arch/arm64/kvm/arch_timer.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2012 ARM Ltd.
   4  * Author: Marc Zyngier <marc.zyngier@arm.com>
   5  */
   6
   7 #include <linux/cpu.h>
   8 #include <linux/kvm.h>
   9 #include <linux/kvm_host.h>
  10 #include <linux/interrupt.h>
  11 #include <linux/irq.h>
  12 #include <linux/irqdomain.h>
  13 #include <linux/uaccess.h>
  14
  15 #include <clocksource/arm_arch_timer.h>
  16 #include <asm/arch_timer.h>
  17 #include <asm/kvm_emulate.h>
  18 #include <asm/kvm_hyp.h>
  19
  20 #include <kvm/arm_vgic.h>
  21 #include <kvm/arm_arch_timer.h>
  22
  23 #include "trace.h"
  24
  25 static struct timecounter *timecounter;
  26 static unsigned int host_vtimer_irq;
  27 static unsigned int host_ptimer_irq;
  28 static u32 host_vtimer_irq_flags;
  29 static u32 host_ptimer_irq_flags;
  30
  31 static DEFINE_STATIC_KEY_FALSE(has_gic_active_state);
  32
  33 static const struct kvm_irq_level default_ptimer_irq = {
  34         .irq    = 30,
  35         .level  = 1,
  36 };
  37
  38 static const struct kvm_irq_level default_vtimer_irq = {
  39         .irq    = 27,
  40         .level  = 1,
  41 };
  42
  43 static bool kvm_timer_irq_can_fire(struct arch_timer_context *timer_ctx);
  44 static void kvm_timer_update_irq(struct kvm_vcpu *vcpu, bool new_level,
  45                                  struct arch_timer_context *timer_ctx);
  46 static bool kvm_timer_should_fire(struct arch_timer_context *timer_ctx);
  47 static void kvm_arm_timer_write(struct kvm_vcpu *vcpu,
  48                                 struct arch_timer_context *timer,
  49                                 enum kvm_arch_timer_regs treg,
  50                                 u64 val);
  51 static u64 kvm_arm_timer_read(struct kvm_vcpu *vcpu,
  52                               struct arch_timer_context *timer,
  53                               enum kvm_arch_timer_regs treg);
  54
  55 u32 timer_get_ctl(struct arch_timer_context *ctxt)
  56 {
  57         struct kvm_vcpu *vcpu = ctxt->vcpu;
  58
  59         switch(arch_timer_ctx_index(ctxt)) {
  60         case TIMER_VTIMER:
  61                 return __vcpu_sys_reg(vcpu, CNTV_CTL_EL0);
  62         case TIMER_PTIMER:
  63                 return __vcpu_sys_reg(vcpu, CNTP_CTL_EL0);
  64         default:
  65                 WARN_ON(1);
  66                 return 0;
  67         }
  68 }
  69
  70 u64 timer_get_cval(struct arch_timer_context *ctxt)
  71 {
  72         struct kvm_vcpu *vcpu = ctxt->vcpu;
  73
  74         switch(arch_timer_ctx_index(ctxt)) {
  75         case TIMER_VTIMER:
  76                 return __vcpu_sys_reg(vcpu, CNTV_CVAL_EL0);
  77         case TIMER_PTIMER:
  78                 return __vcpu_sys_reg(vcpu, CNTP_CVAL_EL0);
  79         default:
  80                 WARN_ON(1);
  81                 return 0;
  82         }
  83 }
  84
  85 static u64 timer_get_offset(struct arch_timer_context *ctxt)
  86 {
  87         struct kvm_vcpu *vcpu = ctxt->vcpu;
  88
  89         switch(arch_timer_ctx_index(ctxt)) {
  90         case TIMER_VTIMER:
  91                 return __vcpu_sys_reg(vcpu, CNTVOFF_EL2);
  92         default:
  93                 return 0;
  94         }
  95 }
  96
  97 static void timer_set_ctl(struct arch_timer_context *ctxt, u32 ctl)
  98 {
  99         struct kvm_vcpu *vcpu = ctxt->vcpu;
 100
 101         switch(arch_timer_ctx_index(ctxt)) {
 102         case TIMER_VTIMER:
 103                 __vcpu_sys_reg(vcpu, CNTV_CTL_EL0) = ctl;
 104                 break;
 105         case TIMER_PTIMER:
 106                 __vcpu_sys_reg(vcpu, CNTP_CTL_EL0) = ctl;
 107                 break;
 108         default:
 109                 WARN_ON(1);
 110         }
 111 }
 112
 113 static void timer_set_cval(struct arch_timer_context *ctxt, u64 cval)
 114 {
 115         struct kvm_vcpu *vcpu = ctxt->vcpu;
 116
 117         switch(arch_timer_ctx_index(ctxt)) {
 118         case TIMER_VTIMER:
 119                 __vcpu_sys_reg(vcpu, CNTV_CVAL_EL0) = cval;
 120                 break;
 121         case TIMER_PTIMER:
 122                 __vcpu_sys_reg(vcpu, CNTP_CVAL_EL0) = cval;
 123                 break;
 124         default:
 125                 WARN_ON(1);
 126         }
 127 }
 128
 129 static void timer_set_offset(struct arch_timer_context *ctxt, u64 offset)
 130 {
 131         struct kvm_vcpu *vcpu = ctxt->vcpu;
 132
 133         switch(arch_timer_ctx_index(ctxt)) {
 134         case TIMER_VTIMER:
 135                 __vcpu_sys_reg(vcpu, CNTVOFF_EL2) = offset;
 136                 break;
 137         default:
 138                 WARN(offset, "timer %ld\n", arch_timer_ctx_index(ctxt));
 139         }
 140 }
 141
 142 u64 kvm_phys_timer_read(void)
 143 {
 144         return timecounter->cc->read(timecounter->cc);
 145 }
 146
 147 static void get_timer_map(struct kvm_vcpu *vcpu, struct timer_map *map)
 148 {
 149         if (has_vhe()) {
 150                 map->direct_vtimer = vcpu_vtimer(vcpu);
 151                 map->direct_ptimer = vcpu_ptimer(vcpu);
 152                 map->emul_ptimer = NULL;
 153         } else {
 154                 map->direct_vtimer = vcpu_vtimer(vcpu);
 155                 map->direct_ptimer = NULL;
 156                 map->emul_ptimer = vcpu_ptimer(vcpu);
 157         }
 158
 159         trace_kvm_get_timer_map(vcpu->vcpu_id, map);
 160 }
 161
 162 static inline bool userspace_irqchip(struct kvm *kvm)
 163 {
 164         return static_branch_unlikely(&userspace_irqchip_in_use) &&
 165                 unlikely(!irqchip_in_kernel(kvm));
 166 }
 167
 168 static void soft_timer_start(struct hrtimer *hrt, u64 ns)
 169 {
 170         hrtimer_start(hrt, ktime_add_ns(ktime_get(), ns),
 171                       HRTIMER_MODE_ABS_HARD);
 172 }
 173
 174 static void soft_timer_cancel(struct hrtimer *hrt)
 175 {
 176         hrtimer_cancel(hrt);
 177 }
 178
 179 static irqreturn_t kvm_arch_timer_handler(int irq, void *dev_id)
 180 {
 181         struct kvm_vcpu *vcpu = *(struct kvm_vcpu **)dev_id;
 182         struct arch_timer_context *ctx;
 183         struct timer_map map;
 184
 185         /*
 186          * We may see a timer interrupt after vcpu_put() has been called which
 187          * sets the CPU's vcpu pointer to NULL, because even though the timer
 188          * has been disabled in timer_save_state(), the hardware interrupt
 189          * signal may not have been retired from the interrupt controller yet.
