1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (C) 2019 Western Digital Corporation or its affiliates. 4 * 5 * Authors: 6 * Anup Patel <anup.patel@wdc.com> 7 */ 8 9 #include <linux/bitops.h> 10 #include <linux/entry-kvm.h> 11 #include <linux/errno.h> 12 #include <linux/err.h> 13 #include <linux/kdebug.h> 14 #include <linux/module.h> 15 #include <linux/percpu.h> 16 #include <linux/vmalloc.h> 17 #include <linux/sched/signal.h> 18 #include <linux/fs.h> 19 #include <linux/kvm_host.h> 20 #include <asm/csr.h> 21 #include <asm/cacheflush.h> 22 #include <asm/kvm_vcpu_vector.h> 23 24 const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = { 25 KVM_GENERIC_VCPU_STATS(), 26 STATS_DESC_COUNTER(VCPU, ecall_exit_stat), 27 STATS_DESC_COUNTER(VCPU, wfi_exit_stat), 28 STATS_DESC_COUNTER(VCPU, mmio_exit_user), 29 STATS_DESC_COUNTER(VCPU, mmio_exit_kernel), 30 STATS_DESC_COUNTER(VCPU, csr_exit_user), 31 STATS_DESC_COUNTER(VCPU, csr_exit_kernel), 32 STATS_DESC_COUNTER(VCPU, signal_exits), 33 STATS_DESC_COUNTER(VCPU, exits) 34 }; 35 36 const struct kvm_stats_header kvm_vcpu_stats_header = { 37 .name_size = KVM_STATS_NAME_SIZE, 38 .num_desc = ARRAY_SIZE(kvm_vcpu_stats_desc), 39 .id_offset = sizeof(struct kvm_stats_header), 40 .desc_offset = sizeof(struct kvm_stats_header) + KVM_STATS_NAME_SIZE, 41 .data_offset = sizeof(struct kvm_stats_header) + KVM_STATS_NAME_SIZE + 42 sizeof(kvm_vcpu_stats_desc), 43 }; 44 45 static void kvm_riscv_reset_vcpu(struct kvm_vcpu *vcpu) 46 { 47 struct kvm_vcpu_csr *csr = &vcpu->arch.guest_csr; 48 struct kvm_vcpu_csr *reset_csr = &vcpu->arch.guest_reset_csr; 49 struct kvm_cpu_context *cntx = &vcpu->arch.guest_context; 50 struct kvm_cpu_context *reset_cntx = &vcpu->arch.guest_reset_context; 51 bool loaded; 52 53 /** 54 * The preemption should be disabled here because it races with 55 * kvm_sched_out/kvm_sched_in(called from preempt notifiers) which 56 * also calls vcpu_load/put. 57 */ 58 get_cpu(); 59 loaded = (vcpu->cpu != -1); 60 if (loaded) 61 kvm_arch_vcpu_put(vcpu); 62 63 vcpu->arch.last_exit_cpu = -1; 64 65 memcpy(csr, reset_csr, sizeof(*csr)); 66 67 memcpy(cntx, reset_cntx, sizeof(*cntx)); 68 69 kvm_riscv_vcpu_fp_reset(vcpu); 70 71 kvm_riscv_vcpu_vector_reset(vcpu); 72 73 kvm_riscv_vcpu_timer_reset(vcpu); 74 75 kvm_riscv_vcpu_aia_reset(vcpu); 76 77 bitmap_zero(vcpu->arch.irqs_pending, KVM_RISCV_VCPU_NR_IRQS); 78 bitmap_zero(vcpu->arch.irqs_pending_mask, KVM_RISCV_VCPU_NR_IRQS); 79 80 kvm_riscv_vcpu_pmu_reset(vcpu); 81 82 vcpu->arch.hfence_head = 0; 83 vcpu->arch.hfence_tail = 0; 84 memset(vcpu->arch.hfence_queue, 0, sizeof(vcpu->arch.hfence_queue)); 85 86 /* Reset the guest CSRs for hotplug usecase */ 87 if (loaded) 88 kvm_arch_vcpu_load(vcpu, smp_processor_id()); 89 put_cpu(); 90 } 91 92 int kvm_arch_vcpu_precreate(struct kvm *kvm, unsigned int id) 93 { 94 return 0; 95 } 96 97 int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu) 98 { 99 int rc; 100 struct kvm_cpu_context *cntx; 101 struct kvm_vcpu_csr *reset_csr = &vcpu->arch.guest_reset_csr; 102 103 /* Mark