_context) {
+            if (listener->source[i]->io_source) {
+                g_source_destroy(listener->source[i]->io_source);
+                g_source_unref(listener->source[i]->io_source);
+                listener->source[i]->io_source = NULL;
+            }
+        } else {
+            assert(listener->context == NULL);
+            qio_channel_set_aio_fd_handler(
+                QIO_CHANNEL(listener->source[i]->sioc),
+                listener->aio_context, NULL, NULL, NULL, NULL);
+            if (i == listener->nsioc - 1) {
+                object_unref(OBJECT(listener));
+            }
+        }
+    }
+}
+
+void qio_net_listener_add(QIONetListener *listener,
+                          QIOChannelSocket *sioc)
+{
+    if (listener->name) {
+        qio_channel_set_name(QIO_CHANNEL(sioc), listener->name);
+    }
+
+    listener->source = g_renew(typeof(listener->source[0]),
+                               listener->source,
+                               listener->nsioc + 1);
+    listener->source[listener->nsioc] = g_new0(QIONetListenerSource, 1);
+    listener->source[listener->nsioc]->sioc = sioc;
+    listener->source[listener->nsioc]->listener = listener;
+
+    object_ref(OBJECT(sioc));
+    listener->connected = true;
+
+    QEMU_LOCK_GUARD(&listener->lock);
+    listener->nsioc++;
+    qio_net_listener_watch(listener, listener->nsioc - 1, "add");
+}
+
+
+static void
+qio_net_listener_set_client_func_internal(QIONetListener *listener,
+                                          QIONetListenerClientFunc func,
+                                          gpointer data,
+                                          GDestroyNotify notify,
+                                          GMainContext *context,
+                                          AioContext *aio_context)
+{
+    QEMU_LOCK_GUARD(&listener->lock);
+    if (listener->io_func == func && listener->io_data == data &&
+        listener->io_notify == notify && listener->context == context &&
+        listener->aio_context == aio_context) {
+        return;
+    }
+
+    qio_net_listener_unwatch(listener, "set_client_func");
+    if (listener->io_notify) {
+        listener->io_notify(listener->io_data);
+    }
+    listener->io_func = func;
+    listener->io_data = data;
+    listener->io_notify = notify;
+    listener->context = context;
+    listener->aio_context = aio_context;
+
+    qio_net_listener_watch(listener, 0, "set_client_func");
+}
+
+void qio_net_listener_set_client_func_full(QIONetListener *listener,
+                                           QIONetListenerClientFunc func,
+                                           gpointer data,
+                                           GDestroyNotify notify,
+                                           GMainContext *context)
+{
+    qio_net_listener_set_client_func_internal(listener, func, data,
+                                              notify, context, NULL);
+}
+
+void qio_net_listener_set_client_func(QIONetListener *listener,
+                                      QIONetListenerClientFunc func,
+                                      gpointer data,
+                                      GDestroyNotify notify)
+{
+    qio_net_listener_set_client_func_internal(listener, func, data,
+                                              notify, NULL, NULL);
+}
+
+void qio_net_listener_set_client_aio_func(QIONetListener *listener,
+                                          QIONetListenerClientFunc func,
+                                          void *data,
+                                          AioContext *context)
+{
+    if (!context) {
+        assert(qemu_in_main_thread());
+        context = qemu_get_aio_context();
+    } else {
+        /*
+         * TODO: The API was intentionally designed to allow a caller
+         * to pass an alternative AioContext for future expansion;
+         * however, actually implementating that is not possible
+         * without notify callbacks wired into AioContext similar to
+         * how they work in GSource.  So for now, this code hard-codes
+         * the knowledge that the only client needing AioContext is
+         * the NBD server, which uses the global context and does not
+         * suffer from cross-thread safety issues.
