LXR linux/virt/kvm/arm/vgic/vgic-mmio-v2.c

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * VGICv2 MMIO handling functions
   4 */
   5
   6#include <linux/irqchip/arm-gic.h>
   7#include <linux/kvm.h>
   8#include <linux/kvm_host.h>
   9#include <linux/nospec.h>
  10
  11#include <kvm/iodev.h>
  12#include <kvm/arm_vgic.h>
  13
  14#include "vgic.h"
  15#include "vgic-mmio.h"
  16
  17/*
  18 * The Revision field in the IIDR have the following meanings:
  19 *
  20 * Revision 1: Report GICv2 interrupts as group 0 instead of group 1
  21 * Revision 2: Interrupt groups are guest-configurable and signaled using
  22 *             their configured groups.
  23 */
  24
  25static unsigned long vgic_mmio_read_v2_misc(struct kvm_vcpu *vcpu,
  26                                            gpa_t addr, unsigned int len)
  27{
  28        struct vgic_dist *vgic = &vcpu->kvm->arch.vgic;
  29        u32 value;
  30
  31        switch (addr & 0x0c) {
  32        case GIC_DIST_CTRL:
  33                value = vgic->enabled ? GICD_ENABLE : 0;
  34                break;
  35        case GIC_DIST_CTR:
  36                value = vgic->nr_spis + VGIC_NR_PRIVATE_IRQS;
  37                value = (value >> 5) - 1;
  38                value |= (atomic_read(&vcpu->kvm->online_vcpus) - 1) << 5;
  39                break;
  40        case GIC_DIST_IIDR:
  41                value = (PRODUCT_ID_KVM << GICD_IIDR_PRODUCT_ID_SHIFT) |
  42                        (vgic->implementation_rev << GICD_IIDR_REVISION_SHIFT) |
  43                        (IMPLEMENTER_ARM << GICD_IIDR_IMPLEMENTER_SHIFT);
  44                break;
  45        default:
  46                return 0;
  47        }
  48
  49        return value;
  50}
  51
  52static void vgic_mmio_write_v2_misc(struct kvm_vcpu *vcpu,
  53                                    gpa_t addr, unsigned int len,
  54                                    unsigned long val)
  55{
  56        struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
  57        bool was_enabled = dist->enabled;
  58
  59        switch (addr & 0x0c) {
  60        case GIC_DIST_CTRL:
  61                dist->enabled = val & GICD_ENABLE;
  62                if (!was_enabled && dist->enabled)
  63                        vgic_kick_vcpus(vcpu->kvm);
  64                break;
  65        case GIC_DIST_CTR:
  66        case GIC_DIST_IIDR:
  67                /* Nothing to do */
  68                return;
  69        }
  70}
  71
  72static int vgic_mmio_uaccess_write_v2_misc(struct kvm_vcpu *vcpu,
  73                                           gpa_t addr, unsigned int len,
  74                                           unsigned long val)
  75{
  76        switch (addr & 0x0c) {
  77        case GIC_DIST_IIDR:
  78                if (val != vgic_mmio_read_v2_misc(vcpu, addr, len))
  79                        return -EINVAL;
  80
  81                /*
  82                 * If we observe a write to GICD_IIDR we know that userspace
  83                 * has been updated and has had a chance to cope with older
  84                 * kernels (VGICv2 IIDR.Revision == 0) incorrectly reporting
  85                 * interrupts as group 1, and therefore we now allow groups to
  86                 * be user writable.  Doing this by default would break
  87                 * migration from old kernels to new kernels with legacy
  88                 * userspace.