this VCPU never ran */ 104 vcpu->arch.ran_atleast_once = false; 105 vcpu->arch.mmu_page_cache.gfp_zero = __GFP_ZERO; 106 bitmap_zero(vcpu->arch.isa, RISCV_ISA_EXT_MAX); 107 108 /* Setup ISA features available to VCPU */ 109 kvm_riscv_vcpu_setup_isa(vcpu); 110 111 /* Setup vendor, arch, and implementation details */ 112 vcpu->arch.mvendorid = sbi_get_mvendorid(); 113 vcpu->arch.marchid = sbi_get_marchid(); 114 vcpu->arch.mimpid = sbi_get_mimpid(); 115 116 /* Setup VCPU hfence queue */ 117 spin_lock_init(&vcpu->arch.hfence_lock); 118 119 /* Setup reset state of shadow SSTATUS and HSTATUS CSRs */ 120 cntx = &vcpu->arch.guest_reset_context; 121 cntx->sstatus = SR_SPP | SR_SPIE; 122 cntx->hstatus = 0; 123 cntx->hstatus |= HSTATUS_VTW; 124 cntx->hstatus |= HSTATUS_SPVP; 125 cntx->hstatus |= HSTATUS_SPV; 126 127 if (kvm_riscv_vcpu_alloc_vector_context(vcpu, cntx)) 128 return -ENOMEM; 129 130 /* By default, make CY, TM, and IR counters accessible in VU mode */ 131 reset_csr->scounteren = 0x7; 132 133 /* Setup VCPU timer */ 134 kvm_riscv_vcpu_timer_init(vcpu); 135 136 /* setup performance monitoring */ 137 kvm_riscv_vcpu_pmu_init(vcpu); 138 139 /* Setup VCPU AIA */ 140 rc = kvm_riscv_vcpu_aia_init(vcpu); 141 if (rc) 142 return rc; 143 144 /* Reset VCPU */ 145 kvm_riscv_reset_vcpu(vcpu); 146 147 return 0; 148 } 149 150 void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu) 151 { 152 /** 153 * vcpu with id 0 is the designated boot cpu. 154 * Keep all vcpus with non-zero id in power-off state so that 155 * they can be brought up using SBI HSM extension. 156 */ 157 if (vcpu->vcpu_idx != 0) 158 kvm_riscv_vcpu_power_off(vcpu); 159 } 160 161 void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu) 162 { 163 /* Cleanup VCPU AIA context */ 164 kvm_riscv_vcpu_aia_deinit(vcpu); 165 166 /* Cleanup VCPU timer */ 167 kvm_riscv_vcpu_timer_deinit(vcpu); 168 169 kvm_riscv_vcpu_pmu_deinit(vcpu); 170 171 /* Free unused pages pre-allocated for G-stage page table mappings */ 172 kvm_mmu_free_memory_cache(&vcpu->arch.mmu_page_cache); 173 174 /* Free vector context space for host and guest kernel */ 175 kvm_riscv_vcpu_free_vector_context(vcpu); 176 } 177 178 int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu) 179 { 180 return kvm_riscv_vcpu_timer_pending(vcpu); 181 } 182 183 void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu) 184 { 185 kvm_riscv_aia_wakeon_hgei(vcpu, true); 186 } 187 188 void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu) 189 { 190 kvm_riscv_aia_wakeon_hgei(vcpu, false); 191 } 192 193 int kvm_arch_vcpu_runnable(struct kvm_vcpu *vcpu) 194 { 195 return (kvm_riscv_vcpu_has_interrupts(vcpu, -1UL) && 196 !vcpu->arch.power_off && !vcpu->arch.pause); 197 } 198 199 int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu) 200 { 201 return kvm_vcpu_exiting_guest_mode(vcpu) == IN_GUEST_MODE; 202 } 203 204 bool kvm_arch_vcpu_in_kernel(struct kvm_vcpu *vcpu) 205 { 206 return (vcpu->arch.guest_context.sstatus & SR_SPP) ? true : false; 207 } 208 209 vm_fault_t kvm_arch_vcpu_fault(struct