1 /* 2 * libqos virtio driver 3 * 4 * Copyright (c) 2014 Marc Marí 5 * 6 * This work is licensed under the terms of the GNU GPL, version 2 or later. 7 * See the COPYING file in the top-level directory. 8 */ 9 10 #include "qemu/osdep.h" 11 #include "qemu/bswap.h" 12 #include "../libqtest.h" 13 #include "virtio.h" 14 #include "standard-headers/linux/virtio_config.h" 15 #include "standard-headers/linux/virtio_ring.h" 16 17 /* 18 * qtest_readX/writeX() functions transfer host endian from/to guest endian. 19 * This works great for Legacy VIRTIO devices where we need guest endian 20 * accesses. For VIRTIO 1.0 the vring is little-endian so the automatic guest 21 * endianness conversion is not wanted. 22 * 23 * The following qvirtio_readX/writeX() functions handle Legacy and VIRTIO 1.0 24 * accesses seamlessly. 25 */ 26 static uint16_t qvirtio_readw(QVirtioDevice *d, QTestState *qts, uint64_t addr) 27 { 28 uint16_t val; 29 30 if (d->features & (1ull << VIRTIO_F_VERSION_1)) { 31 qtest_memread(qts, addr, &val, sizeof(val)); 32 val = le16_to_cpu(val); 33 } else { 34 val = qtest_readw(qts, addr); 35 } 36 37 return val; 38 } 39 40 static uint32_t qvirtio_readl(QVirtioDevice *d, QTestState *qts, uint64_t addr) 41 { 42 uint32_t val; 43 44 if (d->features & (1ull << VIRTIO_F_VERSION_1)) { 45 qtest_memread(qts, addr, &val, sizeof(val)); 46 val = le32_to_cpu(val); 47 } else { 48 val = qtest_readl(qts, addr); 49 } 50 51 return val; 52 } 53 54 static void qvirtio_writew(QVirtioDevice *d, QTestState *qts, 55 uint64_t addr, uint16_t val) 56 { 57 if (d->features & (1ull << VIRTIO_F_VERSION_1)) { 58 val = cpu_to_le16(val); 59 qtest_memwrite(qts, addr, &val, sizeof(val)); 60 } else { 61 qtest_writew(qts, addr, val); 62 } 63 } 64 65 static void qvirtio_writel(QVirtioDevice *d, QTestState *qts, 66 uint64_t addr, uint32_t val) 67 { 68 if (d->features & (1ull << VIRTIO_F_VERSION_1)) { 69 val = cpu_to_le32(val); 70 qtest_memwrite(qts, addr, &val, sizeof(val)); 71 } else { 72 qtest_writel(qts, addr, val); 73 } 74 } 75 76 static void qvirtio_writeq(QVirtioDevice *d, QTestState *qts, 77 uint64_t addr, uint64_t val) 78 { 79 if (d->features & (1ull << VIRTIO_F_VERSION_1)) { 80 val = cpu_to_le64(val); 81 qtest_memwrite(qts, addr, &val, sizeof(val)); 82 } else { 83 qtest_writeq(qts, addr, val); 84 } 85 } 86 87 uint8_t qvirtio_config_readb(QVirtioDevice *d, uint64_t addr) 88 { 89 g_assert_true(d->features_negotiated); 90 return d->bus->config_readb(d, addr); 91 } 92 93 uint16_t qvirtio_config_readw(QVirtioDevice *d, uint64_t addr) 94 { 95 g_assert_true(d->features_negotiated); 96 return d->bus->config_readw(d, addr); 97 } 98 99 uint32_t qvirtio_config_readl(QVirtioDevice *d, uint64_t addr) 100 { 101 g_assert_true(d->features_negotiated); 102 return d->bus->config_readl(d, addr); 103 } 104 105 uint64_t qvirtio_config_readq(QVirtioDevice *d, uint64_t addr) 106 { 107 g_assert_true(d->features_negotiated); 108 return d->bus->config_readq(d, addr); 109 } 110 111 uint64_t qvirtio_get_features(QVirtioDevice *d) 112 { 113 return d->bus->get_features(d); 114 } 115 116 void qvirtio_set_features(QVirtioDevice *d, uint64_t features) 117 { 118 g_assert(!