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                         BUG_ON(!src);
 188                         val |= (src - 1) << GICH_LR_PHYSID_CPUID_SHIFT;
 189                         irq->source &= ~(1 << (src - 1));
 190                         if (irq->source) {
 191                                 irq->pending_latch = true;
 192                                 val |= GICH_LR_EOI;
 193                         }
 194                 }
 195         }
 196
 197         /*
 198          * Level-triggered mapped IRQs are special because we only observe
 199          * rising edges as input to the VGIC.  We therefore lower the line
 200          * level here, so that we can take new virtual IRQs.  See
 201          * vgic_v2_fold_lr_state for more info.
 202          */
 203         if (vgic_irq_is_mapped_level(irq) && (val & GICH_LR_PENDING_BIT))
 204                 irq->line_level = false;
 205
 206         /* The GICv2 LR only holds five bits of priority. */
 207         val |= (irq->priority >> 3) << GICH_LR_PRIORITY_SHIFT;
 208
 209         vcpu->arch.vgic_cpu.vgic_v2.vgic_lr[lr] = val;
 210 }
 211
 212 void vgic_v2_clear_lr(struct kvm_vcpu *vcpu, int lr)
 213 {
 214         vcpu->arch.vgic_cpu.vgic_v2.vgic_lr[lr] = 0;
 215 }
 216
 217 void vgic_v2_set_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcrp)
 218 {
 219         struct vgic_v2_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v2;
 220         u32 vmcr;
 221
 222         vmcr = (vmcrp->grpen0 << GICH_VMCR_ENABLE_GRP0_SHIFT) &
 223                 GICH_VMCR_ENABLE_GRP0_MASK;
 224         vmcr |= (vmcrp->grpen1 << GICH_VMCR_ENABLE_GRP1_SHIFT) &
 225                 GICH_VMCR_ENABLE_GRP1_MASK;
 226         vmcr |= (vmcrp->ackctl << GICH_VMCR_ACK_CTL_SHIFT) &
 227                 GICH_VMCR_ACK_CTL_MASK;
 228         vmcr |= (vmcrp->fiqen << GICH_VMCR_FIQ_EN_SHIFT) &
 229                 GICH_VMCR_FIQ_EN_MASK;
 230         vmcr |= (vmcrp->cbpr << GICH_VMCR_CBPR_SHIFT) &
 231                 GICH_VMCR_CBPR_MASK;
 232         vmcr |= (vmcrp->eoim << GICH_VMCR_EOI_MODE_SHIFT) &
 233                 GICH_VMCR_EOI_MODE_MASK;
 234         vmcr |= (vmcrp->abpr << GICH_VMCR_ALIAS_BINPOINT_SHIFT) &
 235                 GICH_VMCR_ALIAS_BINPOINT_MASK;
 236         vmcr |= (vmcrp->bpr << GICH_VMCR_BINPOINT_SHIFT) &
 237                 GICH_VMCR_BINPOINT_MASK;
 238         vmcr |= ((vmcrp->pmr >> GICV_PMR_PRIORITY_SHIFT) <<
 239                  GICH_VMCR_PRIMASK_SHIFT) & GICH_VMCR_PRIMASK_MASK;
 240
 241         cpu_if->vgic_vmcr = vmcr;
 242 }
 243
 244 void vgic_v2_get_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcrp)
 245 {
 246         struct vgic_v2_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v2;
 247         u32 vmcr;
 248
 249         vmcr = cpu_if->vgic_vmcr;
 250
 251         vmcrp->grpen0 = (vmcr & GICH_VMCR_ENABLE_GRP0_MASK) >>
 252                 GICH_VMCR_ENABLE_GRP0_SHIFT;
 253         vmcrp->grpen1 = (vmcr & GICH_VMCR_ENABLE_GRP1_MASK) >>
 254                 GICH_VMCR_ENABLE_GRP1_SHIFT;
 255         vmcrp->ackctl = (vmcr & GICH_VMCR_ACK_CTL_MASK) >>
 256                 GICH_VMCR_ACK_CTL_SHIFT;
 257         vmcrp->fiqen = (vmcr & GICH_VMCR_FIQ_EN_MASK) >>
 258                 GICH_VMCR_FIQ_EN_SHIFT;
 259         vmcrp->cbpr = (vmcr & GICH_VMCR_CBPR_MASK) >>
 260                 GICH_VMCR_CBPR_SHIFT;
 261         vmcrp->eoim = (vmcr & GICH_VMCR_EOI_MODE_MASK) >>
 262                 GICH_VMCR_EOI_MODE_SHIFT;
 263
 264         vmcrp->abpr = (vmcr & GICH_VMCR_ALIAS_BINPOINT_MASK) >>
 265                         GICH_VMCR_ALIAS_BINPOINT_SHIFT;
 266         vmcrp->bpr  = (vmcr & GICH_VMCR_BINPOINT_MASK) >>
 267                         GICH_VMCR_BINPOINT_SHIFT;
 268         vmcrp->pmr  = ((vmcr & GICH_VMCR_PRIMASK_MASK) >>
 269                         GICH_VMCR_PRIMASK_SHIFT) << GICV_PMR_PRIORITY_SHIFT;
 270 }
 271
 272 void vgic_v2_enable(struct kvm_vcpu *vcpu)
 273 {
 274         /*
 275          * By forcing VMCR to zero, the GIC will restore the binary
 276          * points to their reset values. Anything else resets to zero
 277          * anyway.
