hw/ppc/spapr_irq.c

   1 /*
   2  * QEMU PowerPC sPAPR IRQ interface
   3  *
   4  * Copyright (c) 2018, IBM Corporation.
   5  *
   6  * This code is licensed under the GPL version 2 or later. See the
   7  * COPYING file in the top-level directory.
   8  */
   9
  10 #include "qemu/osdep.h"
  11 #include "qemu/log.h"
  12 #include "qemu/error-report.h"
  13 #include "qapi/error.h"
  14 #include "hw/irq.h"
  15 #include "hw/ppc/spapr.h"
  16 #include "hw/ppc/spapr_cpu_core.h"
  17 #include "hw/ppc/spapr_xive.h"
  18 #include "hw/ppc/xics.h"
  19 #include "hw/ppc/xics_spapr.h"
  20 #include "hw/qdev-properties.h"
  21 #include "cpu-models.h"
  22 #include "sysemu/kvm.h"
  23
  24 #include "trace.h"
  25
  26 static const TypeInfo spapr_intc_info = {
  27     .name = TYPE_SPAPR_INTC,
  28     .parent = TYPE_INTERFACE,
  29     .class_size = sizeof(SpaprInterruptControllerClass),
  30 };
  31
  32 static void spapr_irq_msi_init(SpaprMachineState *spapr)
  33 {
  34     if (SPAPR_MACHINE_GET_CLASS(spapr)->legacy_irq_allocation) {
  35         /* Legacy mode doesn't use this allocator */
  36         return;
  37     }
  38
  39     spapr->irq_map_nr = spapr_irq_nr_msis(spapr);
  40     spapr->irq_map = bitmap_new(spapr->irq_map_nr);
  41 }
  42
  43 int spapr_irq_msi_alloc(SpaprMachineState *spapr, uint32_t num, bool align,
  44                         Error **errp)
  45 {
  46     int irq;
  47
  48     /*
  49      * The 'align_mask' parameter of bitmap_find_next_zero_area()
  50      * should be one less than a power of 2; 0 means no
  51      * alignment. Adapt the 'align' value of the former allocator
  52      * to fit the requirements of bitmap_find_next_zero_area()
  53      */
  54     align -= 1;
  55
  56     irq = bitmap_find_next_zero_area(spapr->irq_map, spapr->irq_map_nr, 0, num,
  57                                      align);
  58     if (irq == spapr->irq_map_nr) {
  59         error_setg(errp, "can't find a free %d-IRQ block", num);
  60         return -1;
  61     }
  62
  63     bitmap_set(spapr->irq_map, irq, num);
  64
  65     return irq + SPAPR_IRQ_MSI;
  66 }
  67
  68 void spapr_irq_msi_free(SpaprMachineState *spapr, int irq, uint32_t num)
  69 {
  70     bitmap_clear(spapr->irq_map, irq - SPAPR_IRQ_MSI, num);
  71 }
  72
  73 int spapr_irq_init_kvm(SpaprInterruptControllerInitKvm fn,
  74                        SpaprInterruptController *intc,
  75                        uint32_t nr_servers,
  76                        Error **errp)
  77 {
  78     Error *local_err = NULL;
  79
  80     if (kvm_enabled() && kvm_kernel_irqchip_allowed()) {
  81         if (fn(intc, nr_servers, &local_err) < 0) {
  82             if (kvm_kernel_irqchip_required()) {
  83                 error_prepend(&local_err,
  84                               "kernel_irqchip requested but unavailable: ");
  85                 error_propagate(errp, local_err);
  86                 return -1;
  87             }
  88
  89             /*
  90              * We failed to initialize the KVM device, fallback to
  91              * emulated mode
  92              */
  93             error_prepend(&local_err,
  94                           "kernel_irqchip allowed but unavailable: ");
  95             error_append_hint(&local_err,
  96                               "Falling back to kernel-irqchip=off\n");
  97             warn_report_err(local_err);
  98         }
  99     }
 100
 101     return 0;
 102 }
 103
 104 /*
 105  * XICS IRQ backend.
 106  */
 107
 108 SpaprIrq spapr_irq_xics = {
 109     .xics        = true,
 110     .xive        = false,
 111 };
 112
 113 /*
 114  * XIVE IRQ backend.
 115  */
 116
 117 SpaprIrq spapr_irq_xive = {
 118     .xics        = false,
 119     .xive        = true,
 120 };
 121
 122 /*
 123  * Dual XIVE and XICS IRQ backend.
