xref: /openbmc/qemu/hw/vfio/ap.c (revision 66210a1a30f2384bb59f9dad8d769dba56dd30f1)
1  /*
2   * VFIO based AP matrix device assignment
3   *
4   * Copyright 2018 IBM Corp.
5   * Author(s): Tony Krowiak <akrowiak@linux.ibm.com>
6   *            Halil Pasic <pasic@linux.ibm.com>
7   *
8   * This work is licensed under the terms of the GNU GPL, version 2 or (at
9   * your option) any later version. See the COPYING file in the top-level
10   * directory.
11   */
12  
13  #include "qemu/osdep.h"
14  #include CONFIG_DEVICES /* CONFIG_IOMMUFD */
15  #include <linux/vfio.h>
16  #include <sys/ioctl.h>
17  #include "qapi/error.h"
18  #include "hw/vfio/vfio-common.h"
19  #include "sysemu/iommufd.h"
20  #include "hw/s390x/ap-device.h"
21  #include "qemu/error-report.h"
22  #include "qemu/event_notifier.h"
23  #include "qemu/main-loop.h"
24  #include "qemu/module.h"
25  #include "qemu/option.h"
26  #include "qemu/config-file.h"
27  #include "kvm/kvm_s390x.h"
28  #include "migration/vmstate.h"
29  #include "hw/qdev-properties.h"
30  #include "hw/s390x/ap-bridge.h"
31  #include "exec/address-spaces.h"
32  #include "qom/object.h"
33  
34  #define TYPE_VFIO_AP_DEVICE      "vfio-ap"
35  
36  struct VFIOAPDevice {
37      APDevice apdev;
38      VFIODevice vdev;
39      EventNotifier req_notifier;
40  };
41  
42  OBJECT_DECLARE_SIMPLE_TYPE(VFIOAPDevice, VFIO_AP_DEVICE)
43  
44  static void vfio_ap_compute_needs_reset(VFIODevice *vdev)
45  {
46      vdev->needs_reset = false;
47  }
48  
49  /*
50   * We don't need vfio_hot_reset_multi and vfio_eoi operations for
51   * vfio-ap device now.
52   */
53  struct VFIODeviceOps vfio_ap_ops = {
54      .vfio_compute_needs_reset = vfio_ap_compute_needs_reset,
55  };
56  
57  static void vfio_ap_req_notifier_handler(void *opaque)
58  {
59      VFIOAPDevice *vapdev = opaque;
60      Error *err = NULL;
61  
62      if (!event_notifier_test_and_clear(&vapdev->req_notifier)) {
63          return;
64      }
65  
66      qdev_unplug(DEVICE(vapdev), &err);
67  
68      if (err) {
69          warn_reportf_err(err, VFIO_MSG_PREFIX, vapdev->vdev.name);
70      }
71  }
72  
73  static void vfio_ap_register_irq_notifier(VFIOAPDevice *vapdev,
74                                            unsigned int irq, Error **errp)
75  {
76      int fd;
77      size_t argsz;
78      IOHandler *fd_read;
79      EventNotifier *notifier;
80      struct vfio_irq_info *irq_info;
81      VFIODevice *vdev = &vapdev->vdev;
82  
83      switch (irq) {
84      case VFIO_AP_REQ_IRQ_INDEX:
85          notifier = &vapdev->req_notifier;
86          fd_read = vfio_ap_req_notifier_handler;
87          break;
88      default:
89          error_setg(errp, "vfio: Unsupported device irq(%d)", irq);
90          return;
91      }
92  
93      if (vdev->num_irqs < irq + 1) {
94          error_setg(errp, "vfio: IRQ %u not available (number of irqs %u)",
95                     irq, vdev->num_irqs);
96          return;
97      }
98  
99      argsz = sizeof(*irq_info);
100      irq_info = g_malloc0(argsz);
101      irq_info->index = irq;
102      irq_info->argsz = argsz;
103  
104      if (ioctl(vdev->fd, VFIO_DEVICE_GET_IRQ_INFO,
105                irq_info) < 0 || irq_info->count < 1) {
106          error_setg_errno(errp, errno, "vfio: Error getting irq info");
107          goto out_free_info;
108      }
109  
110      if (event_notifier_init(notifier, 0)) {
111          error_setg_errno(errp, errno,
112                           "vfio: Unable to init event notifier for irq (%d)",
113                           irq);
114          goto out_free_info;
115      }
116  
117      fd = event_notifier_get_fd(notifier);
118      qemu_set_fd_handler(fd, fd_read, NULL, vapdev);
119  
120      if (vfio_set_irq_signaling(vdev, irq, 0, VFIO_IRQ_SET_ACTION_TRIGGER, fd,
121                                 errp)) {
122          qemu_set_fd_handler(fd, NULL, NULL, vapdev);
123          event_notifier_cleanup(notifier);
124      }
125  
126  out_free_info:
127      g_free(irq_info);
128  
129  }
130  
131  static void vfio_ap_unregister_irq_notifier(VFIOAPDevice *vapdev,
132                                              unsigned int irq)
133  {
134      Error *err = NULL;
135      EventNotifier *notifier;
136  
137      switch (irq) {
138      case VFIO_AP_REQ_IRQ_INDEX:
139          notifier = &vapdev->req_notifier;
140          break;
141      default:
142          error_report("vfio: Unsupported device irq(%d)", irq);
143          return;
144      }
145  
146      if (vfio_set_irq_signaling(&vapdev->vdev, irq, 0,
147                                 VFIO_IRQ_SET_ACTION_TRIGGER, -1, &err)) {
148          warn_reportf_err(err, VFIO_MSG_PREFIX, vapdev->vdev.name);
149      }
150  
151      qemu_set_fd_handler(event_notifier_get_fd(notifier),
152                          NULL, NULL, vapdev);
153      event_notifier_cleanup(notifier);
154  }
155  
156  static void vfio_ap_realize(DeviceState *dev, Error **errp)
157  {
158      ERRP_GUARD();
159      int ret;
160      Error *err = NULL;
161      VFIOAPDevice *vapdev = VFIO_AP_DEVICE(dev);
162      VFIODevice *vbasedev = &vapdev->vdev;
163  
164      if (vfio_device_get_name(vbasedev, errp) < 0) {
165          return;
166      }
167  
168      ret = vfio_attach_device(vbasedev->name, vbasedev,
169                               &address_space_memory, errp);
170      if (ret) {
171          goto error;
172      }
173  
174      vfio_ap_register_irq_notifier(vapdev, VFIO_AP_REQ_IRQ_INDEX, &err);
175      if (err) {
176          /*
177           * Report this error, but do not make it a failing condition.
