xref: /qemu/tests/qtest/libqos/virtio.c (revision e77abbe98b944990b3ab49c671ec15371904e206)
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 "libqtest.h"
12 #include "libqos/virtio.h"
13 #include "standard-headers/linux/virtio_config.h"
14 #include "standard-headers/linux/virtio_ring.h"
15 
16 uint8_t qvirtio_config_readb(QVirtioDevice *d, uint64_t addr)
17 {
18     return d->bus->config_readb(d, addr);
19 }
20 
21 uint16_t qvirtio_config_readw(QVirtioDevice *d, uint64_t addr)
22 {
23     return d->bus->config_readw(d, addr);
24 }
25 
26 uint32_t qvirtio_config_readl(QVirtioDevice *d, uint64_t addr)
27 {
28     return d->bus->config_readl(d, addr);
29 }
30 
31 uint64_t qvirtio_config_readq(QVirtioDevice *d, uint64_t addr)
32 {
33     return d->bus->config_readq(d, addr);
34 }
35 
36 uint32_t qvirtio_get_features(QVirtioDevice *d)
37 {
38     return d->bus->get_features(d);
39 }
40 
41 void qvirtio_set_features(QVirtioDevice *d, uint32_t features)
42 {
43     d->bus->set_features(d, features);
44 }
45 
46 QVirtQueue *qvirtqueue_setup(QVirtioDevice *d,
47                              QGuestAllocator *alloc, uint16_t index)
48 {
49     return d->bus->virtqueue_setup(d, alloc, index);
50 }
51 
52 void qvirtqueue_cleanup(const QVirtioBus *bus, QVirtQueue *vq,
53                         QGuestAllocator *alloc)
54 {
55     return bus->virtqueue_cleanup(vq, alloc);
56 }
57 
58 void qvirtio_reset(QVirtioDevice *d)
59 {
60     d->bus->set_status(d, 0);
61     g_assert_cmphex(d->bus->get_status(d), ==, 0);
62 }
63 
64 void qvirtio_set_acknowledge(QVirtioDevice *d)
65 {
66     d->bus->set_status(d, d->bus->get_status(d) | VIRTIO_CONFIG_S_ACKNOWLEDGE);
67     g_assert_cmphex(d->bus->get_status(d), ==, VIRTIO_CONFIG_S_ACKNOWLEDGE);
68 }
69 
70 void qvirtio_set_driver(QVirtioDevice *d)
71 {
72     d->bus->set_status(d, d->bus->get_status(d) | VIRTIO_CONFIG_S_DRIVER);
73     g_assert_cmphex(d->bus->get_status(d), ==,
74                     VIRTIO_CONFIG_S_DRIVER | VIRTIO_CONFIG_S_ACKNOWLEDGE);
75 }
76 
77 void qvirtio_set_driver_ok(QVirtioDevice *d)
78 {
79     d->bus->set_status(d, d->bus->get_status(d) | VIRTIO_CONFIG_S_DRIVER_OK);
80     g_assert_cmphex(d->bus->get_status(d), ==, VIRTIO_CONFIG_S_DRIVER_OK |
81                     VIRTIO_CONFIG_S_DRIVER | VIRTIO_CONFIG_S_ACKNOWLEDGE);
82 }
83 
84 void qvirtio_wait_queue_isr(QVirtioDevice *d,
85                             QVirtQueue *vq, gint64 timeout_us)
86 {
87     gint64 start_time = g_get_monotonic_time();
88 
89     for (;;) {
90         clock_step(100);
91         if (d->bus->get_queue_isr_status(d, vq)) {
92             return;
93         }
94         g_assert(g_get_monotonic_time() - start_time <= timeout_us);
95     }
96 }
97 
98 /* Wait for the status byte at given guest memory address to be set
99  *
100  * The virtqueue interrupt must not be raised, making this useful for testing
101  * event_index functionality.
102  */
103 uint8_t qvirtio_wait_status_byte_no_isr(QVirtioDevice *d,
104                                         QVirtQueue *vq,
105                                         uint64_t addr,
106                                         gint64 timeout_us)
107 {
108     gint64 start_time = g_get_monotonic_time();
109     uint8_t val;
110 
111     while ((val = readb(addr)) == 0xff) {
112         clock_step(100);
113         g_assert(!d->bus->get_queue_isr_status(d, vq));
114         g_assert(g_get_monotonic_time() - start_time <= timeout_us);
115     }
116     return val;
117 }
118 
119 /*
120  * qvirtio_wait_used_elem:
121  * @desc_idx: The next expected vq->desc[] index in the used ring
122  * @timeout_us: How many microseconds to wait before failing
123  *
124  * This function waits for the next completed request on the used ring.
