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 "qemu-common.h"
  31 #include "trace.h"
  32 #include "sysemu/kvm.h"
  33 #include "hw/ppc/spapr.h"
  34 #include "hw/ppc/spapr_cpu_core.h"
  35 #include "hw/ppc/xics.h"
  36 #include "hw/ppc/xics_spapr.h"
  37 #include "kvm_ppc.h"
  38 #include "qemu/config-file.h"
  39 #include "qemu/error-report.h"
  40
  41 #include <sys/ioctl.h>
  42
  43 static int kernel_xics_fd = -1;
  44
  45 typedef struct KVMEnabledICP {
  46     unsigned long vcpu_id;
  47     QLIST_ENTRY(KVMEnabledICP) node;
  48 } KVMEnabledICP;
  49
  50 static QLIST_HEAD(, KVMEnabledICP)
  51     kvm_enabled_icps = QLIST_HEAD_INITIALIZER(&kvm_enabled_icps);
  52
  53 static void kvm_disable_icps(void)
  54 {
  55     KVMEnabledICP *enabled_icp, *next;
  56
  57     QLIST_FOREACH_SAFE(enabled_icp, &kvm_enabled_icps, node, next) {
  58         QLIST_REMOVE(enabled_icp, node);
  59         g_free(enabled_icp);
  60     }
  61 }
  62
  63 /*
  64  * ICP-KVM
  65  */
  66 void icp_get_kvm_state(ICPState *icp)
  67 {
  68     uint64_t state;
  69     int ret;
  70
  71     /* The KVM XICS device is not in use */
  72     if (kernel_xics_fd == -1) {
  73         return;
  74     }
  75
  76     /* ICP for this CPU thread is not in use, exiting */
  77     if (!icp->cs) {
  78         return;
  79     }
  80
  81     ret = kvm_get_one_reg(icp->cs, KVM_REG_PPC_ICP_STATE, &state);
  82     if (ret != 0) {
  83         error_report("Unable to retrieve KVM interrupt controller state"
  84                 " for CPU %ld: %s", kvm_arch_vcpu_id(icp->cs), strerror(errno));
  85         exit(1);
  86     }
  87
  88     icp->xirr = state >> KVM_REG_PPC_ICP_XISR_SHIFT;
  89     icp->mfrr = (state >> KVM_REG_PPC_ICP_MFRR_SHIFT)
  90         & KVM_REG_PPC_ICP_MFRR_MASK;
  91     icp->pending_priority = (state >> KVM_REG_PPC_ICP_PPRI_SHIFT)
  92         & KVM_REG_PPC_ICP_PPRI_MASK;
  93 }
  94
  95 static void do_icp_synchronize_state(CPUState *cpu, run_on_cpu_data arg)
  96 {
  97     icp_get_kvm_state(arg.host_ptr);
  98 }
  99
 100 void icp_synchronize_state(ICPState *icp)
 101 {
 102     if (icp->cs) {
 103         run_on_cpu(icp->cs, do_icp_synchronize_state, RUN_ON_CPU_HOST_PTR(icp));
 104     }
 105 }
 106
 107 int icp_set_kvm_state(ICPState *icp, Error **errp)
 108 {
 109     uint64_t state;
 110     int ret;
 111
 112     /* The KVM XICS device is not in use */
 113     if (kernel_xics_fd == -1) {
 114         return 0;
 115     }
 116
 117     /* ICP for this CPU thread is not in use, exiting */
 118     if (!icp->cs) {
 119         return 0;
 120     }
 121
 122     state = ((uint64_t)icp->xirr << KVM_REG_PPC_ICP_XISR_SHIFT)
 123         | ((uint64_t)icp->mfrr << KVM_REG_PPC_ICP_MFRR_SHIFT)
 124         | ((uint64_t)icp->pending_priority << KVM_REG_PPC_ICP_PPRI_SHIFT);
 125
 126     ret = kvm_set_one_reg(icp->cs, KVM_REG_PPC_ICP_STATE, &state);
 127     if (ret < 0) {
 128         error_setg_errno(errp, -ret,
 129                          "Unable to restore KVM interrupt controller state (0x%"
 130                          PRIx64 ") for CPU %ld", state,
 131                          kvm_arch_vcpu_id(icp->cs));
 132         return ret;
 133     }
 134
 135     return 0;
 136 }
 137
 138 void icp_kvm_realize(DeviceState *dev, Error **errp)
 139 {
 140     ICPState *icp = ICP(dev);
 141     CPUState *cs;
 142     KVMEnabledICP *enabled_icp;
 143     unsigned long vcpu_id;
 144     int ret;
 145
 146     /* The KVM XICS device is not in use */
 147     if (kernel_xics_fd == -1) {
 148         return;
 149     }
 150
 151     cs = icp->cs;
 152     vcpu_id = kvm_arch_vcpu_id(cs);
 153
 154     /*
 155      * If we are reusing a parked vCPU fd corresponding to the CPU
 156      * which was hot-removed earlier we don't have to renable
 157      * KVM_CAP_IRQ_XICS capability again.
