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 "hw/sysbus.h"
  23 #include "hw/virtio/virtio.h"
  24 #include "qemu/host-utils.h"
  25 #include "hw/virtio/virtio-bus.h"
  26
  27 /* #define DEBUG_VIRTIO_MMIO */
  28
  29 #ifdef DEBUG_VIRTIO_MMIO
  30
  31 #define DPRINTF(fmt, ...) \
  32 do { printf("virtio_mmio: " fmt , ## __VA_ARGS__); } while (0)
  33 #else
  34 #define DPRINTF(fmt, ...) do {} while (0)
  35 #endif
  36
  37 /* QOM macros */
  38 /* virtio-mmio-bus */
  39 #define TYPE_VIRTIO_MMIO_BUS "virtio-mmio-bus"
  40 #define VIRTIO_MMIO_BUS(obj) \
  41         OBJECT_CHECK(VirtioBusState, (obj), TYPE_VIRTIO_MMIO_BUS)
  42 #define VIRTIO_MMIO_BUS_GET_CLASS(obj) \
  43         OBJECT_GET_CLASS(VirtioBusClass, (obj), TYPE_VIRTIO_MMIO_BUS)
  44 #define VIRTIO_MMIO_BUS_CLASS(klass) \
  45         OBJECT_CLASS_CHECK(VirtioBusClass, (klass), TYPE_VIRTIO_MMIO_BUS)
  46
  47 /* virtio-mmio */
  48 #define TYPE_VIRTIO_MMIO "virtio-mmio"
  49 #define VIRTIO_MMIO(obj) \
  50         OBJECT_CHECK(VirtIOMMIOProxy, (obj), TYPE_VIRTIO_MMIO)
  51
  52 /* Memory mapped register offsets */
  53 #define VIRTIO_MMIO_MAGIC 0x0
  54 #define VIRTIO_MMIO_VERSION 0x4
  55 #define VIRTIO_MMIO_DEVICEID 0x8
  56 #define VIRTIO_MMIO_VENDORID 0xc
  57 #define VIRTIO_MMIO_HOSTFEATURES 0x10
  58 #define VIRTIO_MMIO_HOSTFEATURESSEL 0x14
  59 #define VIRTIO_MMIO_GUESTFEATURES 0x20
  60 #define VIRTIO_MMIO_GUESTFEATURESSEL 0x24
  61 #define VIRTIO_MMIO_GUESTPAGESIZE 0x28
  62 #define VIRTIO_MMIO_QUEUESEL 0x30
  63 #define VIRTIO_MMIO_QUEUENUMMAX 0x34
  64 #define VIRTIO_MMIO_QUEUENUM 0x38
  65 #define VIRTIO_MMIO_QUEUEALIGN 0x3c
  66 #define VIRTIO_MMIO_QUEUEPFN 0x40
  67 #define VIRTIO_MMIO_QUEUENOTIFY 0x50
  68 #define VIRTIO_MMIO_INTERRUPTSTATUS 0x60
  69 #define VIRTIO_MMIO_INTERRUPTACK 0x64
  70 #define VIRTIO_MMIO_STATUS 0x70
  71 /* Device specific config space starts here */
  72 #define VIRTIO_MMIO_CONFIG 0x100
  73
  74 #define VIRT_MAGIC 0x74726976 /* 'virt' */
  75 #define VIRT_VERSION 1
  76 #define VIRT_VENDOR 0x554D4551 /* 'QEMU' */
  77
  78 typedef struct {
  79     /* Generic */
  80     SysBusDevice parent_obj;
  81     MemoryRegion iomem;
  82     qemu_irq irq;
  83     uint32_t host_features;
  84     /* Guest accessible state needing migration and reset */
  85     uint32_t host_features_sel;
  86     uint32_t guest_features_sel;
  87     uint32_t guest_page_shift;
  88     /* virtio-bus */
  89     VirtioBusState bus;
  90 } VirtIOMMIOProxy;
  91
  92 static uint64_t virtio_mmio_read(void *opaque, hwaddr offset, unsigned size)
  93 {
  94     VirtIOMMIOProxy *proxy = (VirtIOMMIOProxy *)opaque;
  95     VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
  96
  97     DPRINTF("virtio_mmio_read offset 0x%x\n", (int)offset);
  98
  99     if (!vdev) {
 100         /* If no backend is present, we treat most registers as
 101          * read-as-zero, except for the magic number, version and
 102          * vendor ID. This is not strictly sanctioned by the virtio
 103          * spec, but it allows us to provide transports with no backend
 104          * plugged in which don't confuse Linux's virtio code: the
 105          * probe won't complain about the bad magic number, but the
 106          * device ID of zero means no backend will claim it.