 190          */
 191         if (!vcpu)
 192                 return IRQ_HANDLED;
 193
 194         get_timer_map(vcpu, &map);
 195
 196         if (irq == host_vtimer_irq)
 197                 ctx = map.direct_vtimer;
 198         else
 199                 ctx = map.direct_ptimer;
 200
 201         if (kvm_timer_should_fire(ctx))
 202                 kvm_timer_update_irq(vcpu, true, ctx);
 203
 204         if (userspace_irqchip(vcpu->kvm) &&
 205             !static_branch_unlikely(&has_gic_active_state))
 206                 disable_percpu_irq(host_vtimer_irq);
 207
 208         return IRQ_HANDLED;
 209 }
 210
 211 static u64 kvm_timer_compute_delta(struct arch_timer_context *timer_ctx)
 212 {
 213         u64 cval, now;
 214
 215         cval = timer_get_cval(timer_ctx);
 216         now = kvm_phys_timer_read() - timer_get_offset(timer_ctx);
 217
 218         if (now < cval) {
 219                 u64 ns;
 220
 221                 ns = cyclecounter_cyc2ns(timecounter->cc,
 222                                          cval - now,
 223                                          timecounter->mask,
 224                                          &timecounter->frac);
 225                 return ns;
 226         }
 227
 228         return 0;
 229 }
 230
 231 static bool kvm_timer_irq_can_fire(struct arch_timer_context *timer_ctx)
 232 {
 233         WARN_ON(timer_ctx && timer_ctx->loaded);
 234         return timer_ctx &&
 235                 ((timer_get_ctl(timer_ctx) &
 236                   (ARCH_TIMER_CTRL_IT_MASK | ARCH_TIMER_CTRL_ENABLE)) == ARCH_TIMER_CTRL_ENABLE);
 237 }
 238
 239 /*
 240  * Returns the earliest expiration time in ns among guest timers.
 241  * Note that it will return 0 if none of timers can fire.
 242  */
 243 static u64 kvm_timer_earliest_exp(struct kvm_vcpu *vcpu)
 244 {
 245         u64 min_delta = ULLONG_MAX;
 246         int i;
 247
 248         for (i = 0; i < NR_KVM_TIMERS; i++) {
 249                 struct arch_timer_context *ctx = &vcpu->arch.timer_cpu.timers[i];
 250
 251                 WARN(ctx->loaded, "timer %d loaded\n", i);
 252                 if (kvm_timer_irq_can_fire(ctx))
 253                         min_delta = min(min_delta, kvm_timer_compute_delta(ctx));
 254         }
 255
 256         /* If none of timers can fire, then return 0 */
 257         if (min_delta == ULLONG_MAX)
 258                 return 0;
 259
 260         return min_delta;
 261 }
 262
 263 static enum hrtimer_restart kvm_bg_timer_expire(struct hrtimer *hrt)
 264 {
 265         struct arch_timer_cpu *timer;
 266         struct kvm_vcpu *vcpu;
 267         u64 ns;
 268
 269         timer = container_of(hrt, struct arch_timer_cpu, bg_timer);
 270         vcpu = container_of(timer, struct kvm_vcpu, arch.timer_cpu);
 271
 272         /*
 273          * Check that the timer has really expired from the guest's
 274          * PoV (NTP on the host may have forced it to expire
 275          * early). If we should have slept longer, restart it.
 276          */
 277         ns = kvm_timer_earliest_exp(vcpu);
 278         if (unlikely(ns)) {
 279                 hrtimer_forward_now(hrt, ns_to_ktime(ns));
 280                 return HRTIMER_RESTART;
 281         }
 282
 283         kvm_vcpu_wake_up(vcpu);
 284         return HRTIMER_NORESTART;
 285 }
 286
 287 static enum hrtimer_restart kvm_hrtimer_expire(struct hrtimer *hrt)
 288 {
 289         struct arch_timer_context *ctx;
 290         struct kvm_vcpu *vcpu;
 291         u64 ns;
 292
 293         ctx = container_of(hrt, struct arch_timer_context, hrtimer);
 294         vcpu = ctx->vcpu;
 295
 296         trace_kvm_timer_hrtimer_expire(ctx);
 297
 298         /*
 299          * Check that the timer has really expired from the guest's
 300          * PoV (NTP on the host may have forced it to expire
 301          * early). If not ready, schedule for a later time.
