hw/intc/xics_kvm.c

   1 /*
   2  * QEMU PowerPC pSeries Logical Partition (aka sPAPR) hardware System Emulator
   3  *
   4  * PAPR Virtualized Interrupt System, aka ICS/ICP aka xics, in-kernel emulation
   5  *
   6  * Copyright (c) 2013 David Gibson, IBM Corporation.
   7  *
   8  * Permission is hereby granted, free of charge, to any person obtaining a copy
   9  * of this software and associated documentation files (the "Software"), to deal
  10  * in the Software without restriction, including without limitation the rights
  11  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  12  * copies of the Software, and to permit persons to whom the Software is
  13  * furnished to do so, subject to the following conditions:
  14  *
  15  * The above copyright notice and this permission notice shall be included in
  16  * all copies or substantial portions of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  19  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  21  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  22  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  23  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  24  * THE SOFTWARE.
  25  *
  26  */
  27
  28 #include "qemu/osdep.h"
  29 #include "qapi/error.h"
  30 #include "trace.h"
  31 #include "sysemu/kvm.h"
  32 #include "hw/ppc/spapr.h"
  33 #include "hw/ppc/spapr_cpu_core.h"
  34 #include "hw/ppc/xics.h"
  35 #include "hw/ppc/xics_spapr.h"
  36 #include "kvm_ppc.h"
  37 #include "qemu/config-file.h"
  38 #include "qemu/error-report.h"
  39
  40 #include <sys/ioctl.h>
  41
  42 static int kernel_xics_fd = -1;
  43
  44 typedef struct KVMEnabledICP {
  45     unsigned long vcpu_id;
  46     QLIST_ENTRY(KVMEnabledICP) node;
  47 } KVMEnabledICP;
  48
  49 static QLIST_HEAD(, KVMEnabledICP)
  50     kvm_enabled_icps = QLIST_HEAD_INITIALIZER(&kvm_enabled_icps);
  51
  52 static void kvm_disable_icps(void)
  53 {
  54     KVMEnabledICP *enabled_icp, *next;
  55
  56     QLIST_FOREACH_SAFE(enabled_icp, &kvm_enabled_icps, node, next) {
  57         QLIST_REMOVE(enabled_icp, node);
  58         g_free(enabled_icp);
  59     }
  60 }
  61
  62 /*
  63  * ICP-KVM
  64  */
  65 void icp_get_kvm_state(ICPState *icp)
  66 {
  67     uint64_t state;
  68     int ret;
  69
  70     /* The KVM XICS device is not in use */
  71     if (kernel_xics_fd == -1) {
  72         return;
  73     }
  74
  75     /* ICP for this CPU thread is not in use, exiting */
  76     if (!icp->cs) {
  77         return;
  78     }
  79
  80     ret = kvm_get_one_reg(icp->cs, KVM_REG_PPC_ICP_STATE, &state);
  81     if (ret != 0) {
  82         error_report("Unable to retrieve KVM interrupt controller state"
  83                 " for CPU %ld: %s", kvm_arch_vcpu_id(icp->cs), strerror(errno));
  84         exit(1);
  85     }
  86
  87     icp->xirr = state >> KVM_REG_PPC_ICP_XISR_SHIFT;
  88     icp->mfrr = (state >> KVM_REG_PPC_ICP_MFRR_SHIFT)
  89         & KVM_REG_PPC_ICP_MFRR_MASK;
  90     icp->pending_priority = (state >> KVM_REG_PPC_ICP_PPRI_SHIFT)
  91         & KVM_REG_PPC_ICP_PPRI_MASK;
  92 }
  93
  94 static void do_icp_synchronize_state(CPUState *cpu, run_on_cpu_data arg)
  95 {
  96     icp_get_kvm_state(arg.host_ptr);
  97 }
  98
  99 void icp_synchronize_state(ICPState *icp)
 100 {
 101     if (icp->cs) {
 102         run_on_cpu(icp->cs, do_icp_synchronize_state, RUN_ON_CPU_HOST_PTR(icp));
 103     }
 104 }
 105
 106 int icp_set_kvm_state(ICPState *icp, Error **errp)
 107 {
 108     uint64_t state;
 109     int ret;
 110
 111     /* The KVM XICS device is not in use */