178           * Lack of this IRQ in the host does not prevent normal operation.
179           */
180          error_report_err(err);
181      }
182  
183      return;
184  
185  error:
186      error_prepend(errp, VFIO_MSG_PREFIX, vbasedev->name);
187      g_free(vbasedev->name);
188  }
189  
190  static void vfio_ap_unrealize(DeviceState *dev)
191  {
192      VFIOAPDevice *vapdev = VFIO_AP_DEVICE(dev);
193  
194      vfio_ap_unregister_irq_notifier(vapdev, VFIO_AP_REQ_IRQ_INDEX);
195      vfio_detach_device(&vapdev->vdev);
196      g_free(vapdev->vdev.name);
197  }
198  
199  static Property vfio_ap_properties[] = {
200      DEFINE_PROP_STRING("sysfsdev", VFIOAPDevice, vdev.sysfsdev),
201  #ifdef CONFIG_IOMMUFD
202      DEFINE_PROP_LINK("iommufd", VFIOAPDevice, vdev.iommufd,
203                       TYPE_IOMMUFD_BACKEND, IOMMUFDBackend *),
204  #endif
205      DEFINE_PROP_END_OF_LIST(),
206  };
207  
208  static void vfio_ap_reset(DeviceState *dev)
209  {
210      int ret;
211      VFIOAPDevice *vapdev = VFIO_AP_DEVICE(dev);
212  
213      ret = ioctl(vapdev->vdev.fd, VFIO_DEVICE_RESET);
214      if (ret) {
215          error_report("%s: failed to reset %s device: %s", __func__,
216                       vapdev->vdev.name, strerror(errno));
217      }
218  }
219  
220  static const VMStateDescription vfio_ap_vmstate = {
221      .name = "vfio-ap",
222      .unmigratable = 1,
223  };
224  
225  static void vfio_ap_instance_init(Object *obj)
226  {
227      VFIOAPDevice *vapdev = VFIO_AP_DEVICE(obj);
228      VFIODevice *vbasedev = &vapdev->vdev;
229  
230      /*
231       * vfio-ap devices operate in a way compatible with discarding of
232       * memory in RAM blocks, as no pages are pinned in the host.
233       * This needs to be set before vfio_get_device() for vfio common to
234       * handle ram_block_discard_disable().
235       */
236      vfio_device_init(vbasedev, VFIO_DEVICE_TYPE_AP, &vfio_ap_ops,
237                       DEVICE(vapdev), true);
238  }
239  
240  #ifdef CONFIG_IOMMUFD
241  static void vfio_ap_set_fd(Object *obj, const char *str, Error **errp)
242  {
243      vfio_device_set_fd(&VFIO_AP_DEVICE(obj)->vdev, str, errp);
244  }
245  #endif
246  
247  static void vfio_ap_class_init(ObjectClass *klass, void *data)
248  {
249      DeviceClass *dc = DEVICE_CLASS(klass);
250  
251      device_class_set_props(dc, vfio_ap_properties);
252  #ifdef CONFIG_IOMMUFD
253      object_class_property_add_str(klass, "fd", NULL, vfio_ap_set_fd);
254  #endif
255      dc->vmsd = &vfio_ap_vmstate;
256      dc->desc = "VFIO-based AP device assignment";
257      set_bit(DEVICE_CATEGORY_MISC, dc->categories);
258      dc->realize = vfio_ap_realize;
259      dc->unrealize = vfio_ap_unrealize;
260      dc->hotpluggable = true;
261      dc->reset = vfio_ap_reset;
262      dc->bus_type = TYPE_AP_BUS;
263  }
264  
265  static const TypeInfo vfio_ap_info = {
266      .name = TYPE_VFIO_AP_DEVICE,
267      .parent = TYPE_AP_DEVICE,
268      .instance_size = sizeof(VFIOAPDevice),
269      .instance_init = vfio_ap_instance_init,
270      .class_init = vfio_ap_class_init,
271  };
272  
273  static void vfio_ap_type_init(void)
274  {
275      type_register_static(&vfio_ap_info);
276  }
277  
278  type_init(vfio_ap_type_init)
279