 302          */
 303         ns = kvm_timer_compute_delta(ctx);
 304         if (unlikely(ns)) {
 305                 hrtimer_forward_now(hrt, ns_to_ktime(ns));
 306                 return HRTIMER_RESTART;
 307         }
 308
 309         kvm_timer_update_irq(vcpu, true, ctx);
 310         return HRTIMER_NORESTART;
 311 }
 312
 313 static bool kvm_timer_should_fire(struct arch_timer_context *timer_ctx)
 314 {
 315         enum kvm_arch_timers index;
 316         u64 cval, now;
 317
 318         if (!timer_ctx)
 319                 return false;
 320
 321         index = arch_timer_ctx_index(timer_ctx);
 322
 323         if (timer_ctx->loaded) {
 324                 u32 cnt_ctl = 0;
 325
 326                 switch (index) {
 327                 case TIMER_VTIMER:
 328                         cnt_ctl = read_sysreg_el0(SYS_CNTV_CTL);
 329                         break;
 330                 case TIMER_PTIMER:
 331                         cnt_ctl = read_sysreg_el0(SYS_CNTP_CTL);
 332                         break;
 333                 case NR_KVM_TIMERS:
 334                         /* GCC is braindead */
 335                         cnt_ctl = 0;
 336                         break;
 337                 }
 338
 339                 return  (cnt_ctl & ARCH_TIMER_CTRL_ENABLE) &&
 340                         (cnt_ctl & ARCH_TIMER_CTRL_IT_STAT) &&
 341                        !(cnt_ctl & ARCH_TIMER_CTRL_IT_MASK);
 342         }
 343
 344         if (!kvm_timer_irq_can_fire(timer_ctx))
 345                 return false;
 346
 347         cval = timer_get_cval(timer_ctx);
 348         now = kvm_phys_timer_read() - timer_get_offset(timer_ctx);
 349
 350         return cval <= now;
 351 }
 352
 353 bool kvm_timer_is_pending(struct kvm_vcpu *vcpu)
 354 {
 355         struct timer_map map;
 356
 357         get_timer_map(vcpu, &map);
 358
 359         return kvm_timer_should_fire(map.direct_vtimer) ||
 360                kvm_timer_should_fire(map.direct_ptimer) ||
 361                kvm_timer_should_fire(map.emul_ptimer);
 362 }
 363
 364 /*
 365  * Reflect the timer output level into the kvm_run structure
 366  */
 367 void kvm_timer_update_run(struct kvm_vcpu *vcpu)
 368 {
 369         struct arch_timer_context *vtimer = vcpu_vtimer(vcpu);
 370         struct arch_timer_context *ptimer = vcpu_ptimer(vcpu);
 371         struct kvm_sync_regs *regs = &vcpu->run->s.regs;
 372
 373         /* Populate the device bitmap with the timer states */
 374         regs->device_irq_level &= ~(KVM_ARM_DEV_EL1_VTIMER |
 375                                     KVM_ARM_DEV_EL1_PTIMER);
 376         if (kvm_timer_should_fire(vtimer))
 377                 regs->device_irq_level |= KVM_ARM_DEV_EL1_VTIMER;
 378         if (kvm_timer_should_fire(ptimer))
 379                 regs->device_irq_level |= KVM_ARM_DEV_EL1_PTIMER;
 380 }
 381
 382 static void kvm_timer_update_irq(struct kvm_vcpu *vcpu, bool new_level,
 383                                  struct arch_timer_context *timer_ctx)
 384 {
 385         int ret;
 386
 387         timer_ctx->irq.level = new_level;
 388         trace_kvm_timer_update_irq(vcpu->vcpu_id, timer_ctx->irq.irq,
 389                                    timer_ctx->irq.level);
 390
 391         if (!userspace_irqchip(vcpu->kvm)) {
 392                 ret = kvm_vgic_inject_irq(vcpu->kvm, vcpu->vcpu_id,
 393                                           timer_ctx->irq.irq,
 394                                           timer_ctx->irq.level,
 395                                           timer_ctx);
 396                 WARN_ON(ret);
 397         }
 398 }
 399
 400 /* Only called for a fully emulated timer */
 401 static void timer_emulate(struct arch_timer_context *ctx)
 402 {
 403         bool should_fire = kvm_timer_should_fire(ctx);
 404
 405         trace_kvm_timer_emulate(ctx, should_fire);
 406
 407         if (should_fire != ctx->irq.level) {
 408                 kvm_timer_update_irq(ctx->vcpu, should_fire, ctx);
 409                 return;
 410         }
 411
 412         /*
 413          * If the timer can fire now, we don't need to have a soft timer
 414          * scheduled for the future.  If the timer cannot fire at all,
 415          * then we also don't need a soft timer.
 416          */
 417         if (!kvm_timer_irq_can_fire(ctx)) {
 418                 soft_timer_cancel(&ctx->hrtimer);
 419                 return;
 420         }
 421
 422         soft_timer_start(&ctx->hrtimer, kvm_timer_compute_delta(ctx));
 423 }
 424
 425 static void timer_save_state(struct arch_timer_context *ctx)
 426 {
 427         struct arch_timer_cpu *timer = vcpu_timer(ctx->vcpu);
 428         enum kvm_arch_timers index = arch_timer_ctx_index(ctx);
 429         unsigned long flags;
 430
 431         if (!timer->enabled)
 432                 return;
 433
 434         local_irq_save(flags);
 435
 436         if (!ctx->loaded)
 437                 goto out;
 438
 439         switch (index) {
 440         case TIMER_VTIMER:
 441                 timer_set_ctl(ctx, read_sysreg_el0(SYS_CNTV_CTL));
 442                 timer_set_cval(ctx, read_sysreg_el0(SYS_CNTV_CVAL));
 443
 444                 /* Disable the timer */
 445                 write_sysreg_el0(0, SYS_CNTV_CTL);
 446                 isb();
 447
 448                 break;
 449         case TIMER_PTIMER:
 450                 timer_set_ctl(ctx, read_sysreg_el0(SYS_CNTP_CTL));
 451                 timer_set_cval(ctx, read_sysreg_el0(SYS_CNTP_CVAL));
 452
 453                 /* Disable the timer */
 454                 write_sysreg_el0(0, SYS_CNTP_CTL);
 455                 isb();
 456
 457                 break;
 458         case NR_KVM_TIMERS:
 459                 BUG();
 460         }
 461
 462         trace_kvm_timer_save_state(ctx);
 463
 464         ctx->loaded = false;
 465 out:
 466         local_irq_restore(flags);
 467 }
 468
 469 /*
 470  * Schedule the background timer before calling kvm_vcpu_block, so that this
 471  * thread is removed from its waitqueue and made runnable when there's a timer
 472  * interrupt to handle.
 473  */
 474 static void kvm_timer_blocking(struct kvm_vcpu *vcpu)
 475 {
 476         struct arch_timer_cpu *timer = vcpu_timer(vcpu);
 477         struct timer_map map;
 478
 479         get_timer_map(vcpu, &map);
 480
 481         /*
 482          * If no timers are capable of raising interrupts (disabled or
 483          * masked), then there's no more work for us to do.
 484          */
 485         if (!kvm_timer_irq_can_fire(map.direct_vtimer) &&
 486             !kvm_timer_irq_can_fire(map.direct_ptimer) &&
 487             !kvm_timer_irq_can_fire(map.emul_ptimer))
 488                 return;
 489
 490         /*
 491          * At least one guest time will expire. Schedule a background timer.
 492          * Set the earliest expiration time among the guest timers.
