hw/virtio/virtio-mmio.c

   1 /*
   2  * Virtio MMIO bindings
   3  *
   4  * Copyright (c) 2011 Linaro Limited
   5  *
   6  * Author:
   7  *  Peter Maydell <peter.maydell@linaro.org>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License; either version 2
  11  * of the License, or (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License along
  19  * with this program; if not, see <http://www.gnu.org/licenses/>.
  20  */
  21
  22 #include "qemu/osdep.h"
  23 #include "standard-headers/linux/virtio_mmio.h"
  24 #include "hw/irq.h"
  25 #include "hw/qdev-properties.h"
  26 #include "hw/sysbus.h"
  27 #include "hw/virtio/virtio.h"
  28 #include "migration/qemu-file-types.h"
  29 #include "qemu/host-utils.h"
  30 #include "qemu/module.h"
  31 #include "sysemu/kvm.h"
  32 #include "sysemu/replay.h"
  33 #include "hw/virtio/virtio-mmio.h"
  34 #include "qemu/error-report.h"
  35 #include "qemu/log.h"
  36 #include "trace.h"
  37
  38 static bool virtio_mmio_ioeventfd_enabled(DeviceState *d)
  39 {
  40     VirtIOMMIOProxy *proxy = VIRTIO_MMIO(d);
  41
  42     return (proxy->flags & VIRTIO_IOMMIO_FLAG_USE_IOEVENTFD) != 0;
  43 }
  44
  45 static int virtio_mmio_ioeventfd_assign(DeviceState *d,
  46                                         EventNotifier *notifier,
  47                                         int n, bool assign)
  48 {
  49     VirtIOMMIOProxy *proxy = VIRTIO_MMIO(d);
  50
  51     if (assign) {
  52         memory_region_add_eventfd(&proxy->iomem, VIRTIO_MMIO_QUEUE_NOTIFY, 4,
  53                                   true, n, notifier);
  54     } else {
  55         memory_region_del_eventfd(&proxy->iomem, VIRTIO_MMIO_QUEUE_NOTIFY, 4,
  56                                   true, n, notifier);
  57     }
  58     return 0;
  59 }
  60
  61 static void virtio_mmio_start_ioeventfd(VirtIOMMIOProxy *proxy)
  62 {
  63     virtio_bus_start_ioeventfd(&proxy->bus);
  64 }
  65
  66 static void virtio_mmio_stop_ioeventfd(VirtIOMMIOProxy *proxy)
  67 {
  68     virtio_bus_stop_ioeventfd(&proxy->bus);
  69 }
  70
  71 static void virtio_mmio_soft_reset(VirtIOMMIOProxy *proxy)
  72 {
  73     int i;
  74
  75     virtio_bus_reset(&proxy->bus);
  76
  77     if (!proxy->legacy) {
  78         for (i = 0; i < VIRTIO_QUEUE_MAX; i++) {
  79             proxy->vqs[i].enabled = 0;
  80         }
  81     }
  82 }
  83
  84 static uint64_t virtio_mmio_read(void *opaque, hwaddr offset, unsigned size)
  85 {
  86     VirtIOMMIOProxy *proxy = (VirtIOMMIOProxy *)opaque;
  87     VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
  88
  89     trace_virtio_mmio_read(offset);
  90
  91     if (!vdev) {
  92         /* If no backend is present, we treat most registers as
  93          * read-as-zero, except for the magic number, version and
  94          * vendor ID. This is not strictly sanctioned by the virtio
  95          * spec, but it allows us to provide transports with no backend
  96          * plugged in which don't confuse Linux's virtio code: the
  97          * probe won't complain about the bad magic number, but the
  98          * device ID of zero means no backend will claim it.
