1 files changed, 162 insertions, 0 deletions
diff --git a/hw/vfio-user/proxy.c b/hw/vfio-user/proxy.c
new file mode 100644
index 0000000000..bb436c9db9
--- /dev/null
+++ b/hw/vfio-user/proxy.c
@@ -0,0 +1,162 @@
+/*
+ * vfio protocol over a UNIX socket.
+ *
+ * Copyright © 2018, 2021 Oracle and/or its affiliates.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "qemu/osdep.h"
+#include <sys/ioctl.h>
+
+#include "hw/vfio/vfio-device.h"
+#include "hw/vfio-user/proxy.h"
+#include "qapi/error.h"
+#include "qemu/error-report.h"
+#include "qemu/lockable.h"
+#include "system/iothread.h"
+
+static IOThread *vfio_user_iothread;
+
+static void vfio_user_shutdown(VFIOUserProxy *proxy);
+
+
+/*
+ * Functions called by main, CPU, or iothread threads
+ */
+
+static void vfio_user_shutdown(VFIOUserProxy *proxy)
+{
+    qio_channel_shutdown(proxy->ioc, QIO_CHANNEL_SHUTDOWN_READ, NULL);
+    qio_channel_set_aio_fd_handler(proxy->ioc, proxy->ctx, NULL,
+                                   proxy->ctx, NULL, NULL);
+}
+
+/*
+ * Functions only called by iothread
+ */
+
+static void vfio_user_cb(void *opaque)
+{
+    VFIOUserProxy *proxy = opaque;
+
+    QEMU_LOCK_GUARD(&proxy->lock);
+
+    proxy->state = VFIO_PROXY_CLOSED;
+    qemu_cond_signal(&proxy->close_cv);
+}
+
+
+/*
+ * Functions called by main or CPU threads
+ */
+
+static QLIST_HEAD(, VFIOUserProxy) vfio_user_sockets =
+    QLIST_HEAD_INITIALIZER(vfio_user_sockets);
+
+VFIOUserProxy *vfio_user_connect_dev(SocketAddress *addr, Error **errp)
+{
+    VFIOUserProxy *proxy;
+    QIOChannelSocket *sioc;
+    QIOChannel *ioc;
+    char *sockname;
+
+    if (addr->type != SOCKET_ADDRESS_TYPE_UNIX) {
+        error_setg(errp, "vfio_user_connect - bad address family");
+        return NULL;
+    }
+    sockname = addr->u.q_unix.path;
+
+    sioc = qio_channel_socket_new();
+    ioc = QIO_CHANNEL(sioc);
+    if (qio_channel_socket_connect_sync(sioc, addr, errp)) {
+        object_unref(OBJECT(ioc));
+        return NULL;
+    }
+    qio_channel_set_blocking(ioc, false, NULL);
+
+    proxy = g_malloc0(sizeof(VFIOUserProxy));
+    proxy->sockname = g_strdup_printf("unix:%s", sockname);
+    proxy->ioc = ioc;
+    proxy->flags = VFIO_PROXY_CLIENT;
+    proxy->state = VFIO_PROXY_CONNECTED;
+
+    qemu_mutex_init(&proxy->lock);
+    qemu_cond_init(&proxy->close_cv);
+
+    if (vfio_user_iothread == NULL) {
+        vfio_user_iothread = iothread_create("VFIO user", errp);
+    }
+
+    proxy->ctx = iothread_get_aio_context(vfio_user_iothread);
+
+    QTAILQ_INIT(&proxy->outgoing);
+    QTAILQ_INIT(&proxy->incoming);
+    QTAILQ_INIT(&proxy->free);
+    QTAILQ_INIT(&proxy->pending);
+    QLIST_INSERT_HEAD(&vfio_user_sockets, proxy, next);
+
+    return proxy;
+}
+
+void vfio_user_disconnect(VFIOUserProxy *proxy)
+{
+    VFIOUserMsg *r1, *r2;
+
+    qemu_mutex_lock(&proxy->lock);
+
+    /* our side is quitting */
+    if (proxy->state == VFIO_PROXY_CONNECTED) {
+        vfio_user_shutdown(proxy);
+        if (!QTAILQ_EMPTY(&proxy->pending)) {
+            error_printf("vfio_user_disconnect: outstanding requests\n");
+        }
+    }
+    object_unref(OBJECT(proxy->ioc));
+    proxy->ioc = NULL;
+
+    proxy->state = VFIO_PROXY_CLOSING;
+    QTAILQ_FOREACH_SAFE(r1, &proxy->outgoing, next, r2) {
+        qemu_cond_destroy(&r1->cv);
+        QTAILQ_REMOVE(&proxy->outgoing, r1, next);
+        g_free(r1);
+    }
+    QTAILQ_FOREACH_SAFE(r1, &proxy->incoming, next, r2) {
+        qemu_cond_destroy(&r1->cv);
+        QTAILQ_REMOVE(&proxy->incoming, r1, next);
+        g_free(r1);
+    }
+    QTAILQ_FOREACH_SAFE(r1, &proxy->pending, next, r2) {
+        qemu_cond_destroy(&r1->cv);
+        QTAILQ_REMOVE(&proxy->pending, r1, next);
+        g_free(r1);
+    }
+    QTAILQ_FOREACH_SAFE(r1, &proxy->free, next, r2) {
+        qemu_cond_destroy(&r1->cv);
+        QTAILQ_REMOVE(&proxy->free, r1, next);
+        g_free(r1);
+    }
+
+    /*
+     * Make sure the iothread isn't blocking anywhere
+     * with a ref to this proxy by waiting for a BH
+     * handler to run after the proxy fd handlers were
+     * deleted above.
+     */
+    aio_bh_schedule_oneshot(proxy->ctx, vfio_user_cb, proxy);
+    qemu_cond_wait(&proxy->close_cv, &proxy->lock);
+
+    /* we now hold the only ref to proxy */
+    qemu_mutex_unlock(&proxy->lock);
+    qemu_cond_destroy(&proxy->close_cv);
+    qemu_mutex_destroy(&proxy->lock);
+
+    QLIST_REMOVE(proxy, next);
+    if (QLIST_EMPTY(&vfio_user_sockets)) {
+        iothread_destroy(vfio_user_iothread);
+        vfio_user_iothread = NULL;
+    }
+
+    g_free(proxy->sockname);
+    g_free(proxy);
+}