 107          */
 108         switch (offset) {
 109         case VIRTIO_MMIO_MAGIC:
 110             return VIRT_MAGIC;
 111         case VIRTIO_MMIO_VERSION:
 112             return VIRT_VERSION;
 113         case VIRTIO_MMIO_VENDORID:
 114             return VIRT_VENDOR;
 115         default:
 116             return 0;
 117         }
 118     }
 119
 120     if (offset >= VIRTIO_MMIO_CONFIG) {
 121         offset -= VIRTIO_MMIO_CONFIG;
 122         switch (size) {
 123         case 1:
 124             return virtio_config_readb(vdev, offset);
 125         case 2:
 126             return virtio_config_readw(vdev, offset);
 127         case 4:
 128             return virtio_config_readl(vdev, offset);
 129         default:
 130             abort();
 131         }
 132     }
 133     if (size != 4) {
 134         DPRINTF("wrong size access to register!\n");
 135         return 0;
 136     }
 137     switch (offset) {
 138     case VIRTIO_MMIO_MAGIC:
 139         return VIRT_MAGIC;
 140     case VIRTIO_MMIO_VERSION:
 141         return VIRT_VERSION;
 142     case VIRTIO_MMIO_DEVICEID:
 143         return vdev->device_id;
 144     case VIRTIO_MMIO_VENDORID:
 145         return VIRT_VENDOR;
 146     case VIRTIO_MMIO_HOSTFEATURES:
 147         if (proxy->host_features_sel) {
 148             return 0;
 149         }
 150         return proxy->host_features;
 151     case VIRTIO_MMIO_QUEUENUMMAX:
 152         if (!virtio_queue_get_num(vdev, vdev->queue_sel)) {
 153             return 0;
 154         }
 155         return VIRTQUEUE_MAX_SIZE;
 156     case VIRTIO_MMIO_QUEUEPFN:
 157         return virtio_queue_get_addr(vdev, vdev->queue_sel)
 158             >> proxy->guest_page_shift;
 159     case VIRTIO_MMIO_INTERRUPTSTATUS:
 160         return vdev->isr;
 161     case VIRTIO_MMIO_STATUS:
 162         return vdev->status;
 163     case VIRTIO_MMIO_HOSTFEATURESSEL:
 164     case VIRTIO_MMIO_GUESTFEATURES:
 165     case VIRTIO_MMIO_GUESTFEATURESSEL:
 166     case VIRTIO_MMIO_GUESTPAGESIZE:
 167     case VIRTIO_MMIO_QUEUESEL:
 168     case VIRTIO_MMIO_QUEUENUM:
 169     case VIRTIO_MMIO_QUEUEALIGN:
 170     case VIRTIO_MMIO_QUEUENOTIFY:
 171     case VIRTIO_MMIO_INTERRUPTACK:
 172         DPRINTF("read of write-only register\n");
 173         return 0;
 174     default:
 175         DPRINTF("bad register offset\n");
 176         return 0;
 177     }
 178     return 0;
 179 }
 180
 181 static void virtio_mmio_write(void *opaque, hwaddr offset, uint64_t value,
 182                               unsigned size)
 183 {
 184     VirtIOMMIOProxy *proxy = (VirtIOMMIOProxy *)opaque;
 185     VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
 186
 187     DPRINTF("virtio_mmio_write offset 0x%x value 0x%" PRIx64 "\n",
 188             (int)offset, value);
 189
 190     if (!vdev) {
 191         /* If no backend is present, we just make all registers
 192          * write-ignored. This allows us to provide transports with
 193          * no backend plugged in.