  89                 */
  90                vcpu->kvm->arch.vgic.v2_groups_user_writable = true;
  91                return 0;
  92        }
  93
  94        vgic_mmio_write_v2_misc(vcpu, addr, len, val);
  95        return 0;
  96}
  97
  98static int vgic_mmio_uaccess_write_v2_group(struct kvm_vcpu *vcpu,
  99                                            gpa_t addr, unsigned int len,
 100                                            unsigned long val)
 101{
 102        if (vcpu->kvm->arch.vgic.v2_groups_user_writable)
 103                vgic_mmio_write_group(vcpu, addr, len, val);
 104
 105        return 0;
 106}
 107
 108static void vgic_mmio_write_sgir(struct kvm_vcpu *source_vcpu,
 109                                 gpa_t addr, unsigned int len,
 110                                 unsigned long val)
 111{
 112        int nr_vcpus = atomic_read(&source_vcpu->kvm->online_vcpus);
 113        int intid = val & 0xf;
 114        int targets = (val >> 16) & 0xff;
 115        int mode = (val >> 24) & 0x03;
 116        int c;
 117        struct kvm_vcpu *vcpu;
 118        unsigned long flags;
 119
 120        switch (mode) {
 121        case 0x0:               /* as specified by targets */
 122                break;
 123        case 0x1:
 124                targets = (1U << nr_vcpus) - 1;                 /* all, ... */
 125                targets &= ~(1U << source_vcpu->vcpu_id);       /* but self */
 126                break;
 127        case 0x2:               /* this very vCPU only */
 128                targets = (1U << source_vcpu->vcpu_id);
 129                break;
 130        case 0x3:               /* reserved */
 131                return;
 132        }
 133
 134        kvm_for_each_vcpu(c, vcpu, source_vcpu->kvm) {
 135                struct vgic_irq *irq;
 136
 137                if (!(targets & (1U << c)))
 138                        continue;
 139
 140                irq = vgic_get_irq(source_vcpu->kvm, vcpu, intid);
 141
 142                raw_spin_lock_irqsave(&irq->irq_lock, flags);
 143                irq->pending_latch = true;
 144                irq->source |= 1U << source_vcpu->vcpu_id;
 145
 146                vgic_queue_irq_unlock(source_vcpu->kvm, irq, flags);
 147                vgic_put_irq(source_vcpu->kvm, irq);
 148        }
 149}
 150
 151static unsigned long vgic_mmio_read_target(struct kvm_vcpu *vcpu,
 152                                           gpa_t addr, unsigned int len)
 153{
 154        u32 intid = VGIC_ADDR_TO_INTID(addr, 8);
 155        int i;
 156        u64 val = 0;
 157
 158        for (i = 0; i < len; i++) {
 159                struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
 160
 161                val |= (u64)irq->targets << (i * 8);
 162
 163                vgic_put_irq(vcpu->kvm, irq);
 164        }
 165
 166        return val;
 167}
 168
 169static void vgic_mmio_write_target(struct kvm_vcpu *vcpu,
 170                                   gpa_t addr, unsigned int len,
 171                                   unsigned long val)
 172{
 173        u32 intid = VGIC_ADDR_TO_INTID(addr, 8);
 174        u8 cpu_mask = GENMASK(atomic_read(&vcpu->kvm->online_vcpus) - 1, 0);
 175        int i;
 176        unsigned long flags;
 177
 178        /* GICD_ITARGETSR[0-7] are read-only */
 179        if (intid < VGIC_NR_PRIVATE_IRQS)
 180                return;
 181
 182        for (i = 0; i < len; i++) {
 183                struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, NULL, intid + i);
 184                int target;
 185
 186                raw_spin_lock_irqsave(&irq->irq_lock, flags);
 187
 188                irq->targets = (val >> (i * 8)) & cpu_mask;
 189                target = irq->targets ? __ffs(irq->targets) : 0;
 190                irq->target_vcpu = kvm_get_vcpu(vcpu->kvm, target);
 191
 192                raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
 193                vgic_put_irq(vcpu->kvm, irq);
 194        }
 195}
 196
 197static unsigned long vgic_mmio_read_sgipend(struct kvm_vcpu *vcpu,
 198                                            gpa_t addr, unsigned int len)
 199{
 200        u32 intid = addr & 0x0f;
 201        int i;
 202        u64 val = 0;
 203
 204        for (i = 0; i < len; i++) {
 205                struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
 206
 207                val |= (u64)irq->source << (i * 8);
 208
 209                vgic_put_irq(vcpu->kvm, irq);
 210        }
 211        return val;
 212}
 213
 214static void vgic_mmio_write_sgipendc(struct kvm_vcpu *vcpu,
 215                                     gpa_t addr, unsigned int len,
 216                                     unsigned long val)
 217{
