tests/qtest/libqos/virtio.c

   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 + 4 +
 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; ++i) {
 284         /* indirect->desc[i].addr */
 285         qvirtio_writeq(d, qs, indirect->desc + (16 * i), 0);
 286
 287         /*
 288          * If it's not the last element of the ring, set
 289          * the chain (VRING_DESC_F_NEXT) flag and
 290          * desc->next. Clear the last element - there's
 291          * no guarantee that guest_alloc() will do it.
 292          */
 293         if (i != elem - 1) {
 294             /* indirect->desc[i].flags */
 295             qvirtio_writew(d, qs, indirect->desc + (16 * i) + 12,
 296                            VRING_DESC_F_NEXT);
 297
 298             /* indirect->desc[i].next */
 299             qvirtio_writew(d, qs, indirect->desc + (16 * i) + 14, i + 1);
 300         } else {
 301             qvirtio_writew(d, qs, indirect->desc + (16 * i) + 12, 0);
 302             qvirtio_writew(d, qs, indirect->desc + (16 * i) + 14, 0);
 303         }
 304     }
 305
 306     return indirect;
 307 }
 308
 309 void qvring_indirect_desc_add(QVirtioDevice *d, QTestState *qts,
 310                               QVRingIndirectDesc *indirect,
 311                               uint64_t data, uint32_t len, bool write)
 312 {
 313     uint16_t flags;
 314
 315     g_assert_cmpint(indirect->index, <, indirect->elem);
 316
 317     flags = qvirtio_readw(d, qts, indirect->desc +
 318                                   (16 * indirect->index) + 12);
 319
 320     if (write) {
 321         flags |= VRING_DESC_F_WRITE;
 322     }
 323
 324     /* indirect->desc[indirect->index].addr */
 325     qvirtio_writeq(d, qts, indirect->desc + (16 * indirect->index), data);
 326     /* indirect->desc[indirect->index].len */
 327     qvirtio_writel(d, qts, indirect->desc + (16 * indirect->index) + 8, len);
 328     /* indirect->desc[indirect->index].flags */
 329     qvirtio_writew(d, qts, indirect->desc + (16 * indirect->index) + 12,
 330                    flags);
 331
 332     indirect->index++;
 333 }
 334
 335 uint32_t qvirtqueue_add(QTestState *qts, QVirtQueue *vq, uint64_t data,
 336                         uint32_t len, bool write, bool next)
 337 {
 338     uint16_t flags = 0;
 339     vq->num_free--;
 340
 341     if (write) {
 342         flags |= VRING_DESC_F_WRITE;
 343     }
 344
 345     if (next) {
 346         flags |= VRING_DESC_F_NEXT;
 347     }
 348
 349     /* vq->desc[vq->free_head].addr */
 350     qvirtio_writeq(vq->vdev, qts, vq->desc + (16 * vq->free_head), data);
 351     /* vq->desc[vq->free_head].len */
 352     qvirtio_writel(vq->vdev, qts, vq->desc + (16 * vq->free_head) + 8, len);
 353     /* vq->desc[vq->free_head].flags */
 354     qvirtio_writew(vq->vdev, qts, vq->desc + (16 * vq->free_head) + 12, flags);
 355
 356     return vq->free_head++; /* Return and increase, in this order */
 357 }
 358
 359 uint32_t qvirtqueue_add_indirect(QTestState *qts, QVirtQueue *vq,
 360                                  QVRingIndirectDesc *indirect)
 361 {
 362     g_assert(vq->indirect);
 363     g_assert_cmpint(vq->size, >=, indirect->elem);
 364     g_assert_cmpint(indirect->index, ==, indirect->elem);
 365
 366     vq->num_free--;
 367
 368     /* vq->desc[vq->free_head].addr */
 369     qvirtio_writeq(vq->vdev, qts, vq->desc + (16 * vq->free_head),
 370                    indirect->desc);