 158      */
 159     QLIST_FOREACH(enabled_icp, &kvm_enabled_icps, node) {
 160         if (enabled_icp->vcpu_id == vcpu_id) {
 161             return;
 162         }
 163     }
 164
 165     ret = kvm_vcpu_enable_cap(cs, KVM_CAP_IRQ_XICS, 0, kernel_xics_fd, vcpu_id);
 166     if (ret < 0) {
 167         Error *local_err = NULL;
 168
 169         error_setg(&local_err, "Unable to connect CPU%ld to kernel XICS: %s",
 170                    vcpu_id, strerror(errno));
 171         if (errno == ENOSPC) {
 172             error_append_hint(&local_err, "Try -smp maxcpus=N with N < %u\n",
 173                               MACHINE(qdev_get_machine())->smp.max_cpus);
 174         }
 175         error_propagate(errp, local_err);
 176         return;
 177     }
 178     enabled_icp = g_malloc(sizeof(*enabled_icp));
 179     enabled_icp->vcpu_id = vcpu_id;
 180     QLIST_INSERT_HEAD(&kvm_enabled_icps, enabled_icp, node);
 181 }
 182
 183 /*
 184  * ICS-KVM
 185  */
 186 void ics_get_kvm_state(ICSState *ics)
 187 {
 188     uint64_t state;
 189     int i;
 190
 191     /* The KVM XICS device is not in use */
 192     if (kernel_xics_fd == -1) {
 193         return;
 194     }
 195
 196     for (i = 0; i < ics->nr_irqs; i++) {
 197         ICSIRQState *irq = &ics->irqs[i];
 198
 199         if (ics_irq_free(ics, i)) {
 200             continue;
 201         }
 202
 203         kvm_device_access(kernel_xics_fd, KVM_DEV_XICS_GRP_SOURCES,
 204                           i + ics->offset, &state, false, &error_fatal);
 205
 206         irq->server = state & KVM_XICS_DESTINATION_MASK;
 207         irq->saved_priority = (state >> KVM_XICS_PRIORITY_SHIFT)
 208             & KVM_XICS_PRIORITY_MASK;
 209         /*
 210          * To be consistent with the software emulation in xics.c, we
 211          * split out the masked state + priority that we get from the
 212          * kernel into 'current priority' (0xff if masked) and
 213          * 'saved priority' (if masked, this is the priority the
 214          * interrupt had before it was masked).  Masking and unmasking
 215          * are done with the ibm,int-off and ibm,int-on RTAS calls.
 216          */
 217         if (state & KVM_XICS_MASKED) {
 218             irq->priority = 0xff;
 219         } else {
 220             irq->priority = irq->saved_priority;
 221         }
 222
 223         irq->status = 0;
 224         if (state & KVM_XICS_PENDING) {
 225             if (state & KVM_XICS_LEVEL_SENSITIVE) {
 226                 irq->status |= XICS_STATUS_ASSERTED;
 227             } else {
 228                 /*
 229                  * A pending edge-triggered interrupt (or MSI)
 230                  * must have been rejected previously when we
 231                  * first detected it and tried to deliver it,
 232                  * so mark it as pending and previously rejected
 233                  * for consistency with how xics.c works.