  99          */
 100         switch (offset) {
 101         case VIRTIO_MMIO_MAGIC_VALUE:
 102             return VIRT_MAGIC;
 103         case VIRTIO_MMIO_VERSION:
 104             if (proxy->legacy) {
 105                 return VIRT_VERSION_LEGACY;
 106             } else {
 107                 return VIRT_VERSION;
 108             }
 109         case VIRTIO_MMIO_VENDOR_ID:
 110             return VIRT_VENDOR;
 111         default:
 112             return 0;
 113         }
 114     }
 115
 116     if (offset >= VIRTIO_MMIO_CONFIG) {
 117         offset -= VIRTIO_MMIO_CONFIG;
 118         if (proxy->legacy) {
 119             switch (size) {
 120             case 1:
 121                 return virtio_config_readb(vdev, offset);
 122             case 2:
 123                 return virtio_config_readw(vdev, offset);
 124             case 4:
 125                 return virtio_config_readl(vdev, offset);
 126             default:
 127                 abort();
 128             }
 129         } else {
 130             switch (size) {
 131             case 1:
 132                 return virtio_config_modern_readb(vdev, offset);
 133             case 2:
 134                 return virtio_config_modern_readw(vdev, offset);
 135             case 4:
 136                 return virtio_config_modern_readl(vdev, offset);
 137             default:
 138                 abort();
 139             }
 140         }
 141     }
 142     if (size != 4) {
 143         qemu_log_mask(LOG_GUEST_ERROR,
 144                       "%s: wrong size access to register!\n",
 145                       __func__);
 146         return 0;
 147     }
 148     switch (offset) {
 149     case VIRTIO_MMIO_MAGIC_VALUE:
 150         return VIRT_MAGIC;
 151     case VIRTIO_MMIO_VERSION:
 152         if (proxy->legacy) {
 153             return VIRT_VERSION_LEGACY;
 154         } else {
 155             return VIRT_VERSION;
 156         }
 157     case VIRTIO_MMIO_DEVICE_ID:
 158         return vdev->device_id;
 159     case VIRTIO_MMIO_VENDOR_ID:
 160         return VIRT_VENDOR;
 161     case VIRTIO_MMIO_DEVICE_FEATURES:
 162         if (proxy->legacy) {
 163             if (proxy->host_features_sel) {
 164                 return 0;
 165             } else {
 166                 return vdev->host_features;
 167             }
 168         } else {
 169             VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev);
 170             return (vdev->host_features & ~vdc->legacy_features)
 171                 >> (32 * proxy->host_features_sel);
 172         }
 173     case VIRTIO_MMIO_QUEUE_NUM_MAX:
 174         if (!virtio_queue_get_num(vdev, vdev->queue_sel)) {
 175             return 0;
 176         }
 177         return VIRTQUEUE_MAX_SIZE;
 178     case VIRTIO_MMIO_QUEUE_PFN:
 179         if (!proxy->legacy) {
 180             qemu_log_mask(LOG_GUEST_ERROR,
 181                           "%s: read from legacy register (0x%"
 182                           HWADDR_PRIx ") in non-legacy mode\n",
 183                           __func__, offset);
 184             return 0;
 185         }
 186         return virtio_queue_get_addr(vdev, vdev->queue_sel)
 187             >> proxy->guest_page_shift;
 188     case VIRTIO_MMIO_QUEUE_READY:
 189         if (proxy->legacy) {
 190             qemu_log_mask(LOG_GUEST_ERROR,
 191                           "%s: read from non-legacy register (0x%"
 192                           HWADDR_PRIx ") in legacy mode\n",
 193                           __func__, offset);
 194             return 0;
 195         }
 196         return proxy->vqs[vdev->queue_sel].enabled;
 197     case VIRTIO_MMIO_INTERRUPT_STATUS:
 198         return qatomic_read(&vdev->isr);
 199     case VIRTIO_MMIO_STATUS:
 200         return vdev->status;
 201     case VIRTIO_MMIO_CONFIG_GENERATION:
 202         if (proxy->legacy) {
 203             qemu_log_mask(LOG_GUEST_ERROR,
 204                           "%s: read from non-legacy register (0x%"
 205                           HWADDR_PRIx ") in legacy mode\n",
 206                           __func__, offset);
 207             return 0;
 208         }
 209         return vdev->generation;
 210    case VIRTIO_MMIO_SHM_LEN_LOW:
 211    case VIRTIO_MMIO_SHM_LEN_HIGH:
 212         /*
 213          * VIRTIO_MMIO_SHM_SEL is unimplemented
 214          * according to the linux driver, if region length is -1
 215          * the shared memory doesn't exist
 216          */
 217         return -1;
 218     case VIRTIO_MMIO_DEVICE_FEATURES_SEL:
 219     case VIRTIO_MMIO_DRIVER_FEATURES:
 220     case VIRTIO_MMIO_DRIVER_FEATURES_SEL:
 221     case VIRTIO_MMIO_GUEST_PAGE_SIZE:
 222     case VIRTIO_MMIO_QUEUE_SEL:
 223     case VIRTIO_MMIO_QUEUE_NUM:
 224     case VIRTIO_MMIO_QUEUE_ALIGN:
 225     case VIRTIO_MMIO_QUEUE_NOTIFY:
 226     case VIRTIO_MMIO_INTERRUPT_ACK:
 227     case VIRTIO_MMIO_QUEUE_DESC_LOW:
 228     case VIRTIO_MMIO_QUEUE_DESC_HIGH:
 229     case VIRTIO_MMIO_QUEUE_AVAIL_LOW:
 230     case VIRTIO_MMIO_QUEUE_AVAIL_HIGH:
 231     case VIRTIO_MMIO_QUEUE_USED_LOW:
 232     case VIRTIO_MMIO_QUEUE_USED_HIGH:
 233         qemu_log_mask(LOG_GUEST_ERROR,
 234                       "%s: read of write-only register (0x%" HWADDR_PRIx ")\n",
 235                       __func__, offset);
 236         return 0;
 237     default:
 238         qemu_log_mask(LOG_GUEST_ERROR,
 239                       "%s: bad register offset (0x%" HWADDR_PRIx ")\n",
 240                       __func__, offset);
 241         return 0;
 242     }
 243     return 0;
 244 }
 245
 246 static void virtio_mmio_write(void *opaque, hwaddr offset, uint64_t value,
 247                               unsigned size)
 248 {
 249     VirtIOMMIOProxy *proxy = (VirtIOMMIOProxy *)opaque;
 250     VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
 251
 252     trace_virtio_mmio_write_offset(offset, value);
 253
 254     if (!vdev) {
 255         /* If no backend is present, we just make all registers
 256          * write-ignored. This allows us to provide transports with
 257          * no backend plugged in.