 218        u32 intid = addr & 0x0f;
 219        int i;
 220        unsigned long flags;
 221
 222        for (i = 0; i < len; i++) {
 223                struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
 224
 225                raw_spin_lock_irqsave(&irq->irq_lock, flags);
 226
 227                irq->source &= ~((val >> (i * 8)) & 0xff);
 228                if (!irq->source)
 229                        irq->pending_latch = false;
 230
 231                raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
 232                vgic_put_irq(vcpu->kvm, irq);
 233        }
 234}
 235
 236static void vgic_mmio_write_sgipends(struct kvm_vcpu *vcpu,
 237                                     gpa_t addr, unsigned int len,
 238                                     unsigned long val)
 239{
 240        u32 intid = addr & 0x0f;
 241        int i;
 242        unsigned long flags;
 243
 244        for (i = 0; i < len; i++) {
 245                struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
 246
 247                raw_spin_lock_irqsave(&irq->irq_lock, flags);
 248
 249                irq->source |= (val >> (i * 8)) & 0xff;
 250
 251                if (irq->source) {
 252                        irq->pending_latch = true;
 253                        vgic_queue_irq_unlock(vcpu->kvm, irq, flags);
 254                } else {
 255                        raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
 256                }
 257                vgic_put_irq(vcpu->kvm, irq);
 258        }
 259}
 260
 261#define GICC_ARCH_VERSION_V2    0x2
 262
 263/* These are for userland accesses only, there is no guest-facing emulation. */
 264static unsigned long vgic_mmio_read_vcpuif(struct kvm_vcpu *vcpu,
 265                                           gpa_t addr, unsigned int len)
 266{
 267        struct vgic_vmcr vmcr;
 268        u32 val;
 269
 270        vgic_get_vmcr(vcpu, &vmcr);
 271
 272        switch (addr & 0xff) {
 273        case GIC_CPU_CTRL:
 274                val = vmcr.grpen0 << GIC_CPU_CTRL_EnableGrp0_SHIFT;
 275                val |= vmcr.grpen1 << GIC_CPU_CTRL_EnableGrp1_SHIFT;
 276                val |= vmcr.ackctl << GIC_CPU_CTRL_AckCtl_SHIFT;
 277                val |= vmcr.fiqen << GIC_CPU_CTRL_FIQEn_SHIFT;
 278                val |= vmcr.cbpr << GIC_CPU_CTRL_CBPR_SHIFT;
 279                val |= vmcr.eoim << GIC_CPU_CTRL_EOImodeNS_SHIFT;
 280
 281                break;
 282        case GIC_CPU_PRIMASK:
 283                /*
 284                 * Our KVM_DEV_TYPE_ARM_VGIC_V2 device ABI exports the
 285                 * the PMR field as GICH_VMCR.VMPriMask rather than
 286                 * GICC_PMR.Priority, so we expose the upper five bits of
 287                 * priority mask to userspace using the lower bits in the
 288                 * unsigned long.
 289                 */
 290                val = (vmcr.pmr & GICV_PMR_PRIORITY_MASK) >>
 291                        GICV_PMR_PRIORITY_SHIFT;
 292                break;
 293        case GIC_CPU_BINPOINT:
 294                val = vmcr.bpr;
 295                break;
 296        case GIC_CPU_ALIAS_BINPOINT:
 297                val = vmcr.abpr;
 298                break;
 299        case GIC_CPU_IDENT:
 300                val = ((PRODUCT_ID_KVM << 20) |
 301                       (GICC_ARCH_VERSION_V2 << 16) |
 302                       IMPLEMENTER_ARM);
 303                break;
 304        default:
 305                return 0;
 306        }
 307
 308        return val;
 309}
 310
 311static void vgic_mmio_write_vcpuif(struct kvm_vcpu *vcpu,
 312                                   gpa_t addr, unsigned int len,
 313                                   unsigned long val)
 314{
 315        struct vgic_vmcr vmcr;
 316
 317        vgic_get_vmcr(vcpu, &vmcr);
 318
 319        switch (addr & 0xff) {
 320        case GIC_CPU_CTRL:
 321                vmcr.grpen0 = !!(val & GIC_CPU_CTRL_EnableGrp0);
 322                vmcr.grpen1 = !!(val & GIC_CPU_CTRL_EnableGrp1);
 323                vmcr.ackctl = !!(val & GIC_CPU_CTRL_AckCtl);
 324                vmcr.fiqen = !!(val & GIC_CPU_CTRL_FIQEn);
 325                vmcr.cbpr = !!(val & GIC_CPU_CTRL_CBPR);
 326                vmcr.eoim = !!(val & GIC_CPU_CTRL_EOImodeNS);
 327
 328                break;
 329        case GIC_CPU_PRIMASK:
 330                /*
 331                 * Our KVM_DEV_TYPE_ARM_VGIC_V2 device ABI exports the
 332                 * the PMR field as GICH_VMCR.VMPriMask rather than
 333                 * GICC_PMR.Priority, so we expose the upper five bits of
 334                 * priority mask to userspace using the lower bits in the
 335                 * unsigned long.
