hw/virtio-net.c

   1 /*
   2  * Virtio Network Device
   3  *
   4  * Copyright IBM, Corp. 2007
   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 "virtio.h"
  15 #include "net.h"
  16 #include "qemu-timer.h"
  17 #include "virtio-net.h"
  18
  19 #define VIRTIO_NET_VM_VERSION    4
  20
  21 typedef struct VirtIONet
  22 {
  23     VirtIODevice vdev;
  24     uint8_t mac[ETH_ALEN];
  25     uint16_t status;
  26     VirtQueue *rx_vq;
  27     VirtQueue *tx_vq;
  28     VirtQueue *ctrl_vq;
  29     VLANClientState *vc;
  30     QEMUTimer *tx_timer;
  31     int tx_timer_active;
  32     int mergeable_rx_bufs;
  33     int promisc;
  34     int allmulti;
  35 } VirtIONet;
  36
  37 /* TODO
  38  * - we could suppress RX interrupt if we were so inclined.
  39  */
  40
  41 static VirtIONet *to_virtio_net(VirtIODevice *vdev)
  42 {
  43     return (VirtIONet *)vdev;
  44 }
  45
  46 static void virtio_net_get_config(VirtIODevice *vdev, uint8_t *config)
  47 {
  48     VirtIONet *n = to_virtio_net(vdev);
  49     struct virtio_net_config netcfg;
  50
  51     netcfg.status = n->status;
  52     memcpy(netcfg.mac, n->mac, ETH_ALEN);
  53     memcpy(config, &netcfg, sizeof(netcfg));
  54 }
  55
  56 static void virtio_net_set_config(VirtIODevice *vdev, const uint8_t *config)
  57 {
  58     VirtIONet *n = to_virtio_net(vdev);
  59     struct virtio_net_config netcfg;
  60
  61     memcpy(&netcfg, config, sizeof(netcfg));
  62
  63     if (memcmp(netcfg.mac, n->mac, ETH_ALEN)) {
  64         memcpy(n->mac, netcfg.mac, ETH_ALEN);
  65         qemu_format_nic_info_str(n->vc, n->mac);
  66     }
  67 }
  68
  69 static void virtio_net_set_link_status(VLANClientState *vc)
  70 {
  71     VirtIONet *n = vc->opaque;
  72     uint16_t old_status = n->status;
  73
  74     if (vc->link_down)
  75         n->status &= ~VIRTIO_NET_S_LINK_UP;
  76     else
  77         n->status |= VIRTIO_NET_S_LINK_UP;
  78
  79     if (n->status != old_status)
  80         virtio_notify_config(&n->vdev);
  81 }
  82
  83 static void virtio_net_reset(VirtIODevice *vdev)
  84 {
  85     VirtIONet *n = to_virtio_net(vdev);
  86
  87     /* Reset back to compatibility mode */
  88     n->promisc = 1;
  89     n->allmulti = 0;
  90 }
  91
  92 static uint32_t virtio_net_get_features(VirtIODevice *vdev)
  93 {
  94     uint32_t features = (1 << VIRTIO_NET_F_MAC) |
  95                         (1 << VIRTIO_NET_F_STATUS) |
  96                         (1 << VIRTIO_NET_F_CTRL_VQ);
  97
  98     return features;
  99 }
 100
 101 static void virtio_net_set_features(VirtIODevice *vdev, uint32_t features)
 102 {
 103     VirtIONet *n = to_virtio_net(vdev);
 104
 105     n->mergeable_rx_bufs = !!(features & (1 << VIRTIO_NET_F_MRG_RXBUF));
 106 }
 107
 108 static int virtio_net_handle_rx_mode(VirtIONet *n, uint8_t cmd,
 109                                      VirtQueueElement *elem)
 110 {
 111     uint8_t on;
 112
 113     if (elem->out_num != 2 || elem->out_sg[1].iov_len != sizeof(on)) {
 114         fprintf(stderr, "virtio-net ctrl invalid rx mode command\n");
 115         exit(1);
 116     }
 117
 118     on = ldub_p(elem->out_sg[1].iov_base);
 119
 120     if (cmd == VIRTIO_NET_CTRL_RX_MODE_PROMISC)
 121         n->promisc = on;
 122     else if (cmd == VIRTIO_NET_CTRL_RX_MODE_ALLMULTI)
 123         n->allmulti = on;
 124     else
 125         return VIRTIO_NET_ERR;
 126
 127     return VIRTIO_NET_OK;
 128 }
 129
 130 static void virtio_net_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
 131 {
 132     VirtIONet *n = to_virtio_net(vdev);
 133     struct virtio_net_ctrl_hdr ctrl;
 134     virtio_net_ctrl_ack status = VIRTIO_NET_ERR;
 135     VirtQueueElement elem;
 136
 137     while (virtqueue_pop(vq, &elem)) {
 138         if ((elem.in_num < 1) || (elem.out_num < 1)) {