 112     if (kernel_xics_fd == -1) {
 113         return 0;
 114     }
 115
 116     /* ICP for this CPU thread is not in use, exiting */
 117     if (!icp->cs) {
 118         return 0;
 119     }
 120
 121     state = ((uint64_t)icp->xirr << KVM_REG_PPC_ICP_XISR_SHIFT)
 122         | ((uint64_t)icp->mfrr << KVM_REG_PPC_ICP_MFRR_SHIFT)
 123         | ((uint64_t)icp->pending_priority << KVM_REG_PPC_ICP_PPRI_SHIFT);
 124
 125     ret = kvm_set_one_reg(icp->cs, KVM_REG_PPC_ICP_STATE, &state);
 126     if (ret < 0) {
 127         error_setg_errno(errp, -ret,
 128                          "Unable to restore KVM interrupt controller state (0x%"
 129                          PRIx64 ") for CPU %ld", state,
 130                          kvm_arch_vcpu_id(icp->cs));
 131         return ret;
 132     }
 133
 134     return 0;
 135 }
 136
 137 void icp_kvm_realize(DeviceState *dev, Error **errp)
 138 {
 139     ICPState *icp = ICP(dev);
 140     CPUState *cs;
 141     KVMEnabledICP *enabled_icp;
 142     unsigned long vcpu_id;
 143     int ret;
 144
 145     /* The KVM XICS device is not in use */
 146     if (kernel_xics_fd == -1) {
 147         return;
 148     }
 149
 150     cs = icp->cs;
 151     vcpu_id = kvm_arch_vcpu_id(cs);
 152
 153     /*
 154      * If we are reusing a parked vCPU fd corresponding to the CPU
 155      * which was hot-removed earlier we don't have to renable
 156      * KVM_CAP_IRQ_XICS capability again.
 157      */
 158     QLIST_FOREACH(enabled_icp, &kvm_enabled_icps, node) {
 159         if (enabled_icp->vcpu_id == vcpu_id) {
 160             return;
 161         }
 162     }
 163
 164     ret = kvm_vcpu_enable_cap(cs, KVM_CAP_IRQ_XICS, 0, kernel_xics_fd, vcpu_id);
 165     if (ret < 0) {
 166         Error *local_err = NULL;
 167
 168         error_setg(&local_err, "Unable to connect CPU%ld to kernel XICS: %s",
 169                    vcpu_id, strerror(errno));
 170         if (errno == ENOSPC) {
 171             error_append_hint(&local_err, "Try -smp maxcpus=N with N < %u\n",
 172                               MACHINE(qdev_get_machine())->smp.max_cpus);
 173         }
 174         error_propagate(errp, local_err);
 175         return;
 176     }
 177     enabled_icp = g_malloc(sizeof(*enabled_icp));
 178     enabled_icp->vcpu_id = vcpu_id;
 179     QLIST_INSERT_HEAD(&kvm_enabled_icps, enabled_icp, node);
 180 }
 181
 182 /*
 183  * ICS-KVM
 184  */
 185 void ics_get_kvm_state(ICSState *ics)
 186 {
 187     uint64_t state;
 188     int i;
 189
 190     /* The KVM XICS device is not in use */
 191     if (kernel_xics_fd == -1) {
 192         return;
 193     }
 194
 195     for (i = 0; i < ics->nr_irqs; i++) {
 196         ICSIRQState *irq = &ics->irqs[i];
 197
 198         if (ics_irq_free(ics, i)) {
 199             continue;
 200         }
 201
 202         kvm_device_access(kernel_xics_fd, KVM_DEV_XICS_GRP_SOURCES,
 203                           i + ics->offset, &state, false, &error_fatal);
 204
 205         irq->server = state & KVM_XICS_DESTINATION_MASK;
 206         irq->saved_priority = (state >> KVM_XICS_PRIORITY_SHIFT)
 207             & KVM_XICS_PRIORITY_MASK;
 208         /*
 209          * To be consistent with the software emulation in xics.c, we
 210          * split out the masked state + priority that we get from the
 211          * kernel into 'current priority' (0xff if masked) and
 212          * 'saved priority' (if masked, this is the priority the
 213          * interrupt had before it was masked).  Masking and unmasking
 214          * are done with the ibm,int-off and ibm,int-on RTAS calls.