 493          */
 494         soft_timer_start(&timer->bg_timer, kvm_timer_earliest_exp(vcpu));
 495 }
 496
 497 static void kvm_timer_unblocking(struct kvm_vcpu *vcpu)
 498 {
 499         struct arch_timer_cpu *timer = vcpu_timer(vcpu);
 500
 501         soft_timer_cancel(&timer->bg_timer);
 502 }
 503
 504 static void timer_restore_state(struct arch_timer_context *ctx)
 505 {
 506         struct arch_timer_cpu *timer = vcpu_timer(ctx->vcpu);
 507         enum kvm_arch_timers index = arch_timer_ctx_index(ctx);
 508         unsigned long flags;
 509
 510         if (!timer->enabled)
 511                 return;
 512
 513         local_irq_save(flags);
 514
 515         if (ctx->loaded)
 516                 goto out;
 517
 518         switch (index) {
 519         case TIMER_VTIMER:
 520                 write_sysreg_el0(timer_get_cval(ctx), SYS_CNTV_CVAL);
 521                 isb();
 522                 write_sysreg_el0(timer_get_ctl(ctx), SYS_CNTV_CTL);
 523                 break;
 524         case TIMER_PTIMER:
 525                 write_sysreg_el0(timer_get_cval(ctx), SYS_CNTP_CVAL);
 526                 isb();
 527                 write_sysreg_el0(timer_get_ctl(ctx), SYS_CNTP_CTL);
 528                 break;
 529         case NR_KVM_TIMERS:
 530                 BUG();
 531         }
 532
 533         trace_kvm_timer_restore_state(ctx);
 534
 535         ctx->loaded = true;
 536 out:
 537         local_irq_restore(flags);
 538 }
 539
 540 static void set_cntvoff(u64 cntvoff)
 541 {
 542         kvm_call_hyp(__kvm_timer_set_cntvoff, cntvoff);
 543 }
 544
 545 static inline void set_timer_irq_phys_active(struct arch_timer_context *ctx, bool active)
 546 {
 547         int r;
 548         r = irq_set_irqchip_state(ctx->host_timer_irq, IRQCHIP_STATE_ACTIVE, active);
 549         WARN_ON(r);
 550 }
 551
 552 static void kvm_timer_vcpu_load_gic(struct arch_timer_context *ctx)
 553 {
 554         struct kvm_vcpu *vcpu = ctx->vcpu;
 555         bool phys_active = false;
 556
 557         /*
 558          * Update the timer output so that it is likely to match the
 559          * state we're about to restore. If the timer expires between
 560          * this point and the register restoration, we'll take the
 561          * interrupt anyway.
 562          */
 563         kvm_timer_update_irq(ctx->vcpu, kvm_timer_should_fire(ctx), ctx);
 564
 565         if (irqchip_in_kernel(vcpu->kvm))
 566                 phys_active = kvm_vgic_map_is_active(vcpu, ctx->irq.irq);
 567
 568         phys_active |= ctx->irq.level;
 569
 570         set_timer_irq_phys_active(ctx, phys_active);
 571 }
 572
 573 static void kvm_timer_vcpu_load_nogic(struct kvm_vcpu *vcpu)
 574 {
 575         struct arch_timer_context *vtimer = vcpu_vtimer(vcpu);
 576
 577         /*
 578          * Update the timer output so that it is likely to match the
 579          * state we're about to restore. If the timer expires between
 580          * this point and the register restoration, we'll take the
 581          * interrupt anyway.
 582          */
 583         kvm_timer_update_irq(vcpu, kvm_timer_should_fire(vtimer), vtimer);
 584
 585         /*
 586          * When using a userspace irqchip with the architected timers and a
 587          * host interrupt controller that doesn't support an active state, we
 588          * must still prevent continuously exiting from the guest, and
 589          * therefore mask the physical interrupt by disabling it on the host
 590          * interrupt controller when the virtual level is high, such that the
 591          * guest can make forward progress.  Once we detect the output level
 592          * being de-asserted, we unmask the interrupt again so that we exit
 593          * from the guest when the timer fires.
 594          */
 595         if (vtimer->irq.level)
 596                 disable_percpu_irq(host_vtimer_irq);
 597         else
 598                 enable_percpu_irq(host_vtimer_irq, host_vtimer_irq_flags);
 599 }
 600
 601 void kvm_timer_vcpu_load(struct kvm_vcpu *vcpu)
 602 {
 603         struct arch_timer_cpu *timer = vcpu_timer(vcpu);
 604         struct timer_map map;
 605
 606         if (unlikely(!timer->enabled))
 607                 return;
 608
 609         get_timer_map(vcpu, &map);
 610
 611         if (static_branch_likely(&has_gic_active_state)) {
 612                 kvm_timer_vcpu_load_gic(map.direct_vtimer);
 613                 if (map.direct_ptimer)
 614                         kvm_timer_vcpu_load_gic(map.direct_ptimer);
 615         } else {
 616                 kvm_timer_vcpu_load_nogic(vcpu);
 617         }
 618
 619         set_cntvoff(timer_get_offset(map.direct_vtimer));
 620
 621         kvm_timer_unblocking(vcpu);
 622
 623         timer_restore_state(map.direct_vtimer);
 624         if (map.direct_ptimer)
 625                 timer_restore_state(map.direct_ptimer);
 626
 627         if (map.emul_ptimer)
 628                 timer_emulate(map.emul_ptimer);
 629 }
 630
 631 bool kvm_timer_should_notify_user(struct kvm_vcpu *vcpu)
 632 {
 633         struct arch_timer_context *vtimer = vcpu_vtimer(vcpu);
 634         struct arch_timer_context *ptimer = vcpu_ptimer(vcpu);
 635         struct kvm_sync_regs *sregs = &vcpu->run->s.regs;
 636         bool vlevel, plevel;
 637
 638         if (likely(irqchip_in_kernel(vcpu->kvm)))
 639                 return false;
 640
 641         vlevel = sregs->device_irq_level & KVM_ARM_DEV_EL1_VTIMER;
 642         plevel = sregs->device_irq_level & KVM_ARM_DEV_EL1_PTIMER;
 643
 644         return kvm_timer_should_fire(vtimer) != vlevel ||
 645                kvm_timer_should_fire(ptimer) != plevel;
 646 }
 647
 648 void kvm_timer_vcpu_put(struct kvm_vcpu *vcpu)
 649 {
 650         struct arch_timer_cpu *timer = vcpu_timer(vcpu);
 651         struct timer_map map;
 652         struct rcuwait *wait = kvm_arch_vcpu_get_wait(vcpu);
 653
 654         if (unlikely(!timer->enabled))
 655                 return;
 656
 657         get_timer_map(vcpu, &map);
 658
 659         timer_save_state(map.direct_vtimer);
 660         if (map.direct_ptimer)
 661                 timer_save_state(map.direct_ptimer);
 662
 663         /*
 664          * Cancel soft timer emulation, because the only case where we
 665          * need it after a vcpu_put is in the context of a sleeping VCPU, and
 666          * in that case we already factor in the deadline for the physical
 667          * timer when scheduling the bg_timer.
 668          *
 669          * In any case, we re-schedule the hrtimer for the physical timer when
 670          * coming back to the VCPU thread in kvm_timer_vcpu_load().
 671          */
 672         if (map.emul_ptimer)
 673                 soft_timer_cancel(&map.emul_ptimer->hrtimer);
 674
 675         if (rcuwait_active(wait))
 676                 kvm_timer_blocking(vcpu);
 677
 678         /*
 679          * The kernel may decide to run userspace after calling vcpu_put, so
 680          * we reset cntvoff to 0 to ensure a consistent read between user
 681          * accesses to the virtual counter and kernel access to the physical
 682          * counter of non-VHE case. For VHE, the virtual counter uses a fixed
 683          * virtual offset of zero, so no need to zero CNTVOFF_EL2 register.