 124  *
 125  * Both interrupt mode, XIVE and XICS, objects are created but the
 126  * machine starts in legacy interrupt mode (XICS). It can be changed
 127  * by the CAS negotiation process and, in that case, the new mode is
 128  * activated after an extra machine reset.
 129  */
 130
 131 /*
 132  * Define values in sync with the XIVE and XICS backend
 133  */
 134 SpaprIrq spapr_irq_dual = {
 135     .xics        = true,
 136     .xive        = true,
 137 };
 138
 139
 140 static int spapr_irq_check(SpaprMachineState *spapr, Error **errp)
 141 {
 142     ERRP_GUARD();
 143     MachineState *machine = MACHINE(spapr);
 144
 145     /*
 146      * Sanity checks on non-P9 machines. On these, XIVE is not
 147      * advertised, see spapr_dt_ov5_platform_support()
 148      */
 149     if (!ppc_type_check_compat(machine->cpu_type, CPU_POWERPC_LOGICAL_3_00,
 150                                0, spapr->max_compat_pvr)) {
 151         /*
 152          * If the 'dual' interrupt mode is selected, force XICS as CAS
 153          * negotiation is useless.
 154          */
 155         if (spapr->irq == &spapr_irq_dual) {
 156             spapr->irq = &spapr_irq_xics;
 157             return 0;
 158         }
 159
 160         /*
 161          * Non-P9 machines using only XIVE is a bogus setup. We have two
 162          * scenarios to take into account because of the compat mode:
 163          *
 164          * 1. POWER7/8 machines should fail to init later on when creating
 165          *    the XIVE interrupt presenters because a POWER9 exception
 166          *    model is required.
 167
 168          * 2. POWER9 machines using the POWER8 compat mode won't fail and
 169          *    will let the OS boot with a partial XIVE setup : DT
 170          *    properties but no hcalls.
 171          *
 172          * To cover both and not confuse the OS, add an early failure in
 173          * QEMU.
 174          */
 175         if (!spapr->irq->xics) {
 176             error_setg(errp, "XIVE-only machines require a POWER9 CPU");
 177             return -1;
 178         }
 179     }
 180
 181     /*
 182      * On a POWER9 host, some older KVM XICS devices cannot be destroyed and
 183      * re-created. Same happens with KVM nested guests. Detect that early to
 184      * avoid QEMU to exit later when the guest reboots.
 185      */
 186     if (kvm_enabled() &&
 187         spapr->irq == &spapr_irq_dual &&
 188         kvm_kernel_irqchip_required() &&
 189         xics_kvm_has_broken_disconnect()) {
 190         error_setg(errp,
 191             "KVM is incompatible with ic-mode=dual,kernel-irqchip=on");
 192         error_append_hint(errp,
 193             "This can happen with an old KVM or in a KVM nested guest.\n");
 194         error_append_hint(errp,
 195             "Try without kernel-irqchip or with kernel-irqchip=off.\n");
 196         return -1;
 197     }
 198
 199     return 0;
 200 }
 201
 202 /*
 203  * sPAPR IRQ frontend routines for devices
 204  */
 205 #define ALL_INTCS(spapr_) \
 206     { SPAPR_INTC((spapr_)->ics), SPAPR_INTC((spapr_)->xive), }
 207
 208 int spapr_irq_cpu_intc_create(SpaprMachineState *spapr,
 209                               PowerPCCPU *cpu, Error **errp)
 210 {
 211     SpaprInterruptController *intcs[] = ALL_INTCS(spapr);
 212     int i;
 213     int rc;
 214
 215     for (i = 0; i < ARRAY_SIZE(intcs); i++) {
 216         SpaprInterruptController *intc = intcs[i];
 217         if (intc) {
 218             SpaprInterruptControllerClass *sicc = SPAPR_INTC_GET_CLASS(intc);
 219             rc = sicc->cpu_intc_create(intc, cpu, errp);
 220             if (rc < 0) {
 221                 return rc;
 222             }
 223         }
 224     }
 225
 226     return 0;
 227 }
 228
 229 void spapr_irq_cpu_intc_reset(SpaprMachineState *spapr, PowerPCCPU *cpu)
 230 {
 231     SpaprInterruptController *intcs[] = ALL_INTCS(spapr);
 232     int i;
 233
 234     for (i = 0; i < ARRAY_SIZE(intcs); i++) {
 235         SpaprInterruptController *intc = intcs[i];
 236         if (intc) {
 237             SpaprInterruptControllerClass *sicc = SPAPR_INTC_GET_CLASS(intc);
 238             sicc->cpu_intc_reset(intc, cpu);
 239         }
 240     }
 241 }
 242
 243 void spapr_irq_cpu_intc_destroy(SpaprMachineState *spapr, PowerPCCPU *cpu)
