1 /* 2 * vfio based subchannel assignment support 3 * 4 * Copyright 2017 IBM Corp. 5 * Author(s): Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com> 6 * Xiao Feng Ren <renxiaof@linux.vnet.ibm.com> 7 * Pierre Morel <pmorel@linux.vnet.ibm.com> 8 * 9 * This work is licensed under the terms of the GNU GPL, version 2 or (at 10 * your option) any later version. See the COPYING file in the top-level 11 * directory. 12 */ 13 14 #include "qemu/osdep.h" 15 #include <linux/vfio.h> 16 #include <linux/vfio_ccw.h> 17 #include <sys/ioctl.h> 18 19 #include "qapi/error.h" 20 #include "hw/sysbus.h" 21 #include "hw/vfio/vfio.h" 22 #include "hw/vfio/vfio-common.h" 23 #include "hw/s390x/s390-ccw.h" 24 #include "hw/s390x/ccw-device.h" 25 #include "qemu/error-report.h" 26 27 #define TYPE_VFIO_CCW "vfio-ccw" 28 typedef struct VFIOCCWDevice { 29 S390CCWDevice cdev; 30 VFIODevice vdev; 31 uint64_t io_region_size; 32 uint64_t io_region_offset; 33 struct ccw_io_region *io_region; 34 EventNotifier io_notifier; 35 } VFIOCCWDevice; 36 37 static void vfio_ccw_compute_needs_reset(VFIODevice *vdev) 38 { 39 vdev->needs_reset = false; 40 } 41 42 /* 43 * We don't need vfio_hot_reset_multi and vfio_eoi operations for 44 * vfio_ccw device now. 45 */ 46 struct VFIODeviceOps vfio_ccw_ops = { 47 .vfio_compute_needs_reset = vfio_ccw_compute_needs_reset, 48 }; 49 50 static IOInstEnding vfio_ccw_handle_request(SubchDev *sch) 51 { 52 S390CCWDevice *cdev = sch->driver_data; 53 VFIOCCWDevice *vcdev = DO_UPCAST(VFIOCCWDevice, cdev, cdev); 54 struct ccw_io_region *region = vcdev->io_region; 55 int ret; 56 57 QEMU_BUILD_BUG_ON(sizeof(region->orb_area) != sizeof(ORB)); 58 QEMU_BUILD_BUG_ON(sizeof(region->scsw_area) != sizeof(SCSW)); 59 QEMU_BUILD_BUG_ON(sizeof(region->irb_area) != sizeof(IRB)); 60 61 memset(region, 0, sizeof(*region)); 62 63 memcpy(region->orb_area, &sch->orb, sizeof(ORB)); 64 memcpy(region->scsw_area, &sch->curr_status.scsw, sizeof(SCSW)); 65 66 again: 67 ret = pwrite(vcdev->vdev.fd, region, 68 vcdev->io_region_size, vcdev->io_region_offset); 69 if (ret != vcdev->io_region_size) { 70 if (errno == EAGAIN) { 71 goto again; 72 } 73 error_report("vfio-ccw: wirte I/O region failed with errno=%d", errno); 74 ret = -errno; 75 } else { 76 ret = region->ret_code; 77 } 78 switch (ret) { 79 case 0: 80 return IOINST_CC_EXPECTED; 81 case -EBUSY: 82 return IOINST_CC_BUSY; 83 case -ENODEV: 84 case -EACCES: 85 return IOINST_CC_NOT_OPERATIONAL; 86 case -EFAULT: 87 default: 88 sch_gen_unit_exception(sch); 89 css_inject_io_interrupt(sch); 90 return IOINST_CC_EXPECTED; 91 } 92 } 93 94 static void vfio_ccw_reset(DeviceState *dev) 95 { 96 CcwDevice *ccw_dev = DO_UPCAST(CcwDevice, parent_obj, dev); 