kvm_vcpu *vcpu, struct vm_fault *vmf) 210 { 211 return VM_FAULT_SIGBUS; 212 } 213 214 long kvm_arch_vcpu_async_ioctl(struct file *filp, 215 unsigned int ioctl, unsigned long arg) 216 { 217 struct kvm_vcpu *vcpu = filp->private_data; 218 void __user *argp = (void __user *)arg; 219 220 if (ioctl == KVM_INTERRUPT) { 221 struct kvm_interrupt irq; 222 223 if (copy_from_user(&irq, argp, sizeof(irq))) 224 return -EFAULT; 225 226 if (irq.irq == KVM_INTERRUPT_SET) 227 return kvm_riscv_vcpu_set_interrupt(vcpu, IRQ_VS_EXT); 228 else 229 return kvm_riscv_vcpu_unset_interrupt(vcpu, IRQ_VS_EXT); 230 } 231 232 return -ENOIOCTLCMD; 233 } 234 235 long kvm_arch_vcpu_ioctl(struct file *filp, 236 unsigned int ioctl, unsigned long arg) 237 { 238 struct kvm_vcpu *vcpu = filp->private_data; 239 void __user *argp = (void __user *)arg; 240 long r = -EINVAL; 241 242 switch (ioctl) { 243 case KVM_SET_ONE_REG: 244 case KVM_GET_ONE_REG: { 245 struct kvm_one_reg reg; 246 247 r = -EFAULT; 248 if (copy_from_user(®, argp, sizeof(reg))) 249 break; 250 251 if (ioctl == KVM_SET_ONE_REG) 252 r = kvm_riscv_vcpu_set_reg(vcpu, ®); 253 else 254 r = kvm_riscv_vcpu_get_reg(vcpu, ®); 255 break; 256 } 257 case KVM_GET_REG_LIST: { 258 struct kvm_reg_list __user *user_list = argp; 259 struct kvm_reg_list reg_list; 260 unsigned int n; 261 262 r = -EFAULT; 263 if (copy_from_user(®_list, user_list, sizeof(reg_list))) 264 break; 265 n = reg_list.n; 266 reg_list.n = kvm_riscv_vcpu_num_regs(vcpu); 267 if (copy_to_user(user_list, ®_list, sizeof(reg_list))) 268 break; 269 r = -E2BIG; 270 if (n < reg_list.n) 271 break; 272 r = kvm_riscv_vcpu_copy_reg_indices(vcpu, user_list->reg); 273 break; 274 } 275 default: 276 break; 277 } 278 279 return r; 280 } 281 282 int kvm_arch_vcpu_ioctl_get_sregs(struct kvm_vcpu *vcpu, 283 struct kvm_sregs *sregs) 284 { 285 return -EINVAL; 286 } 287 288 int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu, 289 struct kvm_sregs *sregs) 290 { 291 return -EINVAL; 292 } 293 294 int kvm_arch_vcpu_ioctl_get_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu) 295 { 296 return -EINVAL; 297 } 298 299 int kvm_arch_vcpu_ioctl_set_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu) 300 { 301 return -EINVAL; 302 } 303 304 int kvm_arch_vcpu_ioctl_translate(struct kvm_vcpu *vcpu, 305 struct kvm_translation *tr) 306 { 307 return -EINVAL; 308 } 309 310 int kvm_arch_vcpu_ioctl_get_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs) 311 { 312 return -EINVAL; 313 } 314 315 int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs) 316 { 317 return -EINVAL; 318 } 319 320 void kvm_riscv_vcpu_flush_interrupts(struct kvm_vcpu *vcpu) 321 { 322 struct kvm_vcpu_csr *csr = &vcpu->arch.guest_csr; 323 unsigned long mask, val; 324 325 if (READ_ONCE(vcpu->arch.irqs_pending_mask[0])) { 326 mask = xchg_acquire(&vcpu->arch.irqs_pending_mask[0], 0); 327 val = READ_ONCE(vcpu->arch.irqs_pending[0]) & mask; 328 329 csr->hvip &= ~mask; 330 csr->hvip |= val; 331 } 332 333 /* Flush AIA high interrupts */ 334 