virtio.c (13969B)
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 */ 26static 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 36static 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 46static 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 55static 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 64static 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 73uint8_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 79uint16_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 85uint32_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 91uint64_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 97uint64_t qvirtio_get_features(QVirtioDevice *d) 98{ 99 return d->bus->get_features(d); 100} 101 102void qvirtio_set_features(QVirtioDevice *d, uint64_t features) 103{ 104 d->features = features; 105 d->bus->set_features(d, features); 106 107 /* 108 * This could be a separate function for drivers that want to access 109 * configuration space before setting FEATURES_OK, but no existing users 110 * need that and it's less code for callers if this is done implicitly. 111 */ 112 if (features & (1ull << VIRTIO_F_VERSION_1)) { 113 uint8_t status = d->bus->get_status(d) | 114 VIRTIO_CONFIG_S_FEATURES_OK; 115 116 d->bus->set_status(d, status); 117 g_assert_cmphex(d->bus->get_status(d), ==, status); 118 } 119 120 d->features_negotiated = true; 121} 122 123QVirtQueue *qvirtqueue_setup(QVirtioDevice *d, 124 QGuestAllocator *alloc, uint16_t index) 125{ 126 g_assert_true(d->features_negotiated); 127 return d->bus->virtqueue_setup(d, alloc, index); 128} 129 130void qvirtqueue_cleanup(const QVirtioBus *bus, QVirtQueue *vq, 131 QGuestAllocator *alloc) 132{ 133 return bus->virtqueue_cleanup(vq, alloc); 134} 135 136void qvirtio_reset(QVirtioDevice *d) 137{ 138 d->bus->set_status(d, 0); 139 g_assert_cmphex(d->bus->get_status(d), ==, 0); 140 d->features_negotiated = false; 141} 142 143void qvirtio_set_acknowledge(QVirtioDevice *d) 144{ 145 d->bus->set_status(d, d->bus->get_status(d) | VIRTIO_CONFIG_S_ACKNOWLEDGE); 146 g_assert_cmphex(d->bus->get_status(d), ==, VIRTIO_CONFIG_S_ACKNOWLEDGE); 147} 148 149void qvirtio_set_driver(QVirtioDevice *d) 150{ 151 d->bus->set_status(d, d->bus->get_status(d) | VIRTIO_CONFIG_S_DRIVER); 152 g_assert_cmphex(d->bus->get_status(d), ==, 153 VIRTIO_CONFIG_S_DRIVER | VIRTIO_CONFIG_S_ACKNOWLEDGE); 154} 155 156void qvirtio_set_driver_ok(QVirtioDevice *d) 157{ 158 d->bus->set_status(d, d->bus->get_status(d) | VIRTIO_CONFIG_S_DRIVER_OK); 159 g_assert_cmphex(d->bus->get_status(d), ==, VIRTIO_CONFIG_S_DRIVER_OK | 160 VIRTIO_CONFIG_S_DRIVER | VIRTIO_CONFIG_S_ACKNOWLEDGE | 161 (d->features & (1ull << VIRTIO_F_VERSION_1) ? 162 VIRTIO_CONFIG_S_FEATURES_OK : 0)); 163} 164 165void qvirtio_wait_queue_isr(QTestState *qts, QVirtioDevice *d, 166 QVirtQueue *vq, gint64 timeout_us) 167{ 168 gint64 start_time = g_get_monotonic_time(); 169 170 for (;;) { 171 qtest_clock_step(qts, 100); 172 if (d->bus->get_queue_isr_status(d, vq)) { 173 return; 174 } 175 g_assert(g_get_monotonic_time() - start_time <= timeout_us); 176 } 177} 178 179/* Wait for the status byte at given guest memory address to be set 180 * 181 * The virtqueue interrupt must not be raised, making this useful for testing 182 * event_index functionality. 