virtio.c (14101B)
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 = qtest_readw(qts, addr); 29 30 if (d->features & (1ull << VIRTIO_F_VERSION_1) && qtest_big_endian(qts)) { 31 val = bswap16(val); 32 } 33 return val; 34 } 35 36 static uint32_t qvirtio_readl(QVirtioDevice *d, QTestState *qts, uint64_t addr) 37 { 38 uint32_t val = qtest_readl(qts, addr); 39 40 if (d->features & (1ull << VIRTIO_F_VERSION_1) && qtest_big_endian(qts)) { 41 val = bswap32(val); 42 } 43 return val; 44 } 45 46 static void qvirtio_writew(QVirtioDevice *d, QTestState *qts, 47 uint64_t addr, uint16_t val) 48 { 49 if (d->features & (1ull << VIRTIO_F_VERSION_1) && qtest_big_endian(qts)) { 50 val = bswap16(val); 51 } 52 qtest_writew(qts, addr, val); 53 } 54 55 static void qvirtio_writel(QVirtioDevice *d, QTestState *qts, 56 uint64_t addr, uint32_t val) 57 { 58 if (d->features & (1ull << VIRTIO_F_VERSION_1) && qtest_big_endian(qts)) { 59 val = bswap32(val); 60 } 61 qtest_writel(qts, addr, val); 62 } 63 64 static void qvirtio_writeq(QVirtioDevice *d, QTestState *qts, 65 uint64_t addr, uint64_t val) 66 { 67 if (d->features & (1ull << VIRTIO_F_VERSION_1) && qtest_big_endian(qts)) { 68 val = bswap64(val); 69 } 70 qtest_writeq(qts, addr, val); 71 } 72 73 uint8_t qvirtio_config_readb(QVirtioDevice *d, uint64_t addr) 74 { 75 g_assert_true(d->features_negotiated); 76 return d->bus->config_readb(d, addr); 77 } 78 79 uint16_t qvirtio_config_readw(QVirtioDevice *d, uint64_t addr) 80 { 81 g_assert_true(d->features_negotiated); 82 return d->bus->config_readw(d, addr); 83 } 84 85 uint32_t qvirtio_config_readl(QVirtioDevice *d, uint64_t addr) 86 { 87 g_assert_true(d->features_negotiated); 88 return d->bus->config_readl(d, addr); 89 } 90 91 uint64_t qvirtio_config_readq(QVirtioDevice *d, uint64_t addr) 92 { 93 g_assert_true(d->features_negotiated); 94 return d->bus->config_readq(d, addr); 95 } 96 97 uint64_t qvirtio_get_features(QVirtioDevice *d) 98 { 99 return d->bus->get_features(d); 100 } 101 102 void qvirtio_set_features(QVirtioDevice *d, uint64_t features) 103 { 104 g_assert(!(features & QVIRTIO_F_BAD_FEATURE)); 105 106 d->features = features; 107 d->bus->set_features(d, features); 108 109 /* 110 * This could be a separate function for drivers that want to access 111 * configuration space before setting FEATURES_OK, but no existing users 112 * need that and it's less code for callers if this is done implicitly. 113 */ 114 if (features & (1ull << VIRTIO_F_VERSION_1)) { 115 uint8_t status = d->bus->get_status(d) | 116 VIRTIO_CONFIG_S_FEATURES_OK; 117 118 d->bus->set_status(d, status); 119 g_assert_cmphex(d->bus->get_status(d), ==, status); 120 } 121 122 d->features_negotiated = true; 123 } 124 125 QVirtQueue *qvirtqueue_setup(QVirtioDevice *d, 126 QGuestAllocator *alloc, uint16_t index) 127 { 128 g_assert_true(d->features_negotiated); 129 return d->bus->virtqueue_setup(d, alloc, index); 130 } 131 132 void qvirtqueue_cleanup(const QVirtioBus *bus, QVirtQueue *vq, 133 QGuestAllocator *alloc) 134 { 135 return bus->virtqueue_cleanup(vq, alloc); 136 } 137 138 void qvirtio_reset(QVirtioDevice *d) 139 { 140 d->bus->set_status(d, 0); 141 g_assert_cmphex(d->bus->get_status(d), ==, 0); 142 