+         */
+        g_assert_not_reached();
+    }
+    qio_net_listener_set_client_func_internal(listener, func, data,
+                                              NULL, NULL, context);
+}
+
+struct QIONetListenerClientWaitData {
+    QIOChannelSocket *sioc;
+    GMainLoop *loop;
+};
+
+
+static gboolean qio_net_listener_wait_client_func(QIOChannel *ioc,
+                                                  GIOCondition condition,
+                                                  gpointer opaque)
+{
+    struct QIONetListenerClientWaitData *data = opaque;
+    QIOChannelSocket *sioc;
+
+    sioc = qio_channel_socket_accept(QIO_CHANNEL_SOCKET(ioc),
+                                     NULL);
+    if (!sioc) {
+        return TRUE;
+    }
+
+    if (data->sioc) {
+        object_unref(OBJECT(sioc));
+    } else {
+        data->sioc = sioc;
+        g_main_loop_quit(data->loop);
+    }
+
+    return TRUE;
+}
+
+QIOChannelSocket *qio_net_listener_wait_client(QIONetListener *listener)
+{
+    GMainContext *ctxt = g_main_context_new();
+    GMainLoop *loop = g_main_loop_new(ctxt, TRUE);
+    GSource **sources;
+    struct QIONetListenerClientWaitData data = {
+        .sioc = NULL,
+        .loop = loop
+    };
+    size_t i;
+
+    WITH_QEMU_LOCK_GUARD(&listener->lock) {
+        qio_net_listener_unwatch(listener, "wait_client");
+    }
+
+    sources = g_new0(GSource *, listener->nsioc);
+    for (i = 0; i < listener->nsioc; i++) {
+        sources[i] = qio_channel_create_watch(
+            QIO_CHANNEL(listener->source[i]->sioc), G_IO_IN);
+
+        g_source_set_callback(sources[i],
+                              (GSourceFunc)qio_net_listener_wait_client_func,
+                              &data,
+                              NULL);
+        g_source_attach(sources[i], ctxt);
+    }
+
+    g_main_loop_run(loop);
+
+    for (i = 0; i < listener->nsioc; i++) {
+        g_source_unref(sources[i]);
+    }
+    g_free(sources);
+    g_main_loop_unref(loop);
+    g_main_context_unref(ctxt);
+
+    WITH_QEMU_LOCK_GUARD(&listener->lock) {
+        qio_net_listener_watch(listener, 0, "wait_client");
+    }
+
+    return data.sioc;
+}
+
+void qio_net_listener_disconnect(QIONetListener *listener)
+{
+    size_t i;
+
+    if (!listener->connected) {
+        return;
+    }
+
+    QEMU_LOCK_GUARD(&listener->lock);
+    qio_net_listener_unwatch(listener, "disconnect");
+    for (i = 0; i < listener->nsioc; i++) {
+        qio_channel_close(QIO_CHANNEL(listener->source[i]->sioc), NULL);
+    }
+    listener->connected = false;
+}
+
+
+bool qio_net_listener_is_connected(QIONetListener *listener)
+{
+    return listener->connected;
+}
+
+size_t qio_net_listener_nsioc(QIONetListener *listener)
+{
+    return listener->nsioc;
+}
+
+QIOChannelSocket *qio_net_listener_sioc(QIONetListener *listener, size_t n)
+{
+    if (n >= listener->nsioc) {
+        return NULL;
+    }
+    return listener->source[n]->sioc;
+}
+
+SocketAddress *
+qio_net_listener_get_local_address(QIONetListener *listener, size_t n,
+                                   Error **errp)
+{
+    QIOChannelSocket *sioc = qio_net_listener_sioc(listener, n);
+
+    if (!sioc) {
+        error_setg(errp, "Listener index out of range");
+        return NULL;
+    }
+
+    return qio_channel_socket_get_local_address(sioc, errp);
+}
+
+static void qio_net_listener_instance_init(Object *obj)
+{
+    QIONetListener *listener = QIO_NET_LISTENER(obj);
+
+    qemu_mutex_init(&listener->lock);
+}
+
+static void qio_net_listener_finalize(Object *obj)
+{
+    QIONetListener *listener = QIO_NET_LISTENER(obj);
+    size_t i;
+
+    qio_net_listener_disconnect(listener);
+    if (listener->io_notify) {
+        listener->io_notify(listener->io_data);
+    }
+
+    for (i = 0; i < listener->nsioc; i++) {
+        object_unref(OBJECT(listener->source[i]->sioc));
+        g_free(listener->source[i]);
+    }
+    g_free(listener->source);
+    g_free(listener->name);
+    qemu_mutex_destroy(&listener->lock);
+}
+
+static const TypeInfo qio_net_listener_info = {
+    .parent = TYPE_OBJECT,
+    .name = TYPE_QIO_NET_LISTENER,
+    .instance_size = sizeof(QIONetListener),
+    .instance_init = qio_net_listener_instance_init,
+    .instance_finalize = qio_net_listener_finalize,
+};
+
+
+static void qio_net_listener_register_types(void)
+{
+    type_register_static(&qio_net_listener_info);
+}
+
+
+type_init(qio_net_listener_register_types);

io/task.c

@@ -0,0 +1,243 @@
+/*
+ * QEMU I/O task
+ *
+ * Copyright (c) 2015 Red Hat, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include "qemu/osdep.h"
+#include "io/task.h"
+#include "qapi/error.h"
+#include "qemu/thread.h"
+#include "qom/object.h"
+#include "trace.h"
+
+struct QIOTaskThreadData {
+    QIOTaskWorker worker;
+    gpointer opaque;
+    GDestroyNotify destroy;
+    GMainContext *context;
+    GSource *completion;
+};
+
+
+struct QIOTask {
+    Object *source;
+    QIOTaskFunc func;
+    gpointer opaque;
