virt/kvm/arm/vgic/vgic-v2.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2015, 2016 ARM Ltd.
   4  */
   5
   6 #include <linux/irqchip/arm-gic.h>
   7 #include <linux/kvm.h>
   8 #include <linux/kvm_host.h>
   9 #include <kvm/arm_vgic.h>
  10 #include <asm/kvm_mmu.h>
  11
  12 #include "vgic.h"
  13
  14 static inline void vgic_v2_write_lr(int lr, u32 val)
  15 {
  16         void __iomem *base = kvm_vgic_global_state.vctrl_base;
  17
  18         writel_relaxed(val, base + GICH_LR0 + (lr * 4));
  19 }
  20
  21 void vgic_v2_init_lrs(void)
  22 {
  23         int i;
  24
  25         for (i = 0; i < kvm_vgic_global_state.nr_lr; i++)
  26                 vgic_v2_write_lr(i, 0);
  27 }
  28
  29 void vgic_v2_set_underflow(struct kvm_vcpu *vcpu)
  30 {
  31         struct vgic_v2_cpu_if *cpuif = &vcpu->arch.vgic_cpu.vgic_v2;
  32
  33         cpuif->vgic_hcr |= GICH_HCR_UIE;
  34 }
  35
  36 static bool lr_signals_eoi_mi(u32 lr_val)
  37 {
  38         return !(lr_val & GICH_LR_STATE) && (lr_val & GICH_LR_EOI) &&
  39                !(lr_val & GICH_LR_HW);
  40 }
  41
  42 /*
  43  * transfer the content of the LRs back into the corresponding ap_list:
  44  * - active bit is transferred as is
  45  * - pending bit is
  46  *   - transferred as is in case of edge sensitive IRQs
  47  *   - set to the line-level (resample time) for level sensitive IRQs
  48  */
  49 void vgic_v2_fold_lr_state(struct kvm_vcpu *vcpu)
  50 {
  51         struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
  52         struct vgic_v2_cpu_if *cpuif = &vgic_cpu->vgic_v2;
  53         int lr;
  54
  55         DEBUG_SPINLOCK_BUG_ON(!irqs_disabled());
  56
  57         cpuif->vgic_hcr &= ~GICH_HCR_UIE;
  58
  59         for (lr = 0; lr < vgic_cpu->used_lrs; lr++) {
  60                 u32 val = cpuif->vgic_lr[lr];
  61                 u32 cpuid, intid = val & GICH_LR_VIRTUALID;
  62                 struct vgic_irq *irq;
  63
  64                 /* Extract the source vCPU id from the LR */
  65                 cpuid = val & GICH_LR_PHYSID_CPUID;
  66                 cpuid >>= GICH_LR_PHYSID_CPUID_SHIFT;
  67                 cpuid &= 7;
  68
  69                 /* Notify fds when the guest EOI'ed a level-triggered SPI */
  70                 if (lr_signals_eoi_mi(val) && vgic_valid_spi(vcpu->kvm, intid))
  71                         kvm_notify_acked_irq(vcpu->kvm, 0,
  72                                              intid - VGIC_NR_PRIVATE_IRQS);
  73
  74                 irq = vgic_get_irq(vcpu->kvm, vcpu, intid);
  75
  76                 raw_spin_lock(&irq->irq_lock);
  77
  78                 /* Always preserve the active bit */
  79                 irq->active = !!(val & GICH_LR_ACTIVE_BIT);
  80
  81                 if (irq->active && vgic_irq_is_sgi(intid))
  82                         irq->active_source = cpuid;
  83
  84                 /* Edge is the only case where we preserve the pending bit */
  85                 if (irq->config == VGIC_CONFIG_EDGE &&
  86                     (val & GICH_LR_PENDING_BIT)) {
  87                         irq->pending_latch = true;
  88
  89                         if (vgic_irq_is_sgi(intid))
  90                                 irq->source |= (1 << cpuid);
  91                 }
  92
  93                 /*
  94                  * Clear soft pending state when level irqs have been acked.
  95                  */
  96                 if (irq->config == VGIC_CONFIG_LEVEL && !(val & GICH_LR_STATE))
  97                         irq->pending_latch = false;
  98
  99                 /*
 100                  * Level-triggered mapped IRQs are special because we only
 101                  * observe rising edges as input to the VGIC.
 102                  *
 103                  * If the guest never acked the interrupt we have to sample
 104                  * the physical line and set the line level, because the
 105                  * device state could have changed or we simply need to
 106                  * process the still pending interrupt later.