 215          */
 216         if (state & KVM_XICS_MASKED) {
 217             irq->priority = 0xff;
 218         } else {
 219             irq->priority = irq->saved_priority;
 220         }
 221
 222         irq->status = 0;
 223         if (state & KVM_XICS_PENDING) {
 224             if (state & KVM_XICS_LEVEL_SENSITIVE) {
 225                 irq->status |= XICS_STATUS_ASSERTED;
 226             } else {
 227                 /*
 228                  * A pending edge-triggered interrupt (or MSI)
 229                  * must have been rejected previously when we
 230                  * first detected it and tried to deliver it,
 231                  * so mark it as pending and previously rejected
 232                  * for consistency with how xics.c works.
 233                  */
 234                 irq->status |= XICS_STATUS_MASKED_PENDING
 235                     | XICS_STATUS_REJECTED;
 236             }
 237         }
 238         if (state & KVM_XICS_PRESENTED) {
 239                 irq->status |= XICS_STATUS_PRESENTED;
 240         }
 241         if (state & KVM_XICS_QUEUED) {
 242                 irq->status |= XICS_STATUS_QUEUED;
 243         }
 244     }
 245 }
 246
 247 void ics_synchronize_state(ICSState *ics)
 248 {
 249     ics_get_kvm_state(ics);
 250 }
 251
 252 int ics_set_kvm_state_one(ICSState *ics, int srcno, Error **errp)
 253 {
 254     uint64_t state;
 255     ICSIRQState *irq = &ics->irqs[srcno];
 256     int ret;
 257
 258     /* The KVM XICS device is not in use */
 259     if (kernel_xics_fd == -1) {
 260         return 0;
 261     }
 262
 263     state = irq->server;
 264     state |= (uint64_t)(irq->saved_priority & KVM_XICS_PRIORITY_MASK)
 265         << KVM_XICS_PRIORITY_SHIFT;
 266     if (irq->priority != irq->saved_priority) {
 267         assert(irq->priority == 0xff);
 268     }
 269
 270     if (irq->priority == 0xff) {
 271         state |= KVM_XICS_MASKED;
 272     }
 273
 274     if (irq->flags & XICS_FLAGS_IRQ_LSI) {
 275         state |= KVM_XICS_LEVEL_SENSITIVE;
 276         if (irq->status & XICS_STATUS_ASSERTED) {
 277             state |= KVM_XICS_PENDING;
 278         }
 279     } else {
 280         if (irq->status & XICS_STATUS_MASKED_PENDING) {
 281             state |= KVM_XICS_PENDING;
 282         }
 283     }
 284     if (irq->status & XICS_STATUS_PRESENTED) {
 285         state |= KVM_XICS_PRESENTED;
 286     }
 287     if (irq->status & XICS_STATUS_QUEUED) {
 288         state |= KVM_XICS_QUEUED;
 289     }
 290
 291     ret = kvm_device_access(kernel_xics_fd, KVM_DEV_XICS_GRP_SOURCES,
 292                             srcno + ics->offset, &state, true, errp);
 293     if (ret < 0) {
 294         return ret;
 295     }
 296
 297     return 0;
 298 }
 299
 300 int ics_set_kvm_state(ICSState *ics, Error **errp)
 301 {
 302     int i;
 303
 304     /* The KVM XICS device is not in use */
 305     if (kernel_xics_fd == -1) {
 306         return 0;
 307     }
 308
 309     for (i = 0; i < ics->nr_irqs; i++) {
 310         int ret;
 311
 312         if (ics_irq_free(ics, i)) {
 313             continue;
 314         }
 315