 258          */
 259         return;
 260     }
 261
 262     if (offset >= VIRTIO_MMIO_CONFIG) {
 263         offset -= VIRTIO_MMIO_CONFIG;
 264         if (proxy->legacy) {
 265             switch (size) {
 266             case 1:
 267                 virtio_config_writeb(vdev, offset, value);
 268                 break;
 269             case 2:
 270                 virtio_config_writew(vdev, offset, value);
 271                 break;
 272             case 4:
 273                 virtio_config_writel(vdev, offset, value);
 274                 break;
 275             default:
 276                 abort();
 277             }
 278             return;
 279         } else {
 280             switch (size) {
 281             case 1:
 282                 virtio_config_modern_writeb(vdev, offset, value);
 283                 break;
 284             case 2:
 285                 virtio_config_modern_writew(vdev, offset, value);
 286                 break;
 287             case 4:
 288                 virtio_config_modern_writel(vdev, offset, value);
 289                 break;
 290             default:
 291                 abort();
 292             }
 293             return;
 294         }
 295     }
 296     if (size != 4) {
 297         qemu_log_mask(LOG_GUEST_ERROR,
 298                       "%s: wrong size access to register!\n",
 299                       __func__);
 300         return;
 301     }
 302     switch (offset) {
 303     case VIRTIO_MMIO_DEVICE_FEATURES_SEL:
 304         if (value) {
 305             proxy->host_features_sel = 1;
 306         } else {
 307             proxy->host_features_sel = 0;
 308         }
 309         break;
 310     case VIRTIO_MMIO_DRIVER_FEATURES:
 311         if (proxy->legacy) {
 312             if (proxy->guest_features_sel) {
 313                 qemu_log_mask(LOG_GUEST_ERROR,
 314                               "%s: attempt to write guest features with "
 315                               "guest_features_sel > 0 in legacy mode\n",
 316                               __func__);
 317             } else {
 318                 virtio_set_features(vdev, value);
 319             }
 320         } else {
 321             proxy->guest_features[proxy->guest_features_sel] = value;
 322         }
 323         break;
 324     case VIRTIO_MMIO_DRIVER_FEATURES_SEL:
 325         if (value) {
 326             proxy->guest_features_sel = 1;
 327         } else {
 328             proxy->guest_features_sel = 0;
 329         }
 330         break;
 331     case VIRTIO_MMIO_GUEST_PAGE_SIZE:
 332         if (!proxy->legacy) {
 333             qemu_log_mask(LOG_GUEST_ERROR,
 334                           "%s: write to legacy register (0x%"
 335                           HWADDR_PRIx ") in non-legacy mode\n",
 336                           __func__, offset);
 337             return;
 338         }
 339         proxy->guest_page_shift = ctz32(value);
 340         if (proxy->guest_page_shift > 31) {
 341             proxy->guest_page_shift = 0;
 342         }
 343         trace_virtio_mmio_guest_page(value, proxy->guest_page_shift);
 344         break;
 345     case VIRTIO_MMIO_QUEUE_SEL:
 346         if (value < VIRTIO_QUEUE_MAX) {
 347             vdev->queue_sel = value;
 348         }
 349         break;
 350     case VIRTIO_MMIO_QUEUE_NUM:
 351         trace_virtio_mmio_queue_write(value, VIRTQUEUE_MAX_SIZE);
 352         virtio_queue_set_num(vdev, vdev->queue_sel, value);
 353
 354         if (proxy->legacy) {
 355             virtio_queue_update_rings(vdev, vdev->queue_sel);
 356         } else {
 357             virtio_init_region_cache(vdev, vdev->queue_sel);
 358             proxy->vqs[vdev->queue_sel].num = value;
 359         }
 360         break;
 361     case VIRTIO_MMIO_QUEUE_ALIGN:
 362         if (!proxy->legacy) {
 363             qemu_log_mask(LOG_GUEST_ERROR,
 364                           "%s: write to legacy register (0x%"