183 */ 184uint8_t qvirtio_wait_status_byte_no_isr(QTestState *qts, QVirtioDevice *d, 185 QVirtQueue *vq, 186 uint64_t addr, 187 gint64 timeout_us) 188{ 189 gint64 start_time = g_get_monotonic_time(); 190 uint8_t val; 191 192 while ((val = qtest_readb(qts, addr)) == 0xff) { 193 qtest_clock_step(qts, 100); 194 g_assert(!d->bus->get_queue_isr_status(d, vq)); 195 g_assert(g_get_monotonic_time() - start_time <= timeout_us); 196 } 197 return val; 198} 199 200/* 201 * qvirtio_wait_used_elem: 202 * @desc_idx: The next expected vq->desc[] index in the used ring 203 * @len: A pointer that is filled with the length written into the buffer, may 204 * be NULL 205 * @timeout_us: How many microseconds to wait before failing 206 * 207 * This function waits for the next completed request on the used ring. 208 */ 209void qvirtio_wait_used_elem(QTestState *qts, QVirtioDevice *d, 210 QVirtQueue *vq, 211 uint32_t desc_idx, 212 uint32_t *len, 213 gint64 timeout_us) 214{ 215 gint64 start_time = g_get_monotonic_time(); 216 217 for (;;) { 218 uint32_t got_desc_idx; 219 220 qtest_clock_step(qts, 100); 221 222 if (d->bus->get_queue_isr_status(d, vq) && 223 qvirtqueue_get_buf(qts, vq, &got_desc_idx, len)) { 224 g_assert_cmpint(got_desc_idx, ==, desc_idx); 225 return; 226 } 227 228 g_assert(g_get_monotonic_time() - start_time <= timeout_us); 229 } 230} 231 232void qvirtio_wait_config_isr(QVirtioDevice *d, gint64 timeout_us) 233{ 234 d->bus->wait_config_isr_status(d, timeout_us); 235} 236 237void qvring_init(QTestState *qts, const QGuestAllocator *alloc, QVirtQueue *vq, 238 uint64_t addr) 239{ 240 int i; 241 242 vq->desc = addr; 243 vq->avail = vq->desc + vq->size * sizeof(struct vring_desc); 244 vq->used = (uint64_t)((vq->avail + sizeof(uint16_t) * (3 + vq->size) 245 + vq->align - 1) & ~(vq->align - 1)); 246 247 for (i = 0; i < vq->size - 1; i++) { 248 /* vq->desc[i].addr */ 249 qvirtio_writeq(vq->vdev, qts, vq->desc + (16 * i), 0); 250 /* vq->desc[i].next */ 251 qvirtio_writew(vq->vdev, qts, vq->desc + (16 * i) + 14, i + 1); 252 } 253 254 /* vq->avail->flags */ 255 qvirtio_writew(vq->vdev, qts, vq->avail, 0); 256 /* vq->avail->idx */ 257 qvirtio_writew(vq->vdev, qts, vq->avail + 2, 0); 258 /* vq->avail->used_event */ 259 qvirtio_writew(vq->vdev, qts, vq->avail + 4 + (2 * vq->size), 0); 260 261 /* vq->used->flags */ 262 qvirtio_writew(vq->vdev, qts, vq->used, 0); 263 /* vq->used->avail_event */ 264 qvirtio_writew(vq->vdev, qts, vq->used + 2 + 265 sizeof(struct vring_used_elem) * vq->size, 0); 266} 267 268QVRingIndirectDesc *qvring_indirect_desc_setup(QTestState *qs, QVirtioDevice *d, 269 QGuestAllocator *alloc, 270 uint16_t elem) 271{ 272 int i; 273 QVRingIndirectDesc *indirect = g_malloc(sizeof(*indirect)); 274 275 indirect->index = 0; 276 indirect->elem = elem; 277 indirect->desc = guest_alloc(alloc, sizeof(struct vring_desc) * elem); 278 279 for (i = 0; i < elem - 1; ++i) { 280 /* indirect->desc[i].addr */ 281 qvirtio_writeq(d, qs, indirect->desc + (16 * i), 0); 282 /* indirect->desc[i].flags */ 283 qvirtio_writew(d, qs, indirect->desc + (16 * i) + 12, 284 VRING_DESC_F_NEXT); 285 /* indirect->desc[i].next */ 286 qvirtio_writew(d, qs, indirect->desc + (16 * i) + 14, i + 1); 287 } 288 289 return indirect; 290} 291 292void qvring_indirect_desc_add(QVirtioDevice *d, QTestState *qts, 293 QVRingIndirectDesc *indirect, 294 uint64_t data, uint32_t len, bool write) 295{ 296 uint16_t flags; 297 298 g_assert_cmpint(indirect->index, <, indirect->elem); 299 300 flags = qvirtio_readw(d, qts, indirect->desc + 301 (16 * indirect->index) + 12); 302 303 if (write) { 304 flags |= VRING_DESC_F_WRITE; 305 } 306 307 /* indirect->desc[indirect->index].addr */ 308 qvirtio_writeq(d, qts, indirect->desc + (16 * indirect->index), data); 309 /* indirect->desc[indirect->index].len */ 310 qvirtio_writel(d, qts, indirect->desc + (16 * indirect->index) + 8, len); 311 /* indirect->desc[indirect->index].flags */ 312 qvirtio_writew(d, qts, indirect->desc + (16 * indirect->index) + 12, 313 flags); 314 315 indirect->index++; 316} 317 318uint32_t qvirtqueue_add(QTestState *qts, QVirtQueue *vq, uint64_t data, 319 uint32_t len, bool write, bool next) 320{ 321 uint16_t flags = 0; 322 vq->num_free--; 323 324 if (write) { 325 flags |= VRING_DESC_F_WRITE; 326 } 