xref: /qemu/tests/qtest/libqos/virtio.c (revision 3008224ca8a7415323f67d58d8c03e69bde49092)
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  */
qvirtio_readw(QVirtioDevice * d,QTestState * qts,uint64_t addr)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 
qvirtio_readl(QVirtioDevice * d,QTestState * qts,uint64_t addr)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 
qvirtio_writew(QVirtioDevice * d,QTestState * qts,uint64_t addr,uint16_t val)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 
qvirtio_writel(QVirtioDevice * d,QTestState * qts,uint64_t addr,uint32_t val)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 
qvirtio_writeq(QVirtioDevice * d,QTestState * qts,uint64_t addr,uint64_t val)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 
qvirtio_config_readb(QVirtioDevice * d,uint64_t addr)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 
qvirtio_config_readw(QVirtioDevice * d,uint64_t addr)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 
qvirtio_config_readl(QVirtioDevice * d,uint64_t addr)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 
qvirtio_config_readq(QVirtioDevice * d,uint64_t addr)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 
qvirtio_get_features(QVirtioDevice * d)111 uint64_t qvirtio_get_features(QVirtioDevice *d)
112 {
113     return d->bus->get_features(d);
114 }
115 
qvirtio_set_features(QVirtioDevice * d,uint64_t features)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 
qvirtqueue_setup(QVirtioDevice * d,QGuestAllocator * alloc,uint16_t index)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 
qvirtqueue_cleanup(const QVirtioBus * bus,QVirtQueue * vq,QGuestAllocator * alloc)146 void qvirtqueue_cleanup(const QVirtioBus *bus, QVirtQueue *vq,
147                         QGuestAllocator *alloc)
148 {
149     return bus->virtqueue_cleanup(vq, alloc);
150 }
151 
qvirtio_reset(QVirtioDevice * d)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 
qvirtio_set_acknowledge(QVirtioDevice * d)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 
qvirtio_set_driver(QVirtioDevice * d)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 
qvirtio_set_driver_ok(QVirtioDevice * d)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 
qvirtio_wait_queue_isr(QTestState * qts,QVirtioDevice * d,QVirtQueue * vq,gint64 timeout_us)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  */
qvirtio_wait_status_byte_no_isr(QTestState * qts,QVirtioDevice * d,QVirtQueue * vq,uint64_t addr,gint64 timeout_us)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  */
qvirtio_wait_used_elem(QTestState * qts,QVirtioDevice * d,QVirtQueue * vq,uint32_t desc_idx,uint32_t * len,gint64 timeout_us)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 
qvirtio_wait_config_isr(QVirtioDevice * d,gint64 timeout_us)244 void qvirtio_wait_config_isr(QVirtioDevice *d, gint64 timeout_us)
245 {
246     d->bus->wait_config_isr_status(d, timeout_us);
247 }
248 
qvring_init(QTestState * qts,const QGuestAllocator * alloc,QVirtQueue * vq,uint64_t addr)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     /* vq->avail->idx */
269     qvirtio_writew(vq->vdev, qts, vq->avail + 2, 0);
270     /* vq->avail->used_event */
271     qvirtio_writew(vq->vdev, qts, vq->avail + 4 + (2 * vq->size), 0);
272 
273     /* vq->used->flags */
274     qvirtio_writew(vq->vdev, qts, vq->used, 0);
275     /* vq->used->idx */
276     qvirtio_writew(vq->vdev, qts, vq->used + 2, 0);
277     /* vq->used->avail_event */
278     qvirtio_writew(vq->vdev, qts, vq->used + 4 +
279                    sizeof(struct vring_used_elem) * vq->size, 0);
280 }
281 
qvring_indirect_desc_setup(QTestState * qs,QVirtioDevice * d,QGuestAllocator * alloc,uint16_t elem)282 QVRingIndirectDesc *qvring_indirect_desc_setup(QTestState *qs, QVirtioDevice *d,
283                                                QGuestAllocator *alloc,
284                                                uint16_t elem)
285 {
286     int i;
287     QVRingIndirectDesc *indirect = g_malloc(sizeof(*indirect));
288 
289     indirect->index = 0;
290     indirect->elem = elem;
291     indirect->desc = guest_alloc(alloc, sizeof(struct vring_desc) * elem);
292 
293     for (i = 0; i < elem; ++i) {
294         /* indirect->desc[i].addr */
295         qvirtio_writeq(d, qs, indirect->desc + (16 * i), 0);
296 
297         /*
298          * If it's not the last element of the ring, set
299          * the chain (VRING_DESC_F_NEXT) flag and
300          * desc->next. Clear the last element - there's
301          * no guarantee that guest_alloc() will do it.
