1 /* 2 * vfio based subchannel assignment support 3 * 4 * Copyright 2017 IBM Corp. 5 * Copyright 2019 Red Hat, Inc. 6 * 7 * Author(s): Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com> 8 * Xiao Feng Ren <renxiaof@linux.vnet.ibm.com> 9 * Pierre Morel <pmorel@linux.vnet.ibm.com> 10 * Cornelia Huck <cohuck@redhat.com> 11 * 12 * This work is licensed under the terms of the GNU GPL, version 2 or (at 13 * your option) any later version. See the COPYING file in the top-level 14 * directory. 15 */ 16 17 #include "qemu/osdep.h" 18 #include <linux/vfio.h> 19 #include <linux/vfio_ccw.h> 20 #include <sys/ioctl.h> 21 22 #include "qapi/error.h" 23 #include "hw/sysbus.h" 24 #include "hw/vfio/vfio.h" 25 #include "hw/vfio/vfio-common.h" 26 #include "hw/s390x/s390-ccw.h" 27 #include "hw/s390x/vfio-ccw.h" 28 #include "hw/qdev-properties.h" 29 #include "hw/s390x/ccw-device.h" 30 #include "exec/address-spaces.h" 31 #include "qemu/error-report.h" 32 #include "qemu/main-loop.h" 33 #include "qemu/module.h" 34 35 struct VFIOCCWDevice { 36 S390CCWDevice cdev; 37 VFIODevice vdev; 38 uint64_t io_region_size; 39 uint64_t io_region_offset; 40 struct ccw_io_region *io_region; 41 uint64_t async_cmd_region_size; 42 uint64_t async_cmd_region_offset; 43 struct ccw_cmd_region *async_cmd_region; 44 EventNotifier io_notifier; 45 bool force_orb_pfch; 46 bool warned_orb_pfch; 47 }; 48 49 static inline void warn_once_pfch(VFIOCCWDevice *vcdev, SubchDev *sch, 50 const char *msg) 51 { 52 warn_report_once_cond(&vcdev->warned_orb_pfch, 53 "vfio-ccw (devno %x.%x.%04x): %s", 54 sch->cssid, sch->ssid, sch->devno, msg); 55 } 56 57 static void vfio_ccw_compute_needs_reset(VFIODevice *vdev) 58 { 59 vdev->needs_reset = false; 60 } 61 62 /* 63 * We don't need vfio_hot_reset_multi and vfio_eoi operations for 64 * vfio_ccw device now. 65 */ 66 struct VFIODeviceOps vfio_ccw_ops = { 67 .vfio_compute_needs_reset = vfio_ccw_compute_needs_reset, 68 }; 69 70 static IOInstEnding vfio_ccw_handle_request(SubchDev *sch) 71 { 72 S390CCWDevice *cdev = sch->driver_data; 73 VFIOCCWDevice *vcdev = DO_UPCAST(VFIOCCWDevice, cdev, cdev); 74 struct ccw_io_region *region = vcdev->io_region; 75 int ret; 76 77 if (!(sch->orb.ctrl0 & ORB_CTRL0_MASK_PFCH)) { 78 if (!(vcdev->force_orb_pfch)) { 79 warn_once_pfch(vcdev, sch, "requires PFCH flag set"); 80 sch_gen_unit_exception(sch); 81 css_inject_io_interrupt(sch); 82 return IOINST_CC_EXPECTED; 83 } else { 84 sch->orb.ctrl0 |= ORB_CTRL0_MASK_PFCH; 85 warn_once_pfch(vcdev, sch, "PFCH flag forced"); 86 } 87 } 88 89 QEMU_BUILD_BUG_ON(sizeof(region->orb_area) != sizeof(ORB)); 90 QEMU_BUILD_BUG_ON(sizeof(region->scsw_area) != sizeof(SCSW)); 91 QEMU_BUILD_BUG_ON(sizeof(region->irb_area) != sizeof(IRB)); 92 93 memset(region, 0, sizeof(*region)); 94 95 memcpy(region->orb_area, &sch->orb, sizeof(ORB)); 96 memcpy(region->scsw_area, &sch->curr_status.scsw, sizeof(SCSW)); 