125  */
126 void qvirtio_wait_used_elem(QVirtioDevice *d,
127                             QVirtQueue *vq,
128                             uint32_t desc_idx,
129                             gint64 timeout_us)
130 {
131     gint64 start_time = g_get_monotonic_time();
132 
133     for (;;) {
134         uint32_t got_desc_idx;
135 
136         clock_step(100);
137 
138         if (d->bus->get_queue_isr_status(d, vq) &&
139             qvirtqueue_get_buf(vq, &got_desc_idx)) {
140             g_assert_cmpint(got_desc_idx, ==, desc_idx);
141             return;
142         }
143 
144         g_assert(g_get_monotonic_time() - start_time <= timeout_us);
145     }
146 }
147 
148 void qvirtio_wait_config_isr(QVirtioDevice *d, gint64 timeout_us)
149 {
150     gint64 start_time = g_get_monotonic_time();
151 
152     for (;;) {
153         clock_step(100);
154         if (d->bus->get_config_isr_status(d)) {
155             return;
156         }
157         g_assert(g_get_monotonic_time() - start_time <= timeout_us);
158     }
159 }
160 
161 void qvring_init(const QGuestAllocator *alloc, QVirtQueue *vq, uint64_t addr)
162 {
163     int i;
164 
165     vq->desc = addr;
166     vq->avail = vq->desc + vq->size * sizeof(struct vring_desc);
167     vq->used = (uint64_t)((vq->avail + sizeof(uint16_t) * (3 + vq->size)
168         + vq->align - 1) & ~(vq->align - 1));
169 
170     for (i = 0; i < vq->size - 1; i++) {
171         /* vq->desc[i].addr */
172         writeq(vq->desc + (16 * i), 0);
173         /* vq->desc[i].next */
174         writew(vq->desc + (16 * i) + 14, i + 1);
175     }
176 
177     /* vq->avail->flags */
178     writew(vq->avail, 0);
179     /* vq->avail->idx */
180     writew(vq->avail + 2, 0);
181     /* vq->avail->used_event */
182     writew(vq->avail + 4 + (2 * vq->size), 0);
183 
184     /* vq->used->flags */
185     writew(vq->used, 0);
186     /* vq->used->avail_event */
187     writew(vq->used + 2 + sizeof(struct vring_used_elem) * vq->size, 0);
188 }
189 
190 QVRingIndirectDesc *qvring_indirect_desc_setup(QVirtioDevice *d,
191                                         QGuestAllocator *alloc, uint16_t elem)
192 {
193     int i;
194     QVRingIndirectDesc *indirect = g_malloc(sizeof(*indirect));
195 
196     indirect->index = 0;
197     indirect->elem = elem;
198     indirect->desc = guest_alloc(alloc, sizeof(struct vring_desc) * elem);
199 
200     for (i = 0; i < elem - 1; ++i) {
201         /* indirect->desc[i].addr */
202         writeq(indirect->desc + (16 * i), 0);
203         /* indirect->desc[i].flags */
204         writew(indirect->desc + (16 * i) + 12, VRING_DESC_F_NEXT);
205         /* indirect->desc[i].next */
206         writew(indirect->desc + (16 * i) + 14, i + 1);
207     }
208 
209     return indirect;
210 }
211 
212 void qvring_indirect_desc_add(QVRingIndirectDesc *indirect, uint64_t data,
213                                                     uint32_t len, bool write)
214 {
215     uint16_t flags;
216 
217     g_assert_cmpint(indirect->index, <, indirect->elem);
218 
219     flags = readw(indirect->desc + (16 * indirect->index) + 12);
220 
221     if (write) {
222         flags |= VRING_DESC_F_WRITE;
223     }
224 
225     /* indirect->desc[indirect->index].addr */
226     writeq(indirect->desc + (16 * indirect->index), data);
227     /* indirect->desc[indirect->index].len */
228     writel(indirect->desc + (16 * indirect->index) + 8, len);
229     /* indirect->desc[indirect->index].flags */
230     writew(indirect->desc + (16 * indirect->index) + 12, flags);
231 
232     indirect->index++;
233 }
234 
