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 "hw/qdev.h" 16 #include "qapi/error.h" 17 #include "qapi/qmp/qerror.h" 18 #include "qemu/error-report.h" 19 #include "qom/object_interfaces.h" 20 #include "sysemu/vhost-user-backend.h" 21 #include "sysemu/kvm.h" 22 #include "io/channel-command.h" 23 #include "hw/virtio/virtio-bus.h" 24 25 static bool 26 ioeventfd_enabled(void) 27 { 28 return kvm_enabled() && kvm_eventfds_enabled(); 29 } 30 31 int 32 vhost_user_backend_dev_init(VhostUserBackend *b, VirtIODevice *vdev, 33 unsigned nvqs, Error **errp) 34 { 35 int ret; 36 37 assert(!b->vdev && vdev); 38 39 if (!ioeventfd_enabled()) { 40 error_setg(errp, "vhost initialization failed: requires kvm"); 41 return -1; 42 } 43 44 if (!vhost_user_init(&b->vhost_user, &b->chr, errp)) { 45 return -1; 46 } 47 48 b->vdev = vdev; 49 b->dev.nvqs = nvqs; 50 b->dev.vqs = g_new(struct vhost_virtqueue, nvqs); 51 52 ret = vhost_dev_init(&b->dev, &b->vhost_user, VHOST_BACKEND_TYPE_USER, 0); 53 if (ret < 0) { 54 error_setg_errno(errp, -ret, "vhost initialization failed"); 55 return -1; 56 } 57 58 return 0; 59 } 60 61 void 62 vhost_user_backend_start(VhostUserBackend *b) 63 { 64 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(b->vdev))); 65 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 66 int ret, i ; 67 68 if (b->started) { 69 return; 70 } 71 72 if (!k->set_guest_notifiers) { 73 error_report("binding does not support guest notifiers"); 74 return; 75 } 76 77 ret = vhost_dev_enable_notifiers(&b->dev, b->vdev); 78 if (ret < 0) { 79 return; 80 } 81 82 ret = k->set_guest_notifiers(qbus->parent, b->dev.nvqs, true); 83 if (ret < 0) { 84 error_report("Error binding guest notifier"); 85 goto err_host_notifiers; 86 } 87 88 b->dev.acked_features = b->vdev->guest_features; 89 ret = vhost_dev_start(&b->dev, b->vdev); 90 if (ret < 0) { 91 error_report("Error start vhost dev"); 92 goto err_guest_notifiers; 93 } 94 95 /* guest_notifier_mask/pending not used yet, so just unmask 96 * everything here. virtio-pci will do the right thing by 97 * enabling/disabling irqfd. 98 */ 99 for (i = 0; i < b->dev.nvqs; i++) { 100 vhost_virtqueue_mask(&b->dev, b->vdev, 101 b->dev.vq_index + i, false); 102 } 103 104 b->started = true; 105 return; 106 107 err_guest_notifiers: 108 k->set_guest_notifiers(qbus->parent, b->dev.nvqs, false); 109 err_host_notifiers: 110 vhost_dev_disable_notifiers(&b->dev, b->vdev); 111 } 112 113 void 114 vhost_user_backend_stop(VhostUserBackend *b) 115 { 116 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(b->vdev))); 117 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 118 int ret = 0; 119 120 if (!b->started) { 121 return; 122 } 123 124 vhost_dev_stop(&b->dev, b->vdev); 125 126 if (k->set_guest_notifiers) { 127 ret = k->set_guest_notifiers(qbus->parent, 128 b->dev.nvqs, false); 129 if (ret < 0) { 130 error_report("vhost guest notifier cleanup failed: %d", ret); 131 } 132 } 133 assert(ret >= 0); 134 135 vhost_dev_disable_notifiers(&b->dev, b->vdev); 136 b->started = false; 137 } 138 139 static void set_chardev(Object *obj, const char *value, Error **errp) 140 { 141 VhostUserBackend *b = VHOST_USER_BACKEND(obj); 142 Chardev *chr; 143 144 if (b->completed) { 145 error_setg(errp, QERR_PERMISSION_DENIED); 146 return; 147 } 148 149 g_free(b->chr_name); 150 b->chr_name = g_strdup(value); 151 152 chr = qemu_chr_find(b->chr_name); 153 if (chr == NULL) { 154 error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND, 155 "Chardev '%s' not found", b->chr_name); 156 return; 157 } 158 159 if (!qemu_chr_fe_init(&b->chr, chr, errp)) { 160 return; 161 } 162 163 b->completed = true; 164 /* could call vhost_dev_init() so early message can be exchanged */ 165 } 166 167 static char *get_chardev(Object *obj, Error **errp) 168 { 169 VhostUserBackend *b = VHOST_USER_BACKEND(obj); 170 Chardev *chr = qemu_chr_fe_get_driver(&b->chr); 171 172 if (chr && chr->label) { 173 return g_strdup(chr->label); 174 } 175 176 return NULL; 177 } 178 179 static void vhost_user_backend_init(Object *obj) 180 { 181 object_property_add_str(obj, "chardev", get_chardev, set_chardev, NULL); 182 } 183 184 static void vhost_user_backend_finalize(Object *obj) 185 { 186 VhostUserBackend *b = VHOST_USER_BACKEND(obj); 187 188 g_free(b->dev.vqs); 189 g_free(b->chr_name); 190 191 vhost_user_cleanup(&b->vhost_user); 192 qemu_chr_fe_deinit(&b->chr, true); 193 } 194 195 static const TypeInfo vhost_user_backend_info = { 196 .name = TYPE_VHOST_USER_BACKEND, 197 .parent = TYPE_OBJECT, 198 .instance_size = sizeof(VhostUserBackend), 199 .instance_init = vhost_user_backend_init, 200 .instance_finalize = vhost_user_backend_finalize, 201 .class_size = sizeof(VhostUserBackendClass), 202 }; 203 204 static void register_types(void) 205 { 206 type_register_static(&vhost_user_backend_info); 207 } 208 209 type_init(register_types); 210