 278          */
 279         vcpu->arch.vgic_cpu.vgic_v2.vgic_vmcr = 0;
 280
 281         /* Get the show on the road... */
 282         vcpu->arch.vgic_cpu.vgic_v2.vgic_hcr = GICH_HCR_EN;
 283 }
 284
 285 /* check for overlapping regions and for regions crossing the end of memory */
 286 static bool vgic_v2_check_base(gpa_t dist_base, gpa_t cpu_base)
 287 {
 288         if (dist_base + KVM_VGIC_V2_DIST_SIZE < dist_base)
 289                 return false;
 290         if (cpu_base + KVM_VGIC_V2_CPU_SIZE < cpu_base)
 291                 return false;
 292
 293         if (dist_base + KVM_VGIC_V2_DIST_SIZE <= cpu_base)
 294                 return true;
 295         if (cpu_base + KVM_VGIC_V2_CPU_SIZE <= dist_base)
 296                 return true;
 297
 298         return false;
 299 }
 300
 301 int vgic_v2_map_resources(struct kvm *kvm)
 302 {
 303         struct vgic_dist *dist = &kvm->arch.vgic;
 304         int ret = 0;
 305
 306         if (vgic_ready(kvm))
 307                 goto out;
 308
 309         if (IS_VGIC_ADDR_UNDEF(dist->vgic_dist_base) ||
 310             IS_VGIC_ADDR_UNDEF(dist->vgic_cpu_base)) {
 311                 kvm_err("Need to set vgic cpu and dist addresses first\n");
 312                 ret = -ENXIO;
 313                 goto out;
 314         }
 315
 316         if (!vgic_v2_check_base(dist->vgic_dist_base, dist->vgic_cpu_base)) {
 317                 kvm_err("VGIC CPU and dist frames overlap\n");
 318                 ret = -EINVAL;
 319                 goto out;
 320         }
 321
 322         /*
 323          * Initialize the vgic if this hasn't already been done on demand by
 324          * accessing the vgic state from userspace.
 325          */
 326         ret = vgic_init(kvm);
 327         if (ret) {
 328                 kvm_err("Unable to initialize VGIC dynamic data structures\n");
 329                 goto out;
 330         }
 331
 332         ret = vgic_register_dist_iodev(kvm, dist->vgic_dist_base, VGIC_V2);
 333         if (ret) {
 334                 kvm_err("Unable to register VGIC MMIO regions\n");
 335                 goto out;
 336         }
 337
 338         if (!static_branch_unlikely(&vgic_v2_cpuif_trap)) {
 339                 ret = kvm_phys_addr_ioremap(kvm, dist->vgic_cpu_base,
 340                                             kvm_vgic_global_state.vcpu_base,
 341                                             KVM_VGIC_V2_CPU_SIZE, true);
 342                 if (ret) {
 343                         kvm_err("Unable to remap VGIC CPU to VCPU\n");
 344                         goto out;
 345                 }
 346         }
 347
 348         dist->ready = true;
 349
 350 out:
 351         return ret;
 352 }
 353
 354 DEFINE_STATIC_KEY_FALSE(vgic_v2_cpuif_trap);
 355
 356 /**
 357  * vgic_v2_probe - probe for a GICv2 compatible interrupt controller in DT
 358  * @node:       pointer to the DT node
 359  *
 360  * Returns 0 if a GICv2 has been found, returns an error code otherwise
 361  */
 362 int vgic_v2_probe(const struct gic_kvm_info *info)
 363 {
 364         int ret;
 365         u32 vtr;
 366
 367         if (!info->vctrl.start) {
 368                 kvm_err("GICH not present in the firmware table\n");
 369                 return -ENXIO;
 370         }
 371
 372         if (!PAGE_ALIGNED(info->vcpu.start) ||
 373             !PAGE_ALIGNED(resource_size(&info->vcpu))) {
 374                 kvm_info("GICV region size/alignment is unsafe, using trapping (reduced performance)\n");
 375
 376                 ret = create_hyp_io_mappings(info->vcpu.start,
 377                                              resource_size(&info->vcpu),
 378                                              &kvm_vgic_global_state.vcpu_base_va,
 379                                              &kvm_vgic_global_state.vcpu_hyp_va);
 380                 if (ret) {
 381                         kvm_err("Cannot map GICV into hyp\n");
 382                         goto out;
 383                 }
 384
 385                 static_branch_enable(&vgic_v2_cpuif_trap);
 386         }
