xref: /qemu/hw/virtio/vdpa-dev.c (revision 10229ec3) 
1 /*
2  * Vhost Vdpa Device
3  *
4  * Copyright (c) Huawei Technologies Co., Ltd. 2022. All Rights Reserved.
5  *
6  * Authors:
7  *   Longpeng <longpeng2@huawei.com>
8  *
9  * Largely based on the "vhost-user-blk-pci.c" and "vhost-user-blk.c"
10  * implemented by:
11  *   Changpeng Liu <changpeng.liu@intel.com>
12  *
13  * This work is licensed under the terms of the GNU LGPL, version 2 or later.
14  * See the COPYING.LIB file in the top-level directory.
15  */
16 #include "qemu/osdep.h"
17 #include <sys/ioctl.h>
18 #include <linux/vhost.h>
19 #include "qapi/error.h"
20 #include "qemu/error-report.h"
21 #include "qemu/cutils.h"
22 #include "hw/qdev-core.h"
23 #include "hw/qdev-properties.h"
24 #include "hw/qdev-properties-system.h"
25 #include "hw/virtio/vhost.h"
26 #include "hw/virtio/virtio.h"
27 #include "hw/virtio/virtio-bus.h"
28 #include "hw/virtio/virtio-access.h"
29 #include "hw/virtio/vdpa-dev.h"
30 #include "sysemu/sysemu.h"
31 #include "sysemu/runstate.h"
32 
33 static void
34 vhost_vdpa_device_dummy_handle_output(VirtIODevice *vdev, VirtQueue *vq)
35 {
36     /* Nothing to do */
37 }
38 
39 static uint32_t
40 vhost_vdpa_device_get_u32(int fd, unsigned long int cmd, Error **errp)
41 {
42     uint32_t val = (uint32_t)-1;
43 
44     if (ioctl(fd, cmd, &val) < 0) {
45         error_setg(errp, "vhost-vdpa-device: cmd 0x%lx failed: %s",
46                    cmd, strerror(errno));
47     }
48 
49     return val;
50 }
51 
52 static void vhost_vdpa_device_realize(DeviceState *dev, Error **errp)
53 {
54     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
55     VhostVdpaDevice *v = VHOST_VDPA_DEVICE(vdev);
56     uint16_t max_queue_size;
57     struct vhost_virtqueue *vqs;
58     int i, ret;
59 
60     if (!v->vhostdev) {
61         error_setg(errp, "vhost-vdpa-device: vhostdev are missing");
62         return;
63     }
64 
65     v->vhostfd = qemu_open(v->vhostdev, O_RDWR, errp);
66     if (*errp) {
67         return;
68     }
69     v->vdpa.device_fd = v->vhostfd;
70 
71     v->vdev_id = vhost_vdpa_device_get_u32(v->vhostfd,
72                                            VHOST_VDPA_GET_DEVICE_ID, errp);
73     if (*errp) {
74         goto out;
75     }
76 
77     max_queue_size = vhost_vdpa_device_get_u32(v->vhostfd,
78                                                VHOST_VDPA_GET_VRING_NUM, errp);
79     if (*errp) {
80         goto out;
81     }
82 
83     if (v->queue_size > max_queue_size) {
84         error_setg(errp, "vhost-vdpa-device: invalid queue_size: %u (max:%u)",
85                    v->queue_size, max_queue_size);
86         goto out;
87     } else if (!v->queue_size) {
88         v->queue_size = max_queue_size;
89     }
90 
91     v->num_queues = vhost_vdpa_device_get_u32(v->vhostfd,
92                                               VHOST_VDPA_GET_VQS_COUNT, errp);
93     if (*errp) {
94         goto out;
95     }
96 
97     if (!v->num_queues || v->num_queues > VIRTIO_QUEUE_MAX) {
98         error_setg(errp, "invalid number of virtqueues: %u (max:%u)",
99                    v->num_queues, VIRTIO_QUEUE_MAX);
100         goto out;
101     }
102 
103     v->dev.nvqs = v->num_queues;
104     vqs = g_new0(struct vhost_virtqueue, v->dev.nvqs);
105     v->dev.vqs = vqs;
106     v->dev.vq_index = 0;
107     v->dev.vq_index_end = v->dev.nvqs;
108     v->dev.backend_features = 0;
109     v->started = false;
110 
111     ret = vhost_dev_init(&v->dev, &v->vdpa, VHOST_BACKEND_TYPE_VDPA, 0, NULL);
112     if (ret < 0) {
113         error_setg(errp, "vhost-vdpa-device: vhost initialization failed: %s",
114                    strerror(-ret));
115         goto free_vqs;
116     }
117 
118     v->config_size = vhost_vdpa_device_get_u32(v->vhostfd,
119                                                VHOST_VDPA_GET_CONFIG_SIZE,
120                                                errp);
121     if (*errp) {
122         goto vhost_cleanup;
123     }
124 
125     /*
126      * Invoke .post_init() to initialize the transport-specific fields
127      * before calling virtio_init().
