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