 365                           HWADDR_PRIx ") in non-legacy mode\n",
 366                           __func__, offset);
 367             return;
 368         }
 369         virtio_queue_set_align(vdev, vdev->queue_sel, value);
 370         break;
 371     case VIRTIO_MMIO_QUEUE_PFN:
 372         if (!proxy->legacy) {
 373             qemu_log_mask(LOG_GUEST_ERROR,
 374                           "%s: write to legacy register (0x%"
 375                           HWADDR_PRIx ") in non-legacy mode\n",
 376                           __func__, offset);
 377             return;
 378         }
 379         if (value == 0) {
 380             virtio_mmio_soft_reset(proxy);
 381         } else {
 382             virtio_queue_set_addr(vdev, vdev->queue_sel,
 383                                   value << proxy->guest_page_shift);
 384         }
 385         break;
 386     case VIRTIO_MMIO_QUEUE_READY:
 387         if (proxy->legacy) {
 388             qemu_log_mask(LOG_GUEST_ERROR,
 389                           "%s: write to non-legacy register (0x%"
 390                           HWADDR_PRIx ") in legacy mode\n",
 391                           __func__, offset);
 392             return;
 393         }
 394         if (value) {
 395             virtio_queue_set_num(vdev, vdev->queue_sel,
 396                                  proxy->vqs[vdev->queue_sel].num);
 397             virtio_queue_set_rings(vdev, vdev->queue_sel,
 398                 ((uint64_t)proxy->vqs[vdev->queue_sel].desc[1]) << 32 |
 399                 proxy->vqs[vdev->queue_sel].desc[0],
 400                 ((uint64_t)proxy->vqs[vdev->queue_sel].avail[1]) << 32 |
 401                 proxy->vqs[vdev->queue_sel].avail[0],
 402                 ((uint64_t)proxy->vqs[vdev->queue_sel].used[1]) << 32 |
 403                 proxy->vqs[vdev->queue_sel].used[0]);
 404             proxy->vqs[vdev->queue_sel].enabled = 1;
 405         } else {
 406             proxy->vqs[vdev->queue_sel].enabled = 0;
 407         }
 408         break;
 409     case VIRTIO_MMIO_QUEUE_NOTIFY:
 410         if (value < VIRTIO_QUEUE_MAX) {
 411             virtio_queue_notify(vdev, value);
 412         }
 413         break;
 414     case VIRTIO_MMIO_INTERRUPT_ACK:
 415         qatomic_and(&vdev->isr, ~value);
 416         virtio_update_irq(vdev);
 417         break;
 418     case VIRTIO_MMIO_STATUS:
 419         if (!(value & VIRTIO_CONFIG_S_DRIVER_OK)) {
 420             virtio_mmio_stop_ioeventfd(proxy);
 421         }
 422
 423         if (!proxy->legacy && (value & VIRTIO_CONFIG_S_FEATURES_OK)) {
 424             virtio_set_features(vdev,
 425                                 ((uint64_t)proxy->guest_features[1]) << 32 |
 426                                 proxy->guest_features[0]);
 427         }
 428
 429         virtio_set_status(vdev, value & 0xff);
 430
 431         if (value & VIRTIO_CONFIG_S_DRIVER_OK) {
 432             virtio_mmio_start_ioeventfd(proxy);
 433         }
 434
 435         if (vdev->status == 0) {
 436             virtio_mmio_soft_reset(proxy);
 437         }
 438         break;
 439     case VIRTIO_MMIO_QUEUE_DESC_LOW:
 440         if (proxy->legacy) {
 441             qemu_log_mask(LOG_GUEST_ERROR,
 442                           "%s: write to non-legacy register (0x%"
 443                           HWADDR_PRIx ") in legacy mode\n",
 444                           __func__, offset);
 445             return;
 446         }
 447         proxy->vqs[vdev->queue_sel].desc[0] = value;
 448         break;
 449     case VIRTIO_MMIO_QUEUE_DESC_HIGH:
 450         if (proxy->legacy) {
 451             qemu_log_mask(LOG_GUEST_ERROR,
 452                           "%s: write to non-legacy register (0x%"
 453                           HWADDR_PRIx ") in legacy mode\n",
 454                           __func__, offset);
 455             return;
 456         }
 457         proxy->vqs[vdev->queue_sel].desc[1] = value;
 458         break;
 459     case VIRTIO_MMIO_QUEUE_AVAIL_LOW:
