Merge remote-tracking branch 'remotes/kraxel/tags/input-20190513-v2-pull-request' into staging

input: add vhost-user-input, virtio-input fixes.

# gpg: Signature made Mon 13 May 2019 07:52:39 BST
# gpg:                using RSA key 4CB6D8EED3E87138
# gpg: Good signature from "Gerd Hoffmann (work) <kraxel@redhat.com>" [full]
# gpg:                 aka "Gerd Hoffmann <gerd@kraxel.org>" [full]
# gpg:                 aka "Gerd Hoffmann (private) <kraxel@gmail.com>" [full]
# Primary key fingerprint: A032 8CFF B93A 17A7 9901  FE7D 4CB6 D8EE D3E8 7138

* remotes/kraxel/tags/input-20190513-v2-pull-request:
  virtio-input: fix Kconfig dependency and Makefile
  virtio-input-host-pci: cleanup types
  util: simplify unix_listen()
  Add vhost-user-input-pci
  Add vhost-user-backend
  libvhost-user: add PROTOCOL_F_CONFIG if {set, get}_config
  libvhost-user: fix -Waddress-of-packed-member

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

13 files changed, 484 insertions, 28 deletions

diff --git a/MAINTAINERS b/MAINTAINERS
index f25729a06d..a73a61a546 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1485,6 +1485,8 @@ F: hw/*/*vhost*
 F: docs/interop/vhost-user.json
 F: docs/interop/vhost-user.txt
 F: contrib/vhost-user-*/
+F: backends/vhost-user.c
+F: include/sysemu/vhost-user-backend.h
 
 virtio
 M: Michael S. Tsirkin <mst@redhat.com>
@@ -1526,6 +1528,7 @@ L: qemu-s390x@nongnu.org
 virtio-input
 M: Gerd Hoffmann <kraxel@redhat.com>
 S: Maintained
+F: hw/input/vhost-user-input.c
 F: hw/input/virtio-input*.c
 F: include/hw/virtio/virtio-input.h
 
diff --git a/backends/Makefile.objs b/backends/Makefile.objs
index ff619d31b4..981e8e122f 100644
--- a/backends/Makefile.objs
+++ b/backends/Makefile.objs
@@ -14,4 +14,6 @@ common-obj-y += cryptodev-vhost.o
 common-obj-$(CONFIG_VHOST_CRYPTO) += cryptodev-vhost-user.o
 endif
 