 234                  */
 235                 irq->status |= XICS_STATUS_MASKED_PENDING
 236                     | XICS_STATUS_REJECTED;
 237             }
 238         }
 239         if (state & KVM_XICS_PRESENTED) {
 240                 irq->status |= XICS_STATUS_PRESENTED;
 241         }
 242         if (state & KVM_XICS_QUEUED) {
 243                 irq->status |= XICS_STATUS_QUEUED;
 244         }
 245     }
 246 }
 247
 248 void ics_synchronize_state(ICSState *ics)
 249 {
 250     ics_get_kvm_state(ics);
 251 }
 252
 253 int ics_set_kvm_state_one(ICSState *ics, int srcno, Error **errp)
 254 {
 255     uint64_t state;
 256     ICSIRQState *irq = &ics->irqs[srcno];
 257     int ret;
 258
 259     /* The KVM XICS device is not in use */
 260     if (kernel_xics_fd == -1) {
 261         return 0;
 262     }
 263
 264     state = irq->server;
 265     state |= (uint64_t)(irq->saved_priority & KVM_XICS_PRIORITY_MASK)
 266         << KVM_XICS_PRIORITY_SHIFT;
 267     if (irq->priority != irq->saved_priority) {
 268         assert(irq->priority == 0xff);
 269     }
 270
 271     if (irq->priority == 0xff) {
 272         state |= KVM_XICS_MASKED;
 273     }
 274
 275     if (irq->flags & XICS_FLAGS_IRQ_LSI) {
 276         state |= KVM_XICS_LEVEL_SENSITIVE;
 277         if (irq->status & XICS_STATUS_ASSERTED) {
 278             state |= KVM_XICS_PENDING;
 279         }
 280     } else {
 281         if (irq->status & XICS_STATUS_MASKED_PENDING) {
 282             state |= KVM_XICS_PENDING;
 283         }
 284     }
 285     if (irq->status & XICS_STATUS_PRESENTED) {
 286         state |= KVM_XICS_PRESENTED;
 287     }
 288     if (irq->status & XICS_STATUS_QUEUED) {
 289         state |= KVM_XICS_QUEUED;
 290     }
 291
 292     ret = kvm_device_access(kernel_xics_fd, KVM_DEV_XICS_GRP_SOURCES,
 293                             srcno + ics->offset, &state, true, errp);
 294     if (ret < 0) {
 295         return ret;
 296     }
 297
 298     return 0;
 299 }
 300
 301 int ics_set_kvm_state(ICSState *ics, Error **errp)
 302 {
 303     int i;
 304
 305     /* The KVM XICS device is not in use */
 306     if (kernel_xics_fd == -1) {
 307         return 0;
 308     }
 309
 310     for (i = 0; i < ics->nr_irqs; i++) {
 311         int ret;
 312
 313         if (ics_irq_free(ics, i)) {
 314             continue;
 315         }
 316
 317         ret = ics_set_kvm_state_one(ics, i, errp);
 318         if (ret < 0) {
 319             return ret;
 320         }
 321     }
 322
 323     return 0;
 324 }
 325
 326 void ics_kvm_set_irq(ICSState *ics, int srcno, int val)
 327 {
 328     struct kvm_irq_level args;
 329     int rc;
 330
 331     /* The KVM XICS device should be in use */
 332     assert(kernel_xics_fd != -1);
 333
 334     args.irq = srcno + ics->offset;
 335     if (ics->irqs[srcno].flags & XICS_FLAGS_IRQ_MSI) {
 336         if (!val) {
 337             return;
 338         }
 339         args.level = KVM_INTERRUPT_SET;
 340     } else {
 341         args.level = val ? KVM_INTERRUPT_SET_LEVEL : KVM_INTERRUPT_UNSET;
 342     }
 343     rc = kvm_vm_ioctl(kvm_state, KVM_IRQ_LINE, &args);
 344     if (rc < 0) {
 345         perror("kvm_irq_line");
 346     }
 347 }
 348
 349 int xics_kvm_connect(SpaprInterruptController *intc, uint32_t nr_servers,
 350                      Error **errp)
 351 {
 352     ICSState *ics = ICS_SPAPR(intc);
 353     int rc;
 354     CPUState *cs;
 355     Error *local_err = NULL;
 356
 357     /*
 358      * The KVM XICS device already in use. This is the case when
 359      * rebooting under the XICS-only interrupt mode.
