1 /* 2 * Virtio 9p backend 3 * 4 * Copyright IBM, Corp. 2010 5 * 6 * Authors: 7 * Anthony Liguori <aliguori@us.ibm.com> 8 * 9 * This work is licensed under the terms of the GNU GPL, version 2. See 10 * the COPYING file in the top-level directory. 11 * 12 */ 13 14 #include "qemu/osdep.h" 15 #include "hw/virtio/virtio.h" 16 #include "qemu/sockets.h" 17 #include "virtio-9p.h" 18 #include "fsdev/qemu-fsdev.h" 19 #include "coth.h" 20 #include "hw/virtio/virtio-access.h" 21 #include "qemu/iov.h" 22 23 static const struct V9fsTransport virtio_9p_transport; 24 25 static void virtio_9p_push_and_notify(V9fsPDU *pdu) 26 { 27 V9fsState *s = pdu->s; 28 V9fsVirtioState *v = container_of(s, V9fsVirtioState, state); 29 VirtQueueElement *elem = v->elems[pdu->idx]; 30 31 /* push onto queue and notify */ 32 virtqueue_push(v->vq, elem, pdu->size); 33 g_free(elem); 34 v->elems[pdu->idx] = NULL; 35 36 /* FIXME: we should batch these completions */ 37 virtio_notify(VIRTIO_DEVICE(v), v->vq); 38 } 39 40 static void handle_9p_output(VirtIODevice *vdev, VirtQueue *vq) 41 { 42 V9fsVirtioState *v = (V9fsVirtioState *)vdev; 43 V9fsState *s = &v->state; 44 V9fsPDU *pdu; 45 ssize_t len; 46 VirtQueueElement *elem; 47 48 while ((pdu = pdu_alloc(s))) { 49 P9MsgHeader out; 50 51 elem = virtqueue_pop(vq, sizeof(VirtQueueElement)); 52 if (!elem) { 53 goto out_free_pdu; 54 } 55 56 if (elem->in_num == 0) { 57 virtio_error(vdev, 58 "The guest sent a VirtFS request without space for " 59 "the reply"); 60 goto out_free_req; 61 } 62 QEMU_BUILD_BUG_ON(sizeof(out) != 7); 63 64 v->elems[pdu->idx] = elem; 65 len = iov_to_buf(elem->out_sg, elem->out_num, 0, 66 &out, sizeof(out)); 67 if (len != sizeof(out)) { 68 virtio_error(vdev, "The guest sent a malformed VirtFS request: " 69 "header size is %zd, should be 7", len); 70 goto out_free_req; 71 } 72 73 pdu->size = le32_to_cpu(out.size_le); 74 75 pdu->id = out.id; 76 pdu->tag = le16_to_cpu(out.tag_le); 77 78 qemu_co_queue_init(&pdu->complete); 79 pdu_submit(pdu); 80 } 81 82 return; 83 84 out_free_req: 85 virtqueue_detach_element(vq, elem, 0); 86 g_free(elem); 87 out_free_pdu: 88 pdu_free(pdu); 89 } 90 91 static uint64_t virtio_9p_get_features(VirtIODevice *vdev, uint64_t features, 92 Error **errp) 93 { 94 virtio_add_feature(&features, VIRTIO_9P_MOUNT_TAG); 95 return features; 96 } 97 98 static void virtio_9p_get_config(VirtIODevice *vdev, uint8_t *config) 99 { 100 int len; 101 struct virtio_9p_config *cfg; 102 V9fsVirtioState *v = VIRTIO_9P(vdev); 103 V9fsState *s = &v->state; 104 105 len = strlen(s->tag); 106 cfg = g_malloc0(sizeof(struct virtio_9p_config) + len); 107 virtio_stw_p(vdev, &cfg->tag_len, len); 108 /* We don't copy the terminating null to config space */ 109 memcpy(cfg->tag, s->tag, len); 110 memcpy(config, cfg, v->config_size); 111 g_free(cfg); 112 } 113 114 static void virtio_9p_device_realize(DeviceState *dev, Error **errp) 115 { 116 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 117 V9fsVirtioState *v = VIRTIO_9P(dev); 118 V9fsState *s = &v->state; 119 120 if (v9fs_device_realize_common(s, errp)) { 121 goto out; 122 } 123 124 v->config_size = sizeof(struct virtio_9p_config) + strlen(s->fsconf.tag); 125 virtio_init(vdev, "virtio-9p", VIRTIO_ID_9P, v->config_size); 126 v->vq = virtio_add_queue(vdev, MAX_REQ, handle_9p_output); 127 v9fs_register_transport(s, &virtio_9p_transport); 128 129 out: 130 return; 131 } 132 133 static void virtio_9p_device_unrealize(DeviceState *dev, Error **errp) 134 { 135 