+common-obj-$(call land,$(CONFIG_VHOST_USER),$(CONFIG_VIRTIO)) += vhost-user.o
+
 common-obj-$(CONFIG_LINUX) += hostmem-memfd.o
diff --git a/backends/vhost-user.c b/backends/vhost-user.c
new file mode 100644
index 0000000000..2b055544a7
--- /dev/null
+++ b/backends/vhost-user.c
@@ -0,0 +1,209 @@
+/*
+ * QEMU vhost-user backend
+ *
+ * Copyright (C) 2018 Red Hat Inc
+ *
+ * Authors:
+ *  Marc-André Lureau <marcandre.lureau@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+
+#include "qemu/osdep.h"
+#include "hw/qdev.h"
+#include "qapi/error.h"
+#include "qapi/qmp/qerror.h"
+#include "qemu/error-report.h"
+#include "qom/object_interfaces.h"
+#include "sysemu/vhost-user-backend.h"
+#include "sysemu/kvm.h"
+#include "io/channel-command.h"
+#include "hw/virtio/virtio-bus.h"
+
+static bool
+ioeventfd_enabled(void)
+{
+    return kvm_enabled() && kvm_eventfds_enabled();
+}
+
+int
+vhost_user_backend_dev_init(VhostUserBackend *b, VirtIODevice *vdev,
+                            unsigned nvqs, Error **errp)
+{
+    int ret;
+
+    assert(!b->vdev && vdev);
+
+    if (!ioeventfd_enabled()) {
+        error_setg(errp, "vhost initialization failed: requires kvm");
+        return -1;
+    }
+
+    if (!vhost_user_init(&b->vhost_user, &b->chr, errp)) {
+        return -1;
+    }
+
+    b->vdev = vdev;
+    b->dev.nvqs = nvqs;
+    b->dev.vqs = g_new(struct vhost_virtqueue, nvqs);
+
+    ret = vhost_dev_init(&b->dev, &b->vhost_user, VHOST_BACKEND_TYPE_USER, 0);
+    if (ret < 0) {
+        error_setg_errno(errp, -ret, "vhost initialization failed");
+        return -1;
+    }
+
+    return 0;
+}
+
+void
+vhost_user_backend_start(VhostUserBackend *b)
+{
+    BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(b->vdev)));
+    VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
+    int ret, i ;
+
+    if (b->started) {
+        return;
+    }
+
+    if (!k->set_guest_notifiers) {
+        error_report("binding does not support guest notifiers");
+        return;
+    }
+
+    ret = vhost_dev_enable_notifiers(&b->dev, b->vdev);
+    if (ret < 0) {
+        return;
+    }
+
+    ret = k->set_guest_notifiers(qbus->parent, b->dev.nvqs, true);
+    if (ret < 0) {
+        error_report("Error binding guest notifier");
+        goto err_host_notifiers;
+    }
+
+    b->dev.acked_features = b->vdev->guest_features;
+    ret = vhost_dev_start(&b->dev, b->vdev);
+    if (ret < 0) {
+        error_report("Error start vhost dev");
+        goto err_guest_notifiers;
+    }
+
+    /* guest_notifier_mask/pending not used yet, so just unmask
+     * everything here.  virtio-pci will do the right thing by
+     * enabling/disabling irqfd.
+     */
+    for (i = 0; i < b->dev.nvqs; i++) {
+        vhost_virtqueue_mask(&b->dev, b->vdev,
+                             b->dev.vq_index + i, false);
+    }
+
+    b->started = true;
+    return;
+
+err_guest_notifiers:
+    k->set_guest_notifiers(qbus->parent, b->dev.nvqs, false);
+err_host_notifiers:
+    vhost_dev_disable_notifiers(&b->dev, b->vdev);
+}
+
+void
+vhost_user_backend_stop(VhostUserBackend *b)
+{
+    BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(b->vdev)));
+    VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
+    int ret = 0;
+
+    if (!b->started) {
+        return;
+    }
+
+    vhost_dev_stop(&b->dev, b->vdev);
+
+    if (k->set_guest_notifiers) {
+        ret = k->set_guest_notifiers(qbus->parent,
+                                     b->dev.nvqs, false);
+        if (ret < 0) {
+            error_report("vhost guest notifier cleanup failed: %d", ret);
+        }
+    }
+    assert(ret >= 0);
+
+    vhost_dev_disable_notifiers(&b->dev, b->vdev);
+    b->started = false;
+}
+
+static void set_chardev(Object *obj, const char *value, Error **errp)
+{
+    VhostUserBackend *b = VHOST_USER_BACKEND(obj);
+    Chardev *chr;
+
+    if (b->completed) {
+        error_setg(errp, QERR_PERMISSION_DENIED);
+        return;
+    }
+
+    g_free(b->chr_name);
+    b->chr_name = g_strdup(value);
+
+    chr = qemu_chr_find(b->chr_name);
+    if (chr == NULL) {
+        error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND,
+                  "Chardev '%s' not found", b->chr_name);
+        return;
+    }
+
+    if (!qemu_chr_fe_init(&b->chr, chr, errp)) {
+        return;
+    }
+
+    b->completed = true;
+    /* could call vhost_dev_init() so early message can be exchanged */
+}
+
+static char *get_chardev(Object *obj, Error **errp)
+{
+    VhostUserBackend *b = VHOST_USER_BACKEND(obj);
+    Chardev *chr = qemu_chr_fe_get_driver(&b->chr);
+
+    if (chr && chr->label) {
+        return g_strdup(chr->label);
+    }
+
+    return NULL;
+}
+
+static void vhost_user_backend_init(Object *obj)
+{
+    object_property_add_str(obj, "chardev", get_chardev, set_chardev, NULL);
+}
+
+static void vhost_user_backend_finalize(Object *obj)
+{
+    VhostUserBackend *b = VHOST_USER_BACKEND(obj);
+
+    g_free(b->dev.vqs);
+    g_free(b->chr_name);
+
+    vhost_user_cleanup(&b->vhost_user);
+    qemu_chr_fe_deinit(&b->chr, true);
+}
+
+static const TypeInfo vhost_user_backend_info = {
+    .name = TYPE_VHOST_USER_BACKEND,
+    .parent = TYPE_OBJECT,
+    .instance_size = sizeof(VhostUserBackend),
+    .instance_init = vhost_user_backend_init,
+    .instance_finalize = vhost_user_backend_finalize,
+    .class_size = sizeof(VhostUserBackendClass),
+};
+
+static void register_types(void)
+{
+    type_register_static(&vhost_user_backend_info);
+}
+
+type_init(register_types);
diff --git a/contrib/libvhost-user/libvhost-user.c b/contrib/libvhost-user/libvhost-user.c
index e08d6c7b97..74d42177c5 100644
--- a/contrib/libvhost-user/libvhost-user.c
+++ b/contrib/libvhost-user/libvhost-user.c
@@ -542,7 +542,7 @@ static bool
 vu_set_mem_table_exec_postcopy(VuDev *dev, VhostUserMsg *vmsg)
 {
     int i;
-    VhostUserMemory *memory = &vmsg->payload.memory;
+    VhostUserMemory m = vmsg->payload.memory, *memory = &m;
     dev->nregions = memory->nregions;
 