(features & QVIRTIO_F_BAD_FEATURE)); 119 120 d->features = features; 121 d->bus->set_features(d, features); 122 123 /* 124 * This could be a separate function for drivers that want to access 125 * configuration space before setting FEATURES_OK, but no existing users 126 * need that and it's less code for callers if this is done implicitly. 127 */ 128 if (features & (1ull << VIRTIO_F_VERSION_1)) { 129 uint8_t status = d->bus->get_status(d) | 130 VIRTIO_CONFIG_S_FEATURES_OK; 131 132 d->bus->set_status(d, status); 133 g_assert_cmphex(d->bus->get_status(d), ==, status); 134 } 135 136 d->features_negotiated = true; 137 } 138 139 QVirtQueue *qvirtqueue_setup(QVirtioDevice *d, 140 QGuestAllocator *alloc, uint16_t index) 141 { 142 g_assert_true(d->features_negotiated); 143 return d->bus->virtqueue_setup(d, alloc, index); 144 } 145 146 void qvirtqueue_cleanup(const QVirtioBus *bus, QVirtQueue *vq, 147 QGuestAllocator *alloc) 148 { 149 return bus->virtqueue_cleanup(vq, alloc); 150 } 151 152 void qvirtio_reset(QVirtioDevice *d) 153 { 154 d->bus->set_status(d, 0); 155 g_assert_cmphex(d->bus->get_status(d), ==, 0); 156 d->features_negotiated = false; 157 } 158 159 void qvirtio_set_acknowledge(QVirtioDevice *d) 160 { 161 d->bus->set_status(d, d->bus->get_status(d) | VIRTIO_CONFIG_S_ACKNOWLEDGE); 162 g_assert_cmphex(d->bus->get_status(d), ==, VIRTIO_CONFIG_S_ACKNOWLEDGE); 163 } 164 165 void qvirtio_set_driver(QVirtioDevice *d) 166 { 167 d->bus->set_status(d, d->bus->get_status(d) | VIRTIO_CONFIG_S_DRIVER); 168 g_assert_cmphex(d->bus->get_status(d), ==, 169 VIRTIO_CONFIG_S_DRIVER | VIRTIO_CONFIG_S_ACKNOWLEDGE); 170 } 171 172 void qvirtio_set_driver_ok(QVirtioDevice *d) 173 { 174 d->bus->set_status(d, d->bus->get_status(d) | VIRTIO_CONFIG_S_DRIVER_OK); 175 g_assert_cmphex(d->bus->get_status(d), ==, VIRTIO_CONFIG_S_DRIVER_OK | 176 VIRTIO_CONFIG_S_DRIVER | VIRTIO_CONFIG_S_ACKNOWLEDGE | 177 (d->features & (1ull << VIRTIO_F_VERSION_1) ? 178 VIRTIO_CONFIG_S_FEATURES_OK : 0)); 179 } 180 181 void qvirtio_wait_queue_isr(QTestState *qts, QVirtioDevice *d, 182 QVirtQueue *vq, gint64 timeout_us) 183 { 184 gint64 start_time = g_get_monotonic_time(); 185 186 for (;;) { 187 if (d->bus->get_queue_isr_status(d, vq)) { 188 return; 189 } 190 g_assert(g_get_monotonic_time() - start_time <= timeout_us); 191 } 192 } 193 194 /* Wait for the status byte at given guest memory address to be set 195 * 196 * The virtqueue interrupt must not be raised, making this useful for testing 197 * event_index functionality. 