128      */
129     if (v->post_init && v->post_init(v, errp) < 0) {
130         goto vhost_cleanup;
131     }
132 
133     v->config = g_malloc0(v->config_size);
134 
135     ret = vhost_dev_get_config(&v->dev, v->config, v->config_size, NULL);
136     if (ret < 0) {
137         error_setg(errp, "vhost-vdpa-device: get config failed");
138         goto free_config;
139     }
140 
141     virtio_init(vdev, v->vdev_id, v->config_size);
142 
143     v->virtqs = g_new0(VirtQueue *, v->dev.nvqs);
144     for (i = 0; i < v->dev.nvqs; i++) {
145         v->virtqs[i] = virtio_add_queue(vdev, v->queue_size,
146                                         vhost_vdpa_device_dummy_handle_output);
147     }
148 
149     return;
150 
151 free_config:
152     g_free(v->config);
153 vhost_cleanup:
154     vhost_dev_cleanup(&v->dev);
155 free_vqs:
156     g_free(vqs);
157 out:
158     qemu_close(v->vhostfd);
159     v->vhostfd = -1;
160 }
161 
162 static void vhost_vdpa_device_unrealize(DeviceState *dev)
163 {
164     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
165     VhostVdpaDevice *s = VHOST_VDPA_DEVICE(vdev);
166     int i;
167 
168     virtio_set_status(vdev, 0);
169 
170     for (i = 0; i < s->num_queues; i++) {
171         virtio_delete_queue(s->virtqs[i]);
172     }
173     g_free(s->virtqs);
174     virtio_cleanup(vdev);
175 
176     g_free(s->config);
177     g_free(s->dev.vqs);
178     vhost_dev_cleanup(&s->dev);
179     qemu_close(s->vhostfd);
180     s->vhostfd = -1;
181 }
182 
183 static void
184 vhost_vdpa_device_get_config(VirtIODevice *vdev, uint8_t *config)
185 {
186     VhostVdpaDevice *s = VHOST_VDPA_DEVICE(vdev);
187 
188     memcpy(config, s->config, s->config_size);
189 }
190 
191 static void
192 vhost_vdpa_device_set_config(VirtIODevice *vdev, const uint8_t *config)
193 {
194     VhostVdpaDevice *s = VHOST_VDPA_DEVICE(vdev);
195     int ret;
196 
197     ret = vhost_dev_set_config(&s->dev, s->config, 0, s->config_size,
198                                VHOST_SET_CONFIG_TYPE_MASTER);
199     if (ret) {
200         error_report("set device config space failed");
201         return;
202     }
203 }
204 
205 static uint64_t vhost_vdpa_device_get_features(VirtIODevice *vdev,
206                                                uint64_t features,
207                                                Error **errp)
208 {
209     VhostVdpaDevice *s = VHOST_VDPA_DEVICE(vdev);
210     uint64_t backend_features = s->dev.features;
211 
212     if (!virtio_has_feature(features, VIRTIO_F_IOMMU_PLATFORM)) {
213         virtio_clear_feature(&backend_features, VIRTIO_F_IOMMU_PLATFORM);
214     }
215 
216     return backend_features;
217 }
218 
219 static int vhost_vdpa_device_start(VirtIODevice *vdev, Error **errp)
220 {
221     VhostVdpaDevice *s = VHOST_VDPA_DEVICE(vdev);
222     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
223     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
224     int i, ret;
225 
226     if (!k->set_guest_notifiers) {
227         error_setg(errp, "binding does not support guest notifiers");
228         return -ENOSYS;
229     }
230 
231     ret = vhost_dev_enable_notifiers(&s->dev, vdev);
232     if (ret < 0) {
233         error_setg_errno(errp, -ret, "Error enabling host notifiers");
234         return ret;
235     }
236 
237     ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, true);
238     if (ret < 0) {
239         error_setg_errno(errp, -ret, "Error binding guest notifier");
240         goto err_host_notifiers;
241     }
242 
243     s->dev.acked_features = vdev->guest_features;
244 
245     ret = vhost_dev_start(&s->dev, vdev, false);
246     if (ret < 0) {
247         error_setg_errno(errp, -ret, "Error starting vhost");
248         goto err_guest_notifiers;
249     }
250     s->started = true;
251 
252     /*
253      * guest_notifier_mask/pending not used yet, so just unmask
254      * everything here. virtio-pci will do the right thing by
255      * enabling/disabling irqfd.