97 98 again: 99 ret = pwrite(vcdev->vdev.fd, region, 100 vcdev->io_region_size, vcdev->io_region_offset); 101 if (ret != vcdev->io_region_size) { 102 if (errno == EAGAIN) { 103 goto again; 104 } 105 error_report("vfio-ccw: write I/O region failed with errno=%d", errno); 106 ret = -errno; 107 } else { 108 ret = region->ret_code; 109 } 110 switch (ret) { 111 case 0: 112 return IOINST_CC_EXPECTED; 113 case -EBUSY: 114 return IOINST_CC_BUSY; 115 case -ENODEV: 116 case -EACCES: 117 return IOINST_CC_NOT_OPERATIONAL; 118 case -EFAULT: 119 default: 120 sch_gen_unit_exception(sch); 121 css_inject_io_interrupt(sch); 122 return IOINST_CC_EXPECTED; 123 } 124 } 125 126 static int vfio_ccw_handle_clear(SubchDev *sch) 127 { 128 S390CCWDevice *cdev = sch->driver_data; 129 VFIOCCWDevice *vcdev = DO_UPCAST(VFIOCCWDevice, cdev, cdev); 130 struct ccw_cmd_region *region = vcdev->async_cmd_region; 131 int ret; 132 133 if (!vcdev->async_cmd_region) { 134 /* Async command region not available, fall back to emulation */ 135 return -ENOSYS; 136 } 137 138 memset(region, 0, sizeof(*region)); 139 region->command = VFIO_CCW_ASYNC_CMD_CSCH; 140 141 again: 142 ret = pwrite(vcdev->vdev.fd, region, 143 vcdev->async_cmd_region_size, vcdev->async_cmd_region_offset); 144 if (ret != vcdev->async_cmd_region_size) { 145 if (errno == EAGAIN) { 146 goto again; 147 } 148 error_report("vfio-ccw: write cmd region failed with errno=%d", errno); 149 ret = -errno; 150 } else { 151 ret = region->ret_code; 152 } 153 switch (ret) { 154 case 0: 155 case -ENODEV: 156 case -EACCES: 157 return 0; 158 case -EFAULT: 159 default: 160 sch_gen_unit_exception(sch); 161 css_inject_io_interrupt(sch); 162 return 0; 163 } 164 } 165 166 static int vfio_ccw_handle_halt(SubchDev *sch) 167 { 168 S390CCWDevice *cdev = sch->driver_data; 169 VFIOCCWDevice *vcdev = DO_UPCAST(VFIOCCWDevice, cdev, cdev); 170 struct ccw_cmd_region *region = vcdev->async_cmd_region; 171 int ret; 172 173 if (!vcdev->async_cmd_region) { 174 /* Async command region not available, fall back to emulation */ 175 return -ENOSYS; 176 } 177 178 memset(region, 0, sizeof(*region)); 179 region->command = VFIO_CCW_ASYNC_CMD_HSCH; 180 181 again: 182 ret = pwrite(vcdev->vdev.fd, region, 183 vcdev->async_cmd_region_size, vcdev->async_cmd_region_offset); 184 if (ret != vcdev->async_cmd_region_size) { 185 if (errno == EAGAIN) { 186 goto again; 187 } 188 error_report("vfio-ccw: write cmd region failed with errno=%d", errno); 189 ret = -errno; 190 } else { 191 ret = region->ret_code; 192 } 193 switch (ret) { 194 case 0: 195 case -EBUSY: 196 case -ENODEV: 197 case -EACCES: 198 return 0; 199 case -EFAULT: 200 default: 201 sch_gen_unit_exception(sch); 202 css_inject_io_interrupt(sch); 203 return 0; 204 } 205 } 206 207 static void vfio_ccw_reset(DeviceState *dev) 208 { 209 CcwDevice *ccw_dev = DO_UPCAST(CcwDevice, parent_obj, dev); 