 107                  *
 108                  * If this causes us to lower the level, we have to also clear
 109                  * the physical active state, since we will otherwise never be
 110                  * told when the interrupt becomes asserted again.
 111                  */
 112                 if (vgic_irq_is_mapped_level(irq) && (val & GICH_LR_PENDING_BIT)) {
 113                         irq->line_level = vgic_get_phys_line_level(irq);
 114
 115                         if (!irq->line_level)
 116                                 vgic_irq_set_phys_active(irq, false);
 117                 }
 118
 119                 raw_spin_unlock(&irq->irq_lock);
 120                 vgic_put_irq(vcpu->kvm, irq);
 121         }
 122
 123         vgic_cpu->used_lrs = 0;
 124 }
 125
 126 /*
 127  * Populates the particular LR with the state of a given IRQ:
 128  * - for an edge sensitive IRQ the pending state is cleared in struct vgic_irq
 129  * - for a level sensitive IRQ the pending state value is unchanged;
 130  *   it is dictated directly by the input level
 131  *
 132  * If @irq describes an SGI with multiple sources, we choose the
 133  * lowest-numbered source VCPU and clear that bit in the source bitmap.
 134  *
 135  * The irq_lock must be held by the caller.
 136  */
 137 void vgic_v2_populate_lr(struct kvm_vcpu *vcpu, struct vgic_irq *irq, int lr)
 138 {
 139         u32 val = irq->intid;
 140         bool allow_pending = true;
 141
 142         if (irq->active) {
 143                 val |= GICH_LR_ACTIVE_BIT;
 144                 if (vgic_irq_is_sgi(irq->intid))
 145                         val |= irq->active_source << GICH_LR_PHYSID_CPUID_SHIFT;
 146                 if (vgic_irq_is_multi_sgi(irq)) {
 147                         allow_pending = false;
 148                         val |= GICH_LR_EOI;
 149                 }
 150         }
 151
 152         if (irq->group)
 153                 val |= GICH_LR_GROUP1;
 154
 155         if (irq->hw) {
 156                 val |= GICH_LR_HW;
 157                 val |= irq->hwintid << GICH_LR_PHYSID_CPUID_SHIFT;
 158                 /*
 159                  * Never set pending+active on a HW interrupt, as the
 160                  * pending state is kept at the physical distributor
 161                  * level.
 162                  */
 163                 if (irq->active)
 164                         allow_pending = false;
 165         } else {
 166                 if (irq->config == VGIC_CONFIG_LEVEL) {
 167                         val |= GICH_LR_EOI;
 168
 169                         /*
 170                          * Software resampling doesn't work very well
 171                          * if we allow P+A, so let's not do that.
 172                          */
 173                         if (irq->active)
 174                                 allow_pending = false;
 175                 }
 176         }
 177
 178         if (allow_pending && irq_is_pending(irq)) {
 179                 val |= GICH_LR_PENDING_BIT;
 180
 181                 if (irq->config == VGIC_CONFIG_EDGE)
 182                         irq->pending_latch = false;
 183
 184                 if (vgic_irq_is_sgi(irq->intid)) {
 185                         u32 src = ffs(irq->source);
 186
 187                         if (WARN_RATELIMIT(!src, "No SGI source for INTID %d\n",
 188                                            irq->intid))
 189                                 return;
 190
 191                         val |= (src - 1) << GICH_LR_PHYSID_CPUID_SHIFT;
 192                         irq->source &= ~(1 << (src - 1));
 193                         if (irq->source) {
 194                                 irq->pending_latch = true;
 195                                 val |= GICH_LR_EOI;
 196                         }
 197                 }
 198         }
 199
 200         /*
 201          * Level-triggered mapped IRQs are special because we only observe
 202          * rising edges as input to the VGIC.  We therefore lower the line
 203          * level here, so that we can take new virtual IRQs.  See
 204          * vgic_v2_fold_lr_state for more info.
