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-device.h"
19 #include "system/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 "system/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
OBJECT_DECLARE_SIMPLE_TYPE(VFIOAPDevice,VFIO_AP_DEVICE)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
vfio_ap_req_notifier_handler(void * opaque)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
vfio_ap_register_irq_notifier(VFIOAPDevice * vapdev,unsigned int irq,Error ** errp)73 static bool vfio_ap_register_irq_notifier(VFIOAPDevice *vapdev,
74 unsigned int irq, Error **errp)
75 {
76 int fd;
77 int ret;
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 false;
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 false;
97 }
98
99 ret = vfio_device_get_irq_info(vdev, irq, &irq_info);
100
101 if (ret < 0) {
102 error_setg_errno(errp, -ret, "vfio: Error getting irq info");
103 return false;
104 }
105
106 if (irq_info.count < 1) {
107 error_setg(errp, "vfio: Error getting irq info, count=0");
108 return false;
109 }
110
111 if (event_notifier_init(notifier, 0)) {
112 error_setg_errno(errp, errno,
113 "vfio: Unable to init event notifier for irq (%d)",
114 irq);
115 return false;
116 }
117
118 fd = event_notifier_get_fd(notifier);
119 qemu_set_fd_handler(fd, fd_read, NULL, vapdev);
120
121 if (!vfio_device_irq_set_signaling(vdev, irq, 0, VFIO_IRQ_SET_ACTION_TRIGGER, fd,
122 errp)) {
123 qemu_set_fd_handler(fd, NULL, NULL, vapdev);
124 event_notifier_cleanup(notifier);
125 }
126
127 return true;
128 }
129
vfio_ap_unregister_irq_notifier(VFIOAPDevice * vapdev,unsigned int irq)130 static void vfio_ap_unregister_irq_notifier(VFIOAPDevice *vapdev,
131 unsigned int irq)
132 {
133 Error *err = NULL;
134 EventNotifier *notifier;
135
136 switch (irq) {
137 case VFIO_AP_REQ_IRQ_INDEX:
138 notifier = &vapdev->req_notifier;
139 break;
140 default:
141 error_report("vfio: Unsupported device irq(%d)", irq);
142 return;
143 }
144
145 if (!vfio_device_irq_set_signaling(&vapdev->vdev, irq, 0,
146 VFIO_IRQ_SET_ACTION_TRIGGER, -1, &err)) {
147 warn_reportf_err(err, VFIO_MSG_PREFIX, vapdev->vdev.name);
148 }
149
150 qemu_set_fd_handler(event_notifier_get_fd(notifier),
151 NULL, NULL, vapdev);
152 event_notifier_cleanup(notifier);
153 }
154
vfio_ap_realize(DeviceState * dev,Error ** errp)155 static void vfio_ap_realize(DeviceState *dev, Error **errp)
156 {
157 ERRP_GUARD();
158 Error *err = NULL;
159 VFIOAPDevice *vapdev = VFIO_AP_DEVICE(dev);
160 VFIODevice *vbasedev = &vapdev->vdev;
161
162 if (!vfio_device_get_name(vbasedev, errp)) {
163 return;
164 }
165
166 if (!vfio_device_attach(vbasedev->name, vbasedev,
167 &address_space_memory, errp)) {
168 goto error;
169 }
170
171 if (!vfio_ap_register_irq_notifier(vapdev, VFIO_AP_REQ_IRQ_INDEX, &err)) {
172 /*
173 * Report this error, but do not make it a failing condition.
174 * Lack of this IRQ in the host does not prevent normal operation.