302          */
303         if (i != elem - 1) {
304             /* indirect->desc[i].flags */
305             qvirtio_writew(d, qs, indirect->desc + (16 * i) + 12,
306                            VRING_DESC_F_NEXT);
307 
308             /* indirect->desc[i].next */
309             qvirtio_writew(d, qs, indirect->desc + (16 * i) + 14, i + 1);
310         } else {
311             qvirtio_writew(d, qs, indirect->desc + (16 * i) + 12, 0);
312             qvirtio_writew(d, qs, indirect->desc + (16 * i) + 14, 0);
313         }
314     }
315 
316     return indirect;
317 }
318 
qvring_indirect_desc_add(QVirtioDevice * d,QTestState * qts,QVRingIndirectDesc * indirect,uint64_t data,uint32_t len,bool write)319 void qvring_indirect_desc_add(QVirtioDevice *d, QTestState *qts,
320                               QVRingIndirectDesc *indirect,
321                               uint64_t data, uint32_t len, bool write)
322 {
323     uint16_t flags;
324 
325     g_assert_cmpint(indirect->index, <, indirect->elem);
326 
327     flags = qvirtio_readw(d, qts, indirect->desc +
328                                   (16 * indirect->index) + 12);
329 
330     if (write) {
331         flags |= VRING_DESC_F_WRITE;
332     }
333 
334     /* indirect->desc[indirect->index].addr */
335     qvirtio_writeq(d, qts, indirect->desc + (16 * indirect->index), data);
336     /* indirect->desc[indirect->index].len */
337     qvirtio_writel(d, qts, indirect->desc + (16 * indirect->index) + 8, len);
338     /* indirect->desc[indirect->index].flags */
339     qvirtio_writew(d, qts, indirect->desc + (16 * indirect->index) + 12,
340                    flags);
341 
342     indirect->index++;
343 }
344 
qvirtqueue_add(QTestState * qts,QVirtQueue * vq,uint64_t data,uint32_t len,bool write,bool next)345 uint32_t qvirtqueue_add(QTestState *qts, QVirtQueue *vq, uint64_t data,
346                         uint32_t len, bool write, bool next)
347 {
348     uint16_t flags = 0;
349     vq->num_free--;
350 
351     if (write) {
352         flags |= VRING_DESC_F_WRITE;
353     }
354 
355     if (next) {
356         flags |= VRING_DESC_F_NEXT;
357     }
358 
359     /* vq->desc[vq->free_head].addr */
360     qvirtio_writeq(vq->vdev, qts, vq->desc + (16 * vq->free_head), data);
361     /* vq->desc[vq->free_head].len */
362     qvirtio_writel(vq->vdev, qts, vq->desc + (16 * vq->free_head) + 8, len);
363     /* vq->desc[vq->free_head].flags */
364     qvirtio_writew(vq->vdev, qts, vq->desc + (16 * vq->free_head) + 12, flags);
365 
366     return vq->free_head++; /* Return and increase, in this order */
367 }
368 
qvirtqueue_add_indirect(QTestState * qts,QVirtQueue * vq,QVRingIndirectDesc * indirect)369 uint32_t qvirtqueue_add_indirect(QTestState *qts, QVirtQueue *vq,
370                                  QVRingIndirectDesc *indirect)
371 {
372     g_assert(vq->indirect);
373     g_assert_cmpint(vq->size, >=, indirect->elem);
374     g_assert_cmpint(indirect->index, ==, indirect->elem);
375 
376     vq->num_free--;
377 
378     /* vq->desc[vq->free_head].addr */
379     qvirtio_writeq(vq->vdev, qts, vq->desc + (16 * vq->free_head),
380                    indirect->desc);
381     /* vq->desc[vq->free_head].len */
382     qvirtio_writel(vq->vdev, qts, vq->desc + (16 * vq->free_head) + 8,
383                    sizeof(struct vring_desc) * indirect->elem);
384     /* vq->desc[vq->free_head].flags */