 244 {
 245     SpaprInterruptController *intcs[] = ALL_INTCS(spapr);
 246     int i;
 247
 248     for (i = 0; i < ARRAY_SIZE(intcs); i++) {
 249         SpaprInterruptController *intc = intcs[i];
 250         if (intc) {
 251             SpaprInterruptControllerClass *sicc = SPAPR_INTC_GET_CLASS(intc);
 252             sicc->cpu_intc_destroy(intc, cpu);
 253         }
 254     }
 255 }
 256
 257 static void spapr_set_irq(void *opaque, int irq, int level)
 258 {
 259     SpaprMachineState *spapr = SPAPR_MACHINE(opaque);
 260     SpaprInterruptControllerClass *sicc
 261         = SPAPR_INTC_GET_CLASS(spapr->active_intc);
 262
 263     sicc->set_irq(spapr->active_intc, irq, level);
 264 }
 265
 266 void spapr_irq_print_info(SpaprMachineState *spapr, Monitor *mon)
 267 {
 268     SpaprInterruptControllerClass *sicc
 269         = SPAPR_INTC_GET_CLASS(spapr->active_intc);
 270
 271     sicc->print_info(spapr->active_intc, mon);
 272 }
 273
 274 void spapr_irq_dt(SpaprMachineState *spapr, uint32_t nr_servers,
 275                   void *fdt, uint32_t phandle)
 276 {
 277     SpaprInterruptControllerClass *sicc
 278         = SPAPR_INTC_GET_CLASS(spapr->active_intc);
 279
 280     sicc->dt(spapr->active_intc, nr_servers, fdt, phandle);
 281 }
 282
 283 uint32_t spapr_irq_nr_msis(SpaprMachineState *spapr)
 284 {
 285     SpaprMachineClass *smc = SPAPR_MACHINE_GET_CLASS(spapr);
 286
 287     if (smc->legacy_irq_allocation) {
 288         return smc->nr_xirqs;
 289     } else {
 290         return SPAPR_XIRQ_BASE + smc->nr_xirqs - SPAPR_IRQ_MSI;
 291     }
 292 }
 293
 294 void spapr_irq_init(SpaprMachineState *spapr, Error **errp)
 295 {
 296     SpaprMachineClass *smc = SPAPR_MACHINE_GET_CLASS(spapr);
 297
 298     if (kvm_enabled() && kvm_kernel_irqchip_split()) {
 299         error_setg(errp, "kernel_irqchip split mode not supported on pseries");
 300         return;
 301     }
 302
 303     if (spapr_irq_check(spapr, errp) < 0) {
 304         return;
 305     }
 306
 307     /* Initialize the MSI IRQ allocator. */
 308     spapr_irq_msi_init(spapr);
 309
 310     if (spapr->irq->xics) {
 311         Object *obj;
 312
 313         obj = object_new(TYPE_ICS_SPAPR);
 314
 315         object_property_add_child(OBJECT(spapr), "ics", obj);
 316         object_property_set_link(obj, ICS_PROP_XICS, OBJECT(spapr),
 317                                  &error_abort);
 318         object_property_set_int(obj, "nr-irqs", smc->nr_xirqs, &error_abort);
 319         if (!qdev_realize(DEVICE(obj), NULL, errp)) {
 320             return;
 321         }
 322
 323         spapr->ics = ICS_SPAPR(obj);
 324     }
 325
 326     if (spapr->irq->xive) {
 327         uint32_t nr_servers = spapr_max_server_number(spapr);
 328         DeviceState *dev;
 329         int i;
 330
 331         dev = qdev_new(TYPE_SPAPR_XIVE);
 332         qdev_prop_set_uint32(dev, "nr-irqs", smc->nr_xirqs + SPAPR_XIRQ_BASE);
 333         /*
 334          * 8 XIVE END structures per CPU. One for each available
 335          * priority
 336          */
 337         qdev_prop_set_uint32(dev, "nr-ends", nr_servers << 3);
 338         object_property_set_link(OBJECT(dev), "xive-fabric", OBJECT(spapr),
 339                                  &error_abort);
 340         sysbus_realize_and_unref(SYS_BUS_DEVICE(dev), &error_fatal);
 341
 342         spapr->xive = SPAPR_XIVE(dev);
 343
 344         /* Enable the CPU IPIs */
 345         for (i = 0; i < nr_servers; ++i) {
 346             SpaprInterruptControllerClass *sicc
 347                 = SPAPR_INTC_GET_CLASS(spapr->xive);
 348
 349             if (sicc->claim_irq(SPAPR_INTC(spapr->xive), SPAPR_IRQ_IPI + i,
 350                                 false, errp) < 0) {
 351                 return;
 352             }
 353         }
 354
 355         spapr_xive_hcall_init(spapr);
 356     }
 357
 358     spapr->qirqs = qemu_allocate_irqs(spapr_set_irq, spapr,
 359                                       smc->nr_xirqs + SPAPR_XIRQ_BASE);
 360
 361     /*
 362      * Mostly we don't actually need this until reset, except that not
 363      * having this set up can cause VFIO devices to issue a
 364      * false-positive warning during realize(), because they don't yet
 365      * have an in-kernel irq chip.