210 S390CCWDevice *cdev = DO_UPCAST(S390CCWDevice, parent_obj, ccw_dev); 211 VFIOCCWDevice *vcdev = DO_UPCAST(VFIOCCWDevice, cdev, cdev); 212 213 ioctl(vcdev->vdev.fd, VFIO_DEVICE_RESET); 214 } 215 216 static void vfio_ccw_io_notifier_handler(void *opaque) 217 { 218 VFIOCCWDevice *vcdev = opaque; 219 struct ccw_io_region *region = vcdev->io_region; 220 S390CCWDevice *cdev = S390_CCW_DEVICE(vcdev); 221 CcwDevice *ccw_dev = CCW_DEVICE(cdev); 222 SubchDev *sch = ccw_dev->sch; 223 SCHIB *schib = &sch->curr_status; 224 SCSW s; 225 IRB irb; 226 int size; 227 228 if (!event_notifier_test_and_clear(&vcdev->io_notifier)) { 229 return; 230 } 231 232 size = pread(vcdev->vdev.fd, region, vcdev->io_region_size, 233 vcdev->io_region_offset); 234 if (size == -1) { 235 switch (errno) { 236 case ENODEV: 237 /* Generate a deferred cc 3 condition. */ 238 schib->scsw.flags |= SCSW_FLAGS_MASK_CC; 239 schib->scsw.ctrl &= ~SCSW_CTRL_MASK_STCTL; 240 schib->scsw.ctrl |= (SCSW_STCTL_ALERT | SCSW_STCTL_STATUS_PEND); 241 goto read_err; 242 case EFAULT: 243 /* Memory problem, generate channel data check. */ 244 schib->scsw.ctrl &= ~SCSW_ACTL_START_PEND; 245 schib->scsw.cstat = SCSW_CSTAT_DATA_CHECK; 246 schib->scsw.ctrl &= ~SCSW_CTRL_MASK_STCTL; 247 schib->scsw.ctrl |= SCSW_STCTL_PRIMARY | SCSW_STCTL_SECONDARY | 248 SCSW_STCTL_ALERT | SCSW_STCTL_STATUS_PEND; 249 goto read_err; 250 default: 251 /* Error, generate channel program check. */ 252 schib->scsw.ctrl &= ~SCSW_ACTL_START_PEND; 253 schib->scsw.cstat = SCSW_CSTAT_PROG_CHECK; 254 schib->scsw.ctrl &= ~SCSW_CTRL_MASK_STCTL; 255 schib->scsw.ctrl |= SCSW_STCTL_PRIMARY | SCSW_STCTL_SECONDARY | 256 SCSW_STCTL_ALERT | SCSW_STCTL_STATUS_PEND; 257 goto read_err; 258 } 259 } else if (size != vcdev->io_region_size) { 260 /* Information transfer error, generate channel-control check. */ 261 schib->scsw.ctrl &= ~SCSW_ACTL_START_PEND; 262 schib->scsw.cstat = SCSW_CSTAT_CHN_CTRL_CHK; 263 schib->scsw.ctrl &= ~SCSW_CTRL_MASK_STCTL; 264 schib->scsw.ctrl |= SCSW_STCTL_PRIMARY | SCSW_STCTL_SECONDARY | 265 SCSW_STCTL_ALERT | SCSW_STCTL_STATUS_PEND; 266 goto read_err; 267 } 268 269 memcpy(&irb, region->irb_area, sizeof(IRB)); 270 271 /* Update control block via irb. */ 272 s = schib->scsw; 273 copy_scsw_to_guest(&s, &irb.scsw); 274 schib->scsw = s; 275 276 /* If a uint check is pending, copy sense data. */ 277 if ((schib->scsw.dstat & SCSW_DSTAT_UNIT_CHECK) && 278 (schib->pmcw.chars & PMCW_CHARS_MASK_CSENSE)) { 279 memcpy(sch->sense_data, irb.ecw, sizeof(irb.ecw)); 280 } 281 282 read_err: 283 css_inject_io_interrupt(sch); 284 } 285 286 static void vfio_ccw_register_io_notifier(VFIOCCWDevice *vcdev, Error **errp) 287 { 288 VFIODevice *vdev = &vcdev->vdev; 289 struct vfio_irq_info *irq_info; 290 size_t argsz; 291 int fd; 292 293 if (vdev->num_irqs < VFIO_CCW_IO_IRQ_INDEX + 1) { 294 error_setg(errp, "vfio: unexpected number