d->features_negotiated = false; 143 } 144 145 void qvirtio_set_acknowledge(QVirtioDevice *d) 146 { 147 d->bus->set_status(d, d->bus->get_status(d) | VIRTIO_CONFIG_S_ACKNOWLEDGE); 148 g_assert_cmphex(d->bus->get_status(d), ==, VIRTIO_CONFIG_S_ACKNOWLEDGE); 149 } 150 151 void qvirtio_set_driver(QVirtioDevice *d) 152 { 153 d->bus->set_status(d, d->bus->get_status(d) | VIRTIO_CONFIG_S_DRIVER); 154 g_assert_cmphex(d->bus->get_status(d), ==, 155 VIRTIO_CONFIG_S_DRIVER | VIRTIO_CONFIG_S_ACKNOWLEDGE); 156 } 157 158 void qvirtio_set_driver_ok(QVirtioDevice *d) 159 { 160 d->bus->set_status(d, d->bus->get_status(d) | VIRTIO_CONFIG_S_DRIVER_OK); 161 g_assert_cmphex(d->bus->get_status(d), ==, VIRTIO_CONFIG_S_DRIVER_OK | 162 VIRTIO_CONFIG_S_DRIVER | VIRTIO_CONFIG_S_ACKNOWLEDGE | 163 (d->features & (1ull << VIRTIO_F_VERSION_1) ? 164 VIRTIO_CONFIG_S_FEATURES_OK : 0)); 165 } 166 167 void qvirtio_wait_queue_isr(QTestState *qts, QVirtioDevice *d, 168 QVirtQueue *vq, gint64 timeout_us) 169 { 170 gint64 start_time = g_get_monotonic_time(); 171 172 for (;;) { 173 qtest_clock_step(qts, 100); 174 if (d->bus->get_queue_isr_status(d, vq)) { 175 return; 176 } 177 g_assert(g_get_monotonic_time() - start_time <= timeout_us); 178 } 179 } 180 181 /* Wait for the status byte at given guest memory address to be set 182 * 183 * The virtqueue interrupt must not be raised, making this useful for testing 184 * event_index functionality. 185 */ 186 uint8_t qvirtio_wait_status_byte_no_isr(QTestState *qts, QVirtioDevice *d, 187 QVirtQueue *vq, 188 uint64_t addr, 189 gint64 timeout_us) 190 { 191 gint64 start_time = g_get_monotonic_time(); 192 uint8_t val; 193 194 while ((val = qtest_readb(qts, addr)) == 0xff) { 195 qtest_clock_step(qts, 100); 196 g_assert(!d->bus->get_queue_isr_status(d, vq)); 197 g_assert(g_get_monotonic_time() - start_time <= timeout_us); 198 } 199 return val; 200 } 201 202 /* 203 * qvirtio_wait_used_elem: 204 * @desc_idx: The next expected vq->desc[] index in the used ring 205 * @len: A pointer that is filled with the length written into the buffer, may 206 * be NULL 207 * @timeout_us: How many microseconds to wait before failing 208 * 209 * This function waits for the next completed request on the used ring. 210 */ 211 void qvirtio_wait_used_elem(QTestState *qts, QVirtioDevice *d, 212 QVirtQueue *vq, 213 uint32_t desc_idx, 214 uint32_t *len, 215 gint64 timeout_us) 216 { 217 gint64 start_time = g_get_monotonic_time(); 218 219 for (;;) { 220 uint32_t got_desc_idx; 221 222 qtest_clock_step(qts, 100); 223 224 if (d->bus->get_queue_isr_status(d, vq) && 225 qvirtqueue_get_buf(qts, vq, &got_desc_idx, len)) { 226 g_assert_cmpint(got_desc_idx, ==, desc_idx); 227 return; 228 } 229 230 g_assert(g_get_monotonic_time() - start_time <= timeout_us); 231 } 232 } 233 234 void qvirtio_wait_config_isr(QVirtioDevice *d, gint64 timeout_us) 235 { 236 d->bus->wait_config_isr_status(d, timeout_us); 237 } 238 239 void qvring_init(QTestState *qts, const QGuestAllocator *alloc, QVirtQueue *vq, 240 uint64_t addr) 241 { 242 int i; 243 244 vq->desc = addr; 245 vq->avail = vq->desc + vq->size * sizeof(struct vring_desc); 246 vq->used = (uint64_t)((vq->avail + sizeof(uint16_t) * (3 + vq->size) 