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 void virtio_mmio_bus_new(VirtioBusState *bus, size_t bus_size, 93 VirtIOMMIOProxy *dev); 94 95 static uint64_t virtio_mmio_read(void *opaque, hwaddr offset, unsigned size) 96 { 97 VirtIOMMIOProxy *proxy = (VirtIOMMIOProxy *)opaque; 98 VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus); 99 100 DPRINTF("virtio_mmio_read offset 0x%x\n", (int)offset); 101 102 if (!vdev) { 103 /* If no backend is present, we treat most registers as 104 * read-as-zero, except for the magic number, version and 105 * vendor ID. This is not strictly sanctioned by the virtio 106 * spec, but it allows us to provide transports with no backend 107 * plugged in which don't confuse Linux's virtio code: the 108 * probe won't complain about the bad magic number, but the 109 * device ID of zero means no backend will claim it. 110 */ 111 switch (offset) { 112 case VIRTIO_MMIO_MAGIC: 113 return VIRT_MAGIC; 114 case VIRTIO_MMIO_VERSION: 115 return VIRT_VERSION; 116 case VIRTIO_MMIO_VENDORID: 117 return VIRT_VENDOR; 118 default: 119 return 0; 120 } 121 } 122 123 if (offset >= VIRTIO_MMIO_CONFIG) { 124 offset -= VIRTIO_MMIO_CONFIG; 125 switch (size) { 126 case 1: 127 return virtio_config_readb(vdev, offset); 128 case 2: 129 return virtio_config_readw(vdev, offset); 130 case 4: 131 return virtio_config_readl(vdev, offset); 132 default: 133 abort(); 134 } 135 } 136 if (size != 4) { 137 DPRINTF("wrong size access to register!\n"); 138 return 0; 139 } 140 switch (offset) { 141 case VIRTIO_MMIO_MAGIC: 142 return VIRT_MAGIC; 143 case VIRTIO_MMIO_VERSION: 144 return VIRT_VERSION; 145 case VIRTIO_MMIO_DEVICEID: 146 return vdev->device_id; 147 case VIRTIO_MMIO_VENDORID: 148 return VIRT_VENDOR; 149 case VIRTIO_MMIO_HOSTFEATURES: 150 if (proxy->host_features_sel) { 151 return 0; 152 } 153 return proxy->host_features; 154 case VIRTIO_MMIO_QUEUENUMMAX: 155 if (!virtio_queue_get_num(vdev, vdev->queue_sel)) { 156 return 0; 157 } 158 return VIRTQUEUE_MAX_SIZE; 159 case VIRTIO_MMIO_QUEUEPFN: 160 return virtio_queue_get_addr(vdev, vdev->queue_sel) 161 >> proxy->guest_page_shift; 162 case VIRTIO_MMIO_INTERRUPTSTATUS: 163 return vdev->isr; 164 case VIRTIO_MMIO_STATUS: 165 return vdev->status; 166 case VIRTIO_MMIO_HOSTFEATURESSEL: 167 case VIRTIO_MMIO_GUESTFEATURES: 168 case VIRTIO_MMIO_GUESTFEATURESSEL: 169 case VIRTIO_MMIO_GUESTPAGESIZE: 170 case VIRTIO_MMIO_QUEUESEL: 171 case VIRTIO_MMIO_QUEUENUM: 172 case VIRTIO_MMIO_QUEUEALIGN: 173 case VIRTIO_MMIO_QUEUENOTIFY: 174 case VIRTIO_MMIO_INTERRUPTACK: 175 DPRINTF("read of write-only register\n"); 176 return 0; 177 default: 178 DPRINTF("bad register offset\n"); 179 return 0; 180 } 181 return 0; 182 } 183 184 static void virtio_mmio_write(void *opaque, hwaddr offset, uint64_t value, 185 unsigned size) 186 { 187 VirtIOMMIOProxy *proxy = (VirtIOMMIOProxy *)opaque; 188 VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus); 189 190 DPRINTF("virtio_mmio_write offset 0x%x value 0x%" PRIx64 "\n", 191 (int)offset, value); 192 193 if (!vdev) { 194 /* If no backend is present, we just make all registers 195 * write-ignored. This allows us to provide transports with 196 * no backend plugged in. 197 */ 198 return; 199 } 200 201 if (offset >= VIRTIO_MMIO_CONFIG) { 202 offset -= VIRTIO_MMIO_CONFIG; 203 switch (size) { 204 case 1: 205 virtio_config_writeb(vdev, offset, value); 206 break; 207 case 2: 208 virtio_config_writew(vdev, offset, value); 209 break; 210 case 4: 211 virtio_config_writel(vdev, offset, value); 212 break; 213 default: 214 abort(); 215 } 216 return; 217 } 218 if (size != 4) { 219 DPRINTF("wrong size access to register!