of io irqs %u", 295 vdev->num_irqs); 296 return; 297 } 298 299 argsz = sizeof(*irq_info); 300 irq_info = g_malloc0(argsz); 301 irq_info->index = VFIO_CCW_IO_IRQ_INDEX; 302 irq_info->argsz = argsz; 303 if (ioctl(vdev->fd, VFIO_DEVICE_GET_IRQ_INFO, 304 irq_info) < 0 || irq_info->count < 1) { 305 error_setg_errno(errp, errno, "vfio: Error getting irq info"); 306 goto out_free_info; 307 } 308 309 if (event_notifier_init(&vcdev->io_notifier, 0)) { 310 error_setg_errno(errp, errno, 311 "vfio: Unable to init event notifier for IO"); 312 goto out_free_info; 313 } 314 315 fd = event_notifier_get_fd(&vcdev->io_notifier); 316 qemu_set_fd_handler(fd, vfio_ccw_io_notifier_handler, NULL, vcdev); 317 318 if (vfio_set_irq_signaling(vdev, VFIO_CCW_IO_IRQ_INDEX, 0, 319 VFIO_IRQ_SET_ACTION_TRIGGER, fd, errp)) { 320 qemu_set_fd_handler(fd, NULL, NULL, vcdev); 321 event_notifier_cleanup(&vcdev->io_notifier); 322 } 323 324 out_free_info: 325 g_free(irq_info); 326 } 327 328 static void vfio_ccw_unregister_io_notifier(VFIOCCWDevice *vcdev) 329 { 330 Error *err = NULL; 331 332 if (vfio_set_irq_signaling(&vcdev->vdev, VFIO_CCW_IO_IRQ_INDEX, 0, 333 VFIO_IRQ_SET_ACTION_TRIGGER, -1, &err)) { 334 error_reportf_err(err, VFIO_MSG_PREFIX, vcdev->vdev.name); 335 } 336 337 qemu_set_fd_handler(event_notifier_get_fd(&vcdev->io_notifier), 338 NULL, NULL, vcdev); 339 event_notifier_cleanup(&vcdev->io_notifier); 340 } 341 342 static void vfio_ccw_get_region(VFIOCCWDevice *vcdev, Error **errp) 343 { 344 VFIODevice *vdev = &vcdev->vdev; 345 struct vfio_region_info *info; 346 int ret; 347 348 /* Sanity check device */ 349 if (!(vdev->flags & VFIO_DEVICE_FLAGS_CCW)) { 350 error_setg(errp, "vfio: Um, this isn't a vfio-ccw device"); 351 return; 352 } 353 354 /* 355 * We always expect at least the I/O region to be present. We also 356 * may have a variable number of regions governed by capabilities. 357 */ 358 if (vdev->num_regions < VFIO_CCW_CONFIG_REGION_INDEX + 1) { 359 error_setg(errp, "vfio: too few regions (%u), expected at least %u", 360 vdev->num_regions, VFIO_CCW_CONFIG_REGION_INDEX + 1); 361 return; 362 } 363 364 ret = vfio_get_region_info(vdev, VFIO_CCW_CONFIG_REGION_INDEX, &info); 365 if (ret) { 366 error_setg_errno(errp, -ret, "vfio: Error getting config info"); 367 return; 368 } 369 370 vcdev->io_region_size = info->size; 371 if (sizeof(*vcdev->io_region) != vcdev->io_region_size) { 372 error_setg(errp, "vfio: Unexpected size of the I/O region"); 373 g_free(info); 374 return; 375 } 376 377 vcdev->io_region_offset = info->offset; 378 vcdev->io_region = g_malloc0(info->size); 379 380 /* check for the optional async command region */ 381 ret = vfio_get_dev_region_info(vdev, VFIO_REGION_TYPE_CCW, 382 VFIO_REGION_SUBTYPE_CCW_ASYNC_CMD, &info); 383 if (!ret) { 384 vcdev->async_cmd_region_size = info->size; 385 if (sizeof(*vcdev->async_cmd_region) != vcdev->async_cmd_region_size) { 