     DPRINT("Nregions: %d\n", memory->nregions);
@@ -684,7 +684,7 @@ static bool
 vu_set_mem_table_exec(VuDev *dev, VhostUserMsg *vmsg)
 {
     int i;
-    VhostUserMemory *memory = &vmsg->payload.memory;
+    VhostUserMemory m = vmsg->payload.memory, *memory = &m;
 
     for (i = 0; i < dev->nregions; i++) {
         VuDevRegion *r = &dev->regions[i];
@@ -813,7 +813,7 @@ vu_set_vring_num_exec(VuDev *dev, VhostUserMsg *vmsg)
 static bool
 vu_set_vring_addr_exec(VuDev *dev, VhostUserMsg *vmsg)
 {
-    struct vhost_vring_addr *vra = &vmsg->payload.addr;
+    struct vhost_vring_addr addr = vmsg->payload.addr, *vra = &addr;
     unsigned int index = vra->index;
     VuVirtq *vq = &dev->vq[index];
 
@@ -1157,6 +1157,10 @@ vu_get_protocol_features_exec(VuDev *dev, VhostUserMsg *vmsg)
         features |= 1ULL << VHOST_USER_PROTOCOL_F_PAGEFAULT;
     }
 
+    if (dev->iface->get_config && dev->iface->set_config) {
+        features |= 1ULL << VHOST_USER_PROTOCOL_F_CONFIG;
+    }
+
     if (dev->iface->get_protocol_features) {
         features |= dev->iface->get_protocol_features(dev);
     }
diff --git a/hw/input/Kconfig b/hw/input/Kconfig
index e2e66f0858..889363d8ae 100644
--- a/hw/input/Kconfig
+++ b/hw/input/Kconfig
@@ -27,7 +27,12 @@ config VIRTIO_INPUT
 config VIRTIO_INPUT_HOST
     bool
     default y
-    depends on VIRTIO && LINUX
+    depends on VIRTIO_INPUT && LINUX
+
+config VHOST_USER_INPUT
+    bool
+    default y
+    depends on VIRTIO_INPUT && VHOST_USER
 
 config TSC210X
     bool
diff --git a/hw/input/Makefile.objs b/hw/input/Makefile.objs
index c8b00f71ec..d1de307708 100644
--- a/hw/input/Makefile.objs
+++ b/hw/input/Makefile.objs
@@ -9,9 +9,8 @@ common-obj-$(CONFIG_TSC2005) += tsc2005.o
 
