main-loop: create main-loop.c

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

11 files changed, 523 insertions, 454 deletions

diff --git a/Makefile.objs b/Makefile.objs
index 9e2077833e..01587c8f8f 100644
--- a/Makefile.objs
+++ b/Makefile.objs
@@ -81,7 +81,7 @@ common-obj-y += $(oslib-obj-y)
 common-obj-$(CONFIG_WIN32) += os-win32.o
 common-obj-$(CONFIG_POSIX) += os-posix.o
 
-common-obj-y += tcg-runtime.o host-utils.o
+common-obj-y += tcg-runtime.o host-utils.o main-loop.o
 common-obj-y += irq.o input.o
 common-obj-$(CONFIG_PTIMER) += ptimer.o
 common-obj-$(CONFIG_MAX7310) += max7310.o
diff --git a/cpus.c b/cpus.c
index 64237b4255..b9f1573f87 100644
--- a/cpus.c
+++ b/cpus.c
@@ -542,143 +542,10 @@ static void qemu_kvm_eat_signals(CPUState *env)
 #endif /* !CONFIG_LINUX */
 
 #ifndef _WIN32
-static int io_thread_fd = -1;
-
-static void qemu_event_increment(void)
-{
-    /* Write 8 bytes to be compatible with eventfd.  */
-    static const uint64_t val = 1;
-    ssize_t ret;
-
-    if (io_thread_fd == -1) {
-        return;
-    }
-    do {
-        ret = write(io_thread_fd, &val, sizeof(val));
-    } while (ret < 0 && errno == EINTR);
-
-    /* EAGAIN is fine, a read must be pending.  */
-    if (ret < 0 && errno != EAGAIN) {
-        fprintf(stderr, "qemu_event_increment: write() failed: %s\n",
-                strerror(errno));
-        exit (1);
-    }
-}
-
-static void qemu_event_read(void *opaque)
-{
-    int fd = (intptr_t)opaque;
-    ssize_t len;
-    char buffer[512];
-
-    /* Drain the notify pipe.  For eventfd, only 8 bytes will be read.  */
-    do {
-        len = read(fd, buffer, sizeof(buffer));
-    } while ((len == -1 && errno == EINTR) || len == sizeof(buffer));
-}
-
-static int qemu_event_init(void)
-{
-    int err;
-    int fds[2];
-
-    err = qemu_eventfd(fds);
-    if (err == -1) {
-        return -errno;
-    }
-    err = fcntl_setfl(fds[0], O_NONBLOCK);
-    if (err < 0) {
-        goto fail;
-    }
-    err = fcntl_setfl(fds[1], O_NONBLOCK);
-    if (err < 0) {
-        goto fail;
-    }
-    qemu_set_fd_handler2(fds[0], NULL, qemu_event_read, NULL,
-                         (void *)(intptr_t)fds[0]);
-
-    io_thread_fd = fds[1];
-    return 0;
-
-fail:
-    close(fds[0]);
-    close(fds[1]);
-    return err;
-}
-
 static void dummy_signal(int sig)
 {
 }
 
-/* If we have signalfd, we mask out the signals we want to handle and then
- * use signalfd to listen for them.  We rely on whatever the current signal
- * handler is to dispatch the signals when we receive them.
- */
-static void sigfd_handler(void *opaque)
-{
-    int fd = (intptr_t)opaque;
-    struct qemu_signalfd_siginfo info;
-    struct sigaction action;
-    ssize_t len;
-
-    while (1) {
-        do {
-            len = read(fd, &info, sizeof(info));
-        } while (len == -1 && errno == EINTR);
-
-        if (len == -1 && errno == EAGAIN) {
-            break;
-        }
-
-        if (len != sizeof(info)) {
-            printf("read from sigfd returned %zd: %m\n", len);
-            return;
-        }
-
-        sigaction(info.ssi_signo, NULL, &action);
-        if ((action.sa_flags & SA_SIGINFO) && action.sa_sigaction) {
-            action.sa_sigaction(info.ssi_signo,
-                                (siginfo_t *)&info, NULL);
-        } else if (action.sa_handler) {
-            action.sa_handler(info.ssi_signo);
-        }
-    }
-}
-
-static int qemu_signal_init(void)
-{
-    int sigfd;
-    sigset_t set;
-
-    /*
-     * SIG_IPI must be blocked in the main thread and must not be caught
-     * by sigwait() in the signal thread. Otherwise, the cpu thread will
-     * not catch it reliably.
-     */
-    sigemptyset(&set);
-    sigaddset(&set, SIG_IPI);
-    pthread_sigmask(SIG_BLOCK, &set, NULL);
-
-    sigemptyset(&set);
-    sigaddset(&set, SIGIO);
-    sigaddset(&set, SIGALRM);
-    sigaddset(&set, SIGBUS);
-    pthread_sigmask(SIG_BLOCK, &set, NULL);
-
-    sigfd = qemu_signalfd(&set);
-    if (sigfd == -1) {
-        fprintf(stderr, "failed to create signalfd\n");
-        return -errno;
-    }
-
-    fcntl_setfl(sigfd, O_NONBLOCK);
-
-    qemu_set_fd_handler2(sigfd, NULL, sigfd_handler, NULL,
-                         (void *)(intptr_t)sigfd);
-
-    return 0;
-}
-
 static void qemu_kvm_init_cpu_signals(CPUState *env)
 {
     int r;
@@ -722,38 +589,6 @@ static void qemu_tcg_init_cpu_signals(void)
 }
 