 684          */
 685         set_cntvoff(0);
 686 }
 687
 688 /*
 689  * With a userspace irqchip we have to check if the guest de-asserted the
 690  * timer and if so, unmask the timer irq signal on the host interrupt
 691  * controller to ensure that we see future timer signals.
 692  */
 693 static void unmask_vtimer_irq_user(struct kvm_vcpu *vcpu)
 694 {
 695         struct arch_timer_context *vtimer = vcpu_vtimer(vcpu);
 696
 697         if (!kvm_timer_should_fire(vtimer)) {
 698                 kvm_timer_update_irq(vcpu, false, vtimer);
 699                 if (static_branch_likely(&has_gic_active_state))
 700                         set_timer_irq_phys_active(vtimer, false);
 701                 else
 702                         enable_percpu_irq(host_vtimer_irq, host_vtimer_irq_flags);
 703         }
 704 }
 705
 706 void kvm_timer_sync_user(struct kvm_vcpu *vcpu)
 707 {
 708         struct arch_timer_cpu *timer = vcpu_timer(vcpu);
 709
 710         if (unlikely(!timer->enabled))
 711                 return;
 712
 713         if (unlikely(!irqchip_in_kernel(vcpu->kvm)))
 714                 unmask_vtimer_irq_user(vcpu);
 715 }
 716
 717 int kvm_timer_vcpu_reset(struct kvm_vcpu *vcpu)
 718 {
 719         struct arch_timer_cpu *timer = vcpu_timer(vcpu);
 720         struct timer_map map;
 721
 722         get_timer_map(vcpu, &map);
 723
 724         /*
 725          * The bits in CNTV_CTL are architecturally reset to UNKNOWN for ARMv8
 726          * and to 0 for ARMv7.  We provide an implementation that always
 727          * resets the timer to be disabled and unmasked and is compliant with
 728          * the ARMv7 architecture.
 729          */
 730         timer_set_ctl(vcpu_vtimer(vcpu), 0);
 731         timer_set_ctl(vcpu_ptimer(vcpu), 0);
 732
 733         if (timer->enabled) {
 734                 kvm_timer_update_irq(vcpu, false, vcpu_vtimer(vcpu));
 735                 kvm_timer_update_irq(vcpu, false, vcpu_ptimer(vcpu));
 736
 737                 if (irqchip_in_kernel(vcpu->kvm)) {
 738                         kvm_vgic_reset_mapped_irq(vcpu, map.direct_vtimer->irq.irq);
 739                         if (map.direct_ptimer)
 740                                 kvm_vgic_reset_mapped_irq(vcpu, map.direct_ptimer->irq.irq);
 741                 }
 742         }
 743
 744         if (map.emul_ptimer)
 745                 soft_timer_cancel(&map.emul_ptimer->hrtimer);
 746
 747         return 0;
 748 }
 749
 750 /* Make the updates of cntvoff for all vtimer contexts atomic */
 751 static void update_vtimer_cntvoff(struct kvm_vcpu *vcpu, u64 cntvoff)
 752 {
 753         int i;
 754         struct kvm *kvm = vcpu->kvm;
 755         struct kvm_vcpu *tmp;
 756
 757         mutex_lock(&kvm->lock);
 758         kvm_for_each_vcpu(i, tmp, kvm)
 759                 timer_set_offset(vcpu_vtimer(tmp), cntvoff);
 760
 761         /*
 762          * When called from the vcpu create path, the CPU being created is not
 763          * included in the loop above, so we just set it here as well.
 764          */
 765         timer_set_offset(vcpu_vtimer(vcpu), cntvoff);
 766         mutex_unlock(&kvm->lock);
 767 }
 768
 769 void kvm_timer_vcpu_init(struct kvm_vcpu *vcpu)
 770 {
 771         struct arch_timer_cpu *timer = vcpu_timer(vcpu);
 772         struct arch_timer_context *vtimer = vcpu_vtimer(vcpu);
 773         struct arch_timer_context *ptimer = vcpu_ptimer(vcpu);
 774
 775         vtimer->vcpu = vcpu;
 776         ptimer->vcpu = vcpu;
 777
 778         /* Synchronize cntvoff across all vtimers of a VM. */
 779         update_vtimer_cntvoff(vcpu, kvm_phys_timer_read());
 780         timer_set_offset(ptimer, 0);
 781
 782         hrtimer_init(&timer->bg_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_HARD);
 783         timer->bg_timer.function = kvm_bg_timer_expire;
 784
 785         hrtimer_init(&vtimer->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_HARD);
 786         hrtimer_init(&ptimer->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_HARD);
 787         vtimer->hrtimer.function = kvm_hrtimer_expire;
 788         ptimer->hrtimer.function = kvm_hrtimer_expire;
 789
 790         vtimer->irq.irq = default_vtimer_irq.irq;
 791         ptimer->irq.irq = default_ptimer_irq.irq;
 792
 793         vtimer->host_timer_irq = host_vtimer_irq;
 794         ptimer->host_timer_irq = host_ptimer_irq;
 795
 796         vtimer->host_timer_irq_flags = host_vtimer_irq_flags;
 797         ptimer->host_timer_irq_flags = host_ptimer_irq_flags;
 798 }
 799
 800 static void kvm_timer_init_interrupt(void *info)
 801 {
 802         enable_percpu_irq(host_vtimer_irq, host_vtimer_irq_flags);
 803         enable_percpu_irq(host_ptimer_irq, host_ptimer_irq_flags);
 804 }
 805
 806 int kvm_arm_timer_set_reg(struct kvm_vcpu *vcpu, u64 regid, u64 value)
 807 {
 808         struct arch_timer_context *timer;
 809
 810         switch (regid) {
 811         case KVM_REG_ARM_TIMER_CTL:
 812                 timer = vcpu_vtimer(vcpu);
 813                 kvm_arm_timer_write(vcpu, timer, TIMER_REG_CTL, value);
 814                 break;
 815         case KVM_REG_ARM_TIMER_CNT:
 816                 timer = vcpu_vtimer(vcpu);
 817                 update_vtimer_cntvoff(vcpu, kvm_phys_timer_read() - value);
 818                 break;
 819         case KVM_REG_ARM_TIMER_CVAL:
 820                 timer = vcpu_vtimer(vcpu);
 821                 kvm_arm_timer_write(vcpu, timer, TIMER_REG_CVAL, value);
 822                 break;
 823         case KVM_REG_ARM_PTIMER_CTL:
 824                 timer = vcpu_ptimer(vcpu);
 825                 kvm_arm_timer_write(vcpu, timer, TIMER_REG_CTL, value);
 826                 break;
 827         case KVM_REG_ARM_PTIMER_CVAL:
 828                 timer = vcpu_ptimer(vcpu);
 829                 kvm_arm_timer_write(vcpu, timer, TIMER_REG_CVAL, value);
 830                 break;
 831
 832         default:
 833                 return -1;
 834         }
 835
 836         return 0;
 837 }
 838
 839 static u64 read_timer_ctl(struct arch_timer_context *timer)
 840 {
 841         /*
 842          * Set ISTATUS bit if it's expired.