 205          */
 206         if (vgic_irq_is_mapped_level(irq) && (val & GICH_LR_PENDING_BIT))
 207                 irq->line_level = false;
 208
 209         /* The GICv2 LR only holds five bits of priority. */
 210         val |= (irq->priority >> 3) << GICH_LR_PRIORITY_SHIFT;
 211
 212         vcpu->arch.vgic_cpu.vgic_v2.vgic_lr[lr] = val;
 213 }
 214
 215 void vgic_v2_clear_lr(struct kvm_vcpu *vcpu, int lr)
 216 {
 217         vcpu->arch.vgic_cpu.vgic_v2.vgic_lr[lr] = 0;
 218 }
 219
 220 void vgic_v2_set_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcrp)
 221 {
 222         struct vgic_v2_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v2;
 223         u32 vmcr;
 224
 225         vmcr = (vmcrp->grpen0 << GICH_VMCR_ENABLE_GRP0_SHIFT) &
 226                 GICH_VMCR_ENABLE_GRP0_MASK;
 227         vmcr |= (vmcrp->grpen1 << GICH_VMCR_ENABLE_GRP1_SHIFT) &
 228                 GICH_VMCR_ENABLE_GRP1_MASK;
 229         vmcr |= (vmcrp->ackctl << GICH_VMCR_ACK_CTL_SHIFT) &
 230                 GICH_VMCR_ACK_CTL_MASK;
 231         vmcr |= (vmcrp->fiqen << GICH_VMCR_FIQ_EN_SHIFT) &
 232                 GICH_VMCR_FIQ_EN_MASK;
 233         vmcr |= (vmcrp->cbpr << GICH_VMCR_CBPR_SHIFT) &
 234                 GICH_VMCR_CBPR_MASK;
 235         vmcr |= (vmcrp->eoim << GICH_VMCR_EOI_MODE_SHIFT) &
 236                 GICH_VMCR_EOI_MODE_MASK;
 237         vmcr |= (vmcrp->abpr << GICH_VMCR_ALIAS_BINPOINT_SHIFT) &
 238                 GICH_VMCR_ALIAS_BINPOINT_MASK;
 239         vmcr |= (vmcrp->bpr << GICH_VMCR_BINPOINT_SHIFT) &
 240                 GICH_VMCR_BINPOINT_MASK;
 241         vmcr |= ((vmcrp->pmr >> GICV_PMR_PRIORITY_SHIFT) <<
 242                  GICH_VMCR_PRIMASK_SHIFT) & GICH_VMCR_PRIMASK_MASK;
 243
 244         cpu_if->vgic_vmcr = vmcr;
 245 }
 246
 247 void vgic_v2_get_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcrp)
 248 {
 249         struct vgic_v2_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v2;
 250         u32 vmcr;
 251
 252         vmcr = cpu_if->vgic_vmcr;
 253
 254         vmcrp->grpen0 = (vmcr & GICH_VMCR_ENABLE_GRP0_MASK) >>
 255                 GICH_VMCR_ENABLE_GRP0_SHIFT;
 256         vmcrp->grpen1 = (vmcr & GICH_VMCR_ENABLE_GRP1_MASK) >>
 257                 GICH_VMCR_ENABLE_GRP1_SHIFT;
 258         vmcrp->ackctl = (vmcr & GICH_VMCR_ACK_CTL_MASK) >>
 259                 GICH_VMCR_ACK_CTL_SHIFT;
 260         vmcrp->fiqen = (vmcr & GICH_VMCR_FIQ_EN_MASK) >>
 261                 GICH_VMCR_FIQ_EN_SHIFT;
 262         vmcrp->cbpr = (vmcr & GICH_VMCR_CBPR_MASK) >>
 263                 GICH_VMCR_CBPR_SHIFT;
 264         vmcrp->eoim = (vmcr & GICH_VMCR_EOI_MODE_MASK) >>
 265                 GICH_VMCR_EOI_MODE_SHIFT;
 266
 267         vmcrp->abpr = (vmcr & GICH_VMCR_ALIAS_BINPOINT_MASK) >>
 268                         GICH_VMCR_ALIAS_BINPOINT_SHIFT;
 269         vmcrp->bpr  = (vmcr & GICH_VMCR_BINPOINT_MASK) >>
 270                         GICH_VMCR_BINPOINT_SHIFT;
 271         vmcrp->pmr  = ((vmcr & GICH_VMCR_PRIMASK_MASK) >>
 272                         GICH_VMCR_PRIMASK_SHIFT) << GICV_PMR_PRIORITY_SHIFT;
 273 }
 274
 275 void vgic_v2_enable(struct kvm_vcpu *vcpu)
 276 {
 277         /*
 278          * By forcing VMCR to zero, the GIC will restore the binary
 279          * points to their reset values. Anything else resets to zero
 280          * anyway.