+    GDestroyNotify destroy;
+    Error *err;
+    gpointer result;
+    GDestroyNotify destroyResult;
+    QemuMutex thread_lock;
+    QemuCond thread_cond;
+    struct QIOTaskThreadData *thread;
+};
+
+
+QIOTask *qio_task_new(Object *source,
+                      QIOTaskFunc func,
+                      gpointer opaque,
+                      GDestroyNotify destroy)
+{
+    QIOTask *task;
+
+    task = g_new0(QIOTask, 1);
+
+    task->source = source;
+    object_ref(source);
+    task->func = func;
+    task->opaque = opaque;
+    task->destroy = destroy;
+    qemu_mutex_init(&task->thread_lock);
+    qemu_cond_init(&task->thread_cond);
+
+    trace_qio_task_new(task, source, func, opaque);
+
+    return task;
+}
+
+void qio_task_free(QIOTask *task)
+{
+    if (!task) {
+        return;
+    }
+
+    qemu_mutex_lock(&task->thread_lock);
+    if (task->thread) {
+        if (task->thread->destroy) {
+            task->thread->destroy(task->thread->opaque);
+        }
+
+        if (task->thread->context) {
+            g_main_context_unref(task->thread->context);
+        }
+
+        g_free(task->thread);
+    }
+
+    if (task->destroy) {
+        task->destroy(task->opaque);
+    }
+    if (task->destroyResult) {
+        task->destroyResult(task->result);
+    }
+    error_free(task->err);
+    object_unref(task->source);
+
+    qemu_mutex_unlock(&task->thread_lock);
+    qemu_mutex_destroy(&task->thread_lock);
+    qemu_cond_destroy(&task->thread_cond);
+
+    g_free(task);
+}
+
+
+static gboolean qio_task_thread_result(gpointer opaque)
+{
+    QIOTask *task = opaque;
+
+    trace_qio_task_thread_result(task);
+    qio_task_complete(task);
+    qio_task_free(task);
+
+    return FALSE;
+}
+
+
+static gpointer qio_task_thread_worker(gpointer opaque)
+{
+    QIOTask *task = opaque;
+
+    trace_qio_task_thread_run(task);
+
+    task->thread->worker(task, task->thread->opaque);
+
+    /* We're running in the background thread, and must only
+     * ever report the task results in the main event loop
+     * thread. So we schedule an idle callback to report
+     * the worker results
+     */
+    trace_qio_task_thread_exit(task);
+
+    qemu_mutex_lock(&task->thread_lock);
+
+    task->thread->completion = g_idle_source_new();
+    g_source_set_callback(task->thread->completion,
+                          qio_task_thread_result, task, NULL);
+    g_source_attach(task->thread->completion,
+                    task->thread->context);
+    g_source_unref(task->thread->completion);
+    trace_qio_task_thread_source_attach(task, task->thread->completion);
+
+    qemu_cond_signal(&task->thread_cond);
+    qemu_mutex_unlock(&task->thread_lock);
+
+    return NULL;
+}
+
+
+void qio_task_run_in_thread(QIOTask *task,
+                            QIOTaskWorker worker,
+                            gpointer opaque,
+                            GDestroyNotify destroy,
+                            GMainContext *context)
+{
+    struct QIOTaskThreadData *data = g_new0(struct QIOTaskThreadData, 1);
+    QemuThread thread;
+
+    if (context) {
+        g_main_context_ref(context);
+    }
+
+    data->worker = worker;
+    data->opaque = opaque;
+    data->destroy = destroy;
+    data->context = context;
+
+    task->thread = data;
+
+    trace_qio_task_thread_start(task, worker, opaque);
+    qemu_thread_create(&thread,
+                       "io-task-worker",
+                       qio_task_thread_worker,
+                       task,
+                       QEMU_THREAD_DETACHED);
+}
+
+
+void qio_task_wait_thread(QIOTask *task)
+{
+    qemu_mutex_lock(&task->thread_lock);
+    g_assert(task->thread != NULL);
+    while (task->thread->completion == NULL) {
+        qemu_cond_wait(&task->thread_cond, &task->thread_lock);
+    }
+
+    trace_qio_task_thread_source_cancel(task, task->thread->completion);
+    g_source_destroy(task->thread->completion);
+    qemu_mutex_unlock(&task->thread_lock);
+
+    qio_task_thread_result(task);
+}
+
+
+void qio_task_complete(QIOTask *task)
+{
+    task->func(task, task->opaque);
+    trace_qio_task_complete(task);
+}
+
+
+void qio_task_set_error(QIOTask *task,
+                        Error *err)
+{
+    error_propagate(&task->err, err);
+}
+
+
+bool qio_task_propagate_error(QIOTask *task,
+                              Error **errp)
+{
+    if (task->err) {
+        error_propagate(errp, task->err);
+        task->err = NULL;
+        return true;
+    }
+
+    return false;
+}
+
+
+void qio_task_set_result_pointer(QIOTask *task,
+                                 gpointer result,
+                                 GDestroyNotify destroy)
+{
+    task->result = result;
+    task->destroyResult = destroy;
+}
+
+
+gpointer qio_task_get_result_pointer(QIOTask *task)
+{
+    return task->result;
+}
+
+
+Object *qio_task_get_source(QIOTask *task)
+{
+    return task->source;
+}

io/trace-events

@@ -0,0 +1,79 @@
+# See docs/devel/tracing.rst for syntax documentation.