 #else /* _WIN32 */
-
-HANDLE qemu_event_handle;
-
-static void dummy_event_handler(void *opaque)
-{
-}
-
-static int qemu_event_init(void)
-{
-    qemu_event_handle = CreateEvent(NULL, FALSE, FALSE, NULL);
-    if (!qemu_event_handle) {
-        fprintf(stderr, "Failed CreateEvent: %ld\n", GetLastError());
-        return -1;
-    }
-    qemu_add_wait_object(qemu_event_handle, dummy_event_handler, NULL);
-    return 0;
-}
-
-static void qemu_event_increment(void)
-{
-    if (!SetEvent(qemu_event_handle)) {
-        fprintf(stderr, "qemu_event_increment: SetEvent failed: %ld\n",
-                GetLastError());
-        exit (1);
-    }
-}
-
-static int qemu_signal_init(void)
-{
-    return 0;
-}
-
 static void qemu_kvm_init_cpu_signals(CPUState *env)
 {
     abort();
@@ -779,33 +614,16 @@ static QemuCond qemu_cpu_cond;
 static QemuCond qemu_pause_cond;
 static QemuCond qemu_work_cond;
 
-int qemu_init_main_loop(void)
+void qemu_init_cpu_loop(void)
 {
-    int ret;
-
     qemu_init_sigbus();
-
-    ret = qemu_signal_init();
-    if (ret) {
-        return ret;
-    }
-
-    /* Note eventfd must be drained before signalfd handlers run */
-    ret = qemu_event_init();
-    if (ret) {
-        return ret;
-    }
-
     qemu_cond_init(&qemu_cpu_cond);
     qemu_cond_init(&qemu_pause_cond);
     qemu_cond_init(&qemu_work_cond);
     qemu_cond_init(&qemu_io_proceeded_cond);
     qemu_mutex_init(&qemu_global_mutex);
-    qemu_mutex_lock(&qemu_global_mutex);
 
     qemu_thread_get_self(&io_thread);
-
-    return 0;
 }
 
 void qemu_main_loop_start(void)
@@ -1129,11 +947,6 @@ void qemu_init_vcpu(void *_env)
     }
 }
 
-void qemu_notify_event(void)
-{
-    qemu_event_increment();
-}
-
 void cpu_stop_current(void)
 {
     if (cpu_single_env) {
diff --git a/cpus.h b/cpus.h
index 4ccf986d3f..7422584336 100644
--- a/cpus.h
+++ b/cpus.h
@@ -2,6 +2,7 @@
 #define QEMU_CPUS_H
 