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 136 V9fsVirtioState *v = VIRTIO_9P(dev); 137 V9fsState *s = &v->state; 138 139 virtio_cleanup(vdev); 140 v9fs_device_unrealize_common(s, errp); 141 } 142 143 static void virtio_9p_reset(VirtIODevice *vdev) 144 { 145 V9fsVirtioState *v = (V9fsVirtioState *)vdev; 146 147 v9fs_reset(&v->state); 148 } 149 150 static ssize_t virtio_pdu_vmarshal(V9fsPDU *pdu, size_t offset, 151 const char *fmt, va_list ap) 152 { 153 V9fsState *s = pdu->s; 154 V9fsVirtioState *v = container_of(s, V9fsVirtioState, state); 155 VirtQueueElement *elem = v->elems[pdu->idx]; 156 157 return v9fs_iov_vmarshal(elem->in_sg, elem->in_num, offset, 1, fmt, ap); 158 } 159 160 static ssize_t virtio_pdu_vunmarshal(V9fsPDU *pdu, size_t offset, 161 const char *fmt, va_list ap) 162 { 163 V9fsState *s = pdu->s; 164 V9fsVirtioState *v = container_of(s, V9fsVirtioState, state); 165 VirtQueueElement *elem = v->elems[pdu->idx]; 166 167 return v9fs_iov_vunmarshal(elem->out_sg, elem->out_num, offset, 1, fmt, ap); 168 } 169 170 /* The size parameter is used by other transports. Do not drop it. */ 171 static void virtio_init_in_iov_from_pdu(V9fsPDU *pdu, struct iovec **piov, 172 unsigned int *pniov, size_t size) 173 { 174 V9fsState *s = pdu->s; 175 V9fsVirtioState *v = container_of(s, V9fsVirtioState, state); 176 VirtQueueElement *elem = v->elems[pdu->idx]; 177 178 *piov = elem->in_sg; 179 *pniov = elem->in_num; 180 } 181 182 static void virtio_init_out_iov_from_pdu(V9fsPDU *pdu, struct iovec **piov, 183 unsigned int *pniov) 184 { 185 V9fsState *s = pdu->s; 186 V9fsVirtioState *v = container_of(s, V9fsVirtioState, state); 187 VirtQueueElement *elem = v->elems[pdu->idx]; 188 189 *piov = elem->out_sg; 190 *pniov = elem->out_num; 191 } 192 193 static const struct V9fsTransport virtio_9p_transport = { 194 .pdu_vmarshal = virtio_pdu_vmarshal, 195 .pdu_vunmarshal = virtio_pdu_vunmarshal, 196 .init_in_iov_from_pdu = virtio_init_in_iov_from_pdu, 197 .init_out_iov_from_pdu = virtio_init_out_iov_from_pdu, 198 .push_and_notify = virtio_9p_push_and_notify, 199 }; 200 201 /* virtio-9p device */ 202 203 static const VMStateDescription vmstate_virtio_9p = { 204 .name = "virtio-9p", 205 .minimum_version_id = 1, 206 .version_id = 1, 207 .fields = (VMStateField[]) { 208 VMSTATE_VIRTIO_DEVICE, 209 VMSTATE_END_OF_LIST() 210 }, 211 }; 212 213 static Property virtio_9p_properties[] = { 214 DEFINE_PROP_STRING("mount_tag", V9fsVirtioState, state.fsconf.tag), 215 DEFINE_PROP_STRING("fsdev", V9fsVirtioState, state.fsconf.fsdev_id), 216 DEFINE_PROP_END_OF_LIST(), 217 }; 218 219 static void virtio_9p_class_init(ObjectClass *klass, void *data) 220 { 221 DeviceClass *dc = DEVICE_CLASS(klass); 222 VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass); 223 224 dc->props = virtio_9p_properties; 225 dc->vmsd = &vmstate_virtio_9p; 226 set_bit(DEVICE_CATEGORY_STORAGE, dc->categories); 227 vdc->realize = virtio_9p_device_realize; 228 vdc->unrealize = virtio_9p_device_unrealize; 229 vdc->get_features = virtio_9p_get_features; 230 vdc->get_config = virtio_9p_get_config; 231 vdc->reset = virtio_9p_reset; 232 } 233 234 static const TypeInfo virtio_device_info = { 235 .name = TYPE_VIRTIO_9P, 236 .parent = TYPE_VIRTIO_DEVICE, 237 .instance_size = sizeof(V9fsVirtioState), 238 .class_init = virtio_9p_class_init, 239 }; 240 241 static void virtio_9p_register_types(void) 242 { 243 type_register_static(&virtio_device_info); 244 } 245 246 type_init(virtio_9p_register_types) 247