235 uint32_t qvirtqueue_add(QVirtQueue *vq, uint64_t data, uint32_t len, bool write,
236                                                                     bool next)
237 {
238     uint16_t flags = 0;
239     vq->num_free--;
240 
241     if (write) {
242         flags |= VRING_DESC_F_WRITE;
243     }
244 
245     if (next) {
246         flags |= VRING_DESC_F_NEXT;
247     }
248 
249     /* vq->desc[vq->free_head].addr */
250     writeq(vq->desc + (16 * vq->free_head), data);
251     /* vq->desc[vq->free_head].len */
252     writel(vq->desc + (16 * vq->free_head) + 8, len);
253     /* vq->desc[vq->free_head].flags */
254     writew(vq->desc + (16 * vq->free_head) + 12, flags);
255 
256     return vq->free_head++; /* Return and increase, in this order */
257 }
258 
259 uint32_t qvirtqueue_add_indirect(QVirtQueue *vq, QVRingIndirectDesc *indirect)
260 {
261     g_assert(vq->indirect);
262     g_assert_cmpint(vq->size, >=, indirect->elem);
263     g_assert_cmpint(indirect->index, ==, indirect->elem);
264 
265     vq->num_free--;
266 
267     /* vq->desc[vq->free_head].addr */
268     writeq(vq->desc + (16 * vq->free_head), indirect->desc);
269     /* vq->desc[vq->free_head].len */
270     writel(vq->desc + (16 * vq->free_head) + 8,
271            sizeof(struct vring_desc) * indirect->elem);
272     /* vq->desc[vq->free_head].flags */
273     writew(vq->desc + (16 * vq->free_head) + 12, VRING_DESC_F_INDIRECT);
274 
275     return vq->free_head++; /* Return and increase, in this order */
276 }
277 
278 void qvirtqueue_kick(QVirtioDevice *d, QVirtQueue *vq, uint32_t free_head)
279 {
280     /* vq->avail->idx */
281     uint16_t idx = readw(vq->avail + 2);
282     /* vq->used->flags */
283     uint16_t flags;
284     /* vq->used->avail_event */
285     uint16_t avail_event;
286 
287     /* vq->avail->ring[idx % vq->size] */
288     writew(vq->avail + 4 + (2 * (idx % vq->size)), free_head);
289     /* vq->avail->idx */
290     writew(vq->avail + 2, idx + 1);
291 
292     /* Must read after idx is updated */
293     flags = readw(vq->avail);
294     avail_event = readw(vq->used + 4 +
295                                 sizeof(struct vring_used_elem) * vq->size);
296 
297     /* < 1 because we add elements to avail queue one by one */
298     if ((flags & VRING_USED_F_NO_NOTIFY) == 0 &&
299                             (!vq->event || (uint16_t)(idx-avail_event) < 1)) {
300         d->bus->virtqueue_kick(d, vq);
301     }
302 }
303 
304 /*
305  * qvirtqueue_get_buf:
306  * @desc_idx: A pointer that is filled with the vq->desc[] index, may be NULL
307  *
308  * This function gets the next used element if there is one ready.
309  *
310  * Returns: true if an element was ready, false otherwise
311  */
312 bool qvirtqueue_get_buf(QVirtQueue *vq, uint32_t *desc_idx)
313 {
314     uint16_t idx;
315 
316     idx = readw(vq->used + offsetof(struct vring_used, idx));
317     if (idx == vq->last_used_idx) {
318         return false;
319     }
320 
321     if (desc_idx) {
322         uint64_t elem_addr;
323 
324         elem_addr = vq->used +
325                     offsetof(struct vring_used, ring) +
326                     (vq->last_used_idx % vq->size) *
327                     sizeof(struct vring_used_elem);
328         *desc_idx = readl(elem_addr + offsetof(struct vring_used_elem, id));
329     }
330 
331     vq->last_used_idx++;
332     return true;
333 }
334 
335 void qvirtqueue_set_used_event(QVirtQueue *vq, uint16_t idx)
336 {
337     g_assert(vq->event);
338 
339     /* vq->avail->used_event */
340     writew(vq->avail + 4 + (2 * vq->size), idx);
341 }
342