175 */
176 warn_report_err(err);
177 }
178
179 return;
180
181 error:
182 error_prepend(errp, VFIO_MSG_PREFIX, vbasedev->name);
183 g_free(vbasedev->name);
184 }
185
vfio_ap_unrealize(DeviceState * dev)186 static void vfio_ap_unrealize(DeviceState *dev)
187 {
188 VFIOAPDevice *vapdev = VFIO_AP_DEVICE(dev);
189
190 vfio_ap_unregister_irq_notifier(vapdev, VFIO_AP_REQ_IRQ_INDEX);
191 vfio_device_detach(&vapdev->vdev);
192 g_free(vapdev->vdev.name);
193 }
194
195 static const Property vfio_ap_properties[] = {
196 DEFINE_PROP_STRING("sysfsdev", VFIOAPDevice, vdev.sysfsdev),
197 #ifdef CONFIG_IOMMUFD
198 DEFINE_PROP_LINK("iommufd", VFIOAPDevice, vdev.iommufd,
199 TYPE_IOMMUFD_BACKEND, IOMMUFDBackend *),
200 #endif
201 };
202
vfio_ap_reset(DeviceState * dev)203 static void vfio_ap_reset(DeviceState *dev)
204 {
205 int ret;
206 VFIOAPDevice *vapdev = VFIO_AP_DEVICE(dev);
207
208 ret = ioctl(vapdev->vdev.fd, VFIO_DEVICE_RESET);
209 if (ret) {
210 error_report("%s: failed to reset %s device: %s", __func__,
211 vapdev->vdev.name, strerror(errno));
212 }
213 }
214
215 static const VMStateDescription vfio_ap_vmstate = {
216 .name = "vfio-ap",
217 .unmigratable = 1,
218 };
219
vfio_ap_instance_init(Object * obj)220 static void vfio_ap_instance_init(Object *obj)
221 {
222 VFIOAPDevice *vapdev = VFIO_AP_DEVICE(obj);
223 VFIODevice *vbasedev = &vapdev->vdev;
224
225 /*
226 * vfio-ap devices operate in a way compatible with discarding of
227 * memory in RAM blocks, as no pages are pinned in the host.
228 * This needs to be set before vfio_get_device() for vfio common to
229 * handle ram_block_discard_disable().
230 */
231 vfio_device_init(vbasedev, VFIO_DEVICE_TYPE_AP, &vfio_ap_ops,
232 DEVICE(vapdev), true);
233
234 /* AP device is mdev type device */
235 vbasedev->mdev = true;
236 }
237
238 #ifdef CONFIG_IOMMUFD
vfio_ap_set_fd(Object * obj,const char * str,Error ** errp)239 static void vfio_ap_set_fd(Object *obj, const char *str, Error **errp)
240 {
241 vfio_device_set_fd(&VFIO_AP_DEVICE(obj)->vdev, str, errp);
242 }
243 #endif
244
vfio_ap_class_init(ObjectClass * klass,const void * data)245 static void vfio_ap_class_init(ObjectClass *klass, const void *data)
246 {
247 DeviceClass *dc = DEVICE_CLASS(klass);
248
249 device_class_set_props(dc, vfio_ap_properties);
250 #ifdef CONFIG_IOMMUFD
251 object_class_property_add_str(klass, "fd", NULL, vfio_ap_set_fd);
252 #endif
253 dc->vmsd = &vfio_ap_vmstate;
254 dc->desc = "VFIO-based AP device assignment";
255 set_bit(DEVICE_CATEGORY_MISC, dc->categories);
256 dc->realize = vfio_ap_realize;
257 dc->unrealize = vfio_ap_unrealize;
258 dc->hotpluggable = true;
259 device_class_set_legacy_reset(dc, vfio_ap_reset);
260 dc->bus_type = TYPE_AP_BUS;
261
262 object_class_property_set_description(klass, /* 3.1 */
263 "sysfsdev",
264 "Host sysfs path of assigned device");
265 #ifdef CONFIG_IOMMUFD
266 object_class_property_set_description(klass, /* 9.0 */
267 "iommufd",
268 "Set host IOMMUFD backend device");
269 #endif
270 }
271
272 static const TypeInfo vfio_ap_info = {
273 .name = TYPE_VFIO_AP_DEVICE,
274 .parent = TYPE_AP_DEVICE,
275 .instance_size = sizeof(VFIOAPDevice),
276 .instance_init = vfio_ap_instance_init,
277 .class_init = vfio_ap_class_init,
278 };
279
vfio_ap_type_init(void)280 static void vfio_ap_type_init(void)
281 {
282 type_register_static(&vfio_ap_info);
283 }
284
285 type_init(vfio_ap_type_init)
286