 843          * Note that according to ARMv8 ARM Issue A.k, ISTATUS bit is
 844          * UNKNOWN when ENABLE bit is 0, so we chose to set ISTATUS bit
 845          * regardless of ENABLE bit for our implementation convenience.
 846          */
 847         u32 ctl = timer_get_ctl(timer);
 848
 849         if (!kvm_timer_compute_delta(timer))
 850                 ctl |= ARCH_TIMER_CTRL_IT_STAT;
 851
 852         return ctl;
 853 }
 854
 855 u64 kvm_arm_timer_get_reg(struct kvm_vcpu *vcpu, u64 regid)
 856 {
 857         switch (regid) {
 858         case KVM_REG_ARM_TIMER_CTL:
 859                 return kvm_arm_timer_read(vcpu,
 860                                           vcpu_vtimer(vcpu), TIMER_REG_CTL);
 861         case KVM_REG_ARM_TIMER_CNT:
 862                 return kvm_arm_timer_read(vcpu,
 863                                           vcpu_vtimer(vcpu), TIMER_REG_CNT);
 864         case KVM_REG_ARM_TIMER_CVAL:
 865                 return kvm_arm_timer_read(vcpu,
 866                                           vcpu_vtimer(vcpu), TIMER_REG_CVAL);
 867         case KVM_REG_ARM_PTIMER_CTL:
 868                 return kvm_arm_timer_read(vcpu,
 869                                           vcpu_ptimer(vcpu), TIMER_REG_CTL);
 870         case KVM_REG_ARM_PTIMER_CNT:
 871                 return kvm_arm_timer_read(vcpu,
 872                                           vcpu_ptimer(vcpu), TIMER_REG_CNT);
 873         case KVM_REG_ARM_PTIMER_CVAL:
 874                 return kvm_arm_timer_read(vcpu,
 875                                           vcpu_ptimer(vcpu), TIMER_REG_CVAL);
 876         }
 877         return (u64)-1;
 878 }
 879
 880 static u64 kvm_arm_timer_read(struct kvm_vcpu *vcpu,
 881                               struct arch_timer_context *timer,
 882                               enum kvm_arch_timer_regs treg)
 883 {
 884         u64 val;
 885
 886         switch (treg) {
 887         case TIMER_REG_TVAL:
 888                 val = timer_get_cval(timer) - kvm_phys_timer_read() + timer_get_offset(timer);
 889                 val = lower_32_bits(val);
 890                 break;
 891
 892         case TIMER_REG_CTL:
 893                 val = read_timer_ctl(timer);
 894                 break;
 895
 896         case TIMER_REG_CVAL:
 897                 val = timer_get_cval(timer);
 898                 break;
 899
 900         case TIMER_REG_CNT:
 901                 val = kvm_phys_timer_read() - timer_get_offset(timer);
 902                 break;
 903
 904         default:
 905                 BUG();
 906         }
 907
 908         return val;
 909 }
 910
 911 u64 kvm_arm_timer_read_sysreg(struct kvm_vcpu *vcpu,
 912                               enum kvm_arch_timers tmr,
 913                               enum kvm_arch_timer_regs treg)
 914 {
 915         u64 val;
 916
 917         preempt_disable();
 918         kvm_timer_vcpu_put(vcpu);
 919
 920         val = kvm_arm_timer_read(vcpu, vcpu_get_timer(vcpu, tmr), treg);
 921
 922         kvm_timer_vcpu_load(vcpu);
 923         preempt_enable();
 924
 925         return val;
 926 }
 927
 928 static void kvm_arm_timer_write(struct kvm_vcpu *vcpu,
 929                                 struct arch_timer_context *timer,
 930                                 enum kvm_arch_timer_regs treg,
 931                                 u64 val)
 932 {
 933         switch (treg) {
 934         case TIMER_REG_TVAL:
 935                 timer_set_cval(timer, kvm_phys_timer_read() - timer_get_offset(timer) + (s32)val);
 936                 break;
 937
 938         case TIMER_REG_CTL:
 939                 timer_set_ctl(timer, val & ~ARCH_TIMER_CTRL_IT_STAT);
 940                 break;
 941
 942         case TIMER_REG_CVAL:
 943                 timer_set_cval(timer, val);
 944                 break;
 945
 946         default:
 947                 BUG();
 948         }
 949 }
 950
 951 void kvm_arm_timer_write_sysreg(struct kvm_vcpu *vcpu,
 952                                 enum kvm_arch_timers tmr,
 953                                 enum kvm_arch_timer_regs treg,
 954                                 u64 val)
 955 {
 956         preempt_disable();
 957         kvm_timer_vcpu_put(vcpu);
 958
 959         kvm_arm_timer_write(vcpu, vcpu_get_timer(vcpu, tmr), treg, val);
 960
 961         kvm_timer_vcpu_load(vcpu);
 962         preempt_enable();
 963 }
 964
 965 static int kvm_timer_starting_cpu(unsigned int cpu)
 966 {
 967         kvm_timer_init_interrupt(NULL);
 968         return 0;
 969 }
 970
 971 static int kvm_timer_dying_cpu(unsigned int cpu)
 972 {
 973         disable_percpu_irq(host_vtimer_irq);
 974         return 0;
 975 }
 976
 977 static int timer_irq_set_vcpu_affinity(struct irq_data *d, void *vcpu)
 978 {
 979         if (vcpu)
 980                 irqd_set_forwarded_to_vcpu(d);
 981         else
 982                 irqd_clr_forwarded_to_vcpu(d);
 983
 984         return 0;
 985 }
 986
 987 static int timer_irq_set_irqchip_state(struct irq_data *d,
 988                                        enum irqchip_irq_state which, bool val)
 989 {
 990         if (which != IRQCHIP_STATE_ACTIVE || !irqd_is_forwarded_to_vcpu(d))
 991                 return irq_chip_set_parent_state(d, which, val);
 992
 993         if (val)
 994                 irq_chip_mask_parent(d);
 995         else
 996                 irq_chip_unmask_parent(d);
 997
 998         return 0;
 999 }
1000
1001 static void timer_irq_eoi(struct irq_data *d)
1002 {
1003         if (!irqd_is_forwarded_to_vcpu(d))
1004                 irq_chip_eoi_parent(d);
1005 }
1006
1007 static void timer_irq_ack(struct irq_data *d)
1008 {
1009         d = d->parent_data;
1010         if (d->chip->irq_ack)
1011                 d->chip->irq_ack(d);
1012 }
1013
1014 static struct irq_chip timer_chip = {
1015         .name                   = "KVM",
1016         .irq_ack                = timer_irq_ack,
1017         .irq_mask               = irq_chip_mask_parent,
1018         .irq_unmask             = irq_chip_unmask_parent,
1019         .irq_eoi                = timer_irq_eoi,
1020         .irq_set_type           = irq_chip_set_type_parent,
1021         .irq_set_vcpu_affinity  = timer_irq_set_vcpu_affinity,
1022         .irq_set_irqchip_state  = timer_irq_set_irqchip_state,
1023 };
1024
1025 static int timer_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