 316         ret = ics_set_kvm_state_one(ics, i, errp);
 317         if (ret < 0) {
 318             return ret;
 319         }
 320     }
 321
 322     return 0;
 323 }
 324
 325 void ics_kvm_set_irq(ICSState *ics, int srcno, int val)
 326 {
 327     struct kvm_irq_level args;
 328     int rc;
 329
 330     /* The KVM XICS device should be in use */
 331     assert(kernel_xics_fd != -1);
 332
 333     args.irq = srcno + ics->offset;
 334     if (ics->irqs[srcno].flags & XICS_FLAGS_IRQ_MSI) {
 335         if (!val) {
 336             return;
 337         }
 338         args.level = KVM_INTERRUPT_SET;
 339     } else {
 340         args.level = val ? KVM_INTERRUPT_SET_LEVEL : KVM_INTERRUPT_UNSET;
 341     }
 342     rc = kvm_vm_ioctl(kvm_state, KVM_IRQ_LINE, &args);
 343     if (rc < 0) {
 344         perror("kvm_irq_line");
 345     }
 346 }
 347
 348 int xics_kvm_connect(SpaprInterruptController *intc, uint32_t nr_servers,
 349                      Error **errp)
 350 {
 351     ICSState *ics = ICS_SPAPR(intc);
 352     int rc;
 353     CPUState *cs;
 354     Error *local_err = NULL;
 355
 356     /*
 357      * The KVM XICS device already in use. This is the case when
 358      * rebooting under the XICS-only interrupt mode.
 359      */
 360     if (kernel_xics_fd != -1) {
 361         return 0;
 362     }
 363
 364     if (!kvm_enabled() || !kvm_check_extension(kvm_state, KVM_CAP_IRQ_XICS)) {
 365         error_setg(errp,
 366                    "KVM and IRQ_XICS capability must be present for in-kernel XICS");
 367         return -1;
 368     }
 369
 370     rc = kvmppc_define_rtas_kernel_token(RTAS_IBM_SET_XIVE, "ibm,set-xive");
 371     if (rc < 0) {
 372         error_setg_errno(&local_err, -rc,
 373                          "kvmppc_define_rtas_kernel_token: ibm,set-xive");
 374         goto fail;
 375     }
 376
 377     rc = kvmppc_define_rtas_kernel_token(RTAS_IBM_GET_XIVE, "ibm,get-xive");
 378     if (rc < 0) {
 379         error_setg_errno(&local_err, -rc,
 380                          "kvmppc_define_rtas_kernel_token: ibm,get-xive");
 381         goto fail;
 382     }
 383
 384     rc = kvmppc_define_rtas_kernel_token(RTAS_IBM_INT_ON, "ibm,int-on");
 385     if (rc < 0) {
 386         error_setg_errno(&local_err, -rc,
 387                          "kvmppc_define_rtas_kernel_token: ibm,int-on");
 388         goto fail;
 389     }
 390
 391     rc = kvmppc_define_rtas_kernel_token(RTAS_IBM_INT_OFF, "ibm,int-off");
 392     if (rc < 0) {
 393         error_setg_errno(&local_err, -rc,
 394                          "kvmppc_define_rtas_kernel_token: ibm,int-off");
 395         goto fail;
 396     }
 397
 398     /* Create the KVM XICS device */
 399     rc = kvm_create_device(kvm_state, KVM_DEV_TYPE_XICS, false);
 400     if (rc < 0) {
 401         error_setg_errno(&local_err, -rc, "Error on KVM_CREATE_DEVICE for XICS");
 402         goto fail;
 403     }
 404
 405     /* Tell KVM about the # of VCPUs we may have (POWER9 and newer only) */
 406     if (kvm_device_check_attr(rc, KVM_DEV_XICS_GRP_CTRL,
 407                               KVM_DEV_XICS_NR_SERVERS)) {