 /* cpus.c */
+void qemu_init_cpu_loop(void);
 void qemu_main_loop_start(void);
 void resume_all_vcpus(void);
 void pause_all_vcpus(void);
diff --git a/main-loop.c b/main-loop.c
new file mode 100644
index 0000000000..bfecdb7769
--- /dev/null
+++ b/main-loop.c
@@ -0,0 +1,495 @@
+/*
+ * QEMU System Emulator
+ *
+ * Copyright (c) 2003-2008 Fabrice Bellard
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+#include "config-host.h"
+#include <unistd.h>
+#include <signal.h>
+#include <time.h>
+#include <errno.h>
+#include <sys/time.h>
+#include <stdbool.h>
+
+#ifdef _WIN32
+#include <windows.h>
+#include <winsock2.h>
+#include <ws2tcpip.h>
+#else
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <net/if.h>
+#include <arpa/inet.h>
+#include <sys/select.h>
+#include <sys/stat.h>
+#include "compatfd.h"
+#endif
+
+#include <glib.h>
+
+#include "main-loop.h"
+#include "qemu-timer.h"
+#include "slirp/libslirp.h"
+
+#ifndef _WIN32
+
+static int io_thread_fd = -1;
+
+void qemu_notify_event(void)
+{
+    /* Write 8 bytes to be compatible with eventfd.  */
+    static const uint64_t val = 1;
+    ssize_t ret;
+
+    if (io_thread_fd == -1) {
+        return;
+    }
+    do {
+        ret = write(io_thread_fd, &val, sizeof(val));
+    } while (ret < 0 && errno == EINTR);
+
+    /* EAGAIN is fine, a read must be pending.  */
+    if (ret < 0 && errno != EAGAIN) {
+        fprintf(stderr, "qemu_notify_event: write() failed: %s\n",
+                strerror(errno));
+        exit(1);
+    }
+}
+
+static void qemu_event_read(void *opaque)
+{
+    int fd = (intptr_t)opaque;
+    ssize_t len;
+    char buffer[512];
+
+    /* Drain the notify pipe.  For eventfd, only 8 bytes will be read.  */
+    do {
+        len = read(fd, buffer, sizeof(buffer));
+    } while ((len == -1 && errno == EINTR) || len == sizeof(buffer));
+}
+
+static int qemu_event_init(void)
+{
+    int err;
+    int fds[2];
+
+    err = qemu_eventfd(fds);
+    if (err == -1) {
+        return -errno;
+    }
+    err = fcntl_setfl(fds[0], O_NONBLOCK);
+    if (err < 0) {
+        goto fail;
+    }
+    err = fcntl_setfl(fds[1], O_NONBLOCK);
+    if (err < 0) {
+        goto fail;
+    }
+    qemu_set_fd_handler2(fds[0], NULL, qemu_event_read, NULL,
+                         (void *)(intptr_t)fds[0]);
+
+    io_thread_fd = fds[1];
+    return 0;
+
+fail:
+    close(fds[0]);
+    close(fds[1]);
+    return err;
+}
+
+/* If we have signalfd, we mask out the signals we want to handle and then
+ * use signalfd to listen for them.  We rely on whatever the current signal
+ * handler is to dispatch the signals when we receive them.
+ */
+static void sigfd_handler(void *opaque)
+{
+    int fd = (intptr_t)opaque;
+    struct qemu_signalfd_siginfo info;
+    struct sigaction action;
+    ssize_t len;
+
+    while (1) {
+        do {
+            len = read(fd, &info, sizeof(info));
+        } while (len == -1 && errno == EINTR);
+
+        if (len == -1 && errno == EAGAIN) {
+            break;
+        }
+
+        if (len != sizeof(info)) {
+            printf("read from sigfd returned %zd: %m\n", len);
+            return;
+        }
+
+        sigaction(info.ssi_signo, NULL, &action);
+        if ((action.sa_flags & SA_SIGINFO) && action.sa_sigaction) {
+            action.sa_sigaction(info.ssi_signo,
+                                (siginfo_t *)&info, NULL);
+        } else if (action.sa_handler) {
+            action.sa_handler(info.ssi_signo);
+        }
+    }
+}
+
+static int qemu_signal_init(void)
+{
+    int sigfd;
+    sigset_t set;
+
+    /*
+     * SIG_IPI must be blocked in the main thread and must not be caught
+     * by sigwait() in the signal thread. Otherwise, the cpu thread will
+     * not catch it reliably.
+     */
+    sigemptyset(&set);
+    sigaddset(&set, SIG_IPI);
+    pthread_sigmask(SIG_BLOCK, &set, NULL);
+
+    sigemptyset(&set);
+    sigaddset(&set, SIGIO);
+    sigaddset(&set, SIGALRM);
+    sigaddset(&set, SIGBUS);
+    pthread_sigmask(SIG_BLOCK, &set, NULL);
+
+    sigfd = qemu_signalfd(&set);
+    if (sigfd == -1) {
+        fprintf(stderr, "failed to create signalfd\n");
+        return -errno;
+    }
+
+    fcntl_setfl(sigfd, O_NONBLOCK);
+
+    qemu_set_fd_handler2(sigfd, NULL, sigfd_handler, NULL,
+                         (void *)(intptr_t)sigfd);
+
+    return 0;
+}
+
+#else /* _WIN32 */
+
+HANDLE qemu_event_handle;
+
+static void dummy_event_handler(void *opaque)
+{
+}
+
+static int qemu_event_init(void)
+{
+    qemu_event_handle = CreateEvent(NULL, FALSE, FALSE, NULL);
+    if (!qemu_event_handle) {
+        fprintf(stderr, "Failed CreateEvent: %ld\n", GetLastError());
+        return -1;
+    }
+    qemu_add_wait_object(qemu_event_handle, dummy_event_handler, NULL);
+    return 0;
+}
+
+void qemu_notify_event(void)
+{
+    if (!SetEvent(qemu_event_handle)) {
+        fprintf(stderr, "qemu_notify_event: SetEvent failed: %ld\n",
+                GetLastError());
+        exit(1);
+    }
+}
+
+static int qemu_signal_init(void)
+{
+    return 0;
+}
+#endif
+
+int qemu_init_main_loop(void)
+{
+    int ret;
+
+    qemu_mutex_lock_iothread();
+    ret = qemu_signal_init();
+    if (ret) {
+        return ret;
+    }
+
+    /* Note eventfd must be drained before signalfd handlers run */
+    ret = qemu_event_init();
+    if (ret) {
+        return ret;
+    }
+
+    return 0;
+}
+
+
+static GPollFD poll_fds[1024 * 2]; /* this is probably overkill */
+static int n_poll_fds;
+static int max_priority;
+
+static void glib_select_fill(int *max_fd, fd_set *rfds, fd_set *wfds,
+                             fd_set *xfds, struct timeval *tv)
+{
+    GMainContext *context = g_main_context_default();
+    int i;
+    int timeout = 0, cur_timeout;
+
+    g_main_context_prepare(context, &max_priority);
+
+    n_poll_fds = g_main_context_query(context, max_priority, &timeout,
+                                      poll_fds, ARRAY_SIZE(poll_fds));
+    g_assert(n_poll_fds <= ARRAY_SIZE(poll_fds));
+
+    for (i = 0; i < n_poll_fds; i++) {
+        GPollFD *p = &poll_fds[i];
+
+        if ((p->events & G_IO_IN)) {
+            FD_SET(p->fd, rfds);
+            *max_fd = MAX(*max_fd, p->fd);
+        }
+        if ((p->events & G_IO_OUT)) {
+            FD_SET(p->fd, wfds);
+            *max_fd = MAX(*max_fd, p->fd);
+        }
+        if ((p->events & G_IO_ERR)) {
