1 /* 2 * QEMU vhost-user backend 3 * 4 * Copyright (C) 2018 Red Hat Inc 5 * 6 * Authors: 7 * Marc-André Lureau <marcandre.lureau@redhat.com> 8 * 9 * This work is licensed under the terms of the GNU GPL, version 2 or later. 10 * See the COPYING file in the top-level directory. 11 */ 12 13 14 #include "qemu/osdep.h" 15 #include "qapi/error.h" 16 #include "qapi/qmp/qerror.h" 17 #include "qemu/error-report.h" 18 #include "qom/object_interfaces.h" 19 #include "sysemu/vhost-user-backend.h" 20 #include "sysemu/kvm.h" 21 #include "io/channel-command.h" 22 #include "hw/virtio/virtio-bus.h" 23 24 static bool 25 ioeventfd_enabled(void) 26 { 27 return kvm_enabled() && kvm_eventfds_enabled(); 28 } 29 30 int 31 vhost_user_backend_dev_init(VhostUserBackend *b, VirtIODevice *vdev, 32 unsigned nvqs, Error **errp) 33 { 34 int ret; 35 36 assert(!b->vdev && vdev); 37 38 if (!ioeventfd_enabled()) { 39 error_setg(errp, "vhost initialization failed: requires kvm"); 40 return -1; 41 } 42 43 if (!vhost_user_init(&b->vhost_user, &b->chr, errp)) { 44 return -1; 45 } 46 47 b->vdev = vdev; 48 b->dev.nvqs = nvqs; 49 b->dev.vqs = g_new0(struct vhost_virtqueue, nvqs); 50 51 ret = vhost_dev_init(&b->dev, &b->vhost_user, VHOST_BACKEND_TYPE_USER, 0); 52 if (ret < 0) { 53 error_setg_errno(errp, -ret, "vhost initialization failed"); 54 return -1; 55 } 56 57 return 0; 58 } 59 60 void 61 vhost_user_backend_start(VhostUserBackend *b) 62 { 63 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(b->vdev))); 64 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 65 int ret, i ; 66 67 if (b->started) { 68 return; 69 } 70 71 if (!k->set_guest_notifiers) { 72 error_report("binding does not support guest notifiers"); 73 return; 74 } 75 76 ret = vhost_dev_enable_notifiers(&b->dev, b->vdev); 77 if (ret < 0) { 78 return; 79 } 80 81 ret = k->set_guest_notifiers(qbus->parent, b->dev.nvqs, true); 82 if (ret < 0) { 83 error_report("Error binding guest notifier"); 84 goto err_host_notifiers; 85 } 86 87 b->dev.acked_features = b->vdev->guest_features; 88 ret = vhost_dev_start(&b->dev, b->vdev); 89 if (ret < 0) { 90 error_report("Error start vhost dev"); 91 goto err_guest_notifiers; 92 } 93 94 /* guest_notifier_mask/pending not used yet, so just unmask 95 * everything here. virtio-pci will do the right thing by 96 * enabling/disabling irqfd. 97 */ 98 for (i = 0; i < b->dev.nvqs; i++) { 99 vhost_virtqueue_mask(&b->dev, b->vdev, 100 b->dev.vq_index + i, false); 101 } 102 103 b->started = true; 104 return; 105 106 err_guest_notifiers: 107 k->set_guest_notifiers(qbus->parent, b->dev.nvqs, false); 108 err_host_notifiers: 109 vhost_dev_disable_notifiers(&b->dev, b->vdev); 110 } 111 112 void 113 vhost_user_backend_stop(VhostUserBackend *b) 114 { 115 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(b->vdev))); 116 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 117 int ret = 0; 118 119 if (!b->started) { 120 return; 121 } 122 123 vhost_dev_stop(&b->dev, b->vdev); 124 125 if (k->set_guest_notifiers) { 126 ret = k->set_guest_notifiers(qbus->parent, 127 b->dev.nvqs, false); 128 if (ret < 0) { 129 error_report("vhost guest notifier cleanup failed: %d", ret); 130 } 131 } 132 assert(ret >= 0); 133 134 vhost_dev_disable_notifiers(&b->dev, b->vdev); 135 b->started = false; 136 } 137 138 static void set_chardev(Object *obj, const char *value, Error **errp) 139 { 140 VhostUserBackend *b = VHOST_USER_BACKEND(obj); 141 Chardev *chr; 142 143 if (b->completed) { 144 error_setg(errp, QERR_PERMISSION_DENIED); 145 return; 146 } 147 148 g_free(b->chr_name); 149 b->chr_name = g_strdup(value); 150 151 chr = qemu_chr_find(b->chr_name); 152 if (chr == NULL) { 153 error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND, 154 "Chardev '%s' not found", b->chr_name); 155 return; 156 } 157 158 if (!qemu_chr_fe_init(&b->chr, chr, errp)) { 159 return; 160 } 161 162 b->completed = true; 163 /* could call vhost_dev_init() so early message can be exchanged */ 164 } 165 166 static char *get_chardev(Object *obj, Error **errp) 167 { 168 VhostUserBackend *b = VHOST_USER_BACKEND(obj); 169 Chardev *chr = qemu_chr_fe_get_driver(&b->chr); 170 171 if (chr && chr->label) { 172 return g_strdup(chr->label); 173 } 174 175 return NULL; 176 } 177 178 static void vhost_user_backend_init(Object *obj) 179 { 180 object_property_add_str(obj, "chardev", get_chardev, set_chardev); 181 } 182 183 static void vhost_user_backend_finalize(Object *obj) 184 { 185 VhostUserBackend *b = VHOST_USER_BACKEND(obj); 186 187 g_free(b->dev.vqs); 188 g_free(b->chr_name); 189 190 vhost_user_cleanup(&b->vhost_user); 191 qemu_chr_fe_deinit(&b->chr, true); 192 } 193 194 static const TypeInfo vhost_user_backend_info = { 195 .name = TYPE_VHOST_USER_BACKEND, 196 .parent = TYPE_OBJECT, 197 .instance_size = sizeof(VhostUserBackend), 198 .instance_init = vhost_user_backend_init, 199 .instance_finalize = vhost_user_backend_finalize, 200 .class_size = sizeof(VhostUserBackendClass), 201 }; 202 203 static void register_types(void) 204 { 205 type_register_static(&vhost_user_backend_info); 206 } 207 208 type_init(register_types); 209