 366      */
 367     spapr_irq_update_active_intc(spapr);
 368 }
 369
 370 int spapr_irq_claim(SpaprMachineState *spapr, int irq, bool lsi, Error **errp)
 371 {
 372     SpaprInterruptController *intcs[] = ALL_INTCS(spapr);
 373     int i;
 374     SpaprMachineClass *smc = SPAPR_MACHINE_GET_CLASS(spapr);
 375     int rc;
 376
 377     assert(irq >= SPAPR_XIRQ_BASE);
 378     assert(irq < (smc->nr_xirqs + SPAPR_XIRQ_BASE));
 379
 380     for (i = 0; i < ARRAY_SIZE(intcs); i++) {
 381         SpaprInterruptController *intc = intcs[i];
 382         if (intc) {
 383             SpaprInterruptControllerClass *sicc = SPAPR_INTC_GET_CLASS(intc);
 384             rc = sicc->claim_irq(intc, irq, lsi, errp);
 385             if (rc < 0) {
 386                 return rc;
 387             }
 388         }
 389     }
 390
 391     return 0;
 392 }
 393
 394 void spapr_irq_free(SpaprMachineState *spapr, int irq, int num)
 395 {
 396     SpaprInterruptController *intcs[] = ALL_INTCS(spapr);
 397     int i, j;
 398     SpaprMachineClass *smc = SPAPR_MACHINE_GET_CLASS(spapr);
 399
 400     assert(irq >= SPAPR_XIRQ_BASE);
 401     assert((irq + num) <= (smc->nr_xirqs + SPAPR_XIRQ_BASE));
 402
 403     for (i = irq; i < (irq + num); i++) {
 404         for (j = 0; j < ARRAY_SIZE(intcs); j++) {
 405             SpaprInterruptController *intc = intcs[j];
 406
 407             if (intc) {
 408                 SpaprInterruptControllerClass *sicc
 409                     = SPAPR_INTC_GET_CLASS(intc);
 410                 sicc->free_irq(intc, i);
 411             }
 412         }
 413     }
 414 }
 415
 416 qemu_irq spapr_qirq(SpaprMachineState *spapr, int irq)
 417 {
 418     SpaprMachineClass *smc = SPAPR_MACHINE_GET_CLASS(spapr);
 419
 420     /*
 421      * This interface is basically for VIO and PHB devices to find the
 422      * right qemu_irq to manipulate, so we only allow access to the
 423      * external irqs for now.  Currently anything which needs to
 424      * access the IPIs most naturally gets there via the guest side
 425      * interfaces, we can change this if we need to in future.
 426      */
 427     assert(irq >= SPAPR_XIRQ_BASE);
 428     assert(irq < (smc->nr_xirqs + SPAPR_XIRQ_BASE));
 429
 430     if (spapr->ics) {
 431         assert(ics_valid_irq(spapr->ics, irq));
 432     }
 433     if (spapr->xive) {
 434         assert(irq < spapr->xive->nr_irqs);
 435         assert(xive_eas_is_valid(&spapr->xive->eat[irq]));
 436     }
 437
 438     return spapr->qirqs[irq];
 439 }
 440
 441 int spapr_irq_post_load(SpaprMachineState *spapr, int version_id)
 442 {
 443     SpaprInterruptControllerClass *sicc;
 444
 445     spapr_irq_update_active_intc(spapr);
 446     sicc = SPAPR_INTC_GET_CLASS(spapr->active_intc);
 447     return sicc->post_load(spapr->active_intc, version_id);
 448 }
 449
 450 void spapr_irq_reset(SpaprMachineState *spapr, Error **errp)
 451 {
 452     assert(!spapr->irq_map || bitmap_empty(spapr->irq_map, spapr->irq_map_nr));
 453
 454     spapr_irq_update_active_intc(spapr);
 455 }
 456
 457 int spapr_irq_get_phandle(SpaprMachineState *spapr, void *fdt, Error **errp)
 458 {
 459     const char *nodename = "interrupt-controller";
 460     int offset, phandle;
 461
 462     offset = fdt_subnode_offset(fdt, 0, nodename);
 463     if (offset < 0) {
 464         error_setg(errp, "Can't find node \"%s\": %s",
 465                    nodename, fdt_strerror(offset));
 466         return -1;
 467     }
 468
 469     phandle = fdt_get_phandle(fdt, offset);
 470     if (!phandle) {
 471         error_setg(errp, "Can't get phandle of node \"%s\"", nodename);
 472         return -1;
 473     }
 474
