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     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
 123 QVirtQueue *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
 130 void qvirtqueue_cleanup(const QVirtioBus *bus, QVirtQueue *vq,
 131                         QGuestAllocator *alloc)
 132 {
 133     return bus->virtqueue_cleanup(vq, alloc);
 134 }
 135
 136 void 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
 143 void 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
 149 void 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
 156 void 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
 165 void 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  */
 184 uint8_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  */
 209 void 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
 232 void qvirtio_wait_config_isr(QVirtioDevice *d, gint64 timeout_us)
 233 {
 234     d->bus->wait_config_isr_status(d, timeout_us);
 235 }
 236
 237 void 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
 268 QVRingIndirectDesc *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
 292 void 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
 318 uint32_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
 342 uint32_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
 364 void 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  */
 401 bool 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
 432 void 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
 440 void qvirtio_start_device(QVirtioDevice *vdev)
 441 {
 442     qvirtio_reset(vdev);
 443     qvirtio_set_acknowledge(vdev);
 444     qvirtio_set_driver(vdev);
 445 }
 446
 447 bool qvirtio_is_big_endian(QVirtioDevice *d)
 448 {
 449     return d->big_endian;
 450 }