 460         if (proxy->legacy) {
 461             qemu_log_mask(LOG_GUEST_ERROR,
 462                           "%s: write to non-legacy register (0x%"
 463                           HWADDR_PRIx ") in legacy mode\n",
 464                           __func__, offset);
 465             return;
 466         }
 467         proxy->vqs[vdev->queue_sel].avail[0] = value;
 468         break;
 469     case VIRTIO_MMIO_QUEUE_AVAIL_HIGH:
 470         if (proxy->legacy) {
 471             qemu_log_mask(LOG_GUEST_ERROR,
 472                           "%s: write to non-legacy register (0x%"
 473                           HWADDR_PRIx ") in legacy mode\n",
 474                           __func__, offset);
 475             return;
 476         }
 477         proxy->vqs[vdev->queue_sel].avail[1] = value;
 478         break;
 479     case VIRTIO_MMIO_QUEUE_USED_LOW:
 480         if (proxy->legacy) {
 481             qemu_log_mask(LOG_GUEST_ERROR,
 482                           "%s: write to non-legacy register (0x%"
 483                           HWADDR_PRIx ") in legacy mode\n",
 484                           __func__, offset);
 485             return;
 486         }
 487         proxy->vqs[vdev->queue_sel].used[0] = value;
 488         break;
 489     case VIRTIO_MMIO_QUEUE_USED_HIGH:
 490         if (proxy->legacy) {
 491             qemu_log_mask(LOG_GUEST_ERROR,
 492                           "%s: write to non-legacy register (0x%"
 493                           HWADDR_PRIx ") in legacy mode\n",
 494                           __func__, offset);
 495             return;
 496         }
 497         proxy->vqs[vdev->queue_sel].used[1] = value;
 498         break;
 499     case VIRTIO_MMIO_MAGIC_VALUE:
 500     case VIRTIO_MMIO_VERSION:
 501     case VIRTIO_MMIO_DEVICE_ID:
 502     case VIRTIO_MMIO_VENDOR_ID:
 503     case VIRTIO_MMIO_DEVICE_FEATURES:
 504     case VIRTIO_MMIO_QUEUE_NUM_MAX:
 505     case VIRTIO_MMIO_INTERRUPT_STATUS:
 506     case VIRTIO_MMIO_CONFIG_GENERATION:
 507         qemu_log_mask(LOG_GUEST_ERROR,
 508                       "%s: write to read-only register (0x%" HWADDR_PRIx ")\n",
 509                       __func__, offset);
 510         break;
 511
 512     default:
 513         qemu_log_mask(LOG_GUEST_ERROR,
 514                       "%s: bad register offset (0x%" HWADDR_PRIx ")\n",
 515                       __func__, offset);
 516     }
 517 }
 518
 519 static const MemoryRegionOps virtio_legacy_mem_ops = {
 520     .read = virtio_mmio_read,
 521     .write = virtio_mmio_write,
 522     .endianness = DEVICE_NATIVE_ENDIAN,
 523 };
 524
 525 static const MemoryRegionOps virtio_mem_ops = {
 526     .read = virtio_mmio_read,
 527     .write = virtio_mmio_write,
 528     .endianness = DEVICE_LITTLE_ENDIAN,
 529 };
 530
 531 static void virtio_mmio_update_irq(DeviceState *opaque, uint16_t vector)
 532 {
 533     VirtIOMMIOProxy *proxy = VIRTIO_MMIO(opaque);
 534     VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
 535     int level;
 536
 537     if (!vdev) {
 538         return;
 539     }
 540     level = (qatomic_read(&vdev->isr) != 0);
 541     trace_virtio_mmio_setting_irq(level);
 542     qemu_set_irq(proxy->irq, level);
 543 }
 544
 545 static int virtio_mmio_load_config(DeviceState *opaque, QEMUFile *f)
 546 {
 547     VirtIOMMIOProxy *proxy = VIRTIO_MMIO(opaque);
 548
 549     proxy->host_features_sel = qemu_get_be32(f);
 550     proxy->guest_features_sel = qemu_get_be32(f);
 551     proxy->guest_page_shift = qemu_get_be32(f);
 552     return 0;
 553 }
 554
 555 static void virtio_mmio_save_config(DeviceState *opaque, QEMUFile *f)
 556 {
 557     VirtIOMMIOProxy *proxy = VIRTIO_MMIO(opaque);
 558
 559     qemu_put_be32(f, proxy->host_features_sel);
 560     qemu_put_be32(f, proxy->guest_features_sel);
 561     qemu_put_be32(f, proxy->guest_page_shift);
 562 }
 563
 564 static const VMStateDescription vmstate_virtio_mmio_queue_state = {
 565     .name = "virtio_mmio/queue_state",