327 328 if (next) { 329 flags |= VRING_DESC_F_NEXT; 330 } 331 332 /* vq->desc[vq->free_head].addr */ 333 qvirtio_writeq(vq->vdev, qts, vq->desc + (16 * vq->free_head), data); 334 /* vq->desc[vq->free_head].len */ 335 qvirtio_writel(vq->vdev, qts, vq->desc + (16 * vq->free_head) + 8, len); 336 /* vq->desc[vq->free_head].flags */ 337 qvirtio_writew(vq->vdev, qts, vq->desc + (16 * vq->free_head) + 12, flags); 338 339 return vq->free_head++; /* Return and increase, in this order */ 340} 341 342uint32_t qvirtqueue_add_indirect(QTestState *qts, QVirtQueue *vq, 343 QVRingIndirectDesc *indirect) 344{ 345 g_assert(vq->indirect); 346 g_assert_cmpint(vq->size, >=, indirect->elem); 347 g_assert_cmpint(indirect->index, ==, indirect->elem); 348 349 vq->num_free--; 350 351 /* vq->desc[vq->free_head].addr */ 352 qvirtio_writeq(vq->vdev, qts, vq->desc + (16 * vq->free_head), 353 indirect->desc); 354 /* vq->desc[vq->free_head].len */ 355 qvirtio_writel(vq->vdev, qts, vq->desc + (16 * vq->free_head) + 8, 356 sizeof(struct vring_desc) * indirect->elem); 357 /* vq->desc[vq->free_head].flags */ 358 qvirtio_writew(vq->vdev, qts, vq->desc + (16 * vq->free_head) + 12, 359 VRING_DESC_F_INDIRECT); 360 361 return vq->free_head++; /* Return and increase, in this order */ 362} 363 364void qvirtqueue_kick(QTestState *qts, QVirtioDevice *d, QVirtQueue *vq, 365 uint32_t free_head) 366{ 367 /* vq->avail->idx */ 368 uint16_t idx = qvirtio_readw(d, qts, vq->avail + 2); 369 /* vq->used->flags */ 370 uint16_t flags; 371 /* vq->used->avail_event */ 372 uint16_t avail_event; 373 374 /* vq->avail->ring[idx % vq->size] */ 375 qvirtio_writew(d, qts, vq->avail + 4 + (2 * (idx % vq->size)), free_head); 376 /* vq->avail->idx */ 377 qvirtio_writew(d, qts, vq->avail + 2, idx + 1); 378 379 /* Must read after idx is updated */ 380 flags = qvirtio_readw(d, qts, vq->avail); 381 avail_event = qvirtio_readw(d, qts, vq->used + 4 + 382 sizeof(struct vring_used_elem) * vq->size); 383 384 /* < 1 because we add elements to avail queue one by one */ 385 if ((flags & VRING_USED_F_NO_NOTIFY) == 0 && 386 (!vq->event || (uint16_t)(idx-avail_event) < 1)) { 387 d->bus->virtqueue_kick(d, vq); 388 } 389} 390 391/* 392 * qvirtqueue_get_buf: 393 * @desc_idx: A pointer that is filled with the vq->desc[] index, may be NULL 394 * @len: A pointer that is filled with the length written into the buffer, may 395 * be NULL 396 * 397 * This function gets the next used element if there is one ready. 398 * 399 * Returns: true if an element was ready, false otherwise 400 */ 401bool qvirtqueue_get_buf(QTestState *qts, QVirtQueue *vq, uint32_t *desc_idx, 402 uint32_t *len) 403{ 404 uint16_t idx; 405 uint64_t elem_addr, addr; 406 407 idx = qvirtio_readw(vq->vdev, qts, 408 vq->used + offsetof(struct vring_used, idx)); 409 if (idx == vq->last_used_idx) { 410 return false; 411 } 412 413 elem_addr = vq->used + 414 offsetof(struct vring_used, ring) + 415 (vq->last_used_idx % vq->size) * 416 sizeof(struct vring_used_elem); 417 418 if (desc_idx) { 419 addr = elem_addr + offsetof(struct vring_used_elem, id); 420 *desc_idx = qvirtio_readl(vq->vdev, qts, addr); 421 } 422 423 if (len) { 424 addr = elem_addr + offsetof(struct vring_used_elem, len); 425 *len = qvirtio_readw(vq->vdev, qts, addr); 426 } 427 428 vq->last_used_idx++; 429 return true; 430} 431 432void qvirtqueue_set_used_event(QTestState *qts, QVirtQueue *vq, uint16_t idx) 433{ 434 g_assert(vq->event); 435 436 /* vq->avail->used_event */ 437 qvirtio_writew(vq->vdev, qts, vq->avail + 4 + (2 * vq->size), idx); 438} 439 440void qvirtio_start_device(QVirtioDevice *vdev) 441{ 442 qvirtio_reset(vdev); 443 qvirtio_set_acknowledge(vdev); 444 qvirtio_set_driver(vdev); 445} 446 447bool qvirtio_is_big_endian(QVirtioDevice *d) 448{ 449 return d->big_endian; 450}