97 S390CCWDevice *cdev = DO_UPCAST(S390CCWDevice, parent_obj, ccw_dev); 98 VFIOCCWDevice *vcdev = DO_UPCAST(VFIOCCWDevice, cdev, cdev); 99 100 ioctl(vcdev->vdev.fd, VFIO_DEVICE_RESET); 101 } 102 103 static void vfio_ccw_io_notifier_handler(void *opaque) 104 { 105 VFIOCCWDevice *vcdev = opaque; 106 struct ccw_io_region *region = vcdev->io_region; 107 S390CCWDevice *cdev = S390_CCW_DEVICE(vcdev); 108 CcwDevice *ccw_dev = CCW_DEVICE(cdev); 109 SubchDev *sch = ccw_dev->sch; 110 SCSW *s = &sch->curr_status.scsw; 111 PMCW *p = &sch->curr_status.pmcw; 112 IRB irb; 113 int size; 114 115 if (!event_notifier_test_and_clear(&vcdev->io_notifier)) { 116 return; 117 } 118 119 size = pread(vcdev->vdev.fd, region, vcdev->io_region_size, 120 vcdev->io_region_offset); 121 if (size == -1) { 122 switch (errno) { 123 case ENODEV: 124 /* Generate a deferred cc 3 condition. */ 125 s->flags |= SCSW_FLAGS_MASK_CC; 126 s->ctrl &= ~SCSW_CTRL_MASK_STCTL; 127 s->ctrl |= (SCSW_STCTL_ALERT | SCSW_STCTL_STATUS_PEND); 128 goto read_err; 129 case EFAULT: 130 /* Memory problem, generate channel data check. */ 131 s->ctrl &= ~SCSW_ACTL_START_PEND; 132 s->cstat = SCSW_CSTAT_DATA_CHECK; 133 s->ctrl &= ~SCSW_CTRL_MASK_STCTL; 134 s->ctrl |= SCSW_STCTL_PRIMARY | SCSW_STCTL_SECONDARY | 135 SCSW_STCTL_ALERT | SCSW_STCTL_STATUS_PEND; 136 goto read_err; 137 default: 138 /* Error, generate channel program check. */ 139 s->ctrl &= ~SCSW_ACTL_START_PEND; 140 s->cstat = SCSW_CSTAT_PROG_CHECK; 141 s->ctrl &= ~SCSW_CTRL_MASK_STCTL; 142 s->ctrl |= SCSW_STCTL_PRIMARY | SCSW_STCTL_SECONDARY | 143 SCSW_STCTL_ALERT | SCSW_STCTL_STATUS_PEND; 144 goto read_err; 145 } 146 } else if (size != vcdev->io_region_size) { 147 /* Information transfer error, generate channel-control check. */ 148 s->ctrl &= ~SCSW_ACTL_START_PEND; 149 s->cstat = SCSW_CSTAT_CHN_CTRL_CHK; 150 s->ctrl &= ~SCSW_CTRL_MASK_STCTL; 151 s->ctrl |= SCSW_STCTL_PRIMARY | SCSW_STCTL_SECONDARY | 152 SCSW_STCTL_ALERT | SCSW_STCTL_STATUS_PEND; 153 goto read_err; 154 } 155 156 memcpy(&irb, region->irb_area, sizeof(IRB)); 157 158 /* Update control block via irb. */ 159 copy_scsw_to_guest(s, &irb.scsw); 160 161 /* If a uint check is pending, copy sense data. */ 162 if ((s->dstat & SCSW_DSTAT_UNIT_CHECK) && 163 (p->chars & PMCW_CHARS_MASK_CSENSE)) { 164 memcpy(sch->sense_data, irb.ecw, sizeof(irb.ecw)); 165 } 166 167 read_err: 168 css_inject_io_interrupt(sch); 169 } 170 171 static void vfio_ccw_register_io_notifier(VFIOCCWDevice *vcdev, Error **errp) 172 { 173 VFIODevice *vdev = &vcdev->vdev; 174 struct vfio_irq_info *irq_info; 175 struct vfio_irq_set *irq_set; 176 size_t argsz; 177 int32_t *pfd; 178 179 if (vdev->num_irqs < VFIO_CCW_IO_IRQ_INDEX + 1) { 180 error_setg(errp, "vfio: unexpected number of io irqs %u", 181 vdev->num_irqs); 182 return; 183 } 184 185 argsz = sizeof(*irq_info); 186 irq_info = g_malloc0(argsz); 187 irq_info->index = VFIO_CCW_IO_IRQ_INDEX; 188 irq_info->argsz = argsz; 189 if (ioctl(vdev->fd, VFIO_DEVICE_GET_IRQ_INFO, 190 irq_info) < 0 || irq_info->count < 1) { 191 error_setg_errno(errp, errno, "vfio: Error getting irq info"); 192 goto out_free_info; 193 } 194 195 if (event_notifier_init(&vcdev->io_notifier, 0)) { 196 error_setg_errno(errp, errno, 197 "vfio: Unable to init event notifier for IO"); 198 goto out_free_info; 199 } 200 201 argsz = sizeof(*irq_set) + sizeof(*pfd); 202 irq_set = g_malloc0(argsz); 203 irq_set->argsz = argsz; 204 irq_set->flags = VFIO_IRQ_SET_DATA_EVENTFD | 205 VFIO_IRQ_SET_ACTION_TRIGGER; 206 irq_set->index = VFIO_CCW_IO_IRQ_INDEX; 207 irq_set->start = 0; 208 irq_set->count = 1; 209 pfd = (int32_t *) &irq_set->data; 210 211 *pfd = event_notifier_get_fd(&vcdev->io_notifier); 212 qemu_set_fd_handler(*pfd, vfio_ccw_io_notifier_handler, NULL, vcdev); 213 if (ioctl(vdev->fd, VFIO_DEVICE_SET_IRQS, irq_set)) { 214 error_setg(errp, "vfio: Failed to set up io notification"); 215 qemu_set_fd_handler(*pfd, NULL, NULL, vcdev); 216 event_notifier_cleanup(&vcdev->io_notifier); 217 } 218 219 g_free(irq_set); 220 221 out_free_info: 222 g_free(irq_info); 223 } 224 225 static void vfio_ccw_unregister_io_notifier(VFIOCCWDevice *vcdev) 226 { 227 struct vfio_irq_set *irq_set; 228 size_t argsz; 229 int32_t *pfd; 230 231 argsz = sizeof(*irq_set) + sizeof(*pfd); 232 irq_set = g_malloc0(argsz); 233 irq_set->argsz = argsz; 234 irq_set->flags = VFIO_IRQ_SET_DATA_EVENTFD | 235 VFIO_IRQ_SET_ACTION_TRIGGER; 236 irq_set->index = VFIO_CCW_IO_IRQ_INDEX; 237 irq_set->start = 0; 238 irq_set->count = 1; 239 pfd = (int32_t *) &irq_set->data; 240 *pfd = -1; 241 242 if (ioctl(vcdev->vdev.fd, VFIO_DEVICE_SET_IRQS, irq_set)) { 243 error_report("vfio: Failed to de-assign device io fd: %m"); 244 } 245 246 qemu_set_fd_handler(event_notifier_get_fd(&vcdev->io_notifier), 247 NULL, NULL, vcdev); 248 event_notifier_cleanup(&vcdev->io_notifier); 249 250 g_free(irq_set); 251 } 252 253 static void vfio_ccw_get_region(VFIOCCWDevice *vcdev, Error **errp) 254 { 255 VFIODevice *vdev = &vcdev->vdev; 256 struct vfio_region_info *info; 257 int ret; 258 259 /* Sanity check device */ 260 if (!