 566     .version_id = 1,
 567     .minimum_version_id = 1,
 568     .fields = (VMStateField[]) {
 569         VMSTATE_UINT16(num, VirtIOMMIOQueue),
 570         VMSTATE_BOOL(enabled, VirtIOMMIOQueue),
 571         VMSTATE_UINT32_ARRAY(desc, VirtIOMMIOQueue, 2),
 572         VMSTATE_UINT32_ARRAY(avail, VirtIOMMIOQueue, 2),
 573         VMSTATE_UINT32_ARRAY(used, VirtIOMMIOQueue, 2),
 574         VMSTATE_END_OF_LIST()
 575     }
 576 };
 577
 578 static const VMStateDescription vmstate_virtio_mmio_state_sub = {
 579     .name = "virtio_mmio/state",
 580     .version_id = 1,
 581     .minimum_version_id = 1,
 582     .fields = (VMStateField[]) {
 583         VMSTATE_UINT32_ARRAY(guest_features, VirtIOMMIOProxy, 2),
 584         VMSTATE_STRUCT_ARRAY(vqs, VirtIOMMIOProxy, VIRTIO_QUEUE_MAX, 0,
 585                              vmstate_virtio_mmio_queue_state,
 586                              VirtIOMMIOQueue),
 587         VMSTATE_END_OF_LIST()
 588     }
 589 };
 590
 591 static const VMStateDescription vmstate_virtio_mmio = {
 592     .name = "virtio_mmio",
 593     .version_id = 1,
 594     .minimum_version_id = 1,
 595     .fields = (VMStateField[]) {
 596         VMSTATE_END_OF_LIST()
 597     },
 598     .subsections = (const VMStateDescription * []) {
 599         &vmstate_virtio_mmio_state_sub,
 600         NULL
 601     }
 602 };
 603
 604 static void virtio_mmio_save_extra_state(DeviceState *opaque, QEMUFile *f)
 605 {
 606     VirtIOMMIOProxy *proxy = VIRTIO_MMIO(opaque);
 607
 608     vmstate_save_state(f, &vmstate_virtio_mmio, proxy, NULL);
 609 }
 610
 611 static int virtio_mmio_load_extra_state(DeviceState *opaque, QEMUFile *f)
 612 {
 613     VirtIOMMIOProxy *proxy = VIRTIO_MMIO(opaque);
 614
 615     return vmstate_load_state(f, &vmstate_virtio_mmio, proxy, 1);
 616 }
 617
 618 static bool virtio_mmio_has_extra_state(DeviceState *opaque)
 619 {
 620     VirtIOMMIOProxy *proxy = VIRTIO_MMIO(opaque);
 621
 622     return !proxy->legacy;
 623 }
 624
 625 static void virtio_mmio_reset(DeviceState *d)
 626 {
 627     VirtIOMMIOProxy *proxy = VIRTIO_MMIO(d);
 628     int i;
 629
 630     virtio_mmio_soft_reset(proxy);
 631
 632     proxy->host_features_sel = 0;
 633     proxy->guest_features_sel = 0;
 634     proxy->guest_page_shift = 0;
 635
 636     if (!proxy->legacy) {
 637         proxy->guest_features[0] = proxy->guest_features[1] = 0;
 638
 639         for (i = 0; i < VIRTIO_QUEUE_MAX; i++) {
 640             proxy->vqs[i].num = 0;
 641             proxy->vqs[i].desc[0] = proxy->vqs[i].desc[1] = 0;
 642             proxy->vqs[i].avail[0] = proxy->vqs[i].avail[1] = 0;
 643             proxy->vqs[i].used[0] = proxy->vqs[i].used[1] = 0;
 644         }
 645     }
 646 }
 647
 648 static int virtio_mmio_set_guest_notifier(DeviceState *d, int n, bool assign,
 649                                           bool with_irqfd)
 650 {
 651     VirtIOMMIOProxy *proxy = VIRTIO_MMIO(d);
 652     VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
 653     VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev);
 654     VirtQueue *vq = virtio_get_queue(vdev, n);
 655     EventNotifier *notifier = virtio_queue_get_guest_notifier(vq);
 656
 657     if (assign) {
 658         int r = event_notifier_init(notifier, 0);
 659         if (r < 0) {
 660             return r;
 661         }
 662         virtio_queue_set_guest_notifier_fd_handler(vq, true, with_irqfd);
 663     } else {
 664         virtio_queue_set_guest_notifier_fd_handler(vq, false, with_irqfd);
 665         event_notifier_cleanup(notifier);
 666     }
 667
 668     if (vdc->guest_notifier_mask && vdev->use_guest_notifier_mask) {
 669         vdc->guest_notifier_mask(vdev, n, !assign);
 670     }
 671
 672     return 0;
 673 }
 674 static int virtio_mmio_set_config_guest_notifier(DeviceState *d, bool assign,
 675                                                  bool with_irqfd)
 676 {
 677     VirtIOMMIOProxy *proxy = VIRTIO_MMIO(d);