+            FD_SET(p->fd, xfds);
+            *max_fd = MAX(*max_fd, p->fd);
+        }
+    }
+
+    cur_timeout = (tv->tv_sec * 1000) + ((tv->tv_usec + 500) / 1000);
+    if (timeout >= 0 && timeout < cur_timeout) {
+        tv->tv_sec = timeout / 1000;
+        tv->tv_usec = (timeout % 1000) * 1000;
+    }
+}
+
+static void glib_select_poll(fd_set *rfds, fd_set *wfds, fd_set *xfds,
+                             bool err)
+{
+    GMainContext *context = g_main_context_default();
+
+    if (!err) {
+        int i;
+
+        for (i = 0; i < n_poll_fds; i++) {
+            GPollFD *p = &poll_fds[i];
+
+            if ((p->events & G_IO_IN) && FD_ISSET(p->fd, rfds)) {
+                p->revents |= G_IO_IN;
+            }
+            if ((p->events & G_IO_OUT) && FD_ISSET(p->fd, wfds)) {
+                p->revents |= G_IO_OUT;
+            }
+            if ((p->events & G_IO_ERR) && FD_ISSET(p->fd, xfds)) {
+                p->revents |= G_IO_ERR;
+            }
+        }
+    }
+
+    if (g_main_context_check(context, max_priority, poll_fds, n_poll_fds)) {
+        g_main_context_dispatch(context);
+    }
+}
+
+#ifdef _WIN32
+/***********************************************************/
+/* Polling handling */
+
+typedef struct PollingEntry {
+    PollingFunc *func;
+    void *opaque;
+    struct PollingEntry *next;
+} PollingEntry;
+
+static PollingEntry *first_polling_entry;
+
+int qemu_add_polling_cb(PollingFunc *func, void *opaque)
+{
+    PollingEntry **ppe, *pe;
+    pe = g_malloc0(sizeof(PollingEntry));
+    pe->func = func;
+    pe->opaque = opaque;
+    for(ppe = &first_polling_entry; *ppe != NULL; ppe = &(*ppe)->next);
+    *ppe = pe;
+    return 0;
+}
+
+void qemu_del_polling_cb(PollingFunc *func, void *opaque)
+{
+    PollingEntry **ppe, *pe;
+    for(ppe = &first_polling_entry; *ppe != NULL; ppe = &(*ppe)->next) {
+        pe = *ppe;
+        if (pe->func == func && pe->opaque == opaque) {
+            *ppe = pe->next;
+            g_free(pe);
+            break;
+        }
+    }
+}
+
+/***********************************************************/
+/* Wait objects support */
+typedef struct WaitObjects {
+    int num;
+    HANDLE events[MAXIMUM_WAIT_OBJECTS + 1];
+    WaitObjectFunc *func[MAXIMUM_WAIT_OBJECTS + 1];
+    void *opaque[MAXIMUM_WAIT_OBJECTS + 1];
+} WaitObjects;
+
+static WaitObjects wait_objects = {0};
+
+int qemu_add_wait_object(HANDLE handle, WaitObjectFunc *func, void *opaque)
+{
+    WaitObjects *w = &wait_objects;
+    if (w->num >= MAXIMUM_WAIT_OBJECTS) {
+        return -1;
+    }
+    w->events[w->num] = handle;
+    w->func[w->num] = func;
+    w->opaque[w->num] = opaque;
+    w->num++;
+    return 0;
+}
+
+void qemu_del_wait_object(HANDLE handle, WaitObjectFunc *func, void *opaque)
+{
+    int i, found;
+    WaitObjects *w = &wait_objects;
+
+    found = 0;
+    for (i = 0; i < w->num; i++) {
+        if (w->events[i] == handle) {
+            found = 1;
+        }
+        if (found) {
+            w->events[i] = w->events[i + 1];
+            w->func[i] = w->func[i + 1];
+            w->opaque[i] = w->opaque[i + 1];
+        }
+    }
+    if (found) {
+        w->num--;
+    }
+}
+
+static void os_host_main_loop_wait(int *timeout)
+{
+    int ret, ret2, i;
+    PollingEntry *pe;
+
+    /* XXX: need to suppress polling by better using win32 events */
+    ret = 0;
+    for (pe = first_polling_entry; pe != NULL; pe = pe->next) {
+        ret |= pe->func(pe->opaque);
+    }
+    if (ret == 0) {
+        int err;
+        WaitObjects *w = &wait_objects;
+
+        qemu_mutex_unlock_iothread();
+        ret = WaitForMultipleObjects(w->num, w->events, FALSE, *timeout);
+        qemu_mutex_lock_iothread();
+        if (WAIT_OBJECT_0 + 0 <= ret && ret <= WAIT_OBJECT_0 + w->num - 1) {
+            if (w->func[ret - WAIT_OBJECT_0]) {
+                w->func[ret - WAIT_OBJECT_0](w->opaque[ret - WAIT_OBJECT_0]);
+            }
+
+            /* Check for additional signaled events */
+            for (i = (ret - WAIT_OBJECT_0 + 1); i < w->num; i++) {
+                /* Check if event is signaled */
+                ret2 = WaitForSingleObject(w->events[i], 0);
+                if (ret2 == WAIT_OBJECT_0) {
+                    if (w->func[i]) {
+                        w->func[i](w->opaque[i]);
+                    }
+                } else if (ret2 != WAIT_TIMEOUT) {
+                    err = GetLastError();
+                    fprintf(stderr, "WaitForSingleObject error %d %d\n", i, err);
+                }
+            }
+        } else if (ret != WAIT_TIMEOUT) {
+            err = GetLastError();
+            fprintf(stderr, "WaitForMultipleObjects error %d %d\n", ret, err);
+        }
+    }
+
+    *timeout = 0;
+}
+#else
+static inline void os_host_main_loop_wait(int *timeout)
+{
+}
+#endif
+
+int main_loop_wait(int nonblocking)
+{
+    fd_set rfds, wfds, xfds;
+    int ret, nfds;
+    struct timeval tv;
+    int timeout;
+
+    if (nonblocking) {
+        timeout = 0;
+    } else {
+        timeout = qemu_calculate_timeout();
+        qemu_bh_update_timeout(&timeout);
+    }
+
+    os_host_main_loop_wait(&timeout);
+
+    tv.tv_sec = timeout / 1000;
+    tv.tv_usec = (timeout % 1000) * 1000;
+
+    /* poll any events */
+    /* XXX: separate device handlers from system ones */
+    nfds = -1;
+    FD_ZERO(&rfds);
+    FD_ZERO(&wfds);
+    FD_ZERO(&xfds);
+
+#ifdef CONFIG_SLIRP
+    slirp_select_fill(&nfds, &rfds, &wfds, &xfds);
+#endif
+    qemu_iohandler_fill(&nfds, &rfds, &wfds, &xfds);
+    glib_select_fill(&nfds, &rfds, &wfds, &xfds, &tv);
+
+    if (timeout > 0) {
+        qemu_mutex_unlock_iothread();
+    }
+
+    ret = select(nfds + 1, &rfds, &wfds, &xfds, &tv);
+
+    if (timeout > 0) {
+        qemu_mutex_lock_iothread();
+    }
+
+    glib_select_poll(&rfds, &wfds, &xfds, (ret < 0));
+    qemu_iohandler_poll(&rfds, &wfds, &xfds, ret);
+#ifdef CONFIG_SLIRP
+    slirp_select_poll(&rfds, &wfds, &xfds, (ret < 0));
+#endif
+
+    qemu_run_all_timers();
+
+    /* Check bottom-halves last in case any of the earlier events triggered
+       them.  */
+    qemu_bh_poll();
+
+    return ret;
+}
diff --git a/main-loop.h b/main-loop.h
index a73b9c0bbe..8a716b133f 100644
--- a/main-loop.h
+++ b/main-loop.h
@@ -315,6 +315,30 @@ void qemu_bh_delete(QEMUBH *bh);
 int qemu_add_child_watch(pid_t pid);
 #endif
 