 194          */
 195         return;
 196     }
 197
 198     if (offset >= VIRTIO_MMIO_CONFIG) {
 199         offset -= VIRTIO_MMIO_CONFIG;
 200         switch (size) {
 201         case 1:
 202             virtio_config_writeb(vdev, offset, value);
 203             break;
 204         case 2:
 205             virtio_config_writew(vdev, offset, value);
 206             break;
 207         case 4:
 208             virtio_config_writel(vdev, offset, value);
 209             break;
 210         default:
 211             abort();
 212         }
 213         return;
 214     }
 215     if (size != 4) {
 216         DPRINTF("wrong size access to register!\n");
 217         return;
 218     }
 219     switch (offset) {
 220     case VIRTIO_MMIO_HOSTFEATURESSEL:
 221         proxy->host_features_sel = value;
 222         break;
 223     case VIRTIO_MMIO_GUESTFEATURES:
 224         if (!proxy->guest_features_sel) {
 225             virtio_set_features(vdev, value);
 226         }
 227         break;
 228     case VIRTIO_MMIO_GUESTFEATURESSEL:
 229         proxy->guest_features_sel = value;
 230         break;
 231     case VIRTIO_MMIO_GUESTPAGESIZE:
 232         proxy->guest_page_shift = ctz32(value);
 233         if (proxy->guest_page_shift > 31) {
 234             proxy->guest_page_shift = 0;
 235         }
 236         DPRINTF("guest page size %" PRIx64 " shift %d\n", value,
 237                 proxy->guest_page_shift);
 238         break;
 239     case VIRTIO_MMIO_QUEUESEL:
 240         if (value < VIRTIO_PCI_QUEUE_MAX) {
 241             vdev->queue_sel = value;
 242         }
 243         break;
 244     case VIRTIO_MMIO_QUEUENUM:
 245         DPRINTF("mmio_queue write %d max %d\n", (int)value, VIRTQUEUE_MAX_SIZE);
 246         virtio_queue_set_num(vdev, vdev->queue_sel, value);
 247         break;
 248     case VIRTIO_MMIO_QUEUEALIGN:
 249         virtio_queue_set_align(vdev, vdev->queue_sel, value);
 250         break;
 251     case VIRTIO_MMIO_QUEUEPFN:
 252         if (value == 0) {
 253             virtio_reset(vdev);
 254         } else {
 255             virtio_queue_set_addr(vdev, vdev->queue_sel,
 256                                   value << proxy->guest_page_shift);
 257         }
 258         break;
 259     case VIRTIO_MMIO_QUEUENOTIFY:
 260         if (value < VIRTIO_PCI_QUEUE_MAX) {
 261             virtio_queue_notify(vdev, value);
 262         }
 263         break;
 264     case VIRTIO_MMIO_INTERRUPTACK:
 265         vdev->isr &= ~value;
 266         virtio_update_irq(vdev);
 267         break;
 268     case VIRTIO_MMIO_STATUS:
 269         virtio_set_status(vdev, value & 0xff);
 270         if (vdev->status == 0) {
 271             virtio_reset(vdev);
 272         }
 273         break;
 274     case VIRTIO_MMIO_MAGIC:
 275     case VIRTIO_MMIO_VERSION:
 276     case VIRTIO_MMIO_DEVICEID:
 277     case VIRTIO_MMIO_VENDORID:
 278     case VIRTIO_MMIO_HOSTFEATURES:
 279     case VIRTIO_MMIO_QUEUENUMMAX:
 280     case VIRTIO_MMIO_INTERRUPTSTATUS:
 281         DPRINTF("write to readonly register\n");
 282         break;
 283
 284     default:
 285         DPRINTF("bad register offset\n");
 286     }
 287 }
 288
 289 static const MemoryRegionOps virtio_mem_ops = {
 290     .read = virtio_mmio_read,
 291     .write = virtio_mmio_write,
 292     .endianness = DEVICE_NATIVE_ENDIAN,
 293 };
 294
 295 static void virtio_mmio_update_irq(DeviceState *opaque, uint16_t vector)
 296 {
 297     VirtIOMMIOProxy *proxy = VIRTIO_MMIO(opaque);
 298     VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
 299     int level;
 300
 301     if (!vdev) {
 302         return;
 303     }
 304     level = (vdev->isr != 0);
 305     DPRINTF("virtio_mmio setting IRQ %d\n", level);
 306     qemu_set_irq(proxy->irq, level);
 307 }
 308
 309 static unsigned int virtio_mmio_get_features(DeviceState *opaque)
 310 {