247 + vq->align - 1) & ~(vq->align - 1)); 248 249 for (i = 0; i < vq->size - 1; i++) { 250 /* vq->desc[i].addr */ 251 qvirtio_writeq(vq->vdev, qts, vq->desc + (16 * i), 0); 252 /* vq->desc[i].next */ 253 qvirtio_writew(vq->vdev, qts, vq->desc + (16 * i) + 14, i + 1); 254 } 255 256 /* vq->avail->flags */ 257 qvirtio_writew(vq->vdev, qts, vq->avail, 0); 258 /* vq->avail->idx */ 259 qvirtio_writew(vq->vdev, qts, vq->avail + 2, 0); 260 /* vq->avail->used_event */ 261 qvirtio_writew(vq->vdev, qts, vq->avail + 4 + (2 * vq->size), 0); 262 263 /* vq->used->flags */ 264 qvirtio_writew(vq->vdev, qts, vq->used, 0); 265 /* vq->used->idx */ 266 qvirtio_writew(vq->vdev, qts, vq->used + 2, 0); 267 /* vq->used->avail_event */ 268 qvirtio_writew(vq->vdev, qts, vq->used + 2 + 269 sizeof(struct vring_used_elem) * vq->size, 0); 270 } 271 272 QVRingIndirectDesc *qvring_indirect_desc_setup(QTestState *qs, QVirtioDevice *d, 273 QGuestAllocator *alloc, 274 uint16_t elem) 275 { 276 int i; 277 QVRingIndirectDesc *indirect = g_malloc(sizeof(*indirect)); 278 279 indirect->index = 0; 280 indirect->elem = elem; 281 indirect->desc = guest_alloc(alloc, sizeof(struct vring_desc) * elem); 282 283 for (i = 0; i < elem - 1; ++i) { 284 /* indirect->desc[i].addr */ 285 qvirtio_writeq(d, qs, indirect->desc + (16 * i), 0); 286 /* indirect->desc[i].flags */ 287 qvirtio_writew(d, qs, indirect->desc + (16 * i) + 12, 288 VRING_DESC_F_NEXT); 289 /* indirect->desc[i].next */ 290 qvirtio_writew(d, qs, indirect->desc + (16 * i) + 14, i + 1); 291 } 292 293 return indirect; 294 } 295 296 void qvring_indirect_desc_add(QVirtioDevice *d, QTestState *qts, 297 QVRingIndirectDesc *indirect, 298 uint64_t data, uint32_t len, bool write) 299 { 300 uint16_t flags; 301 302 g_assert_cmpint(indirect->index, <, indirect->elem); 303 304 flags = qvirtio_readw(d, qts, indirect->desc + 305 (16 * indirect->index) + 12); 306 307 if (write) { 308 flags |= VRING_DESC_F_WRITE; 309 } 310 311 /* indirect->desc[indirect->index].addr */ 312 qvirtio_writeq(d, qts, indirect->desc + (16 * indirect->index), data); 313 /* indirect->desc[indirect->index].len */ 314 qvirtio_writel(d, qts, indirect->desc + (16 * indirect->index) + 8, len); 315 /* indirect->desc[indirect->index].flags */ 316 qvirtio_writew(d, qts, indirect->desc + (16 * indirect->index) + 12, 317 flags); 318 319 indirect->index++; 320 } 321 322 uint32_t qvirtqueue_add(QTestState *qts, QVirtQueue *vq, uint64_t data, 323 uint32_t len, bool write, bool next) 324 { 325 uint16_t flags = 0; 326 vq->num_free--; 327 328 if (write) { 329 flags |= VRING_DESC_F_WRITE; 330 } 331 332 if (next) { 333 flags |= VRING_DESC_F_NEXT; 334 } 335 336 /* vq->desc[vq->free_head].addr */ 337 qvirtio_writeq(vq->vdev, qts, vq->desc + (16 * vq->free_head), data); 338 /* vq->desc[vq->free_head].len */ 339 qvirtio_writel(vq->vdev, qts, vq->desc + (16 * vq->free_head) + 8, len); 340 /* vq->desc[vq->free_head].flags */ 341 qvirtio_writew(vq->vdev, qts, vq->desc + (16 * vq->free_head) + 12, flags); 342 343 return vq->free_head++; /* Return and increase, in this order */ 344 } 345 346 uint32_t qvirtqueue_add_indirect(QTestState *qts, QVirtQueue *vq, 347 QVRingIndirectDesc *indirect) 348 { 349 