+
+# task.c
+qio_task_new(void *task, void *source, void *func, void *opaque) "Task new task=%p source=%p func=%p opaque=%p"
+qio_task_complete(void *task) "Task complete task=%p"
+qio_task_thread_start(void *task, void *worker, void *opaque) "Task thread start task=%p worker=%p opaque=%p"
+qio_task_thread_run(void *task) "Task thread run task=%p"
+qio_task_thread_exit(void *task) "Task thread exit task=%p"
+qio_task_thread_result(void *task) "Task thread result task=%p"
+qio_task_thread_source_attach(void *task, void *source) "Task thread source attach task=%p source=%p"
+qio_task_thread_source_cancel(void *task, void *source) "Task thread source cancel task=%p source=%p"
+
+# channel-null.c
+qio_channel_null_new(void *ioc) "Null new ioc=%p"
+
+# channel-socket.c
+qio_channel_socket_new(void *ioc) "Socket new ioc=%p"
+qio_channel_socket_new_fd(void *ioc, int fd) "Socket new ioc=%p fd=%d"
+qio_channel_socket_connect_sync(void *ioc, void *addr) "Socket connect sync ioc=%p addr=%p"
+qio_channel_socket_connect_async(void *ioc, void *addr) "Socket connect async ioc=%p addr=%p"
+qio_channel_socket_connect_fail(void *ioc) "Socket connect fail ioc=%p"
+qio_channel_socket_connect_complete(void *ioc, int fd) "Socket connect complete ioc=%p fd=%d"
+qio_channel_socket_listen_sync(void *ioc, void *addr, int num) "Socket listen sync ioc=%p addr=%p num=%d"
+qio_channel_socket_listen_async(void *ioc, void *addr, int num) "Socket listen async ioc=%p addr=%p num=%d"
+qio_channel_socket_listen_fail(void *ioc) "Socket listen fail ioc=%p"
+qio_channel_socket_listen_complete(void *ioc, int fd) "Socket listen complete ioc=%p fd=%d"
+qio_channel_socket_dgram_sync(void *ioc, void *localAddr, void *remoteAddr) "Socket dgram sync ioc=%p localAddr=%p remoteAddr=%p"
+qio_channel_socket_dgram_async(void *ioc, void *localAddr, void *remoteAddr) "Socket dgram async ioc=%p localAddr=%p remoteAddr=%p"
+qio_channel_socket_dgram_fail(void *ioc) "Socket dgram fail ioc=%p"
+qio_channel_socket_dgram_complete(void *ioc, int fd) "Socket dgram complete ioc=%p fd=%d"
+qio_channel_socket_accept(void *ioc) "Socket accept start ioc=%p"
+qio_channel_socket_accept_fail(void *ioc) "Socket accept fail ioc=%p"
+qio_channel_socket_accept_complete(void *ioc, void *cioc, int fd) "Socket accept complete ioc=%p cioc=%p fd=%d"
+
+# channel-file.c
+qio_channel_file_new_fd(void *ioc, int fd) "File new fd ioc=%p fd=%d"
+qio_channel_file_new_path(void *ioc, const char *path, int flags, int mode, int fd) "File new fd ioc=%p path=%s flags=%d mode=%d fd=%d"
+
+# channel-tls.c
+qio_channel_tls_new_client(void *ioc, void *master, void *creds, const char *hostname) "TLS new client ioc=%p master=%p creds=%p hostname=%s"
+qio_channel_tls_new_server(void *ioc, void *master, void *creds, const char *aclname) "TLS new client ioc=%p master=%p creds=%p acltname=%s"
+qio_channel_tls_handshake_start(void *ioc) "TLS handshake start ioc=%p"
+qio_channel_tls_handshake_pending(void *ioc, int status) "TLS handshake pending ioc=%p status=%d"
+qio_channel_tls_handshake_fail(void *ioc) "TLS handshake fail ioc=%p"
+qio_channel_tls_handshake_complete(void *ioc) "TLS handshake complete ioc=%p"
+qio_channel_tls_handshake_cancel(void *ioc) "TLS handshake cancel ioc=%p"