kvm_riscv_vcpu_aia_flush_interrupts(vcpu); 335 } 336 337 void kvm_riscv_vcpu_sync_interrupts(struct kvm_vcpu *vcpu) 338 { 339 unsigned long hvip; 340 struct kvm_vcpu_arch *v = &vcpu->arch; 341 struct kvm_vcpu_csr *csr = &vcpu->arch.guest_csr; 342 343 /* Read current HVIP and VSIE CSRs */ 344 csr->vsie = csr_read(CSR_VSIE); 345 346 /* Sync-up HVIP.VSSIP bit changes does by Guest */ 347 hvip = csr_read(CSR_HVIP); 348 if ((csr->hvip ^ hvip) & (1UL << IRQ_VS_SOFT)) { 349 if (hvip & (1UL << IRQ_VS_SOFT)) { 350 if (!test_and_set_bit(IRQ_VS_SOFT, 351 v->irqs_pending_mask)) 352 set_bit(IRQ_VS_SOFT, v->irqs_pending); 353 } else { 354 if (!test_and_set_bit(IRQ_VS_SOFT, 355 v->irqs_pending_mask)) 356 clear_bit(IRQ_VS_SOFT, v->irqs_pending); 357 } 358 } 359 360 /* Sync-up AIA high interrupts */ 361 kvm_riscv_vcpu_aia_sync_interrupts(vcpu); 362 363 /* Sync-up timer CSRs */ 364 kvm_riscv_vcpu_timer_sync(vcpu); 365 } 366 367 int kvm_riscv_vcpu_set_interrupt(struct kvm_vcpu *vcpu, unsigned int irq) 368 { 369 /* 370 * We only allow VS-mode software, timer, and external 371 * interrupts when irq is one of the local interrupts 372 * defined by RISC-V privilege specification. 373 */ 374 if (irq < IRQ_LOCAL_MAX && 375 irq != IRQ_VS_SOFT && 376 irq != IRQ_VS_TIMER && 377 irq != IRQ_VS_EXT) 378 return -EINVAL; 379 380 set_bit(irq, vcpu->arch.irqs_pending); 381 smp_mb__before_atomic(); 382 set_bit(irq, vcpu->arch.irqs_pending_mask); 383 384 kvm_vcpu_kick(vcpu); 385 386 return 0; 387 } 388 389 int kvm_riscv_vcpu_unset_interrupt(struct kvm_vcpu *vcpu, unsigned int irq) 390 { 391 /* 392 * We only allow VS-mode software, timer, and external 393 * interrupts when irq is one of the local interrupts 394 * defined by RISC-V privilege specification. 395 */ 396 if (irq < IRQ_LOCAL_MAX && 397 irq != IRQ_VS_SOFT && 398 irq != IRQ_VS_TIMER && 399 irq != IRQ_VS_EXT) 400 return -EINVAL; 401 402 clear_bit(irq, vcpu->arch.irqs_pending); 403 smp_mb__before_atomic(); 404 set_bit(irq, vcpu->arch.irqs_pending_mask); 405 406 return 0; 407 } 408 409 bool kvm_riscv_vcpu_has_interrupts(struct kvm_vcpu *vcpu, u64 mask) 410 { 411 unsigned long ie; 412 413 ie = ((vcpu->arch.guest_csr.vsie & VSIP_VALID_MASK) 414 << VSIP_TO_HVIP_SHIFT) & (unsigned long)mask; 415 ie |= vcpu->arch.guest_csr.vsie & ~IRQ_LOCAL_MASK & 416 (unsigned long)mask; 417 if (READ_ONCE(vcpu->arch.irqs_pending[0]) & ie) 418 return true; 419 420 /* Check AIA high interrupts */ 421 return kvm_riscv_vcpu_aia_has_interrupts(vcpu, mask); 422 } 423 424 void kvm_riscv_vcpu_power_off(struct kvm_vcpu *vcpu) 425 { 426 vcpu->arch.power_off = true; 427 kvm_make_request(KVM_REQ_SLEEP, vcpu); 428 kvm_vcpu_kick(vcpu); 429 } 430 431 void kvm_riscv_vcpu_power_on(struct kvm_vcpu *vcpu) 432 { 433 vcpu->arch.power_off = false; 434 kvm_vcpu_wake_up(vcpu); 435 } 436 437 int kvm_arch_vcpu_ioctl_get_mpstate(struct kvm_vcpu *vcpu, 438 struct kvm_mp_state *mp_state) 439 { 440 if (vcpu->arch.power_off) 441 mp_state->mp_state = KVM_MP_STATE_STOPPED; 442 else 443 mp_state->mp_state = KVM_MP_STATE_RUNNABLE; 444 445 return 