 139             fprintf(stderr, "virtio-net ctrl missing headers\n");
 140             exit(1);
 141         }
 142
 143         if (elem.out_sg[0].iov_len < sizeof(ctrl) ||
 144             elem.out_sg[elem.in_num - 1].iov_len < sizeof(status)) {
 145             fprintf(stderr, "virtio-net ctrl header not in correct element\n");
 146             exit(1);
 147         }
 148
 149         ctrl.class = ldub_p(elem.out_sg[0].iov_base);
 150         ctrl.cmd = ldub_p(elem.out_sg[0].iov_base + sizeof(ctrl.class));
 151
 152         if (ctrl.class == VIRTIO_NET_CTRL_RX_MODE)
 153             status = virtio_net_handle_rx_mode(n, ctrl.cmd, &elem);
 154
 155         stb_p(elem.in_sg[elem.in_num - 1].iov_base, status);
 156
 157         virtqueue_push(vq, &elem, sizeof(status));
 158         virtio_notify(vdev, vq);
 159     }
 160 }
 161
 162 /* RX */
 163
 164 static void virtio_net_handle_rx(VirtIODevice *vdev, VirtQueue *vq)
 165 {
 166 }
 167
 168 static int do_virtio_net_can_receive(VirtIONet *n, int bufsize)
 169 {
 170     if (!virtio_queue_ready(n->rx_vq) ||
 171         !(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK))
 172         return 0;
 173
 174     if (virtio_queue_empty(n->rx_vq) ||
 175         (n->mergeable_rx_bufs &&
 176          !virtqueue_avail_bytes(n->rx_vq, bufsize, 0))) {
 177         virtio_queue_set_notification(n->rx_vq, 1);
 178         return 0;
 179     }
 180
 181     virtio_queue_set_notification(n->rx_vq, 0);
 182     return 1;
 183 }
 184
 185 static int virtio_net_can_receive(void *opaque)
 186 {
 187     VirtIONet *n = opaque;
 188
 189     return do_virtio_net_can_receive(n, VIRTIO_NET_MAX_BUFSIZE);
 190 }
 191
 192 static int iov_fill(struct iovec *iov, int iovcnt, const void *buf, int count)
 193 {
 194     int offset, i;
 195
 196     offset = i = 0;
 197     while (offset < count && i < iovcnt) {
 198         int len = MIN(iov[i].iov_len, count - offset);
 199         memcpy(iov[i].iov_base, buf + offset, len);
 200         offset += len;
 201         i++;
 202     }
 203
 204     return offset;
 205 }
 206
 207 static int receive_header(VirtIONet *n, struct iovec *iov, int iovcnt,
 208                           const void *buf, size_t size, size_t hdr_len)
 209 {
 210     struct virtio_net_hdr *hdr = iov[0].iov_base;
 211     int offset = 0;
 212
 213     hdr->flags = 0;
 214     hdr->gso_type = VIRTIO_NET_HDR_GSO_NONE;
 215
 216     /* We only ever receive a struct virtio_net_hdr from the tapfd,
 217      * but we may be passing along a larger header to the guest.
 218      */
 219     iov[0].iov_base += hdr_len;
 220     iov[0].iov_len  -= hdr_len;
 221
 222     return offset;
 223 }
 224
 225 static int receive_filter(VirtIONet *n, const uint8_t *buf, int size)
 226 {
 227     static const uint8_t bcast[] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
 228     uint8_t *ptr = (uint8_t *)buf;
 229
 230     if (n->promisc)
 231         return 1;
 232
 233 #ifdef TAP_VNET_HDR
 234     if (tap_has_vnet_hdr(n->vc->vlan->first_client))
 235         ptr += sizeof(struct virtio_net_hdr);
 236 #endif
 237
 238     if ((ptr[0] & 1) && n->allmulti)
 239         return 1;
 240
 241     if (!memcmp(ptr, bcast, sizeof(bcast)))
 242         return 1;
 243
 244     if (!memcmp(ptr, n->mac, ETH_ALEN))
 245         return 1;
 246
 247     return 0;
 248 }
 249
 250 static void virtio_net_receive(void *opaque, const uint8_t *buf, int size)
 251 {
 252     VirtIONet *n = opaque;
 253     struct virtio_net_hdr_mrg_rxbuf *mhdr = NULL;
 254     size_t hdr_len, offset, i;
 255
 256     if (!do_virtio_net_can_receive(n, size))
 257         return;
 258
 259     if (!receive_filter(n, buf, size))
 260         return;
 261
 262     /* hdr_len refers to the header we supply to the guest */
 263     hdr_len = n->mergeable_rx_bufs ?