+qio_channel_tls_bye_start(void *ioc) "TLS termination start ioc=%p"
+qio_channel_tls_bye_pending(void *ioc, int status) "TLS termination pending ioc=%p status=%d"
+qio_channel_tls_bye_fail(void *ioc) "TLS termination fail ioc=%p"
+qio_channel_tls_bye_complete(void *ioc) "TLS termination complete ioc=%p"
+qio_channel_tls_bye_cancel(void *ioc) "TLS termination cancel ioc=%p"
+qio_channel_tls_credentials_allow(void *ioc) "TLS credentials allow ioc=%p"
+qio_channel_tls_credentials_deny(void *ioc) "TLS credentials deny ioc=%p"
+
+# channel-websock.c
+qio_channel_websock_new_server(void *ioc, void *master) "Websock new client ioc=%p master=%p"
+qio_channel_websock_handshake_start(void *ioc) "Websock handshake start ioc=%p"
+qio_channel_websock_handshake_pending(void *ioc, int status) "Websock handshake pending ioc=%p status=%d"
+qio_channel_websock_handshake_reply(void *ioc) "Websock handshake reply ioc=%p"
+qio_channel_websock_handshake_fail(void *ioc, const char *msg) "Websock handshake fail ioc=%p err=%s"
+qio_channel_websock_handshake_complete(void *ioc) "Websock handshake complete ioc=%p"
+qio_channel_websock_http_greeting(void *ioc, const char *greeting) "Websocket HTTP request ioc=%p greeting='%s'"
+qio_channel_websock_http_request(void *ioc, const char *protocols, const char *version, const char *host, const char *connection, const char *upgrade, const char *key) "Websocket HTTP request ioc=%p protocols='%s' version='%s' host='%s' connection='%s' upgrade='%s' key='%s'"
+qio_channel_websock_header_partial_decode(void *ioc, size_t payloadlen, unsigned char fin, unsigned char opcode, unsigned char has_mask) "Websocket header decoded ioc=%p payload-len=%zu fin=0x%x opcode=0x%x has_mask=0x%x"
+qio_channel_websock_header_full_decode(void *ioc, size_t headerlen, size_t payloadlen, uint32_t mask) "Websocket header decoded ioc=%p header-len=%zu payload-len=%zu mask=0x%x"
+qio_channel_websock_payload_decode(void *ioc, uint8_t opcode, size_t payload_remain) "Websocket header decoded ioc=%p opcode=0x%x payload-remain=%zu"
+qio_channel_websock_encode(void *ioc, uint8_t opcode, size_t payloadlen, size_t headerlen) "Websocket encoded ioc=%p opcode=0x%x header-len=%zu payload-len=%zu"
+qio_channel_websock_close(void *ioc) "Websocket close ioc=%p"
+
+# channel-command.c
+qio_channel_command_new_pid(void *ioc, int writefd, int readfd, int pid) "Command new pid ioc=%p writefd=%d readfd=%d pid=%d"
+qio_channel_command_new_spawn(void *ioc, const char *binary, int flags) "Command new spawn ioc=%p binary=%s flags=%d"
+qio_channel_command_abort(void *ioc, int pid) "Command abort ioc=%p pid=%d"
+qio_channel_command_wait(void *ioc, int pid, int ret, int status) "Command abort ioc=%p pid=%d ret=%d status=%d"
+
+# net-listener.c
+qio_net_listener_watch(void *listener, void *func, void *gctx, void *actx, const char *extra) "Net listener=%p watch enabled func=%p ctx=%p/%p by %s"
+qio_net_listener_unwatch(void *listener, void *func, void *gctx, void *actx, const char *extra) "Net listener=%p watch disabled func=%p ctx=%p/%p by %s"
+qio_net_listener_callback(void *listener, void *func, void *gctx, void *actx) "Net listener=%p callback forwarding to func=%p ctx=%p/%p"

io/trace.h

@@ -0,0 +1 @@
+#include "trace/trace-io.h"