 360      */
 361     if (kernel_xics_fd != -1) {
 362         return 0;
 363     }
 364
 365     if (!kvm_enabled() || !kvm_check_extension(kvm_state, KVM_CAP_IRQ_XICS)) {
 366         error_setg(errp,
 367                    "KVM and IRQ_XICS capability must be present for in-kernel XICS");
 368         return -1;
 369     }
 370
 371     rc = kvmppc_define_rtas_kernel_token(RTAS_IBM_SET_XIVE, "ibm,set-xive");
 372     if (rc < 0) {
 373         error_setg_errno(&local_err, -rc,
 374                          "kvmppc_define_rtas_kernel_token: ibm,set-xive");
 375         goto fail;
 376     }
 377
 378     rc = kvmppc_define_rtas_kernel_token(RTAS_IBM_GET_XIVE, "ibm,get-xive");
 379     if (rc < 0) {
 380         error_setg_errno(&local_err, -rc,
 381                          "kvmppc_define_rtas_kernel_token: ibm,get-xive");
 382         goto fail;
 383     }
 384
 385     rc = kvmppc_define_rtas_kernel_token(RTAS_IBM_INT_ON, "ibm,int-on");
 386     if (rc < 0) {
 387         error_setg_errno(&local_err, -rc,
 388                          "kvmppc_define_rtas_kernel_token: ibm,int-on");
 389         goto fail;
 390     }
 391
 392     rc = kvmppc_define_rtas_kernel_token(RTAS_IBM_INT_OFF, "ibm,int-off");
 393     if (rc < 0) {
 394         error_setg_errno(&local_err, -rc,
 395                          "kvmppc_define_rtas_kernel_token: ibm,int-off");
 396         goto fail;
 397     }
 398
 399     /* Create the KVM XICS device */
 400     rc = kvm_create_device(kvm_state, KVM_DEV_TYPE_XICS, false);
 401     if (rc < 0) {
 402         error_setg_errno(&local_err, -rc, "Error on KVM_CREATE_DEVICE for XICS");
 403         goto fail;
 404     }
 405
 406     /* Tell KVM about the # of VCPUs we may have (POWER9 and newer only) */
 407     if (kvm_device_check_attr(rc, KVM_DEV_XICS_GRP_CTRL,
 408                               KVM_DEV_XICS_NR_SERVERS)) {
 409         if (kvm_device_access(rc, KVM_DEV_XICS_GRP_CTRL,
 410                               KVM_DEV_XICS_NR_SERVERS, &nr_servers, true,
 411                               &local_err)) {
 412             goto fail;
 413         }
 414     }
 415
 416     kernel_xics_fd = rc;
 417     kvm_kernel_irqchip = true;
 418     kvm_msi_via_irqfd_allowed = true;
 419     kvm_gsi_direct_mapping = true;
 420
 421     /* Create the presenters */
 422     CPU_FOREACH(cs) {
 423         PowerPCCPU *cpu = POWERPC_CPU(cs);
 424
 425         icp_kvm_realize(DEVICE(spapr_cpu_state(cpu)->icp), &local_err);
 426         if (local_err) {
 427             goto fail;
 428         }
 429     }
 430
 431     /* Update the KVM sources */
 432     ics_set_kvm_state(ics, &local_err);
 433     if (local_err) {
 434         goto fail;
 435     }
 436
 437     /* Connect the presenters to the initial VCPUs of the machine */
 438     CPU_FOREACH(cs) {
 439         PowerPCCPU *cpu = POWERPC_CPU(cs);
 440         icp_set_kvm_state(spapr_cpu_state(cpu)->icp, &local_err);
 441         if (local_err) {
 442             goto fail;
 443         }
 444     }
 445
 446     return 0;
 447
 448 fail:
 449     error_propagate(errp, local_err);
 450     xics_kvm_disconnect(intc);
 451     return -1;
 452 }
 453
 454 void xics_kvm_disconnect(SpaprInterruptController *intc)
 455 {
 456     /*
 457      * Only on P9 using the XICS-on XIVE KVM device:
 458      *
 459      * When the KVM device fd is closed, the device is destroyed and
 460      * removed from the list of devices of the VM. The VCPU presenters
 461      * are also detached from the device.
 462      */
 463     if (kernel_xics_fd != -1) {
 464         close(kernel_xics_fd);
 465         kernel_xics_fd = -1;
 466     }
 467
 468     kvmppc_define_rtas_kernel_token(0, "ibm,set-xive");
 469     kvmppc_define_rtas_kernel_token(0, "ibm,get-xive");
 470     kvmppc_define_rtas_kernel_token(0, "ibm,int-on");
 471     kvmppc_define_rtas_kernel_token(0, "ibm,int-off");
 472
 473     kvm_kernel_irqchip = false;
 474     kvm_msi_via_irqfd_allowed = false;
 475     kvm_gsi_direct_mapping = false;
 476
 477     /* Clear the presenter from the VCPUs */
 478     kvm_disable_icps();
 479 }
 480
 481 /*
 482  * This is a heuristic to detect older KVMs on POWER9 hosts that don't
 483  * support destruction of a KVM XICS device while the VM is running.
 484  * Required to start a spapr machine with ic-mode=dual,kernel-irqchip=on.
 485  */
 486 bool xics_kvm_has_broken_disconnect(void)
 487 {
 488     int rc;
 489
 490     rc = kvm_create_device(kvm_state, KVM_DEV_TYPE_XICS, false);
 491     if (rc < 0) {
 492         /*
 493          * The error is ignored on purpose. The KVM XICS setup code
 494          * will catch it again anyway. The goal here is to see if
 495          * close() actually destroys the device or not.
 496          */
 497         return false;
 498     }
 499
 500     close(rc);
 501
 502     rc = kvm_create_device(kvm_state, KVM_DEV_TYPE_XICS, false);
 503     if (rc >= 0) {
 504         close(rc);
 505         return false;
 506     }
 507
 508     return errno == EEXIST;
 509 }