256      */
257     for (i = 0; i < s->dev.nvqs; i++) {
258         vhost_virtqueue_mask(&s->dev, vdev, i, false);
259     }
260 
261     return ret;
262 
263 err_guest_notifiers:
264     k->set_guest_notifiers(qbus->parent, s->dev.nvqs, false);
265 err_host_notifiers:
266     vhost_dev_disable_notifiers(&s->dev, vdev);
267     return ret;
268 }
269 
270 static void vhost_vdpa_device_stop(VirtIODevice *vdev)
271 {
272     VhostVdpaDevice *s = VHOST_VDPA_DEVICE(vdev);
273     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
274     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
275     int ret;
276 
277     if (!s->started) {
278         return;
279     }
280     s->started = false;
281 
282     if (!k->set_guest_notifiers) {
283         return;
284     }
285 
286     vhost_dev_stop(&s->dev, vdev, false);
287 
288     ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, false);
289     if (ret < 0) {
290         error_report("vhost guest notifier cleanup failed: %d", ret);
291         return;
292     }
293 
294     vhost_dev_disable_notifiers(&s->dev, vdev);
295 }
296 
297 static void vhost_vdpa_device_set_status(VirtIODevice *vdev, uint8_t status)
298 {
299     VhostVdpaDevice *s = VHOST_VDPA_DEVICE(vdev);
300     bool should_start = virtio_device_started(vdev, status);
301     Error *local_err = NULL;
302     int ret;
303 
304     if (!vdev->vm_running) {
305         should_start = false;
306     }
307 
308     if (s->started == should_start) {
309         return;
310     }
311 
312     if (should_start) {
313         ret = vhost_vdpa_device_start(vdev, &local_err);
314         if (ret < 0) {
315             error_reportf_err(local_err, "vhost-vdpa-device: start failed: ");
316         }
317     } else {
318         vhost_vdpa_device_stop(vdev);
319     }
320 }
321 
322 static Property vhost_vdpa_device_properties[] = {
323     DEFINE_PROP_STRING("vhostdev", VhostVdpaDevice, vhostdev),
324     DEFINE_PROP_UINT16("queue-size", VhostVdpaDevice, queue_size, 0),
325     DEFINE_PROP_END_OF_LIST(),
326 };
327 
328 static const VMStateDescription vmstate_vhost_vdpa_device = {
329     .name = "vhost-vdpa-device",
330     .unmigratable = 1,
331     .minimum_version_id = 1,
332     .version_id = 1,
333     .fields = (VMStateField[]) {
334         VMSTATE_VIRTIO_DEVICE,
335         VMSTATE_END_OF_LIST()
336     },
337 };
338 
339 static void vhost_vdpa_device_class_init(ObjectClass *klass, void *data)
340 {
341     DeviceClass *dc = DEVICE_CLASS(klass);
342     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
343 
344     device_class_set_props(dc, vhost_vdpa_device_properties);
345     dc->desc = "VDPA-based generic device assignment";
346     dc->vmsd = &vmstate_vhost_vdpa_device;
347     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
348     vdc->realize = vhost_vdpa_device_realize;
349     vdc->unrealize = vhost_vdpa_device_unrealize;
350     vdc->get_config = vhost_vdpa_device_get_config;
351     vdc->set_config = vhost_vdpa_device_set_config;
352     vdc->get_features = vhost_vdpa_device_get_features;
353     vdc->set_status = vhost_vdpa_device_set_status;
354 }
355 
356 static void vhost_vdpa_device_instance_init(Object *obj)
357 {
358     VhostVdpaDevice *s = VHOST_VDPA_DEVICE(obj);
359 
360     device_add_bootindex_property(obj, &s->bootindex, "bootindex",
361                                   NULL, DEVICE(obj));
362 }
363 
364 static const TypeInfo vhost_vdpa_device_info = {
365     .name = TYPE_VHOST_VDPA_DEVICE,
366     .parent = TYPE_VIRTIO_DEVICE,
367     .instance_size = sizeof(VhostVdpaDevice),
368     .class_init = vhost_vdpa_device_class_init,
369     .instance_init = vhost_vdpa_device_instance_init,
370 };
371 
372 static void register_vhost_vdpa_device_type(void)
373 {
374     type_register_static(&vhost_vdpa_device_info);
375 }
376 
377 type_init(register_vhost_vdpa_device_type);
378