(vdev->flags & VFIO_DEVICE_FLAGS_CCW)) { 261 error_setg(errp, "vfio: Um, this isn't a vfio-ccw device"); 262 return; 263 } 264 265 if (vdev->num_regions < VFIO_CCW_CONFIG_REGION_INDEX + 1) { 266 error_setg(errp, "vfio: Unexpected number of the I/O region %u", 267 vdev->num_regions); 268 return; 269 } 270 271 ret = vfio_get_region_info(vdev, VFIO_CCW_CONFIG_REGION_INDEX, &info); 272 if (ret) { 273 error_setg_errno(errp, -ret, "vfio: Error getting config info"); 274 return; 275 } 276 277 vcdev->io_region_size = info->size; 278 if (sizeof(*vcdev->io_region) != vcdev->io_region_size) { 279 error_setg(errp, "vfio: Unexpected size of the I/O region"); 280 g_free(info); 281 return; 282 } 283 284 vcdev->io_region_offset = info->offset; 285 vcdev->io_region = g_malloc0(info->size); 286 287 g_free(info); 288 } 289 290 static void vfio_ccw_put_region(VFIOCCWDevice *vcdev) 291 { 292 g_free(vcdev->io_region); 293 } 294 295 static void vfio_ccw_put_device(VFIOCCWDevice *vcdev) 296 { 297 g_free(vcdev->vdev.name); 298 vfio_put_base_device(&vcdev->vdev); 299 } 300 301 static void vfio_ccw_get_device(VFIOGroup *group, VFIOCCWDevice *vcdev, 302 Error **errp) 303 { 304 char *name = g_strdup_printf("%x.%x.%04x", vcdev->cdev.hostid.cssid, 305 vcdev->cdev.hostid.ssid, 306 vcdev->cdev.hostid.devid); 307 VFIODevice *vbasedev; 308 309 QLIST_FOREACH(vbasedev, &group->device_list, next) { 310 if (strcmp(vbasedev->name, name) == 0) { 311 error_setg(errp, "vfio: subchannel %s has already been attached", 312 name); 313 goto out_err; 314 } 315 } 316 317 if (vfio_get_device(group, vcdev->cdev.mdevid, &vcdev->vdev, errp)) { 318 goto out_err; 319 } 320 321 vcdev->vdev.ops = &vfio_ccw_ops; 322 vcdev->vdev.type = VFIO_DEVICE_TYPE_CCW; 323 vcdev->vdev.name = name; 324 vcdev->vdev.dev = &vcdev->cdev.parent_obj.parent_obj; 325 326 return; 327 328 out_err: 329 g_free(name); 330 } 331 332 static VFIOGroup *vfio_ccw_get_group(S390CCWDevice *cdev, Error **errp) 333 { 334 char *tmp, group_path[PATH_MAX]; 335 ssize_t len; 336 int groupid; 337 338 tmp = g_strdup_printf("/sys/bus/css/devices/%x.%x.%04x/%s/iommu_group", 339 cdev->hostid.cssid, cdev->hostid.ssid, 340 cdev->hostid.devid, cdev->mdevid); 341 len = readlink(tmp, group_path, sizeof(group_path)); 342 g_free(tmp); 343 344 if (len <= 0 || len >= sizeof(group_path)) { 345 error_setg(errp, "vfio: no iommu_group found"); 346 return NULL; 347 } 348 349 group_path[len] = 0; 350 351 if (sscanf(basename(group_path), "%d", &groupid) != 1) { 352 error_setg(errp, "vfio: failed to read %s", group_path); 353 return NULL; 354 } 355 356 return vfio_get_group(groupid, &address_space_memory, errp); 357 } 358 359 static void vfio_ccw_realize(DeviceState *dev, Error **errp) 360 { 361 VFIOGroup *group; 362 CcwDevice *ccw_dev = DO_UPCAST(CcwDevice, parent_obj, dev); 363 S390CCWDevice *cdev = DO_UPCAST(S390CCWDevice, parent_obj, ccw_dev); 364 VFIOCCWDevice *vcdev = DO_UPCAST(VFIOCCWDevice, cdev, cdev); 365 S390CCWDeviceClass *cdc = S390_CCW_DEVICE_GET_CLASS(cdev); 366 Error *err = NULL; 367 368 /* Call the class init function for subchannel. */ 369 if (cdc->realize) { 370 cdc->realize(cdev, vcdev->vdev.sysfsdev, &err); 371 if (err) { 372 goto out_err_propagate; 373 } 374 } 375 376 group = vfio_ccw_get_group(cdev, &err); 377 if (!group) { 378 goto out_group_err; 379 } 380 381 vfio_ccw_get_device(group, vcdev, &err); 382 if (err) { 383 goto out_device_err; 384 } 385 386 vfio_ccw_get_region(vcdev, &err); 387 if (err) { 388 goto out_region_err; 389 } 390 391 vfio_ccw_register_io_notifier(vcdev, &err); 392 if (err) { 393 goto out_notifier_err; 394 } 395 396 return; 397 398 out_notifier_err: 399 vfio_ccw_put_region(vcdev); 400 out_region_err: 401 vfio_ccw_put_device(vcdev); 402 out_device_err: 403 vfio_put_group(group); 404 out_group_err: 405 if (cdc->unrealize) { 406 cdc->unrealize(cdev, NULL); 407 } 408 out_err_propagate: 409 error_propagate(errp, err); 410 } 411 412 static void vfio_ccw_unrealize(DeviceState *dev, Error **errp) 413 { 414 CcwDevice *ccw_dev = DO_UPCAST(CcwDevice, parent_obj, dev); 415 S390CCWDevice *cdev = DO_UPCAST(S390CCWDevice, parent_obj, ccw_dev); 416 VFIOCCWDevice *vcdev = DO_UPCAST(VFIOCCWDevice, cdev, cdev); 417 S390CCWDeviceClass *cdc = S390_CCW_DEVICE_GET_CLASS(cdev); 418 VFIOGroup *group = vcdev->vdev.group; 419 420 vfio_ccw_unregister_io_notifier(vcdev); 421 vfio_ccw_put_region(vcdev); 422 vfio_ccw_put_device(vcdev); 423 vfio_put_group(group); 424 425 if (cdc->unrealize) { 426 cdc->unrealize(cdev, errp); 427 } 428 } 429 430 static Property vfio_ccw_properties[] = { 431 DEFINE_PROP_STRING("sysfsdev", VFIOCCWDevice, vdev.sysfsdev), 432 DEFINE_PROP_END_OF_LIST(), 433 }; 434 435 static const VMStateDescription vfio_ccw_vmstate = { 436 .name = TYPE_VFIO_CCW, 437 .unmigratable = 1, 438 }; 439 440 static void vfio_ccw_class_init(ObjectClass *klass, void *data) 441 { 442 DeviceClass *dc = DEVICE_CLASS(klass); 443 S390CCWDeviceClass *cdc = S390_CCW_DEVICE_CLASS(klass); 444 445 dc->props = vfio_ccw_properties; 446 dc->vmsd = &vfio_ccw_vmstate; 447 dc->desc = "VFIO-based subchannel assignment"; 448 set_bit(DEVICE_CATEGORY_MISC, dc->categories); 449 dc->realize = vfio_ccw_realize; 450 dc->unrealize = vfio_ccw_unrealize; 451 dc->reset = vfio_ccw_reset; 452 453 cdc->handle_request = vfio_ccw_handle_request; 454 } 455 456 static const TypeInfo vfio_ccw_info = { 457 .name = TYPE_VFIO_CCW, 458 .parent = TYPE_S390_CCW, 459 .instance_size = sizeof(VFIOCCWDevice), 460 .class_init = vfio_ccw_class_init, 461 }; 462 463 static void register_vfio_ccw_type(void) 464 { 465 type_register_static(&vfio_ccw_info); 466 } 467 468 type_init(register_vfio_ccw_type) 469