1026                                   unsigned int nr_irqs, void *arg)
1027 {
1028         irq_hw_number_t hwirq = (uintptr_t)arg;
1029
1030         return irq_domain_set_hwirq_and_chip(domain, virq, hwirq,
1031                                              &timer_chip, NULL);
1032 }
1033
1034 static void timer_irq_domain_free(struct irq_domain *domain, unsigned int virq,
1035                                   unsigned int nr_irqs)
1036 {
1037 }
1038
1039 static const struct irq_domain_ops timer_domain_ops = {
1040         .alloc  = timer_irq_domain_alloc,
1041         .free   = timer_irq_domain_free,
1042 };
1043
1044 static struct irq_ops arch_timer_irq_ops = {
1045         .get_input_level = kvm_arch_timer_get_input_level,
1046 };
1047
1048 static void kvm_irq_fixup_flags(unsigned int virq, u32 *flags)
1049 {
1050         *flags = irq_get_trigger_type(virq);
1051         if (*flags != IRQF_TRIGGER_HIGH && *flags != IRQF_TRIGGER_LOW) {
1052                 kvm_err("Invalid trigger for timer IRQ%d, assuming level low\n",
1053                         virq);
1054                 *flags = IRQF_TRIGGER_LOW;
1055         }
1056 }
1057
1058 static int kvm_irq_init(struct arch_timer_kvm_info *info)
1059 {
1060         struct irq_domain *domain = NULL;
1061
1062         if (info->virtual_irq <= 0) {
1063                 kvm_err("kvm_arch_timer: invalid virtual timer IRQ: %d\n",
1064                         info->virtual_irq);
1065                 return -ENODEV;
1066         }
1067
1068         host_vtimer_irq = info->virtual_irq;
1069         kvm_irq_fixup_flags(host_vtimer_irq, &host_vtimer_irq_flags);
1070
1071         if (kvm_vgic_global_state.no_hw_deactivation) {
1072                 struct fwnode_handle *fwnode;
1073                 struct irq_data *data;
1074
1075                 fwnode = irq_domain_alloc_named_fwnode("kvm-timer");
1076                 if (!fwnode)
1077                         return -ENOMEM;
1078
1079                 /* Assume both vtimer and ptimer in the same parent */
1080                 data = irq_get_irq_data(host_vtimer_irq);
1081                 domain = irq_domain_create_hierarchy(data->domain, 0,
1082                                                      NR_KVM_TIMERS, fwnode,
1083                                                      &timer_domain_ops, NULL);
1084                 if (!domain) {
1085                         irq_domain_free_fwnode(fwnode);
1086                         return -ENOMEM;
1087                 }
1088
1089                 arch_timer_irq_ops.flags |= VGIC_IRQ_SW_RESAMPLE;
1090                 WARN_ON(irq_domain_push_irq(domain, host_vtimer_irq,
1091                                             (void *)TIMER_VTIMER));
1092         }
1093
1094         if (info->physical_irq > 0) {
1095                 host_ptimer_irq = info->physical_irq;
1096                 kvm_irq_fixup_flags(host_ptimer_irq, &host_ptimer_irq_flags);
1097
1098                 if (domain)
1099                         WARN_ON(irq_domain_push_irq(domain, host_ptimer_irq,
1100                                                     (void *)TIMER_PTIMER));
1101         }
1102
1103         return 0;
1104 }
1105
1106 int kvm_timer_hyp_init(bool has_gic)
1107 {
1108         struct arch_timer_kvm_info *info;
1109         int err;
1110
1111         info = arch_timer_get_kvm_info();
1112         timecounter = &info->timecounter;
1113
1114         if (!timecounter->cc) {
1115                 kvm_err("kvm_arch_timer: uninitialized timecounter\n");
1116                 return -ENODEV;
1117         }
1118
1119         err = kvm_irq_init(info);
1120         if (err)
1121                 return err;
1122
1123         /* First, do the virtual EL1 timer irq */
1124
1125         err = request_percpu_irq(host_vtimer_irq, kvm_arch_timer_handler,
1126                                  "kvm guest vtimer", kvm_get_running_vcpus());
1127         if (err) {
1128                 kvm_err("kvm_arch_timer: can't request vtimer interrupt %d (%d)\n",
1129                         host_vtimer_irq, err);
1130                 return err;
1131         }
1132
1133         if (has_gic) {
1134                 err = irq_set_vcpu_affinity(host_vtimer_irq,
1135                                             kvm_get_running_vcpus());
1136                 if (err) {
1137                         kvm_err("kvm_arch_timer: error setting vcpu affinity\n");
1138                         goto out_free_irq;
1139                 }
1140
1141                 static_branch_enable(&has_gic_active_state);
1142         }
1143
1144         kvm_debug("virtual timer IRQ%d\n", host_vtimer_irq);
1145
1146         /* Now let's do the physical EL1 timer irq */
1147
1148         if (info->physical_irq > 0) {
1149                 err = request_percpu_irq(host_ptimer_irq, kvm_arch_timer_handler,
1150                                          "kvm guest ptimer", kvm_get_running_vcpus());
1151                 if (err) {
1152                         kvm_err("kvm_arch_timer: can't request ptimer interrupt %d (%d)\n",
1153                                 host_ptimer_irq, err);
1154                         return err;
1155                 }
1156
1157                 if (has_gic) {
1158                         err = irq_set_vcpu_affinity(host_ptimer_irq,
1159                                                     kvm_get_running_vcpus());
1160                         if (err) {
1161                                 kvm_err("kvm_arch_timer: error setting vcpu affinity\n");
1162                                 goto out_free_irq;
1163                         }
1164                 }
1165
1166                 kvm_debug("physical timer IRQ%d\n", host_ptimer_irq);
1167         } else if (has_vhe()) {
1168                 kvm_err("kvm_arch_timer: invalid physical timer IRQ: %d\n",
1169                         info->physical_irq);
1170                 err = -ENODEV;
1171                 goto out_free_irq;
1172         }
1173
1174         cpuhp_setup_state(CPUHP_AP_KVM_ARM_TIMER_STARTING,
1175                           "kvm/arm/timer:starting", kvm_timer_starting_cpu,
1176                           kvm_timer_dying_cpu);
1177         return 0;
1178 out_free_irq:
1179         free_percpu_irq(host_vtimer_irq, kvm_get_running_vcpus());
1180         return err;
1181 }
1182