 311     VirtIOMMIOProxy *proxy = VIRTIO_MMIO(opaque);
 312
 313     return proxy->host_features;
 314 }
 315
 316 static int virtio_mmio_load_config(DeviceState *opaque, QEMUFile *f)
 317 {
 318     VirtIOMMIOProxy *proxy = VIRTIO_MMIO(opaque);
 319
 320     proxy->host_features_sel = qemu_get_be32(f);
 321     proxy->guest_features_sel = qemu_get_be32(f);
 322     proxy->guest_page_shift = qemu_get_be32(f);
 323     return 0;
 324 }
 325
 326 static void virtio_mmio_save_config(DeviceState *opaque, QEMUFile *f)
 327 {
 328     VirtIOMMIOProxy *proxy = VIRTIO_MMIO(opaque);
 329
 330     qemu_put_be32(f, proxy->host_features_sel);
 331     qemu_put_be32(f, proxy->guest_features_sel);
 332     qemu_put_be32(f, proxy->guest_page_shift);
 333 }
 334
 335 static void virtio_mmio_reset(DeviceState *d)
 336 {
 337     VirtIOMMIOProxy *proxy = VIRTIO_MMIO(d);
 338
 339     virtio_bus_reset(&proxy->bus);
 340     proxy->host_features_sel = 0;
 341     proxy->guest_features_sel = 0;
 342     proxy->guest_page_shift = 0;
 343 }
 344
 345 /* virtio-mmio device */
 346
 347 /* This is called by virtio-bus just after the device is plugged. */
 348 static void virtio_mmio_device_plugged(DeviceState *opaque)
 349 {
 350     VirtIOMMIOProxy *proxy = VIRTIO_MMIO(opaque);
 351
 352     virtio_add_feature(&proxy->host_features, VIRTIO_F_NOTIFY_ON_EMPTY);
 353     proxy->host_features = virtio_bus_get_vdev_features(&proxy->bus,
 354                                                         proxy->host_features);
 355 }
 356
 357 static void virtio_mmio_realizefn(DeviceState *d, Error **errp)
 358 {
 359     VirtIOMMIOProxy *proxy = VIRTIO_MMIO(d);
 360     SysBusDevice *sbd = SYS_BUS_DEVICE(d);
 361
 362     qbus_create_inplace(&proxy->bus, sizeof(proxy->bus), TYPE_VIRTIO_MMIO_BUS,
 363                         d, NULL);
 364     sysbus_init_irq(sbd, &proxy->irq);
 365     memory_region_init_io(&proxy->iomem, OBJECT(d), &virtio_mem_ops, proxy,
 366                           TYPE_VIRTIO_MMIO, 0x200);
 367     sysbus_init_mmio(sbd, &proxy->iomem);
 368 }
 369
 370 static Property virtio_mmio_properties[] = {
 371     DEFINE_VIRTIO_COMMON_FEATURES(VirtIOMMIOProxy, host_features),
 372     DEFINE_PROP_END_OF_LIST(),
 373 };
 374
 375 static void virtio_mmio_class_init(ObjectClass *klass, void *data)
 376 {
 377     DeviceClass *dc = DEVICE_CLASS(klass);
 378
 379     dc->props = virtio_mmio_properties;
 380     dc->realize = virtio_mmio_realizefn;
 381     dc->reset = virtio_mmio_reset;
 382     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
 383 }
 384
 385 static const TypeInfo virtio_mmio_info = {
 386     .name          = TYPE_VIRTIO_MMIO,
 387     .parent        = TYPE_SYS_BUS_DEVICE,
 388     .instance_size = sizeof(VirtIOMMIOProxy),
 389     .class_init    = virtio_mmio_class_init,
 390 };
 391
 392 /* virtio-mmio-bus. */
 393
 394 static void virtio_mmio_bus_class_init(ObjectClass *klass, void *data)
 395 {
 396     BusClass *bus_class = BUS_CLASS(klass);
 397     VirtioBusClass *k = VIRTIO_BUS_CLASS(klass);
 398
 399     k->notify = virtio_mmio_update_irq;
 400     k->save_config = virtio_mmio_save_config;
 401     k->load_config = virtio_mmio_load_config;
 402     k->get_features = virtio_mmio_get_features;
 403     k->device_plugged = virtio_mmio_device_plugged;
 404     k->has_variable_vring_alignment = true;
 405     bus_class->max_dev = 1;
 406 }
 407
 408 static const TypeInfo virtio_mmio_bus_info = {
 409     .name          = TYPE_VIRTIO_MMIO_BUS,
 410     .parent        = TYPE_VIRTIO_BUS,
 411     .instance_size = sizeof(VirtioBusState),
 412     .class_init    = virtio_mmio_bus_class_init,
 413 };
 414
 415 static void virtio_mmio_register_types(void)
 416 {
 417     type_register_static(&virtio_mmio_bus_info);
 418     type_register_static(&virtio_mmio_info);
 419 }
 420
 421 type_init(virtio_mmio_register_types)