 678     VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
 679     VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev);
 680     EventNotifier *notifier = virtio_config_get_guest_notifier(vdev);
 681     int r = 0;
 682
 683     if (assign) {
 684         r = event_notifier_init(notifier, 0);
 685         if (r < 0) {
 686             return r;
 687         }
 688         virtio_config_set_guest_notifier_fd_handler(vdev, assign, with_irqfd);
 689     } else {
 690         virtio_config_set_guest_notifier_fd_handler(vdev, assign, with_irqfd);
 691         event_notifier_cleanup(notifier);
 692     }
 693     if (vdc->guest_notifier_mask && vdev->use_guest_notifier_mask) {
 694         vdc->guest_notifier_mask(vdev, VIRTIO_CONFIG_IRQ_IDX, !assign);
 695     }
 696     return r;
 697 }
 698 static int virtio_mmio_set_guest_notifiers(DeviceState *d, int nvqs,
 699                                            bool assign)
 700 {
 701     VirtIOMMIOProxy *proxy = VIRTIO_MMIO(d);
 702     VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
 703     /* TODO: need to check if kvm-arm supports irqfd */
 704     bool with_irqfd = false;
 705     int r, n;
 706
 707     nvqs = MIN(nvqs, VIRTIO_QUEUE_MAX);
 708
 709     for (n = 0; n < nvqs; n++) {
 710         if (!virtio_queue_get_num(vdev, n)) {
 711             break;
 712         }
 713
 714         r = virtio_mmio_set_guest_notifier(d, n, assign, with_irqfd);
 715         if (r < 0) {
 716             goto assign_error;
 717         }
 718     }
 719     r = virtio_mmio_set_config_guest_notifier(d, assign, with_irqfd);
 720     if (r < 0) {
 721         goto assign_error;
 722     }
 723
 724     return 0;
 725
 726 assign_error:
 727     /* We get here on assignment failure. Recover by undoing for VQs 0 .. n. */
 728     assert(assign);
 729     while (--n >= 0) {
 730         virtio_mmio_set_guest_notifier(d, n, !assign, false);
 731     }
 732     return r;
 733 }
 734
 735 static void virtio_mmio_pre_plugged(DeviceState *d, Error **errp)
 736 {
 737     VirtIOMMIOProxy *proxy = VIRTIO_MMIO(d);
 738     VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
 739
 740     if (!proxy->legacy) {
 741         virtio_add_feature(&vdev->host_features, VIRTIO_F_VERSION_1);
 742     }
 743 }
 744
 745 /* virtio-mmio device */
 746
 747 static Property virtio_mmio_properties[] = {
 748     DEFINE_PROP_BOOL("format_transport_address", VirtIOMMIOProxy,
 749                      format_transport_address, true),
 750     DEFINE_PROP_BOOL("force-legacy", VirtIOMMIOProxy, legacy, true),
 751     DEFINE_PROP_BIT("ioeventfd", VirtIOMMIOProxy, flags,
 752                     VIRTIO_IOMMIO_FLAG_USE_IOEVENTFD_BIT, true),
 753     DEFINE_PROP_END_OF_LIST(),
 754 };
 755
 756 static void virtio_mmio_realizefn(DeviceState *d, Error **errp)
 757 {
 758     VirtIOMMIOProxy *proxy = VIRTIO_MMIO(d);
 759     SysBusDevice *sbd = SYS_BUS_DEVICE(d);
 760
 761     qbus_init(&proxy->bus, sizeof(proxy->bus), TYPE_VIRTIO_MMIO_BUS, d, NULL);
 762     sysbus_init_irq(sbd, &proxy->irq);
 763
 764     if (!kvm_eventfds_enabled()) {
 765         proxy->flags &= ~VIRTIO_IOMMIO_FLAG_USE_IOEVENTFD;
 766     }
 767
 768     /* fd-based ioevents can't be synchronized in record/replay */
 769     if (replay_mode != REPLAY_MODE_NONE) {
 770         proxy->flags &= ~VIRTIO_IOMMIO_FLAG_USE_IOEVENTFD;
 771     }
 772
 773     if (proxy->legacy) {
 774         memory_region_init_io(&proxy->iomem, OBJECT(d),
 775                               &virtio_legacy_mem_ops, proxy,
 776                               TYPE_VIRTIO_MMIO, 0x200);
 777     } else {
 778         memory_region_init_io(&proxy->iomem, OBJECT(d),
 779                               &virtio_mem_ops, proxy,
 780                               TYPE_VIRTIO_MMIO, 0x200);
 781     }
 782     sysbus_init_mmio(sbd, &proxy->iomem);
 783 }
 784
 785 static void virtio_mmio_class_init(ObjectClass *klass, void *data)