386 error_setg(errp, "vfio: Unexpected size of the async cmd region"); 387 g_free(vcdev->io_region); 388 g_free(info); 389 return; 390 } 391 vcdev->async_cmd_region_offset = info->offset; 392 vcdev->async_cmd_region = g_malloc0(info->size); 393 } 394 395 g_free(info); 396 } 397 398 static void vfio_ccw_put_region(VFIOCCWDevice *vcdev) 399 { 400 g_free(vcdev->async_cmd_region); 401 g_free(vcdev->io_region); 402 } 403 404 static void vfio_ccw_put_device(VFIOCCWDevice *vcdev) 405 { 406 g_free(vcdev->vdev.name); 407 vfio_put_base_device(&vcdev->vdev); 408 } 409 410 static void vfio_ccw_get_device(VFIOGroup *group, VFIOCCWDevice *vcdev, 411 Error **errp) 412 { 413 char *name = g_strdup_printf("%x.%x.%04x", vcdev->cdev.hostid.cssid, 414 vcdev->cdev.hostid.ssid, 415 vcdev->cdev.hostid.devid); 416 VFIODevice *vbasedev; 417 418 QLIST_FOREACH(vbasedev, &group->device_list, next) { 419 if (strcmp(vbasedev->name, name) == 0) { 420 error_setg(errp, "vfio: subchannel %s has already been attached", 421 name); 422 goto out_err; 423 } 424 } 425 426 /* 427 * All vfio-ccw devices are believed to operate in a way compatible with 428 * memory ballooning, ie. pages pinned in the host are in the current 429 * working set of the guest driver and therefore never overlap with pages 430 * available to the guest balloon driver. This needs to be set before 431 * vfio_get_device() for vfio common to handle the balloon inhibitor. 432 */ 433 vcdev->vdev.balloon_allowed = true; 434 435 if (vfio_get_device(group, vcdev->cdev.mdevid, &vcdev->vdev, errp)) { 436 goto out_err; 437 } 438 439 vcdev->vdev.ops = &vfio_ccw_ops; 440 vcdev->vdev.type = VFIO_DEVICE_TYPE_CCW; 441 vcdev->vdev.name = name; 442 vcdev->vdev.dev = &vcdev->cdev.parent_obj.parent_obj; 443 444 return; 445 446 out_err: 447 g_free(name); 448 } 449 450 static VFIOGroup *vfio_ccw_get_group(S390CCWDevice *cdev, Error **errp) 451 { 452 char *tmp, group_path[PATH_MAX]; 453 ssize_t len; 454 int groupid; 455 456 tmp = g_strdup_printf("/sys/bus/css/devices/%x.%x.%04x/%s/iommu_group", 457 cdev->hostid.cssid, cdev->hostid.ssid, 458 cdev->hostid.devid, cdev->mdevid); 459 len = readlink(tmp, group_path, sizeof(group_path)); 460 g_free(tmp); 461 462 if (len <= 0 || len >= sizeof(group_path)) { 463 error_setg(errp, "vfio: no iommu_group found"); 464 return NULL; 465 } 466 467 group_path[len] = 0; 468 469 if (sscanf(basename(group_path), "%d", &groupid) != 1) { 470 error_setg(errp, "vfio: failed to read %s", group_path); 471 return NULL; 472 } 473 474 return vfio_get_group(groupid, &address_space_memory, errp); 475 } 476 477 static void vfio_ccw_realize(DeviceState *dev, Error **errp) 478 { 479 VFIOGroup *group; 480 CcwDevice *ccw_dev = DO_UPCAST(CcwDevice, parent_obj, dev); 481 S390CCWDevice *cdev = DO_UPCAST(S390CCWDevice, parent_obj, ccw_dev); 482 VFIOCCWDevice *vcdev = DO_UPCAST(VFIOCCWDevice, cdev, cdev); 