 475     return phandle;
 476 }
 477
 478 static void set_active_intc(SpaprMachineState *spapr,
 479                             SpaprInterruptController *new_intc)
 480 {
 481     SpaprInterruptControllerClass *sicc;
 482     uint32_t nr_servers = spapr_max_server_number(spapr);
 483
 484     assert(new_intc);
 485
 486     if (new_intc == spapr->active_intc) {
 487         /* Nothing to do */
 488         return;
 489     }
 490
 491     if (spapr->active_intc) {
 492         sicc = SPAPR_INTC_GET_CLASS(spapr->active_intc);
 493         if (sicc->deactivate) {
 494             sicc->deactivate(spapr->active_intc);
 495         }
 496     }
 497
 498     sicc = SPAPR_INTC_GET_CLASS(new_intc);
 499     if (sicc->activate) {
 500         sicc->activate(new_intc, nr_servers, &error_fatal);
 501     }
 502
 503     spapr->active_intc = new_intc;
 504
 505     /*
 506      * We've changed the kernel irqchip, let VFIO devices know they
 507      * need to readjust.
 508      */
 509     kvm_irqchip_change_notify();
 510 }
 511
 512 void spapr_irq_update_active_intc(SpaprMachineState *spapr)
 513 {
 514     SpaprInterruptController *new_intc;
 515
 516     if (!spapr->ics) {
 517         /*
 518          * XXX before we run CAS, ov5_cas is initialized empty, which
 519          * indicates XICS, even if we have ic-mode=xive.  TODO: clean
 520          * up the CAS path so that we have a clearer way of handling
 521          * this.
 522          */
 523         new_intc = SPAPR_INTC(spapr->xive);
 524     } else if (spapr->ov5_cas
 525                && spapr_ovec_test(spapr->ov5_cas, OV5_XIVE_EXPLOIT)) {
 526         new_intc = SPAPR_INTC(spapr->xive);
 527     } else {
 528         new_intc = SPAPR_INTC(spapr->ics);
 529     }
 530
 531     set_active_intc(spapr, new_intc);
 532 }
 533
 534 /*
 535  * XICS legacy routines - to deprecate one day
 536  */
 537
 538 static int ics_find_free_block(ICSState *ics, int num, int alignnum)
 539 {
 540     int first, i;
 541
 542     for (first = 0; first < ics->nr_irqs; first += alignnum) {
 543         if (num > (ics->nr_irqs - first)) {
 544             return -1;
 545         }
 546         for (i = first; i < first + num; ++i) {
 547             if (!ics_irq_free(ics, i)) {
 548                 break;
 549             }
 550         }
 551         if (i == (first + num)) {
 552             return first;
 553         }
 554     }
 555
 556     return -1;
 557 }
 558
 559 int spapr_irq_find(SpaprMachineState *spapr, int num, bool align, Error **errp)
 560 {
 561     ICSState *ics = spapr->ics;
 562     int first = -1;
 563
 564     assert(ics);
 565
 566     /*
 567      * MSIMesage::data is used for storing VIRQ so
 568      * it has to be aligned to num to support multiple
 569      * MSI vectors. MSI-X is not affected by this.
 570      * The hint is used for the first IRQ, the rest should
 571      * be allocated continuously.
 572      */
 573     if (align) {
 574         assert((num == 1) || (num == 2) || (num == 4) ||
 575                (num == 8) || (num == 16) || (num == 32));
 576         first = ics_find_free_block(ics, num, num);
 577     } else {
 578         first = ics_find_free_block(ics, num, 1);
 579     }
 580
 581     if (first < 0) {
 582         error_setg(errp, "can't find a free %d-IRQ block", num);
 583         return -1;
 584     }
 585
 586     return first + ics->offset;
 587 }
 588
 589 SpaprIrq spapr_irq_xics_legacy = {
 590     .xics        = true,
 591     .xive        = false,
 592 };
 593
 594 static void spapr_irq_register_types(void)
 595 {
 596     type_register_static(&spapr_intc_info);
 597 }
 598
 599 type_init(spapr_irq_register_types)