 common-obj-$(CONFIG_VIRTIO_INPUT) += virtio-input.o
 common-obj-$(CONFIG_VIRTIO_INPUT) += virtio-input-hid.o
-ifeq ($(CONFIG_LINUX),y)
-common-obj-$(CONFIG_VIRTIO_INPUT) += virtio-input-host.o
-endif
+common-obj-$(CONFIG_VIRTIO_INPUT_HOST) += virtio-input-host.o
+common-obj-$(CONFIG_VHOST_USER_INPUT) += vhost-user-input.o
 
 obj-$(CONFIG_MILKYMIST) += milkymist-softusb.o
 obj-$(CONFIG_PXA2XX) += pxa2xx_keypad.o
diff --git a/hw/input/vhost-user-input.c b/hw/input/vhost-user-input.c
new file mode 100644
index 0000000000..6da497b1a8
--- /dev/null
+++ b/hw/input/vhost-user-input.c
@@ -0,0 +1,129 @@
+/*
+ * This work is licensed under the terms of the GNU GPL, version 2 or
+ * (at your option) any later version.  See the COPYING file in the
+ * top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/error-report.h"
+#include "qapi/error.h"
+#include "qemu-common.h"
+
+#include "hw/qdev.h"
+#include "hw/virtio/virtio-input.h"
+
+static int vhost_input_config_change(struct vhost_dev *dev)
+{
+    error_report("vhost-user-input: unhandled backend config change");
+    return -1;
+}
+
+static const VhostDevConfigOps config_ops = {
+    .vhost_dev_config_notifier = vhost_input_config_change,
+};
+
+static void vhost_input_realize(DeviceState *dev, Error **errp)
+{
+    VHostUserInput *vhi = VHOST_USER_INPUT(dev);
+    VirtIOInput *vinput = VIRTIO_INPUT(dev);
+    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
+
+    vhost_dev_set_config_notifier(&vhi->vhost->dev, &config_ops);
+    vinput->cfg_size = sizeof_field(virtio_input_config, u);
+    if (vhost_user_backend_dev_init(vhi->vhost, vdev, 2, errp) == -1) {
+        return;
+    }
+}
+
+static void vhost_input_change_active(VirtIOInput *vinput)
+{
+    VHostUserInput *vhi = VHOST_USER_INPUT(vinput);
+
+    if (vinput->active) {
+        vhost_user_backend_start(vhi->vhost);
+    } else {
+        vhost_user_backend_stop(vhi->vhost);
+    }
+}
+
+static void vhost_input_get_config(VirtIODevice *vdev, uint8_t *config_data)
+{
+    VirtIOInput *vinput = VIRTIO_INPUT(vdev);
+    VHostUserInput *vhi = VHOST_USER_INPUT(vdev);
+    int ret;
+
+    memset(config_data, 0, vinput->cfg_size);
+
+    ret = vhost_dev_get_config(&vhi->vhost->dev, config_data, vinput->cfg_size);
+    if (ret) {
+        error_report("vhost-user-input: get device config space failed");
+        return;
+    }
+}
+
+static void vhost_input_set_config(VirtIODevice *vdev,
+                                   const uint8_t *config_data)
+{
+    VHostUserInput *vhi = VHOST_USER_INPUT(vdev);
+    int ret;
+
+    ret = vhost_dev_set_config(&vhi->vhost->dev, config_data,
+                               0, sizeof(virtio_input_config),
+                               VHOST_SET_CONFIG_TYPE_MASTER);
+    if (ret) {
+        error_report("vhost-user-input: set device config space failed");
+        return;
+    }
+
+    virtio_notify_config(vdev);
+}
+
+static const VMStateDescription vmstate_vhost_input = {
+    .name = "vhost-user-input",
+    .unmigratable = 1,
+};
+
+static void vhost_input_class_init(ObjectClass *klass, void *data)
+{
+    VirtIOInputClass *vic = VIRTIO_INPUT_CLASS(klass);
+    VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
+    DeviceClass *dc = DEVICE_CLASS(klass);
+
+    dc->vmsd = &vmstate_vhost_input;
+    vdc->get_config = vhost_input_get_config;
+    vdc->set_config = vhost_input_set_config;
+    vic->realize = vhost_input_realize;