 408         if (kvm_device_access(rc, KVM_DEV_XICS_GRP_CTRL,
 409                               KVM_DEV_XICS_NR_SERVERS, &nr_servers, true,
 410                               &local_err)) {
 411             goto fail;
 412         }
 413     }
 414
 415     kernel_xics_fd = rc;
 416     kvm_kernel_irqchip = true;
 417     kvm_msi_via_irqfd_allowed = true;
 418     kvm_gsi_direct_mapping = true;
 419
 420     /* Create the presenters */
 421     CPU_FOREACH(cs) {
 422         PowerPCCPU *cpu = POWERPC_CPU(cs);
 423
 424         icp_kvm_realize(DEVICE(spapr_cpu_state(cpu)->icp), &local_err);
 425         if (local_err) {
 426             goto fail;
 427         }
 428     }
 429
 430     /* Update the KVM sources */
 431     ics_set_kvm_state(ics, &local_err);
 432     if (local_err) {
 433         goto fail;
 434     }
 435
 436     /* Connect the presenters to the initial VCPUs of the machine */
 437     CPU_FOREACH(cs) {
 438         PowerPCCPU *cpu = POWERPC_CPU(cs);
 439         icp_set_kvm_state(spapr_cpu_state(cpu)->icp, &local_err);
 440         if (local_err) {
 441             goto fail;
 442         }
 443     }
 444
 445     return 0;
 446
 447 fail:
 448     error_propagate(errp, local_err);
 449     xics_kvm_disconnect(intc);
 450     return -1;
 451 }
 452
 453 void xics_kvm_disconnect(SpaprInterruptController *intc)
 454 {
 455     /*
 456      * Only on P9 using the XICS-on XIVE KVM device:
 457      *
 458      * When the KVM device fd is closed, the device is destroyed and
 459      * removed from the list of devices of the VM. The VCPU presenters
 460      * are also detached from the device.
 461      */
 462     if (kernel_xics_fd != -1) {
 463         close(kernel_xics_fd);
 464         kernel_xics_fd = -1;
 465     }
 466
 467     kvmppc_define_rtas_kernel_token(0, "ibm,set-xive");
 468     kvmppc_define_rtas_kernel_token(0, "ibm,get-xive");
 469     kvmppc_define_rtas_kernel_token(0, "ibm,int-on");
 470     kvmppc_define_rtas_kernel_token(0, "ibm,int-off");
 471
 472     kvm_kernel_irqchip = false;
 473     kvm_msi_via_irqfd_allowed = false;
 474     kvm_gsi_direct_mapping = false;
 475
 476     /* Clear the presenter from the VCPUs */
 477     kvm_disable_icps();
 478 }
 479
 480 /*
 481  * This is a heuristic to detect older KVMs on POWER9 hosts that don't
 482  * support destruction of a KVM XICS device while the VM is running.
 483  * Required to start a spapr machine with ic-mode=dual,kernel-irqchip=on.
 484  */
 485 bool xics_kvm_has_broken_disconnect(void)
 486 {
 487     int rc;
 488
 489     rc = kvm_create_device(kvm_state, KVM_DEV_TYPE_XICS, false);
 490     if (rc < 0) {
 491         /*
 492          * The error is ignored on purpose. The KVM XICS setup code
 493          * will catch it again anyway. The goal here is to see if
 494          * close() actually destroys the device or not.
 495          */
 496         return false;
 497     }
 498
 499     close(rc);
 500
 501     rc = kvm_create_device(kvm_state, KVM_DEV_TYPE_XICS, false);
 502     if (rc >= 0) {
 503         close(rc);
 504         return false;
 505     }
 506
 507     return errno == EEXIST;
 508 }