+/**
+ * qemu_mutex_lock_iothread: Lock the main loop mutex.
+ *
+ * This function locks the main loop mutex.  The mutex is taken by
+ * qemu_init_main_loop and always taken except while waiting on
+ * external events (such as with select).  The mutex should be taken
+ * by threads other than the main loop thread when calling
+ * qemu_bh_new(), qemu_set_fd_handler() and basically all other
+ * functions documented in this file.
+ */
+void qemu_mutex_lock_iothread(void);
+
+/**
+ * qemu_mutex_unlock_iothread: Unlock the main loop mutex.
+ *
+ * This function unlocks the main loop mutex.  The mutex is taken by
+ * qemu_init_main_loop and always taken except while waiting on
+ * external events (such as with select).  The mutex should be unlocked
+ * as soon as possible by threads other than the main loop thread,
+ * because it prevents the main loop from processing callbacks,
+ * including timers and bottom halves.
+ */
+void qemu_mutex_unlock_iothread(void);
+
 /* internal interfaces */
 
 void qemu_iohandler_fill(int *pnfds, fd_set *readfds, fd_set *writefds, fd_set *xfds);
diff --git a/os-win32.c b/os-win32.c
index f09f01fc49..79094016f1 100644
--- a/os-win32.c
+++ b/os-win32.c
@@ -48,129 +48,6 @@ int setenv(const char *name, const char *value, int overwrite)
     return result;
 }
 