0; 446 } 447 448 int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu, 449 struct kvm_mp_state *mp_state) 450 { 451 int ret = 0; 452 453 switch (mp_state->mp_state) { 454 case KVM_MP_STATE_RUNNABLE: 455 vcpu->arch.power_off = false; 456 break; 457 case KVM_MP_STATE_STOPPED: 458 kvm_riscv_vcpu_power_off(vcpu); 459 break; 460 default: 461 ret = -EINVAL; 462 } 463 464 return ret; 465 } 466 467 int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu, 468 struct kvm_guest_debug *dbg) 469 { 470 /* TODO; To be implemented later. */ 471 return -EINVAL; 472 } 473 474 static void kvm_riscv_vcpu_update_config(const unsigned long *isa) 475 { 476 u64 henvcfg = 0; 477 478 if (riscv_isa_extension_available(isa, SVPBMT)) 479 henvcfg |= ENVCFG_PBMTE; 480 481 if (riscv_isa_extension_available(isa, SSTC)) 482 henvcfg |= ENVCFG_STCE; 483 484 if (riscv_isa_extension_available(isa, ZICBOM)) 485 henvcfg |= (ENVCFG_CBIE | ENVCFG_CBCFE); 486 487 if (riscv_isa_extension_available(isa, ZICBOZ)) 488 henvcfg |= ENVCFG_CBZE; 489 490 csr_write(CSR_HENVCFG, henvcfg); 491 #ifdef CONFIG_32BIT 492 csr_write(CSR_HENVCFGH, henvcfg >> 32); 493 #endif 494 } 495 496 void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu) 497 { 498 struct kvm_vcpu_csr *csr = &vcpu->arch.guest_csr; 499 500 csr_write(CSR_VSSTATUS, csr->vsstatus); 501 csr_write(CSR_VSIE, csr->vsie); 502 csr_write(CSR_VSTVEC, csr->vstvec); 503 csr_write(CSR_VSSCRATCH, csr->vsscratch); 504 csr_write(CSR_VSEPC, csr->vsepc); 505 csr_write(CSR_VSCAUSE, csr->vscause); 506 csr_write(CSR_VSTVAL, csr->vstval); 507 csr_write(CSR_HVIP, csr->hvip); 508 csr_write(CSR_VSATP, csr->vsatp); 509 510 kvm_riscv_vcpu_update_config(vcpu->arch.isa); 511 512 kvm_riscv_gstage_update_hgatp(vcpu); 513 514 kvm_riscv_vcpu_timer_restore(vcpu); 515 516 kvm_riscv_vcpu_host_fp_save(&vcpu->arch.host_context); 517 kvm_riscv_vcpu_guest_fp_restore(&vcpu->arch.guest_context, 518 vcpu->arch.isa); 519 kvm_riscv_vcpu_host_vector_save(&vcpu->arch.host_context); 520 kvm_riscv_vcpu_guest_vector_restore(&vcpu->arch.guest_context, 521 vcpu->arch.isa); 522 523 kvm_riscv_vcpu_aia_load(vcpu, cpu); 524 525 vcpu->cpu = cpu; 526 } 527 528 void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu) 529 { 530 struct kvm_vcpu_csr *csr = &vcpu->arch.guest_csr; 531 532 vcpu->cpu = -1; 533 534 kvm_riscv_vcpu_aia_put(vcpu); 535 536 kvm_riscv_vcpu_guest_fp_save(&vcpu->arch.guest_context, 537 vcpu->arch.isa); 538 kvm_riscv_vcpu_host_fp_restore(&vcpu->arch.host_context); 539 540 kvm_riscv_vcpu_timer_save(vcpu); 541 kvm_riscv_vcpu_guest_vector_save(&vcpu->arch.guest_context, 542 vcpu->arch.isa); 543 kvm_riscv_vcpu_host_vector_restore(&vcpu->arch.host_context); 544 545 csr->vsstatus = csr_read(CSR_VSSTATUS); 546 csr->vsie = csr_read(CSR_VSIE); 547 csr->vstvec = csr_read(CSR_VSTVEC); 548 csr->vsscratch = csr_read(CSR_VSSCRATCH); 549 csr->vsepc = csr_read(CSR_VSEPC); 550 csr->vscause = csr_read(CSR_VSCAUSE); 551 csr->vstval = csr_read(CSR_VSTVAL); 552 csr->hvip = csr_read(CSR_HVIP); 553 csr->vsatp = csr_read(CSR_VSATP); 