385     qvirtio_writew(vq->vdev, qts, vq->desc + (16 * vq->free_head) + 12,
386                    VRING_DESC_F_INDIRECT);
387 
388     return vq->free_head++; /* Return and increase, in this order */
389 }
390 
qvirtqueue_kick(QTestState * qts,QVirtioDevice * d,QVirtQueue * vq,uint32_t free_head)391 void qvirtqueue_kick(QTestState *qts, QVirtioDevice *d, QVirtQueue *vq,
392                      uint32_t free_head)
393 {
394     /* vq->avail->idx */
395     uint16_t idx = qvirtio_readw(d, qts, vq->avail + 2);
396     /* vq->used->flags */
397     uint16_t flags;
398     /* vq->used->avail_event */
399     uint16_t avail_event;
400 
401     /* vq->avail->ring[idx % vq->size] */
402     qvirtio_writew(d, qts, vq->avail + 4 + (2 * (idx % vq->size)), free_head);
403     /* vq->avail->idx */
404     qvirtio_writew(d, qts, vq->avail + 2, idx + 1);
405 
406     /* Must read after idx is updated */
407     flags = qvirtio_readw(d, qts, vq->used);
408     avail_event = qvirtio_readw(d, qts, vq->used + 4 +
409                                 sizeof(struct vring_used_elem) * vq->size);
410 
411     /* < 1 because we add elements to avail queue one by one */
412     if ((flags & VRING_USED_F_NO_NOTIFY) == 0 &&
413                             (!vq->event || (uint16_t)(idx-avail_event) < 1)) {
414         d->bus->virtqueue_kick(d, vq);
415     }
416 }
417 
418 /*
419  * qvirtqueue_get_buf:
420  * @desc_idx: A pointer that is filled with the vq->desc[] index, may be NULL
421  * @len: A pointer that is filled with the length written into the buffer, may
422  *       be NULL
423  *
424  * This function gets the next used element if there is one ready.
425  *
426  * Returns: true if an element was ready, false otherwise
427  */
qvirtqueue_get_buf(QTestState * qts,QVirtQueue * vq,uint32_t * desc_idx,uint32_t * len)428 bool qvirtqueue_get_buf(QTestState *qts, QVirtQueue *vq, uint32_t *desc_idx,
429                         uint32_t *len)
430 {
431     uint16_t idx;
432     uint64_t elem_addr, addr;
433 
434     idx = qvirtio_readw(vq->vdev, qts,
435                         vq->used + offsetof(struct vring_used, idx));
436     if (idx == vq->last_used_idx) {
437         return false;
438     }
439 
440     elem_addr = vq->used +
441         offsetof(struct vring_used, ring) +
442         (vq->last_used_idx % vq->size) *
443         sizeof(struct vring_used_elem);
444 
445     if (desc_idx) {
446         addr = elem_addr + offsetof(struct vring_used_elem, id);
447         *desc_idx = qvirtio_readl(vq->vdev, qts, addr);
448     }
449 
450     if (len) {
451         addr = elem_addr + offsetof(struct vring_used_elem, len);
452         *len = qvirtio_readw(vq->vdev, qts, addr);
453     }
454 
455     vq->last_used_idx++;
456     return true;
457 }
458 
qvirtqueue_set_used_event(QTestState * qts,QVirtQueue * vq,uint16_t idx)459 void qvirtqueue_set_used_event(QTestState *qts, QVirtQueue *vq, uint16_t idx)
460 {
461     g_assert(vq->event);
462 
463     /* vq->avail->used_event */
464     qvirtio_writew(vq->vdev, qts, vq->avail + 4 + (2 * vq->size), idx);
465 }
466 
qvirtio_start_device(QVirtioDevice * vdev)467 void qvirtio_start_device(QVirtioDevice *vdev)
468 {
469     qvirtio_reset(vdev);
470     qvirtio_set_acknowledge(vdev);
471     qvirtio_set_driver(vdev);
472 }
473 
qvirtio_is_big_endian(QVirtioDevice * d)474 bool qvirtio_is_big_endian(QVirtioDevice *d)
475 {
476     return d->big_endian;
477 }
478