-/***********************************************************/
-/* Polling handling */
-
-typedef struct PollingEntry {
-    PollingFunc *func;
-    void *opaque;
-    struct PollingEntry *next;
-} PollingEntry;
-
-static PollingEntry *first_polling_entry;
-
-int qemu_add_polling_cb(PollingFunc *func, void *opaque)
-{
-    PollingEntry **ppe, *pe;
-    pe = g_malloc0(sizeof(PollingEntry));
-    pe->func = func;
-    pe->opaque = opaque;
-    for(ppe = &first_polling_entry; *ppe != NULL; ppe = &(*ppe)->next);
-    *ppe = pe;
-    return 0;
-}
-
-void qemu_del_polling_cb(PollingFunc *func, void *opaque)
-{
-    PollingEntry **ppe, *pe;
-    for(ppe = &first_polling_entry; *ppe != NULL; ppe = &(*ppe)->next) {
-        pe = *ppe;
-        if (pe->func == func && pe->opaque == opaque) {
-            *ppe = pe->next;
-            g_free(pe);
-            break;
-        }
-    }
-}
-
-/***********************************************************/
-/* Wait objects support */
-typedef struct WaitObjects {
-    int num;
-    HANDLE events[MAXIMUM_WAIT_OBJECTS + 1];
-    WaitObjectFunc *func[MAXIMUM_WAIT_OBJECTS + 1];
-    void *opaque[MAXIMUM_WAIT_OBJECTS + 1];
-} WaitObjects;
-
-static WaitObjects wait_objects = {0};
-
-int qemu_add_wait_object(HANDLE handle, WaitObjectFunc *func, void *opaque)
-{
-    WaitObjects *w = &wait_objects;
-
-    if (w->num >= MAXIMUM_WAIT_OBJECTS)
-        return -1;
-    w->events[w->num] = handle;
-    w->func[w->num] = func;
-    w->opaque[w->num] = opaque;
-    w->num++;
-    return 0;
-}
-
-void qemu_del_wait_object(HANDLE handle, WaitObjectFunc *func, void *opaque)
-{
-    int i, found;
-    WaitObjects *w = &wait_objects;
-
-    found = 0;
-    for (i = 0; i < w->num; i++) {
-        if (w->events[i] == handle)
-            found = 1;
-        if (found) {
-            w->events[i] = w->events[i + 1];
-            w->func[i] = w->func[i + 1];
-            w->opaque[i] = w->opaque[i + 1];
-        }
-    }
-    if (found)
-        w->num--;
-}
-
-void os_host_main_loop_wait(int *timeout)
-{
-    int ret, ret2, i;
-    PollingEntry *pe;
-
-    /* XXX: need to suppress polling by better using win32 events */
-    ret = 0;
-    for(pe = first_polling_entry; pe != NULL; pe = pe->next) {
-        ret |= pe->func(pe->opaque);
-    }
-    if (ret == 0) {
-        int err;
-        WaitObjects *w = &wait_objects;
-
-        qemu_mutex_unlock_iothread();
-        ret = WaitForMultipleObjects(w->num, w->events, FALSE, *timeout);
-        qemu_mutex_lock_iothread();
-        if (WAIT_OBJECT_0 + 0 <= ret && ret <= WAIT_OBJECT_0 + w->num - 1) {
-            if (w->func[ret - WAIT_OBJECT_0])
-                w->func[ret - WAIT_OBJECT_0](w->opaque[ret - WAIT_OBJECT_0]);
-
-            /* Check for additional signaled events */
-            for(i = (ret - WAIT_OBJECT_0 + 1); i < w->num; i++) {
-
-                /* Check if event is signaled */
-                ret2 = WaitForSingleObject(w->events[i], 0);
-                if(ret2 == WAIT_OBJECT_0) {
-                    if (w->func[i])
-                        w->func[i](w->opaque[i]);
-                } else if (ret2 == WAIT_TIMEOUT) {
-                } else {
-                    err = GetLastError();
-                    fprintf(stderr, "WaitForSingleObject error %d %d\n", i, err);
-                }
-            }
-        } else if (ret == WAIT_TIMEOUT) {
-        } else {
-            err = GetLastError();
-            fprintf(stderr, "WaitForMultipleObjects error %d %d\n", ret, err);
-        }
-    }
-
-    *timeout = 0;
-}
-
 static BOOL WINAPI qemu_ctrl_handler(DWORD type)
 {
     exit(STATUS_CONTROL_C_EXIT);
diff --git a/qemu-common.h b/qemu-common.h
index 5997f58540..1c15cb17a7 100644
--- a/qemu-common.h
+++ b/qemu-common.h
@@ -169,9 +169,6 @@ const char *path(const char *pathname);
 