 281          */
 282         vcpu->arch.vgic_cpu.vgic_v2.vgic_vmcr = 0;
 283
 284         /* Get the show on the road... */
 285         vcpu->arch.vgic_cpu.vgic_v2.vgic_hcr = GICH_HCR_EN;
 286 }
 287
 288 /* check for overlapping regions and for regions crossing the end of memory */
 289 static bool vgic_v2_check_base(gpa_t dist_base, gpa_t cpu_base)
 290 {
 291         if (dist_base + KVM_VGIC_V2_DIST_SIZE < dist_base)
 292                 return false;
 293         if (cpu_base + KVM_VGIC_V2_CPU_SIZE < cpu_base)
 294                 return false;
 295
 296         if (dist_base + KVM_VGIC_V2_DIST_SIZE <= cpu_base)
 297                 return true;
 298         if (cpu_base + KVM_VGIC_V2_CPU_SIZE <= dist_base)
 299                 return true;
 300
 301         return false;
 302 }
 303
 304 int vgic_v2_map_resources(struct kvm *kvm)
 305 {
 306         struct vgic_dist *dist = &kvm->arch.vgic;
 307         int ret = 0;
 308
 309         if (vgic_ready(kvm))
 310                 goto out;
 311
 312         if (IS_VGIC_ADDR_UNDEF(dist->vgic_dist_base) ||
 313             IS_VGIC_ADDR_UNDEF(dist->vgic_cpu_base)) {
 314                 kvm_err("Need to set vgic cpu and dist addresses first\n");
 315                 ret = -ENXIO;
 316                 goto out;
 317         }
 318
 319         if (!vgic_v2_check_base(dist->vgic_dist_base, dist->vgic_cpu_base)) {
 320                 kvm_err("VGIC CPU and dist frames overlap\n");
 321                 ret = -EINVAL;
 322                 goto out;
 323         }
 324
 325         /*
 326          * Initialize the vgic if this hasn't already been done on demand by
 327          * accessing the vgic state from userspace.
 328          */
 329         ret = vgic_init(kvm);
 330         if (ret) {
 331                 kvm_err("Unable to initialize VGIC dynamic data structures\n");
 332                 goto out;
 333         }
 334
 335         ret = vgic_register_dist_iodev(kvm, dist->vgic_dist_base, VGIC_V2);
 336         if (ret) {
 337                 kvm_err("Unable to register VGIC MMIO regions\n");
 338                 goto out;
 339         }
 340
 341         if (!static_branch_unlikely(&vgic_v2_cpuif_trap)) {
 342                 ret = kvm_phys_addr_ioremap(kvm, dist->vgic_cpu_base,
 343                                             kvm_vgic_global_state.vcpu_base,
 344                                             KVM_VGIC_V2_CPU_SIZE, true);
 345                 if (ret) {
 346                         kvm_err("Unable to remap VGIC CPU to VCPU\n");
 347                         goto out;
 348                 }
 349         }
 350
 351         dist->ready = true;
 352
 353 out:
 354         return ret;
 355 }
 356
 357 DEFINE_STATIC_KEY_FALSE(vgic_v2_cpuif_trap);
 358
 359 /**
 360  * vgic_v2_probe - probe for a VGICv2 compatible interrupt controller
 361  * @info:       pointer to the GIC description
 362  *
 363  * Returns 0 if the VGICv2 has been probed successfully, returns an error code
 364  * otherwise
 365  */
 366 int vgic_v2_probe(const struct gic_kvm_info *info)
 367 {
 368         int ret;
 369         u32 vtr;
 370
 371         if (!info->vctrl.start) {
 372                 kvm_err("GICH not present in the firmware table\n");
 373                 return -ENXIO;
 374         }
 375
 376         if (!PAGE_ALIGNED(info->vcpu.start) ||
 377             !PAGE_ALIGNED(resource_size(&info->vcpu))) {
 378                 kvm_info("GICV region size/alignment is unsafe, using trapping (reduced performance)\n");
 379
 380                 ret = create_hyp_io_mappings(info->vcpu.start,
 381                                              resource_size(&info->vcpu),
 382                                              &kvm_vgic_global_state.vcpu_base_va,
 383                                              &kvm_vgic_global_state.vcpu_hyp_va);
 384                 if (ret) {
 385                         kvm_err("Cannot map GICV into hyp\n");
 386                         goto out;
 387                 }
 388
 389                 static_branch_enable(&vgic_v2_cpuif_trap);
 390         }
 391
 392         ret = create_hyp_io_mappings(info->vctrl.start,