 371     /* vq->desc[vq->free_head].len */
 372     qvirtio_writel(vq->vdev, qts, vq->desc + (16 * vq->free_head) + 8,
 373                    sizeof(struct vring_desc) * indirect->elem);
 374     /* vq->desc[vq->free_head].flags */
 375     qvirtio_writew(vq->vdev, qts, vq->desc + (16 * vq->free_head) + 12,
 376                    VRING_DESC_F_INDIRECT);
 377
 378     return vq->free_head++; /* Return and increase, in this order */
 379 }
 380
 381 void qvirtqueue_kick(QTestState *qts, QVirtioDevice *d, QVirtQueue *vq,
 382                      uint32_t free_head)
 383 {
 384     /* vq->avail->idx */
 385     uint16_t idx = qvirtio_readw(d, qts, vq->avail + 2);
 386     /* vq->used->flags */
 387     uint16_t flags;
 388     /* vq->used->avail_event */
 389     uint16_t avail_event;
 390
 391     /* vq->avail->ring[idx % vq->size] */
 392     qvirtio_writew(d, qts, vq->avail + 4 + (2 * (idx % vq->size)), free_head);
 393     /* vq->avail->idx */
 394     qvirtio_writew(d, qts, vq->avail + 2, idx + 1);
 395
 396     /* Must read after idx is updated */
 397     flags = qvirtio_readw(d, qts, vq->used);
 398     avail_event = qvirtio_readw(d, qts, vq->used + 4 +
 399                                 sizeof(struct vring_used_elem) * vq->size);
 400
 401     /* < 1 because we add elements to avail queue one by one */
 402     if ((flags & VRING_USED_F_NO_NOTIFY) == 0 &&
 403                             (!vq->event || (uint16_t)(idx-avail_event) < 1)) {
 404         d->bus->virtqueue_kick(d, vq);
 405     }
 406 }
 407
 408 /*
 409  * qvirtqueue_get_buf:
 410  * @desc_idx: A pointer that is filled with the vq->desc[] index, may be NULL
 411  * @len: A pointer that is filled with the length written into the buffer, may
 412  *       be NULL
 413  *
 414  * This function gets the next used element if there is one ready.
 415  *
 416  * Returns: true if an element was ready, false otherwise
 417  */
 418 bool qvirtqueue_get_buf(QTestState *qts, QVirtQueue *vq, uint32_t *desc_idx,
 419                         uint32_t *len)
 420 {
 421     uint16_t idx;
 422     uint64_t elem_addr, addr;
 423
 424     idx = qvirtio_readw(vq->vdev, qts,
 425                         vq->used + offsetof(struct vring_used, idx));
 426     if (idx == vq->last_used_idx) {
 427         return false;
 428     }
 429
 430     elem_addr = vq->used +
 431         offsetof(struct vring_used, ring) +
 432         (vq->last_used_idx % vq->size) *
 433         sizeof(struct vring_used_elem);
 434
 435     if (desc_idx) {
 436         addr = elem_addr + offsetof(struct vring_used_elem, id);
 437         *desc_idx = qvirtio_readl(vq->vdev, qts, addr);
 438     }
 439
 440     if (len) {
 441         addr = elem_addr + offsetof(struct vring_used_elem, len);
 442         *len = qvirtio_readw(vq->vdev, qts, addr);
 443     }
 444
 445     vq->last_used_idx++;
 446     return true;
 447 }
 448
 449 void qvirtqueue_set_used_event(QTestState *qts, QVirtQueue *vq, uint16_t idx)
 450 {
 451     g_assert(vq->event);
 452
 453     /* vq->avail->used_event */
 454     qvirtio_writew(vq->vdev, qts, vq->avail + 4 + (2 * vq->size), idx);
 455 }
 456
 457 void qvirtio_start_device(QVirtioDevice *vdev)
 458 {
 459     qvirtio_reset(vdev);
 460     qvirtio_set_acknowledge(vdev);
 461     qvirtio_set_driver(vdev);
 462 }
 463
 464 bool qvirtio_is_big_endian(QVirtioDevice *d)
 465 {
 466     return d->big_endian;
 467 }