 void *qemu_oom_check(void *ptr);
 
-void qemu_mutex_lock_iothread(void);
-void qemu_mutex_unlock_iothread(void);
-
 int qemu_open(const char *name, int flags, ...);
 ssize_t qemu_write_full(int fd, const void *buf, size_t count)
     QEMU_WARN_UNUSED_RESULT;
diff --git a/qemu-os-posix.h b/qemu-os-posix.h
index 81fd9ab389..920499d836 100644
--- a/qemu-os-posix.h
+++ b/qemu-os-posix.h
@@ -26,10 +26,6 @@
 #ifndef QEMU_OS_POSIX_H
 #define QEMU_OS_POSIX_H
 
-static inline void os_host_main_loop_wait(int *timeout)
-{
-}
-
 void os_set_line_buffering(void);
 void os_set_proc_name(const char *s);
 void os_setup_signal_handling(void);
diff --git a/qemu-os-win32.h b/qemu-os-win32.h
index 5a9fd5dade..8eda4bdc20 100644
--- a/qemu-os-win32.h
+++ b/qemu-os-win32.h
@@ -33,8 +33,6 @@
 /* Declaration of ffs() is missing in MinGW's strings.h. */
 int ffs(int i);
 
-void os_host_main_loop_wait(int *timeout);
-
 static inline void os_setup_signal_handling(void) {}
 static inline void os_daemonize(void) {}
 static inline void os_setup_post(void) {}
diff --git a/slirp/libslirp.h b/slirp/libslirp.h
index a7551235e2..890fd86c3c 100644
--- a/slirp/libslirp.h
+++ b/slirp/libslirp.h
@@ -3,8 +3,6 @@
 
 #include "qemu-common.h"
 
-#ifdef CONFIG_SLIRP
-
 struct Slirp;
 typedef struct Slirp Slirp;
 
@@ -44,13 +42,4 @@ void slirp_socket_recv(Slirp *slirp, struct in_addr guest_addr,
 size_t slirp_socket_can_recv(Slirp *slirp, struct in_addr guest_addr,
                              int guest_port);
 
-#else /* !CONFIG_SLIRP */
-
-static inline void slirp_select_fill(int *pnfds, fd_set *readfds,
-                                     fd_set *writefds, fd_set *xfds) { }
-
-static inline void slirp_select_poll(fd_set *readfds, fd_set *writefds,
-                                     fd_set *xfds, int select_error) { }
-#endif /* !CONFIG_SLIRP */
-
 #endif
diff --git a/vl.c b/vl.c
index ef0936a325..7914df7b3c 100644
--- a/vl.c
+++ b/vl.c
@@ -1426,128 +1426,6 @@ void qemu_system_vmstop_request(RunState state)
     qemu_notify_event();
 }
 