1183 void kvm_timer_vcpu_terminate(struct kvm_vcpu *vcpu)
1184 {
1185         struct arch_timer_cpu *timer = vcpu_timer(vcpu);
1186
1187         soft_timer_cancel(&timer->bg_timer);
1188 }
1189
1190 static bool timer_irqs_are_valid(struct kvm_vcpu *vcpu)
1191 {
1192         int vtimer_irq, ptimer_irq;
1193         int i, ret;
1194
1195         vtimer_irq = vcpu_vtimer(vcpu)->irq.irq;
1196         ret = kvm_vgic_set_owner(vcpu, vtimer_irq, vcpu_vtimer(vcpu));
1197         if (ret)
1198                 return false;
1199
1200         ptimer_irq = vcpu_ptimer(vcpu)->irq.irq;
1201         ret = kvm_vgic_set_owner(vcpu, ptimer_irq, vcpu_ptimer(vcpu));
1202         if (ret)
1203                 return false;
1204
1205         kvm_for_each_vcpu(i, vcpu, vcpu->kvm) {
1206                 if (vcpu_vtimer(vcpu)->irq.irq != vtimer_irq ||
1207                     vcpu_ptimer(vcpu)->irq.irq != ptimer_irq)
1208                         return false;
1209         }
1210
1211         return true;
1212 }
1213
1214 bool kvm_arch_timer_get_input_level(int vintid)
1215 {
1216         struct kvm_vcpu *vcpu = kvm_get_running_vcpu();
1217         struct arch_timer_context *timer;
1218
1219         if (vintid == vcpu_vtimer(vcpu)->irq.irq)
1220                 timer = vcpu_vtimer(vcpu);
1221         else if (vintid == vcpu_ptimer(vcpu)->irq.irq)
1222                 timer = vcpu_ptimer(vcpu);
1223         else
1224                 BUG();
1225
1226         return kvm_timer_should_fire(timer);
1227 }
1228
1229 int kvm_timer_enable(struct kvm_vcpu *vcpu)
1230 {
1231         struct arch_timer_cpu *timer = vcpu_timer(vcpu);
1232         struct timer_map map;
1233         int ret;
1234
1235         if (timer->enabled)
1236                 return 0;
1237
1238         /* Without a VGIC we do not map virtual IRQs to physical IRQs */
1239         if (!irqchip_in_kernel(vcpu->kvm))
1240                 goto no_vgic;
1241
1242         /*
1243          * At this stage, we have the guarantee that the vgic is both
1244          * available and initialized.
1245          */
1246         if (!timer_irqs_are_valid(vcpu)) {
1247                 kvm_debug("incorrectly configured timer irqs\n");
1248                 return -EINVAL;
1249         }
1250
1251         get_timer_map(vcpu, &map);
1252
1253         ret = kvm_vgic_map_phys_irq(vcpu,
1254                                     map.direct_vtimer->host_timer_irq,
1255                                     map.direct_vtimer->irq.irq,
1256                                     &arch_timer_irq_ops);
1257         if (ret)
1258                 return ret;
1259
1260         if (map.direct_ptimer) {
1261                 ret = kvm_vgic_map_phys_irq(vcpu,
1262                                             map.direct_ptimer->host_timer_irq,
1263                                             map.direct_ptimer->irq.irq,
1264                                             &arch_timer_irq_ops);
1265         }
1266
1267         if (ret)
1268                 return ret;
1269
1270 no_vgic:
1271         timer->enabled = 1;
1272         return 0;
1273 }
1274
1275 /*
1276  * On VHE system, we only need to configure the EL2 timer trap register once,
1277  * not for every world switch.
1278  * The host kernel runs at EL2 with HCR_EL2.TGE == 1,
1279  * and this makes those bits have no effect for the host kernel execution.
1280  */
1281 void kvm_timer_init_vhe(void)
1282 {
1283         /* When HCR_EL2.E2H ==1, EL1PCEN and EL1PCTEN are shifted by 10 */
1284         u32 cnthctl_shift = 10;
1285         u64 val;
1286
1287         /*
1288          * VHE systems allow the guest direct access to the EL1 physical
1289          * timer/counter.
1290          */
1291         val = read_sysreg(cnthctl_el2);
1292         val |= (CNTHCTL_EL1PCEN << cnthctl_shift);
1293         val |= (CNTHCTL_EL1PCTEN << cnthctl_shift);
1294         write_sysreg(val, cnthctl_el2);
1295 }
1296
1297 static void set_timer_irqs(struct kvm *kvm, int vtimer_irq, int ptimer_irq)
1298 {
1299         struct kvm_vcpu *vcpu;
1300         int i;
1301
1302         kvm_for_each_vcpu(i, vcpu, kvm) {
1303                 vcpu_vtimer(vcpu)->irq.irq = vtimer_irq;
1304                 vcpu_ptimer(vcpu)->irq.irq = ptimer_irq;
1305         }
1306 }
1307
1308 int kvm_arm_timer_set_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr)
1309 {
1310         int __user *uaddr = (int __user *)(long)attr->addr;
1311         struct arch_timer_context *vtimer = vcpu_vtimer(vcpu);
1312         struct arch_timer_context *ptimer = vcpu_ptimer(vcpu);
1313         int irq;
1314
1315         if (!irqchip_in_kernel(vcpu->kvm))
1316                 return -EINVAL;
1317
1318         if (get_user(irq, uaddr))
1319                 return -EFAULT;
1320
1321         if (!(irq_is_ppi(irq)))
1322                 return -EINVAL;
1323
1324         if (vcpu->arch.timer_cpu.enabled)
1325                 return -EBUSY;
1326
1327         switch (attr->attr) {
1328         case KVM_ARM_VCPU_TIMER_IRQ_VTIMER:
1329                 set_timer_irqs(vcpu->kvm, irq, ptimer->irq.irq);
1330                 break;
1331         case KVM_ARM_VCPU_TIMER_IRQ_PTIMER:
1332                 set_timer_irqs(vcpu->kvm, vtimer->irq.irq, irq);
1333                 break;
1334         default:
1335                 return -ENXIO;
1336         }
1337
1338         return 0;
1339 }
1340
1341 int kvm_arm_timer_get_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr)
1342 {
1343         int __user *uaddr = (int __user *)(long)attr->addr;
1344         struct arch_timer_context *timer;
1345         int irq;
1346
1347         switch (attr->attr) {
1348         case KVM_ARM_VCPU_TIMER_IRQ_VTIMER:
1349                 timer = vcpu_vtimer(vcpu);
1350                 break;
1351         case KVM_ARM_VCPU_TIMER_IRQ_PTIMER:
1352                 timer = vcpu_ptimer(vcpu);
1353                 break;
1354         default:
1355                 return -ENXIO;
1356         }
1357
1358         irq = timer->irq.irq;
1359         return put_user(irq, uaddr);
1360 }
1361
1362 int kvm_arm_timer_has_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr)
1363 {
1364         switch (attr->attr) {
1365         case KVM_ARM_VCPU_TIMER_IRQ_VTIMER:
1366         case KVM_ARM_VCPU_TIMER_IRQ_PTIMER:
1367                 return 0;
1368         }
1369
1370         return -ENXIO;
1371 }