 264         sizeof(struct virtio_net_hdr_mrg_rxbuf) : sizeof(struct virtio_net_hdr);
 265
 266     offset = i = 0;
 267
 268     while (offset < size) {
 269         VirtQueueElement elem;
 270         int len, total;
 271         struct iovec sg[VIRTQUEUE_MAX_SIZE];
 272
 273         len = total = 0;
 274
 275         if ((i != 0 && !n->mergeable_rx_bufs) ||
 276             virtqueue_pop(n->rx_vq, &elem) == 0) {
 277             if (i == 0)
 278                 return;
 279             fprintf(stderr, "virtio-net truncating packet\n");
 280             exit(1);
 281         }
 282
 283         if (elem.in_num < 1) {
 284             fprintf(stderr, "virtio-net receive queue contains no in buffers\n");
 285             exit(1);
 286         }
 287
 288         if (!n->mergeable_rx_bufs && elem.in_sg[0].iov_len != hdr_len) {
 289             fprintf(stderr, "virtio-net header not in first element\n");
 290             exit(1);
 291         }
 292
 293         memcpy(&sg, &elem.in_sg[0], sizeof(sg[0]) * elem.in_num);
 294
 295         if (i == 0) {
 296             if (n->mergeable_rx_bufs)
 297                 mhdr = (struct virtio_net_hdr_mrg_rxbuf *)sg[0].iov_base;
 298
 299             offset += receive_header(n, sg, elem.in_num,
 300                                      buf + offset, size - offset, hdr_len);
 301             total += hdr_len;
 302         }
 303
 304         /* copy in packet.  ugh */
 305         len = iov_fill(sg, elem.in_num,
 306                        buf + offset, size - offset);
 307         total += len;
 308
 309         /* signal other side */
 310         virtqueue_fill(n->rx_vq, &elem, total, i++);
 311
 312         offset += len;
 313     }
 314
 315     if (mhdr)
 316         mhdr->num_buffers = i;
 317
 318     virtqueue_flush(n->rx_vq, i);
 319     virtio_notify(&n->vdev, n->rx_vq);
 320 }
 321
 322 /* TX */
 323 static void virtio_net_flush_tx(VirtIONet *n, VirtQueue *vq)
 324 {
 325     VirtQueueElement elem;
 326     int has_vnet_hdr = 0;
 327
 328     if (!(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK))
 329         return;
 330
 331     while (virtqueue_pop(vq, &elem)) {
 332         ssize_t len = 0;
 333         unsigned int out_num = elem.out_num;
 334         struct iovec *out_sg = &elem.out_sg[0];
 335         unsigned hdr_len;
 336
 337         /* hdr_len refers to the header received from the guest */
 338         hdr_len = n->mergeable_rx_bufs ?
 339             sizeof(struct virtio_net_hdr_mrg_rxbuf) :
 340             sizeof(struct virtio_net_hdr);
 341
 342         if (out_num < 1 || out_sg->iov_len != hdr_len) {
 343             fprintf(stderr, "virtio-net header not in first element\n");
 344             exit(1);
 345         }
 346
 347         /* ignore the header if GSO is not supported */
 348         if (!has_vnet_hdr) {
 349             out_num--;
 350             out_sg++;
 351             len += hdr_len;
 352         } else if (n->mergeable_rx_bufs) {
 353             /* tapfd expects a struct virtio_net_hdr */
 354             hdr_len -= sizeof(struct virtio_net_hdr);
 355             out_sg->iov_len -= hdr_len;
 356             len += hdr_len;
 357         }
 358
 359         len += qemu_sendv_packet(n->vc, out_sg, out_num);
 360
 361         virtqueue_push(vq, &elem, len);
 362         virtio_notify(&n->vdev, vq);
 363     }
 364 }
 365
 366 static void virtio_net_handle_tx(VirtIODevice *vdev, VirtQueue *vq)
 367 {
 368     VirtIONet *n = to_virtio_net(vdev);
 369
 370     if (n->tx_timer_active) {
 371         virtio_queue_set_notification(vq, 1);
 372         qemu_del_timer(n->tx_timer);
 373         n->tx_timer_active = 0;
 374         virtio_net_flush_tx(n, vq);
 375     } else {
 376         qemu_mod_timer(n->tx_timer,