-static GPollFD poll_fds[1024 * 2]; /* this is probably overkill */
-static int n_poll_fds;
-static int max_priority;
-
-static void glib_select_fill(int *max_fd, fd_set *rfds, fd_set *wfds,
-                             fd_set *xfds, struct timeval *tv)
-{
-    GMainContext *context = g_main_context_default();
-    int i;
-    int timeout = 0, cur_timeout;
-
-    g_main_context_prepare(context, &max_priority);
-
-    n_poll_fds = g_main_context_query(context, max_priority, &timeout,
-                                      poll_fds, ARRAY_SIZE(poll_fds));
-    g_assert(n_poll_fds <= ARRAY_SIZE(poll_fds));
-
-    for (i = 0; i < n_poll_fds; i++) {
-        GPollFD *p = &poll_fds[i];
-
-        if ((p->events & G_IO_IN)) {
-            FD_SET(p->fd, rfds);
-            *max_fd = MAX(*max_fd, p->fd);
-        }
-        if ((p->events & G_IO_OUT)) {
-            FD_SET(p->fd, wfds);
-            *max_fd = MAX(*max_fd, p->fd);
-        }
-        if ((p->events & G_IO_ERR)) {
-            FD_SET(p->fd, xfds);
-            *max_fd = MAX(*max_fd, p->fd);
-        }
-    }
-
-    cur_timeout = (tv->tv_sec * 1000) + ((tv->tv_usec + 500) / 1000);
-    if (timeout >= 0 && timeout < cur_timeout) {
-        tv->tv_sec = timeout / 1000;
-        tv->tv_usec = (timeout % 1000) * 1000;
-    }
-}
-
-static void glib_select_poll(fd_set *rfds, fd_set *wfds, fd_set *xfds,
-                             bool err)
-{
-    GMainContext *context = g_main_context_default();
-
-    if (!err) {
-        int i;
-
-        for (i = 0; i < n_poll_fds; i++) {
-            GPollFD *p = &poll_fds[i];
-
-            if ((p->events & G_IO_IN) && FD_ISSET(p->fd, rfds)) {
-                p->revents |= G_IO_IN;
-            }
-            if ((p->events & G_IO_OUT) && FD_ISSET(p->fd, wfds)) {
-                p->revents |= G_IO_OUT;
-            }
-            if ((p->events & G_IO_ERR) && FD_ISSET(p->fd, xfds)) {
-                p->revents |= G_IO_ERR;
-            }
-        }
-    }
-
-    if (g_main_context_check(context, max_priority, poll_fds, n_poll_fds)) {
-        g_main_context_dispatch(context);
-    }
-}
-
-int main_loop_wait(int nonblocking)
-{
-    fd_set rfds, wfds, xfds;
-    int ret, nfds;
-    struct timeval tv;
-    int timeout;
-
-    if (nonblocking)
-        timeout = 0;
-    else {
-        timeout = qemu_calculate_timeout();
-        qemu_bh_update_timeout(&timeout);
-    }
-
-    os_host_main_loop_wait(&timeout);
-
-    tv.tv_sec = timeout / 1000;
-    tv.tv_usec = (timeout % 1000) * 1000;
-
-    /* poll any events */
-    /* XXX: separate device handlers from system ones */
-    nfds = -1;
-    FD_ZERO(&rfds);
-    FD_ZERO(&wfds);
-    FD_ZERO(&xfds);
-
-    qemu_iohandler_fill(&nfds, &rfds, &wfds, &xfds);
-    slirp_select_fill(&nfds, &rfds, &wfds, &xfds);
-    glib_select_fill(&nfds, &rfds, &wfds, &xfds, &tv);
-
-    if (timeout > 0) {
-        qemu_mutex_unlock_iothread();
-    }
-
-    ret = select(nfds + 1, &rfds, &wfds, &xfds, &tv);
-
-    if (timeout > 0) {
-        qemu_mutex_lock_iothread();
-    }
-
-    qemu_iohandler_poll(&rfds, &wfds, &xfds, ret);
-    slirp_select_poll(&rfds, &wfds, &xfds, (ret < 0));
-    glib_select_poll(&rfds, &wfds, &xfds, (ret < 0));
-
-    qemu_run_all_timers();
-
-    /* Check bottom-halves last in case any of the earlier events triggered
-       them.  */
-    qemu_bh_poll();
-
-    return ret;
-}
-
 qemu_irq qemu_system_powerdown;
 
 static void main_loop(void)
@@ -3300,6 +3178,7 @@ int main(int argc, char **argv, char **envp)
 
     configure_accelerator();
 
+    qemu_init_cpu_loop();
     if (qemu_init_main_loop()) {
         fprintf(stderr, "qemu_init_main_loop failed\n");
         exit(1);