 786 {
 787     DeviceClass *dc = DEVICE_CLASS(klass);
 788
 789     dc->realize = virtio_mmio_realizefn;
 790     dc->reset = virtio_mmio_reset;
 791     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
 792     device_class_set_props(dc, virtio_mmio_properties);
 793 }
 794
 795 static const TypeInfo virtio_mmio_info = {
 796     .name          = TYPE_VIRTIO_MMIO,
 797     .parent        = TYPE_SYS_BUS_DEVICE,
 798     .instance_size = sizeof(VirtIOMMIOProxy),
 799     .class_init    = virtio_mmio_class_init,
 800 };
 801
 802 /* virtio-mmio-bus. */
 803
 804 static char *virtio_mmio_bus_get_dev_path(DeviceState *dev)
 805 {
 806     BusState *virtio_mmio_bus;
 807     VirtIOMMIOProxy *virtio_mmio_proxy;
 808     char *proxy_path;
 809     char *path;
 810     MemoryRegionSection section;
 811
 812     virtio_mmio_bus = qdev_get_parent_bus(dev);
 813     virtio_mmio_proxy = VIRTIO_MMIO(virtio_mmio_bus->parent);
 814     proxy_path = qdev_get_dev_path(DEVICE(virtio_mmio_proxy));
 815
 816     /*
 817      * If @format_transport_address is false, then we just perform the same as
 818      * virtio_bus_get_dev_path(): we delegate the address formatting for the
 819      * device on the virtio-mmio bus to the bus that the virtio-mmio proxy
 820      * (i.e., the device that implements the virtio-mmio bus) resides on. In
 821      * this case the base address of the virtio-mmio transport will be
 822      * invisible.
 823      */
 824     if (!virtio_mmio_proxy->format_transport_address) {
 825         return proxy_path;
 826     }
 827
 828     /* Otherwise, we append the base address of the transport. */
 829     section = memory_region_find(&virtio_mmio_proxy->iomem, 0, 0x200);
 830     assert(section.mr);
 831
 832     if (proxy_path) {
 833         path = g_strdup_printf("%s/virtio-mmio@" HWADDR_FMT_plx, proxy_path,
 834                                section.offset_within_address_space);
 835     } else {
 836         path = g_strdup_printf("virtio-mmio@" HWADDR_FMT_plx,
 837                                section.offset_within_address_space);
 838     }
 839     memory_region_unref(section.mr);
 840
 841     g_free(proxy_path);
 842     return path;
 843 }
 844
 845 static void virtio_mmio_vmstate_change(DeviceState *d, bool running)
 846 {
 847     VirtIOMMIOProxy *proxy = VIRTIO_MMIO(d);
 848
 849     if (running) {
 850         virtio_mmio_start_ioeventfd(proxy);
 851     } else {
 852         virtio_mmio_stop_ioeventfd(proxy);
 853     }
 854 }
 855
 856 static void virtio_mmio_bus_class_init(ObjectClass *klass, void *data)
 857 {
 858     BusClass *bus_class = BUS_CLASS(klass);
 859     VirtioBusClass *k = VIRTIO_BUS_CLASS(klass);
 860
 861     k->notify = virtio_mmio_update_irq;
 862     k->save_config = virtio_mmio_save_config;
 863     k->load_config = virtio_mmio_load_config;
 864     k->save_extra_state = virtio_mmio_save_extra_state;
 865     k->load_extra_state = virtio_mmio_load_extra_state;
 866     k->has_extra_state = virtio_mmio_has_extra_state;
 867     k->set_guest_notifiers = virtio_mmio_set_guest_notifiers;
 868     k->ioeventfd_enabled = virtio_mmio_ioeventfd_enabled;
 869     k->ioeventfd_assign = virtio_mmio_ioeventfd_assign;
 870     k->pre_plugged = virtio_mmio_pre_plugged;
 871     k->vmstate_change = virtio_mmio_vmstate_change;
 872     k->has_variable_vring_alignment = true;
 873     bus_class->max_dev = 1;
 874     bus_class->get_dev_path = virtio_mmio_bus_get_dev_path;
 875 }
 876
 877 static const TypeInfo virtio_mmio_bus_info = {
 878     .name          = TYPE_VIRTIO_MMIO_BUS,
 879     .parent        = TYPE_VIRTIO_BUS,
 880     .instance_size = sizeof(VirtioBusState),
 881     .class_init    = virtio_mmio_bus_class_init,
 882 };
 883
 884 static void virtio_mmio_register_types(void)
 885 {
 886     type_register_static(&virtio_mmio_bus_info);
 887     type_register_static(&virtio_mmio_info);
 888 }
 889
 890 type_init(virtio_mmio_register_types)