 377                        qemu_get_clock(vm_clock) + TX_TIMER_INTERVAL);
 378         n->tx_timer_active = 1;
 379         virtio_queue_set_notification(vq, 0);
 380     }
 381 }
 382
 383 static void virtio_net_tx_timer(void *opaque)
 384 {
 385     VirtIONet *n = opaque;
 386
 387     n->tx_timer_active = 0;
 388
 389     /* Just in case the driver is not ready on more */
 390     if (!(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK))
 391         return;
 392
 393     virtio_queue_set_notification(n->tx_vq, 1);
 394     virtio_net_flush_tx(n, n->tx_vq);
 395 }
 396
 397 static void virtio_net_save(QEMUFile *f, void *opaque)
 398 {
 399     VirtIONet *n = opaque;
 400
 401     virtio_save(&n->vdev, f);
 402
 403     qemu_put_buffer(f, n->mac, ETH_ALEN);
 404     qemu_put_be32(f, n->tx_timer_active);
 405     qemu_put_be32(f, n->mergeable_rx_bufs);
 406     qemu_put_be16(f, n->status);
 407     qemu_put_be32(f, n->promisc);
 408     qemu_put_be32(f, n->allmulti);
 409 }
 410
 411 static int virtio_net_load(QEMUFile *f, void *opaque, int version_id)
 412 {
 413     VirtIONet *n = opaque;
 414
 415     if (version_id < 2 || version_id > VIRTIO_NET_VM_VERSION)
 416         return -EINVAL;
 417
 418     virtio_load(&n->vdev, f);
 419
 420     qemu_get_buffer(f, n->mac, ETH_ALEN);
 421     n->tx_timer_active = qemu_get_be32(f);
 422     n->mergeable_rx_bufs = qemu_get_be32(f);
 423
 424     if (version_id >= 3)
 425         n->status = qemu_get_be16(f);
 426
 427     if (version_id >= 4) {
 428         n->promisc = qemu_get_be32(f);
 429         n->allmulti = qemu_get_be32(f);
 430     }
 431
 432     if (n->tx_timer_active) {
 433         qemu_mod_timer(n->tx_timer,
 434                        qemu_get_clock(vm_clock) + TX_TIMER_INTERVAL);
 435     }
 436
 437     return 0;
 438 }
 439
 440 void virtio_net_init(PCIBus *bus, NICInfo *nd, int devfn)
 441 {
 442     VirtIONet *n;
 443     static int virtio_net_id;
 444
 445     n = (VirtIONet *)virtio_init_pci(bus, "virtio-net",
 446                                      PCI_VENDOR_ID_REDHAT_QUMRANET,
 447                                      PCI_DEVICE_ID_VIRTIO_NET,
 448                                      PCI_VENDOR_ID_REDHAT_QUMRANET,
 449                                      VIRTIO_ID_NET,
 450                                      PCI_CLASS_NETWORK_ETHERNET, 0x00,
 451                                      sizeof(struct virtio_net_config),
 452                                      sizeof(VirtIONet));
 453     if (!n)
 454         return;
 455
 456     n->vdev.get_config = virtio_net_get_config;
 457     n->vdev.set_config = virtio_net_set_config;
 458     n->vdev.get_features = virtio_net_get_features;
 459     n->vdev.set_features = virtio_net_set_features;
 460     n->vdev.reset = virtio_net_reset;
 461     n->rx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_rx);
 462     n->tx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_tx);
 463     n->ctrl_vq = virtio_add_queue(&n->vdev, 16, virtio_net_handle_ctrl);
 464     memcpy(n->mac, nd->macaddr, ETH_ALEN);
 465     n->status = VIRTIO_NET_S_LINK_UP;
 466     n->vc = qemu_new_vlan_client(nd->vlan, nd->model, nd->name,
 467                                  virtio_net_receive, virtio_net_can_receive, n);
 468     n->vc->link_status_changed = virtio_net_set_link_status;
 469
 470     qemu_format_nic_info_str(n->vc, n->mac);
 471
 472     n->tx_timer = qemu_new_timer(vm_clock, virtio_net_tx_timer, n);
 473     n->tx_timer_active = 0;
 474     n->mergeable_rx_bufs = 0;
 475     n->promisc = 1; /* for compatibility */
 476
 477     register_savevm("virtio-net", virtio_net_id++, VIRTIO_NET_VM_VERSION,
 478                     virtio_net_save, virtio_net_load, n);
 479 }