198 */ 199 uint8_t qvirtio_wait_status_byte_no_isr(QTestState *qts, QVirtioDevice *d, 200 QVirtQueue *vq, 201 uint64_t addr, 202 gint64 timeout_us) 203 { 204 gint64 start_time = g_get_monotonic_time(); 205 uint8_t val; 206 207 while ((val = qtest_readb(qts, addr)) == 0xff) { 208 g_assert(!d->bus->get_queue_isr_status(d, vq)); 209 g_assert(g_get_monotonic_time() - start_time <= timeout_us); 210 } 211 return val; 212 } 213 214 /* 215 * qvirtio_wait_used_elem: 216 * @desc_idx: The next expected vq->desc[] index in the used ring 217 * @len: A pointer that is filled with the length written into the buffer, may 218 * be NULL 219 * @timeout_us: How many microseconds to wait before failing 220 * 221 * This function waits for the next completed request on the used ring. 222 */ 223 void qvirtio_wait_used_elem(QTestState *qts, QVirtioDevice *d, 224 QVirtQueue *vq, 225 uint32_t desc_idx, 226 uint32_t *len, 227 gint64 timeout_us) 228 { 229 gint64 start_time = g_get_monotonic_time(); 230 231 for (;;) { 232 uint32_t got_desc_idx; 233 234 235 if (d->bus->get_queue_isr_status(d, vq) && 236 qvirtqueue_get_buf(qts, vq, &got_desc_idx, len)) { 237 g_assert_cmpint(got_desc_idx, ==, desc_idx); 238 return; 239 } 240 g_assert(g_get_monotonic_time() - start_time <= timeout_us); 241 } 242 } 243 244 void qvirtio_wait_config_isr(QVirtioDevice *d, gint64 timeout_us) 245 { 246 d->bus->wait_config_isr_status(d, timeout_us); 247 } 248 249 void qvring_init(QTestState *qts, const QGuestAllocator *alloc, QVirtQueue *vq, 250 uint64_t addr) 251 { 252 int i; 253 254 vq->desc = addr; 255 vq->avail = vq->desc + vq->size * sizeof(struct vring_desc); 256 vq->used = (uint64_t)((vq->avail + sizeof(uint16_t) * (3 + vq->size) 257 + vq->align - 1) & ~(vq->align - 1)); 258 259 for (i = 0; i < vq->size - 1; i++) { 260 /* vq->desc[i].addr */ 261 qvirtio_writeq(vq->vdev, qts, vq->desc + (16 * i), 0); 262 /* vq->desc[i].next */ 263 qvirtio_writew(vq->vdev, qts, vq->desc + (16 * i) + 14, i + 1); 264 } 265 266 /* vq->avail->flags */ 267 qvirtio_writew(vq->vdev, qts, vq->avail, 0); 268 269 qvirtqueue_set_avail_idx(qts, vq->vdev, vq, 0); 270 271 /* vq->avail->used_event */ 272 qvirtio_writew(vq->vdev, qts, vq->avail + 4 + (2 * vq->size), 0); 273 274 /* vq->used->flags */ 275 qvirtio_writew(vq->vdev, qts, vq->used, 0); 276 /* vq->used->idx */ 277 qvirtio_writew(vq->vdev, qts, vq->used + 2, 0); 278 /* vq->used->avail_event */ 279 qvirtio_writew(vq->vdev, qts, vq->used + 4 + 280 sizeof(struct vring_used_elem) * vq->size, 0); 281 } 282 283 QVRingIndirectDesc *qvring_indirect_desc_setup(QTestState *qs, QVirtioDevice *d, 284 QGuestAllocator *alloc, 285 uint16_t elem) 286 { 287 int i; 288 QVRingIndirectDesc *indirect = g_malloc(sizeof(*indirect)); 289 290 indirect->index = 0; 291 indirect->elem = elem; 292 indirect->desc = guest_alloc(alloc, sizeof(struct vring_desc) * elem); 293 294 for (i = 0; i < elem; ++i) { 295 /* indirect->desc[i].addr */ 296 qvirtio_writeq(d, qs, indirect->desc + (16 * i), 0); 297 298 /* 299 * If it's not the last element of the ring, set 300 * the chain (VRING_DESC_F_NEXT) flag and 301 * desc->next. Clear the last element - there's 302 * no guarantee that guest_alloc() will do it. 303 */ 304 if (i != elem - 1) { 305 /* indirect->desc[i].flags */ 306 qvirtio_writew(d, qs, indirect->desc + (16 * i) + 12, 307 VRING_DESC_F_NEXT); 308 309 /* indirect->desc[i].next */ 310 qvirtio_writew(d, qs, indirect->desc + (16 * i) + 14, i + 1); 311 } else { 312 qvirtio_writew(d, qs, indirect->desc + (16 * i) + 12, 0); 313 qvirtio_writew(d, qs, indirect->desc + (16 * i) + 14, 0); 314 } 315 } 316 317 return indirect; 318 } 319 320 void qvring_indirect_desc_add(QVirtioDevice *d, QTestState *qts, 321 QVRingIndirectDesc *indirect, 322 uint64_t data, uint32_t len, bool write) 323 { 324 uint16_t flags; 325 326 g_assert_cmpint(indirect->index, <, indirect->elem); 327 328 flags = qvirtio_readw(d, qts, indirect->desc + 329 (16 * indirect->index) + 12); 330 331 if (write) { 332 flags |= VRING_DESC_F_WRITE; 333 } 334 335 /* indirect->desc[indirect->index].addr */ 336 qvirtio_writeq(d, qts, indirect->desc + (16 * indirect->index), data); 337 /* indirect->desc[indirect->index].len */ 338 qvirtio_writel(d, qts, indirect->desc + (16 * indirect->index) + 8, len); 339 /* indirect->desc[indirect->index].flags */ 340 qvirtio_writew(d, qts, indirect->desc + (16 * indirect->index) + 12, 341 flags); 342 343 indirect->index++; 344 } 345 346 uint32_t qvirtqueue_add(QTestState *qts, QVirtQueue *vq, uint64_t data, 347 uint32_t len, bool write, bool next) 348 { 349 uint16_t flags = 0; 350 vq->num_free--; 351 352 if (write) { 353 flags |= VRING_DESC_F_WRITE; 354 } 355 356 if (next) { 357 flags |= VRING_DESC_F_NEXT; 358 } 359 360 /* vq->desc[vq->free_head].addr */ 361 qvirtio_writeq(vq->vdev, qts, vq->desc + (16 * vq->free_head), data); 362 /* vq->desc[vq->free_head].len */ 363 qvirtio_writel(vq->vdev, qts, vq->desc + (16 * vq->free_head) + 8, len); 364 /* vq->desc[vq->free_head].flags */ 365 qvirtio_writew(vq->vdev, qts, vq->desc + (16 * vq->free_head) + 12, flags); 366 367 return vq->free_head++; /* Return and increase, in this order */ 368 } 369 370 uint32_t qvirtqueue_add_indirect(QTestState *qts, QVirtQueue *vq, 371 QVRingIndirectDesc *indirect) 372 { 373 g_assert(vq->indirect); 374 g_assert_cmpint(vq->size, >=, indirect->elem); 375 g_assert_cmpint(indirect->index, ==, indirect->elem); 376 377 vq->num_free--; 378 379 /* vq->desc[vq->free_head].addr */ 380 qvirtio_writeq(vq->vdev, qts, vq->desc + (16 * vq->free_head), 381 indirect->desc); 382 /* vq->desc[vq->free_head].len */ 383 qvirtio_writel(vq->vdev, qts, vq->desc + (16 * vq->free_head) + 8, 384 sizeof(struct vring_desc) * indirect->elem); 385 /* vq->desc[vq->free_head].flags */ 386 