+    vic->change_active = vhost_input_change_active;
+}
+
+static void vhost_input_init(Object *obj)
+{
+    VHostUserInput *vhi = VHOST_USER_INPUT(obj);
+
+    vhi->vhost = VHOST_USER_BACKEND(object_new(TYPE_VHOST_USER_BACKEND));
+    object_property_add_alias(obj, "chardev",
+                              OBJECT(vhi->vhost), "chardev", &error_abort);
+}
+
+static void vhost_input_finalize(Object *obj)
+{
+    VHostUserInput *vhi = VHOST_USER_INPUT(obj);
+
+    object_unref(OBJECT(vhi->vhost));
+}
+
+static const TypeInfo vhost_input_info = {
+    .name          = TYPE_VHOST_USER_INPUT,
+    .parent        = TYPE_VIRTIO_INPUT,
+    .instance_size = sizeof(VHostUserInput),
+    .instance_init = vhost_input_init,
+    .instance_finalize = vhost_input_finalize,
+    .class_init    = vhost_input_class_init,
+};
+
+static void vhost_input_register_types(void)
+{
+    type_register_static(&vhost_input_info);
+}
+
+type_init(vhost_input_register_types)
diff --git a/hw/virtio/Makefile.objs b/hw/virtio/Makefile.objs
index f2ab667a21..5570ea8df8 100644
--- a/hw/virtio/Makefile.objs
+++ b/hw/virtio/Makefile.objs
@@ -17,6 +17,7 @@ obj-$(CONFIG_VHOST_VSOCK) += vhost-vsock.o
 ifeq ($(CONFIG_VIRTIO_PCI),y)
 obj-$(CONFIG_VHOST_VSOCK) += vhost-vsock-pci.o
 obj-$(CONFIG_VHOST_USER_BLK) += vhost-user-blk-pci.o
+obj-$(CONFIG_VHOST_USER_INPUT) += vhost-user-input-pci.o
 obj-$(CONFIG_VHOST_USER_SCSI) += vhost-user-scsi-pci.o
 obj-$(CONFIG_VHOST_SCSI) += vhost-scsi-pci.o
 obj-$(CONFIG_VIRTIO_INPUT_HOST) += virtio-input-host-pci.o
diff --git a/hw/virtio/vhost-user-input-pci.c b/hw/virtio/vhost-user-input-pci.c
new file mode 100644
index 0000000000..ae9cff9aed
--- /dev/null
+++ b/hw/virtio/vhost-user-input-pci.c
@@ -0,0 +1,50 @@
+/*
+ * This work is licensed under the terms of the GNU LGPL, version 2 or
+ * later.  See the COPYING.LIB file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+
+#include "hw/virtio/virtio.h"
+#include "hw/virtio/virtio-input.h"
+#include "qapi/error.h"
+#include "qemu/error-report.h"
+#include "virtio-pci.h"
+
+typedef struct VHostUserInputPCI VHostUserInputPCI;
+
+#define TYPE_VHOST_USER_INPUT_PCI "vhost-user-input-pci"
+
+#define VHOST_USER_INPUT_PCI(obj) \
+    OBJECT_CHECK(VHostUserInputPCI, (obj), TYPE_VHOST_USER_INPUT_PCI)
+
+struct VHostUserInputPCI {
+    VirtIOPCIProxy parent_obj;
+    VHostUserInput vhi;
+};
+
+static void vhost_user_input_pci_instance_init(Object *obj)
+{
+    VHostUserInputPCI *dev = VHOST_USER_INPUT_PCI(obj);
+
+    virtio_instance_init_common(obj, &dev->vhi, sizeof(dev->vhi),
+                                TYPE_VHOST_USER_INPUT);
+
+    object_property_add_alias(obj, "chardev",
+                              OBJECT(&dev->vhi), "chardev",
+                              &error_abort);
+}
+
+static const VirtioPCIDeviceTypeInfo vhost_user_input_pci_info = {
+    .generic_name = TYPE_VHOST_USER_INPUT_PCI,
+    .parent = TYPE_VIRTIO_INPUT_PCI,
+    .instance_size = sizeof(VHostUserInputPCI),
+    .instance_init = vhost_user_input_pci_instance_init,
+};
+
+static void vhost_user_input_pci_register(void)
+{
+    virtio_pci_types_register(&vhost_user_input_pci_info);
+}
+
+type_init(vhost_user_input_pci_register)
diff --git a/hw/virtio/virtio-input-host-pci.c b/hw/virtio/virtio-input-host-pci.c
index 725a51ad30..124c4f3447 100644
--- a/hw/virtio/virtio-input-host-pci.c
+++ b/hw/virtio/virtio-input-host-pci.c
@@ -13,7 +13,7 @@
 