554 } 555 556 static void kvm_riscv_check_vcpu_requests(struct kvm_vcpu *vcpu) 557 { 558 struct rcuwait *wait = kvm_arch_vcpu_get_wait(vcpu); 559 560 if (kvm_request_pending(vcpu)) { 561 if (kvm_check_request(KVM_REQ_SLEEP, vcpu)) { 562 kvm_vcpu_srcu_read_unlock(vcpu); 563 rcuwait_wait_event(wait, 564 (!vcpu->arch.power_off) && (!vcpu->arch.pause), 565 TASK_INTERRUPTIBLE); 566 kvm_vcpu_srcu_read_lock(vcpu); 567 568 if (vcpu->arch.power_off || vcpu->arch.pause) { 569 /* 570 * Awaken to handle a signal, request to 571 * sleep again later. 572 */ 573 kvm_make_request(KVM_REQ_SLEEP, vcpu); 574 } 575 } 576 577 if (kvm_check_request(KVM_REQ_VCPU_RESET, vcpu)) 578 kvm_riscv_reset_vcpu(vcpu); 579 580 if (kvm_check_request(KVM_REQ_UPDATE_HGATP, vcpu)) 581 kvm_riscv_gstage_update_hgatp(vcpu); 582 583 if (kvm_check_request(KVM_REQ_FENCE_I, vcpu)) 584 kvm_riscv_fence_i_process(vcpu); 585 586 /* 587 * The generic KVM_REQ_TLB_FLUSH is same as 588 * KVM_REQ_HFENCE_GVMA_VMID_ALL 589 */ 590 if (kvm_check_request(KVM_REQ_HFENCE_GVMA_VMID_ALL, vcpu)) 591 kvm_riscv_hfence_gvma_vmid_all_process(vcpu); 592 593 if (kvm_check_request(KVM_REQ_HFENCE_VVMA_ALL, vcpu)) 594 kvm_riscv_hfence_vvma_all_process(vcpu); 595 596 if (kvm_check_request(KVM_REQ_HFENCE, vcpu)) 597 kvm_riscv_hfence_process(vcpu); 598 } 599 } 600 601 static void kvm_riscv_update_hvip(struct kvm_vcpu *vcpu) 602 { 603 struct kvm_vcpu_csr *csr = &vcpu->arch.guest_csr; 604 605 csr_write(CSR_HVIP, csr->hvip); 606 kvm_riscv_vcpu_aia_update_hvip(vcpu); 607 } 608 609 /* 610 * Actually run the vCPU, entering an RCU extended quiescent state (EQS) while 611 * the vCPU is running. 612 * 613 * This must be noinstr as instrumentation may make use of RCU, and this is not 614 * safe during the EQS. 615 */ 616 static void noinstr kvm_riscv_vcpu_enter_exit(struct kvm_vcpu *vcpu) 617 { 618 guest_state_enter_irqoff(); 619 __kvm_riscv_switch_to(&vcpu->arch); 620 vcpu->arch.last_exit_cpu = vcpu->cpu; 621 guest_state_exit_irqoff(); 622 } 623 624 int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu) 625 { 626 int ret; 627 struct kvm_cpu_trap trap; 628 struct kvm_run *run = vcpu->run; 629 630 /* Mark this VCPU ran at least once */ 631 vcpu->arch.ran_atleast_once = true; 632 633 kvm_vcpu_srcu_read_lock(vcpu); 634 635 switch (run->exit_reason) { 636 case KVM_EXIT_MMIO: 637 /* Process MMIO value returned from user-space */ 638 ret = kvm_riscv_vcpu_mmio_return(vcpu, vcpu->run); 639 break; 640 case KVM_EXIT_RISCV_SBI: 641 /* Process SBI value returned from user-space */ 642 ret = kvm_riscv_vcpu_sbi_return(vcpu, vcpu->run); 643 break; 644 case KVM_EXIT_RISCV_CSR: 645 /* Process CSR value returned from user-space */ 646 ret = kvm_riscv_vcpu_csr_return(vcpu, vcpu->run); 647 break; 648 default: 649 ret = 0; 650 break; 651 } 652 if (ret) { 653 kvm_vcpu_srcu_read_unlock(vcpu); 654 return ret; 655 } 656 657 if (run->immediate_exit) { 658 kvm_vcpu_srcu_read_unlock(vcpu); 659 return -EINTR; 660 } 661 662 vcpu_load(vcpu); 663 664 kvm_sigset_activate(vcpu); 665 666 ret = 1; 667 run->exit_reason = KVM_EXIT_UNKNOWN; 668 while (ret > 0) { 669 /* Check conditions before entering the guest */ 670 ret = xfer_to_guest_mode_handle_work(vcpu); 671 if (ret) 672 continue; 673 ret = 1; 674 675 kvm_riscv_gstage_vmid_update(vcpu); 676 677 kvm_riscv_check_vcpu_requests(vcpu); 678 679 preempt_disable(); 680 681 /* Update AIA HW state before entering guest */ 682 ret = kvm_riscv_vcpu_aia_update(vcpu); 683 if (ret <= 0) { 684 preempt_enable(); 685 continue; 686 } 687 688 local_irq_disable(); 689 690 /* 691 * Ensure we set mode to IN_GUEST_MODE after we disable 692 * interrupts and before the final VCPU requests check. 693 * See the comment in kvm_vcpu_exiting_guest_mode() and 694 * Documentation/virt/kvm/vcpu-requests.rst 695 */ 696 vcpu->mode = IN_GUEST_MODE; 697 698 kvm_vcpu_srcu_read_unlock(vcpu); 699 smp_mb__after_srcu_read_unlock(); 700 701 /* 702 * We might have got VCPU interrupts updated asynchronously 703 * so update it in HW. 704 */ 705 kvm_riscv_vcpu_flush_interrupts(vcpu); 706 707 /* Update HVIP CSR for current CPU */ 708 kvm_riscv_update_hvip(vcpu); 709 710 if (ret <= 0 || 711 kvm_riscv_gstage_vmid_ver_changed(&vcpu->kvm->arch.vmid) || 712 kvm_request_pending(vcpu) || 713 xfer_to_guest_mode_work_pending()) { 714 vcpu->mode = OUTSIDE_GUEST_MODE; 715 local_irq_enable(); 716 preempt_enable(); 717 kvm_vcpu_srcu_read_lock(vcpu); 718 continue; 719 } 720 721 /* 722 * Cleanup stale TLB enteries 723 * 724 * Note: This should be done after G-stage VMID has been 725 * updated using kvm_riscv_gstage_vmid_ver_changed() 726 */ 727 kvm_riscv_local_tlb_sanitize(vcpu); 728 729 guest_timing_enter_irqoff(); 730 731 kvm_riscv_vcpu_enter_exit(vcpu); 732 733 vcpu->mode = OUTSIDE_GUEST_MODE; 734 vcpu->stat.exits++; 735 736 /* 737 * Save SCAUSE, STVAL, HTVAL, and HTINST because we might 738 * get an interrupt between __kvm_riscv_switch_to() and 739 * local_irq_enable() which can potentially change CSRs. 740 */ 741 trap.sepc = vcpu->arch.guest_context.sepc; 742 trap.scause = csr_read(CSR_SCAUSE); 743 trap.stval = csr_read(CSR_STVAL); 744 trap.htval = csr_read(CSR_HTVAL); 745 trap.htinst = csr_read(CSR_HTINST); 746 747 /* Syncup interrupts state with HW */ 748 kvm_riscv_vcpu_sync_interrupts(vcpu); 749 750 /* 751 * We must ensure that any pending interrupts are taken before 752 * we exit guest timing so that timer ticks are accounted as 753 * guest time. Transiently unmask interrupts so that any 754 * pending interrupts are taken. 755 * 756 * There's no barrier which ensures that pending interrupts are 757 * recognised, so we just hope that the CPU takes any pending 758 * interrupts between the enable and disable. 759 */ 760 local_irq_enable(); 761 local_irq_disable(); 762 763 guest_timing_exit_irqoff(); 764 765 local_irq_enable(); 766 767 preempt_enable(); 768 769 kvm_vcpu_srcu_read_lock(vcpu); 770 771 ret = kvm_riscv_vcpu_exit(vcpu, run, &trap); 772 } 773 774 kvm_sigset_deactivate(vcpu); 775 776 vcpu_put(vcpu); 777 778 kvm_vcpu_srcu_read_unlock(vcpu); 779 780 return ret; 781 } 782