qvirtio_writew(vq->vdev, qts, vq->desc + (16 * vq->free_head) + 12, 387 VRING_DESC_F_INDIRECT); 388 389 return vq->free_head++; /* Return and increase, in this order */ 390 } 391 392 void qvirtqueue_set_avail_idx(QTestState *qts, QVirtioDevice *d, 393 QVirtQueue *vq, uint16_t idx) 394 { 395 /* vq->avail->idx */ 396 qvirtio_writew(d, qts, vq->avail + 2, idx); 397 } 398 399 void qvirtqueue_kick(QTestState *qts, QVirtioDevice *d, QVirtQueue *vq, 400 uint32_t free_head) 401 { 402 /* vq->avail->idx */ 403 uint16_t idx = qvirtio_readw(d, qts, vq->avail + 2); 404 /* vq->used->flags */ 405 uint16_t flags; 406 /* vq->used->avail_event */ 407 uint16_t avail_event; 408 409 /* vq->avail->ring[idx % vq->size] */ 410 qvirtio_writew(d, qts, vq->avail + 4 + (2 * (idx % vq->size)), free_head); 411 412 qvirtqueue_set_avail_idx(qts, d, vq, idx + 1); 413 414 /* Must read after idx is updated */ 415 flags = qvirtio_readw(d, qts, vq->used); 416 avail_event = qvirtio_readw(d, qts, vq->used + 4 + 417 sizeof(struct vring_used_elem) * vq->size); 418 419 /* < 1 because we add elements to avail queue one by one */ 420 if ((flags & VRING_USED_F_NO_NOTIFY) == 0 && 421 (!vq->event || (uint16_t)(idx-avail_event) < 1)) { 422 d->bus->virtqueue_kick(d, vq); 423 } 424 } 425 426 /* 427 * qvirtqueue_get_buf: 428 * @desc_idx: A pointer that is filled with the vq->desc[] index, may be NULL 429 * @len: A pointer that is filled with the length written into the buffer, may 430 * be NULL 431 * 432 * This function gets the next used element if there is one ready. 433 * 434 * Returns: true if an element was ready, false otherwise 435 */ 436 bool qvirtqueue_get_buf(QTestState *qts, QVirtQueue *vq, uint32_t *desc_idx, 437 uint32_t *len) 438 { 439 uint16_t idx; 440 uint64_t elem_addr, addr; 441 442 idx = qvirtio_readw(vq->vdev, qts, 443 vq->used + offsetof(struct vring_used, idx)); 444 if (idx == vq->last_used_idx) { 445 return false; 446 } 447 448 elem_addr = vq->used + 449 offsetof(struct vring_used, ring) + 450 (vq->last_used_idx % vq->size) * 451 sizeof(struct vring_used_elem); 452 453 if (desc_idx) { 454 addr = elem_addr + offsetof(struct vring_used_elem, id); 455 *desc_idx = qvirtio_readl(vq->vdev, qts, addr); 456 } 457 458 if (len) { 459 addr = elem_addr + offsetof(struct vring_used_elem, len); 460 *len = qvirtio_readw(vq->vdev, qts, addr); 461 } 462 463 vq->last_used_idx++; 464 return true; 465 } 466 467 void qvirtqueue_set_used_event(QTestState *qts, QVirtQueue *vq, uint16_t idx) 468 { 469 g_assert(vq->event); 470 471 /* vq->avail->used_event */ 472 qvirtio_writew(vq->vdev, qts, vq->avail + 4 + (2 * vq->size), idx); 473 } 474 475 void qvirtio_start_device(QVirtioDevice *vdev) 476 { 477 qvirtio_reset(vdev); 478 qvirtio_set_acknowledge(vdev); 479 qvirtio_set_driver(vdev); 480 } 481 482 bool qvirtio_is_big_endian(QVirtioDevice *d) 483 { 484 return d->big_endian; 485 } 486