 typedef struct VirtIOInputHostPCI VirtIOInputHostPCI;
 
-#define TYPE_VIRTIO_INPUT_HOST_PCI "virtio-input-host-pci-base"
+#define TYPE_VIRTIO_INPUT_HOST_PCI "virtio-input-host-pci"
 #define VIRTIO_INPUT_HOST_PCI(obj) \
         OBJECT_CHECK(VirtIOInputHostPCI, (obj), TYPE_VIRTIO_INPUT_HOST_PCI)
 
@@ -31,10 +31,7 @@ static void virtio_host_initfn(Object *obj)
 }
 
 static const VirtioPCIDeviceTypeInfo virtio_input_host_pci_info = {
-    .base_name             = TYPE_VIRTIO_INPUT_HOST_PCI,
-    .generic_name          = "virtio-input-host-pci",
-    .transitional_name     = "virtio-input-host-pci-transitional",
-    .non_transitional_name = "virtio-input-host-pci-non-transitional",
+    .generic_name  = TYPE_VIRTIO_INPUT_HOST_PCI,
     .parent        = TYPE_VIRTIO_INPUT_PCI,
     .instance_size = sizeof(VirtIOInputHostPCI),
     .instance_init = virtio_host_initfn,
diff --git a/include/hw/virtio/virtio-input.h b/include/hw/virtio/virtio-input.h
index 054c38836f..4fca03e796 100644
--- a/include/hw/virtio/virtio-input.h
+++ b/include/hw/virtio/virtio-input.h
@@ -2,6 +2,7 @@
 #define QEMU_VIRTIO_INPUT_H
 
 #include "ui/input.h"
+#include "sysemu/vhost-user-backend.h"
 
 /* ----------------------------------------------------------------- */
 /* virtio input protocol                                             */
@@ -42,11 +43,18 @@ typedef struct virtio_input_event virtio_input_event;
 #define VIRTIO_INPUT_HOST_GET_PARENT_CLASS(obj) \
         OBJECT_GET_PARENT_CLASS(obj, TYPE_VIRTIO_INPUT_HOST)
 
+#define TYPE_VHOST_USER_INPUT   "vhost-user-input"
+#define VHOST_USER_INPUT(obj)                              \
+    OBJECT_CHECK(VHostUserInput, (obj), TYPE_VHOST_USER_INPUT)
+#define VHOST_USER_INPUT_GET_PARENT_CLASS(obj)             \
+    OBJECT_GET_PARENT_CLASS(obj, TYPE_VHOST_USER_INPUT)
+
 typedef struct VirtIOInput VirtIOInput;
 typedef struct VirtIOInputClass VirtIOInputClass;
 typedef struct VirtIOInputConfig VirtIOInputConfig;
 typedef struct VirtIOInputHID VirtIOInputHID;
 typedef struct VirtIOInputHost VirtIOInputHost;
+typedef struct VHostUserInput VHostUserInput;
 
 struct VirtIOInputConfig {
     virtio_input_config               config;
@@ -98,6 +106,12 @@ struct VirtIOInputHost {
     int                               fd;
 };
 