g_assert(vq->indirect); 350 g_assert_cmpint(vq->size, >=, indirect->elem); 351 g_assert_cmpint(indirect->index, ==, indirect->elem); 352 353 vq->num_free--; 354 355 /* vq->desc[vq->free_head].addr */ 356 qvirtio_writeq(vq->vdev, qts, vq->desc + (16 * vq->free_head), 357 indirect->desc); 358 /* vq->desc[vq->free_head].len */ 359 qvirtio_writel(vq->vdev, qts, vq->desc + (16 * vq->free_head) + 8, 360 sizeof(struct vring_desc) * indirect->elem); 361 /* vq->desc[vq->free_head].flags */ 362 qvirtio_writew(vq->vdev, qts, vq->desc + (16 * vq->free_head) + 12, 363 VRING_DESC_F_INDIRECT); 364 365 return vq->free_head++; /* Return and increase, in this order */ 366 } 367 368 void qvirtqueue_kick(QTestState *qts, QVirtioDevice *d, QVirtQueue *vq, 369 uint32_t free_head) 370 { 371 /* vq->avail->idx */ 372 uint16_t idx = qvirtio_readw(d, qts, vq->avail + 2); 373 /* vq->used->flags */ 374 uint16_t flags; 375 /* vq->used->avail_event */ 376 uint16_t avail_event; 377 378 /* vq->avail->ring[idx % vq->size] */ 379 qvirtio_writew(d, qts, vq->avail + 4 + (2 * (idx % vq->size)), free_head); 380 /* vq->avail->idx */ 381 qvirtio_writew(d, qts, vq->avail + 2, idx + 1); 382 383 /* Must read after idx is updated */ 384 flags = qvirtio_readw(d, qts, vq->avail); 385 avail_event = qvirtio_readw(d, qts, vq->used + 4 + 386 sizeof(struct vring_used_elem) * vq->size); 387 388 /* < 1 because we add elements to avail queue one by one */ 389 if ((flags & VRING_USED_F_NO_NOTIFY) == 0 && 390 (!vq->event || (uint16_t)(idx-avail_event) < 1)) { 391 d->bus->virtqueue_kick(d, vq); 392 } 393 } 394 395 /* 396 * qvirtqueue_get_buf: 397 * @desc_idx: A pointer that is filled with the vq->desc[] index, may be NULL 398 * @len: A pointer that is filled with the length written into the buffer, may 399 * be NULL 400 * 401 * This function gets the next used element if there is one ready. 402 * 403 * Returns: true if an element was ready, false otherwise 404 */ 405 bool qvirtqueue_get_buf(QTestState *qts, QVirtQueue *vq, uint32_t *desc_idx, 406 uint32_t *len) 407 { 408 uint16_t idx; 409 uint64_t elem_addr, addr; 410 411 idx = qvirtio_readw(vq->vdev, qts, 412 vq->used + offsetof(struct vring_used, idx)); 413 if (idx == vq->last_used_idx) { 414 return false; 415 } 416 417 elem_addr = vq->used + 418 offsetof(struct vring_used, ring) + 419 (vq->last_used_idx % vq->size) * 420 sizeof(struct vring_used_elem); 421 422 if (desc_idx) { 423 addr = elem_addr + offsetof(struct vring_used_elem, id); 424 *desc_idx = qvirtio_readl(vq->vdev, qts, addr); 425 } 426 427 if (len) { 428 addr = elem_addr + offsetof(struct vring_used_elem, len); 429 *len = qvirtio_readw(vq->vdev, qts, addr); 430 } 431 432 vq->last_used_idx++; 433 return true; 434 } 435 436 void qvirtqueue_set_used_event(QTestState *qts, QVirtQueue *vq, uint16_t idx) 437 { 438 g_assert(vq->event); 439 440 /* vq->avail->used_event */ 441 qvirtio_writew(vq->vdev, qts, vq->avail + 4 + (2 * vq->size), idx); 442 } 443 444 void qvirtio_start_device(QVirtioDevice *vdev) 445 { 446 qvirtio_reset(vdev); 447 qvirtio_set_acknowledge(vdev); 448 qvirtio_set_driver(vdev); 449 } 450 451 bool qvirtio_is_big_endian(QVirtioDevice *d) 452 { 453 return d->big_endian; 454 }