483 S390CCWDeviceClass *cdc = S390_CCW_DEVICE_GET_CLASS(cdev); 484 Error *err = NULL; 485 486 /* Call the class init function for subchannel. */ 487 if (cdc->realize) { 488 cdc->realize(cdev, vcdev->vdev.sysfsdev, &err); 489 if (err) { 490 goto out_err_propagate; 491 } 492 } 493 494 group = vfio_ccw_get_group(cdev, &err); 495 if (!group) { 496 goto out_group_err; 497 } 498 499 vfio_ccw_get_device(group, vcdev, &err); 500 if (err) { 501 goto out_device_err; 502 } 503 504 vfio_ccw_get_region(vcdev, &err); 505 if (err) { 506 goto out_region_err; 507 } 508 509 vfio_ccw_register_io_notifier(vcdev, &err); 510 if (err) { 511 goto out_notifier_err; 512 } 513 514 return; 515 516 out_notifier_err: 517 vfio_ccw_put_region(vcdev); 518 out_region_err: 519 vfio_ccw_put_device(vcdev); 520 out_device_err: 521 vfio_put_group(group); 522 out_group_err: 523 if (cdc->unrealize) { 524 cdc->unrealize(cdev); 525 } 526 out_err_propagate: 527 error_propagate(errp, err); 528 } 529 530 static void vfio_ccw_unrealize(DeviceState *dev) 531 { 532 CcwDevice *ccw_dev = DO_UPCAST(CcwDevice, parent_obj, dev); 533 S390CCWDevice *cdev = DO_UPCAST(S390CCWDevice, parent_obj, ccw_dev); 534 VFIOCCWDevice *vcdev = DO_UPCAST(VFIOCCWDevice, cdev, cdev); 535 S390CCWDeviceClass *cdc = S390_CCW_DEVICE_GET_CLASS(cdev); 536 VFIOGroup *group = vcdev->vdev.group; 537 538 vfio_ccw_unregister_io_notifier(vcdev); 539 vfio_ccw_put_region(vcdev); 540 vfio_ccw_put_device(vcdev); 541 vfio_put_group(group); 542 543 if (cdc->unrealize) { 544 cdc->unrealize(cdev); 545 } 546 } 547 548 static Property vfio_ccw_properties[] = { 549 DEFINE_PROP_STRING("sysfsdev", VFIOCCWDevice, vdev.sysfsdev), 550 DEFINE_PROP_BOOL("force-orb-pfch", VFIOCCWDevice, force_orb_pfch, false), 551 DEFINE_PROP_END_OF_LIST(), 552 }; 553 554 static const VMStateDescription vfio_ccw_vmstate = { 555 .name = "vfio-ccw", 556 .unmigratable = 1, 557 }; 558 559 static void vfio_ccw_class_init(ObjectClass *klass, void *data) 560 { 561 DeviceClass *dc = DEVICE_CLASS(klass); 562 S390CCWDeviceClass *cdc = S390_CCW_DEVICE_CLASS(klass); 563 564 device_class_set_props(dc, vfio_ccw_properties); 565 dc->vmsd = &vfio_ccw_vmstate; 566 dc->desc = "VFIO-based subchannel assignment"; 567 set_bit(DEVICE_CATEGORY_MISC, dc->categories); 568 dc->realize = vfio_ccw_realize; 569 dc->unrealize = vfio_ccw_unrealize; 570 dc->reset = vfio_ccw_reset; 571 572 cdc->handle_request = vfio_ccw_handle_request; 573 cdc->handle_halt = vfio_ccw_handle_halt; 574 cdc->handle_clear = vfio_ccw_handle_clear; 575 } 576 577 static const TypeInfo vfio_ccw_info = { 578 .name = TYPE_VFIO_CCW, 579 .parent = TYPE_S390_CCW, 580 .instance_size = sizeof(VFIOCCWDevice), 581 .class_init = vfio_ccw_class_init, 582 }; 583 584 static void register_vfio_ccw_type(void) 585 { 586 type_register_static(&vfio_ccw_info); 587 } 588 589 type_init(register_vfio_ccw_type) 590