 393                                      resource_size(&info->vctrl),
 394                                      &kvm_vgic_global_state.vctrl_base,
 395                                      &kvm_vgic_global_state.vctrl_hyp);
 396         if (ret) {
 397                 kvm_err("Cannot map VCTRL into hyp\n");
 398                 goto out;
 399         }
 400
 401         vtr = readl_relaxed(kvm_vgic_global_state.vctrl_base + GICH_VTR);
 402         kvm_vgic_global_state.nr_lr = (vtr & 0x3f) + 1;
 403
 404         ret = kvm_register_vgic_device(KVM_DEV_TYPE_ARM_VGIC_V2);
 405         if (ret) {
 406                 kvm_err("Cannot register GICv2 KVM device\n");
 407                 goto out;
 408         }
 409
 410         kvm_vgic_global_state.can_emulate_gicv2 = true;
 411         kvm_vgic_global_state.vcpu_base = info->vcpu.start;
 412         kvm_vgic_global_state.type = VGIC_V2;
 413         kvm_vgic_global_state.max_gic_vcpus = VGIC_V2_MAX_CPUS;
 414
 415         kvm_debug("vgic-v2@%llx\n", info->vctrl.start);
 416
 417         return 0;
 418 out:
 419         if (kvm_vgic_global_state.vctrl_base)
 420                 iounmap(kvm_vgic_global_state.vctrl_base);
 421         if (kvm_vgic_global_state.vcpu_base_va)
 422                 iounmap(kvm_vgic_global_state.vcpu_base_va);
 423
 424         return ret;
 425 }
 426
 427 static void save_lrs(struct kvm_vcpu *vcpu, void __iomem *base)
 428 {
 429         struct vgic_v2_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v2;
 430         u64 used_lrs = vcpu->arch.vgic_cpu.used_lrs;
 431         u64 elrsr;
 432         int i;
 433
 434         elrsr = readl_relaxed(base + GICH_ELRSR0);
 435         if (unlikely(used_lrs > 32))
 436                 elrsr |= ((u64)readl_relaxed(base + GICH_ELRSR1)) << 32;
 437
 438         for (i = 0; i < used_lrs; i++) {
 439                 if (elrsr & (1UL << i))
 440                         cpu_if->vgic_lr[i] &= ~GICH_LR_STATE;
 441                 else
 442                         cpu_if->vgic_lr[i] = readl_relaxed(base + GICH_LR0 + (i * 4));
 443
 444                 writel_relaxed(0, base + GICH_LR0 + (i * 4));
 445         }
 446 }
 447
 448 void vgic_v2_save_state(struct kvm_vcpu *vcpu)
 449 {
 450         void __iomem *base = kvm_vgic_global_state.vctrl_base;
 451         u64 used_lrs = vcpu->arch.vgic_cpu.used_lrs;
 452
 453         if (!base)
 454                 return;
 455
 456         if (used_lrs) {
 457                 save_lrs(vcpu, base);
 458                 writel_relaxed(0, base + GICH_HCR);
 459         }
 460 }
 461
 462 void vgic_v2_restore_state(struct kvm_vcpu *vcpu)
 463 {
 464         struct vgic_v2_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v2;
 465         void __iomem *base = kvm_vgic_global_state.vctrl_base;
 466         u64 used_lrs = vcpu->arch.vgic_cpu.used_lrs;
 467         int i;
 468
 469         if (!base)
 470                 return;
 471
 472         if (used_lrs) {
 473                 writel_relaxed(cpu_if->vgic_hcr, base + GICH_HCR);
 474                 for (i = 0; i < used_lrs; i++) {
 475                         writel_relaxed(cpu_if->vgic_lr[i],
 476                                        base + GICH_LR0 + (i * 4));
 477                 }
 478         }
 479 }
 480
 481 void vgic_v2_load(struct kvm_vcpu *vcpu)
 482 {
 483         struct vgic_v2_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v2;
 484
 485         writel_relaxed(cpu_if->vgic_vmcr,
 486                        kvm_vgic_global_state.vctrl_base + GICH_VMCR);
 487         writel_relaxed(cpu_if->vgic_apr,
 488                        kvm_vgic_global_state.vctrl_base + GICH_APR);
 489 }
 490
 491 void vgic_v2_vmcr_sync(struct kvm_vcpu *vcpu)
 492 {
 493         struct vgic_v2_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v2;
 494
 495         cpu_if->vgic_vmcr = readl_relaxed(kvm_vgic_global_state.vctrl_base + GICH_VMCR);
 496 }
 497
 498 void vgic_v2_put(struct kvm_vcpu *vcpu)
 499 {
 500         struct vgic_v2_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v2;
 501
 502         vgic_v2_vmcr_sync(vcpu);
 503         cpu_if->vgic_apr = readl_relaxed(kvm_vgic_global_state.vctrl_base + GICH_APR);
 504 }