\n"); 220 return; 221 } 222 switch (offset) { 223 case VIRTIO_MMIO_HOSTFEATURESSEL: 224 proxy->host_features_sel = value; 225 break; 226 case VIRTIO_MMIO_GUESTFEATURES: 227 if (!proxy->guest_features_sel) { 228 virtio_set_features(vdev, value); 229 } 230 break; 231 case VIRTIO_MMIO_GUESTFEATURESSEL: 232 proxy->guest_features_sel = value; 233 break; 234 case VIRTIO_MMIO_GUESTPAGESIZE: 235 proxy->guest_page_shift = ctz32(value); 236 if (proxy->guest_page_shift > 31) { 237 proxy->guest_page_shift = 0; 238 } 239 DPRINTF("guest page size %" PRIx64 " shift %d\n", value, 240 proxy->guest_page_shift); 241 break; 242 case VIRTIO_MMIO_QUEUESEL: 243 if (value < VIRTIO_PCI_QUEUE_MAX) { 244 vdev->queue_sel = value; 245 } 246 break; 247 case VIRTIO_MMIO_QUEUENUM: 248 DPRINTF("mmio_queue write %d max %d\n", (int)value, VIRTQUEUE_MAX_SIZE); 249 virtio_queue_set_num(vdev, vdev->queue_sel, value); 250 break; 251 case VIRTIO_MMIO_QUEUEALIGN: 252 virtio_queue_set_align(vdev, vdev->queue_sel, value); 253 break; 254 case VIRTIO_MMIO_QUEUEPFN: 255 if (value == 0) { 256 virtio_reset(vdev); 257 } else { 258 virtio_queue_set_addr(vdev, vdev->queue_sel, 259 value << proxy->guest_page_shift); 260 } 261 break; 262 case VIRTIO_MMIO_QUEUENOTIFY: 263 if (value < VIRTIO_PCI_QUEUE_MAX) { 264 virtio_queue_notify(vdev, value); 265 } 266 break; 267 case VIRTIO_MMIO_INTERRUPTACK: 268 vdev->isr &= ~value; 269 virtio_update_irq(vdev); 270 break; 271 case VIRTIO_MMIO_STATUS: 272 virtio_set_status(vdev, value & 0xff); 273 if (vdev->status == 0) { 274 virtio_reset(vdev); 275 } 276 break; 277 case VIRTIO_MMIO_MAGIC: 278 case VIRTIO_MMIO_VERSION: 279 case VIRTIO_MMIO_DEVICEID: 280 case VIRTIO_MMIO_VENDORID: 281 case VIRTIO_MMIO_HOSTFEATURES: 282 case VIRTIO_MMIO_QUEUENUMMAX: 283 case VIRTIO_MMIO_INTERRUPTSTATUS: 284 DPRINTF("write to readonly register\n"); 285 break; 286 287 default: 288 DPRINTF("bad register offset\n"); 289 } 290 } 291 292 static const MemoryRegionOps virtio_mem_ops = { 293 .read = virtio_mmio_read, 294 .write = virtio_mmio_write, 295 .endianness = DEVICE_NATIVE_ENDIAN, 296 }; 297 298 static void virtio_mmio_update_irq(DeviceState *opaque, uint16_t vector) 299 { 300 VirtIOMMIOProxy *proxy = VIRTIO_MMIO(opaque); 301 VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus); 302 int level; 303 304 if (!vdev) { 305 return; 306 } 307 level = (vdev->isr != 0); 308 DPRINTF("virtio_mmio setting IRQ %d\n", level); 309 qemu_set_irq(proxy->irq, level); 310 } 311 312 static unsigned int virtio_mmio_get_features(DeviceState *opaque) 313 { 314 VirtIOMMIOProxy *proxy = VIRTIO_MMIO(opaque); 315 316 return proxy->host_features; 317 } 318 319 static int virtio_mmio_load_config(DeviceState *opaque, QEMUFile *f) 320 { 321 VirtIOMMIOProxy *proxy = VIRTIO_MMIO(opaque); 322 323 proxy->host_features_sel = qemu_get_be32(f); 324 proxy->guest_features_sel = qemu_get_be32(f); 325 proxy->guest_page_shift = qemu_get_be32(f); 326 return 0; 327 } 328 329 static void virtio_mmio_save_config(DeviceState *opaque, QEMUFile *f) 330 { 331 VirtIOMMIOProxy *proxy = VIRTIO_MMIO(opaque); 332 333 qemu_put_be32(f, proxy->host_features_sel); 334 qemu_put_be32(f, proxy->guest_features_sel); 335 qemu_put_be32(f, proxy->guest_page_shift); 336 } 337 338 static void virtio_mmio_reset(DeviceState *d) 339 { 340 VirtIOMMIOProxy *proxy = VIRTIO_MMIO(d); 341 342 virtio_bus_reset(&proxy->bus); 343 proxy->host_features_sel = 0; 344 proxy->guest_features_sel = 0; 345 proxy->guest_page_shift = 0; 346 } 347 348 /* virtio-mmio device */ 349 350 /* This is called by virtio-bus just after the device is plugged. */ 351 static void virtio_mmio_device_plugged(DeviceState *opaque) 352 { 353 VirtIOMMIOProxy *proxy = VIRTIO_MMIO(opaque); 354 355 proxy->host_features |= (0x1 << VIRTIO_F_NOTIFY_ON_EMPTY); 356 proxy->host_features = virtio_bus_get_vdev_features(&proxy->bus, 357 proxy->host_features); 358 } 359 360 static void virtio_mmio_realizefn(DeviceState *d, Error **errp) 361 { 362 VirtIOMMIOProxy *proxy = VIRTIO_MMIO(d); 363 SysBusDevice *sbd = SYS_BUS_DEVICE(d); 364 365 virtio_mmio_bus_new(&proxy->bus, sizeof(proxy->bus), proxy); 366 sysbus_init_irq(sbd, &proxy->irq); 367 memory_region_init_io(&proxy->iomem, OBJECT(d), &virtio_mem_ops, proxy, 368 TYPE_VIRTIO_MMIO, 0x200); 369 sysbus_init_mmio(sbd, &proxy->iomem); 370 } 371 372 static void virtio_mmio_class_init(ObjectClass *klass, void *data) 373 { 374 DeviceClass *dc = DEVICE_CLASS(klass); 375 376 dc->realize = virtio_mmio_realizefn; 377 dc->reset = virtio_mmio_reset; 378 set_bit(DEVICE_CATEGORY_MISC, dc->categories); 379 } 380 381 static const TypeInfo virtio_mmio_info = { 382 .name = TYPE_VIRTIO_MMIO, 383 .parent = TYPE_SYS_BUS_DEVICE, 384 .instance_size = sizeof(VirtIOMMIOProxy), 385 .class_init = virtio_mmio_class_init, 386 }; 387 388 /* virtio-mmio-bus. */ 389 390 static void virtio_mmio_bus_new(VirtioBusState *bus, size_t bus_size, 391 VirtIOMMIOProxy *dev) 392 { 393 DeviceState *qdev = DEVICE(dev); 394 BusState *qbus; 395 396 qbus_create_inplace(bus, bus_size, TYPE_VIRTIO_MMIO_BUS, qdev, NULL); 397 qbus = BUS(bus); 398 qbus->allow_hotplug = 0; 399 } 400 401 static void virtio_mmio_bus_class_init(ObjectClass *klass, void *data) 402 { 403 BusClass *bus_class = BUS_CLASS(klass); 404 VirtioBusClass *k = VIRTIO_BUS_CLASS(klass); 405 406 k->notify = virtio_mmio_update_irq; 407 k->save_config = virtio_mmio_save_config; 408 k->load_config = virtio_mmio_load_config; 409 k->get_features = virtio_mmio_get_features; 410 k->device_plugged = virtio_mmio_device_plugged; 411 k->has_variable_vring_alignment = true; 412 bus_class->max_dev = 1; 413 } 414 415 static const TypeInfo virtio_mmio_bus_info = { 416 .name = TYPE_VIRTIO_MMIO_BUS, 417 .parent = TYPE_VIRTIO_BUS, 418 .instance_size = sizeof(VirtioBusState), 419 .class_init = virtio_mmio_bus_class_init, 420 }; 421 422 static void virtio_mmio_register_types(void) 423 { 424 type_register_static(&virtio_mmio_bus_info); 425 type_register_static(&virtio_mmio_info); 426 } 427 428 type_init(virtio_mmio_register_types) 429