+struct VHostUserInput {
+    VirtIOInput                       parent_obj;
+
+    VhostUserBackend                  *vhost;
+};
+
 void virtio_input_send(VirtIOInput *vinput, virtio_input_event *event);
 void virtio_input_init_config(VirtIOInput *vinput,
                               virtio_input_config *config);
diff --git a/include/sysemu/vhost-user-backend.h b/include/sysemu/vhost-user-backend.h
new file mode 100644
index 0000000000..9abf8f06a1
--- /dev/null
+++ b/include/sysemu/vhost-user-backend.h
@@ -0,0 +1,57 @@
+/*
+ * QEMU vhost-user backend
+ *
+ * Copyright (C) 2018 Red Hat Inc
+ *
+ * Authors:
+ *  Marc-André Lureau <marcandre.lureau@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+#ifndef QEMU_VHOST_USER_BACKEND_H
+#define QEMU_VHOST_USER_BACKEND_H
+
+#include "qom/object.h"
+#include "exec/memory.h"
+#include "qemu/option.h"
+#include "qemu/bitmap.h"
+#include "hw/virtio/vhost.h"
+#include "hw/virtio/vhost-user.h"
+#include "chardev/char-fe.h"
+#include "io/channel.h"
+
+#define TYPE_VHOST_USER_BACKEND "vhost-user-backend"
+#define VHOST_USER_BACKEND(obj) \
+    OBJECT_CHECK(VhostUserBackend, (obj), TYPE_VHOST_USER_BACKEND)
+#define VHOST_USER_BACKEND_GET_CLASS(obj) \
+    OBJECT_GET_CLASS(VhostUserBackendClass, (obj), TYPE_VHOST_USER_BACKEND)
+#define VHOST_USER_BACKEND_CLASS(klass) \
+    OBJECT_CLASS_CHECK(VhostUserBackendClass, (klass), TYPE_VHOST_USER_BACKEND)
+
+typedef struct VhostUserBackend VhostUserBackend;
+typedef struct VhostUserBackendClass VhostUserBackendClass;
+
+struct VhostUserBackendClass {
+    ObjectClass parent_class;
+};
+
+struct VhostUserBackend {
+    /* private */
+    Object parent;
+
+    char *chr_name;
+    CharBackend chr;
+    VhostUserState vhost_user;
+    struct vhost_dev dev;
+    VirtIODevice *vdev;
+    bool started;
+    bool completed;
+};
+
+int vhost_user_backend_dev_init(VhostUserBackend *b, VirtIODevice *vdev,
+                                unsigned nvqs, Error **errp);
+void vhost_user_backend_start(VhostUserBackend *b);
+void vhost_user_backend_stop(VhostUserBackend *b);
+
+#endif
diff --git a/util/qemu-sockets.c b/util/qemu-sockets.c
index ba6335e71a..8850a280a8 100644
--- a/util/qemu-sockets.c
+++ b/util/qemu-sockets.c
@@ -970,26 +970,12 @@ static int unix_connect_saddr(UnixSocketAddress *saddr, Error **errp)
 /* compatibility wrapper */
 int unix_listen(const char *str, Error **errp)
 {
-    char *path, *optstr;
-    int sock, len;
     UnixSocketAddress *saddr;
+    int sock;
 
     saddr = g_new0(UnixSocketAddress, 1);
-
-    optstr = strchr(str, ',');
-    if (optstr) {
-        len = optstr - str;
-        if (len) {
-            path = g_malloc(len+1);
-            snprintf(path, len+1, "%.*s", len, str);
-            saddr->path = path;
-        }
-    } else {
-        saddr->path = g_strdup(str);
-    }
-
+    saddr->path = g_strdup(str);
     sock = unix_listen_saddr(saddr, errp);
-
     qapi_free_UnixSocketAddress(saddr);
     return sock;
 }