 387
 388         ret = create_hyp_io_mappings(info->vctrl.start,
 389                                      resource_size(&info->vctrl),
 390                                      &kvm_vgic_global_state.vctrl_base,
 391                                      &kvm_vgic_global_state.vctrl_hyp);
 392         if (ret) {
 393                 kvm_err("Cannot map VCTRL into hyp\n");
 394                 goto out;
 395         }
 396
 397         vtr = readl_relaxed(kvm_vgic_global_state.vctrl_base + GICH_VTR);
 398         kvm_vgic_global_state.nr_lr = (vtr & 0x3f) + 1;
 399
 400         ret = kvm_register_vgic_device(KVM_DEV_TYPE_ARM_VGIC_V2);
 401         if (ret) {
 402                 kvm_err("Cannot register GICv2 KVM device\n");
 403                 goto out;
 404         }
 405
 406         kvm_vgic_global_state.can_emulate_gicv2 = true;
 407         kvm_vgic_global_state.vcpu_base = info->vcpu.start;
 408         kvm_vgic_global_state.type = VGIC_V2;
 409         kvm_vgic_global_state.max_gic_vcpus = VGIC_V2_MAX_CPUS;
 410
 411         kvm_debug("vgic-v2@%llx\n", info->vctrl.start);
 412
 413         return 0;
 414 out:
 415         if (kvm_vgic_global_state.vctrl_base)
 416                 iounmap(kvm_vgic_global_state.vctrl_base);
 417         if (kvm_vgic_global_state.vcpu_base_va)
 418                 iounmap(kvm_vgic_global_state.vcpu_base_va);
 419
 420         return ret;
 421 }
 422
 423 static void save_lrs(struct kvm_vcpu *vcpu, void __iomem *base)
 424 {
 425         struct vgic_v2_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v2;
 426         u64 used_lrs = vcpu->arch.vgic_cpu.used_lrs;
 427         u64 elrsr;
 428         int i;
 429
 430         elrsr = readl_relaxed(base + GICH_ELRSR0);
 431         if (unlikely(used_lrs > 32))
 432                 elrsr |= ((u64)readl_relaxed(base + GICH_ELRSR1)) << 32;
 433
 434         for (i = 0; i < used_lrs; i++) {
 435                 if (elrsr & (1UL << i))
 436                         cpu_if->vgic_lr[i] &= ~GICH_LR_STATE;
 437                 else
 438                         cpu_if->vgic_lr[i] = readl_relaxed(base + GICH_LR0 + (i * 4));
 439
 440                 writel_relaxed(0, base + GICH_LR0 + (i * 4));
 441         }
 442 }
 443
 444 void vgic_v2_save_state(struct kvm_vcpu *vcpu)
 445 {
 446         void __iomem *base = kvm_vgic_global_state.vctrl_base;
 447         u64 used_lrs = vcpu->arch.vgic_cpu.used_lrs;
 448
 449         if (!base)
 450                 return;
 451
 452         if (used_lrs) {
 453                 save_lrs(vcpu, base);
 454                 writel_relaxed(0, base + GICH_HCR);
 455         }
 456 }
 457
 458 void vgic_v2_restore_state(struct kvm_vcpu *vcpu)
 459 {
 460         struct vgic_v2_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v2;
 461         void __iomem *base = kvm_vgic_global_state.vctrl_base;
 462         u64 used_lrs = vcpu->arch.vgic_cpu.used_lrs;
 463         int i;
 464
 465         if (!base)
 466                 return;
 467
 468         if (used_lrs) {
 469                 writel_relaxed(cpu_if->vgic_hcr, base + GICH_HCR);
 470                 for (i = 0; i < used_lrs; i++) {
 471                         writel_relaxed(cpu_if->vgic_lr[i],
 472                                        base + GICH_LR0 + (i * 4));
 473                 }
 474         }
 475 }
 476
 477 void vgic_v2_load(struct kvm_vcpu *vcpu)
 478 {
 479         struct vgic_v2_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v2;
 480
 481         writel_relaxed(cpu_if->vgic_vmcr,
 482                        kvm_vgic_global_state.vctrl_base + GICH_VMCR);
 483         writel_relaxed(cpu_if->vgic_apr,
 484                        kvm_vgic_global_state.vctrl_base + GICH_APR);
 485 }
 486
 487 void vgic_v2_put(struct kvm_vcpu *vcpu)
 488 {
 489         struct vgic_v2_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v2;
 490
 491         cpu_if->vgic_vmcr = readl_relaxed(kvm_vgic_global_state.vctrl_base + GICH_VMCR);
 492         cpu_if->vgic_apr = readl_relaxed(kvm_vgic_global_state.vctrl_base + GICH_APR);
 493 }