 336                 */
 337                vmcr.pmr = (val << GICV_PMR_PRIORITY_SHIFT) &
 338                        GICV_PMR_PRIORITY_MASK;
 339                break;
 340        case GIC_CPU_BINPOINT:
 341                vmcr.bpr = val;
 342                break;
 343        case GIC_CPU_ALIAS_BINPOINT:
 344                vmcr.abpr = val;
 345                break;
 346        }
 347
 348        vgic_set_vmcr(vcpu, &vmcr);
 349}
 350
 351static unsigned long vgic_mmio_read_apr(struct kvm_vcpu *vcpu,
 352                                        gpa_t addr, unsigned int len)
 353{
 354        int n; /* which APRn is this */
 355
 356        n = (addr >> 2) & 0x3;
 357
 358        if (kvm_vgic_global_state.type == VGIC_V2) {
 359                /* GICv2 hardware systems support max. 32 groups */
 360                if (n != 0)
 361                        return 0;
 362                return vcpu->arch.vgic_cpu.vgic_v2.vgic_apr;
 363        } else {
 364                struct vgic_v3_cpu_if *vgicv3 = &vcpu->arch.vgic_cpu.vgic_v3;
 365
 366                if (n > vgic_v3_max_apr_idx(vcpu))
 367                        return 0;
 368
 369                n = array_index_nospec(n, 4);
 370
 371                /* GICv3 only uses ICH_AP1Rn for memory mapped (GICv2) guests */
 372                return vgicv3->vgic_ap1r[n];
 373        }
 374}
 375
 376static void vgic_mmio_write_apr(struct kvm_vcpu *vcpu,
 377                                gpa_t addr, unsigned int len,
 378                                unsigned long val)
 379{
 380        int n; /* which APRn is this */
 381
 382        n = (addr >> 2) & 0x3;
 383
 384        if (kvm_vgic_global_state.type == VGIC_V2) {
 385                /* GICv2 hardware systems support max. 32 groups */
 386                if (n != 0)
 387                        return;
 388                vcpu->arch.vgic_cpu.vgic_v2.vgic_apr = val;
 389        } else {
 390                struct vgic_v3_cpu_if *vgicv3 = &vcpu->arch.vgic_cpu.vgic_v3;
 391
 392                if (n > vgic_v3_max_apr_idx(vcpu))
 393                        return;
 394
 395                n = array_index_nospec(n, 4);
 396
 397                /* GICv3 only uses ICH_AP1Rn for memory mapped (GICv2) guests */
 398                vgicv3->vgic_ap1r[n] = val;
 399        }
 400}
 401
 402static const struct vgic_register_region vgic_v2_dist_registers[] = {
 403        REGISTER_DESC_WITH_LENGTH_UACCESS(GIC_DIST_CTRL,
 404                vgic_mmio_read_v2_misc, vgic_mmio_write_v2_misc,
 405                NULL, vgic_mmio_uaccess_write_v2_misc,
 406                12, VGIC_ACCESS_32bit),
 407        REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_IGROUP,
 408                vgic_mmio_read_group, vgic_mmio_write_group,
 409                NULL, vgic_mmio_uaccess_write_v2_group, 1,
 410                VGIC_ACCESS_32bit),
 411        REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_ENABLE_SET,
 412                vgic_mmio_read_enable, vgic_mmio_write_senable, NULL, NULL, 1,
 413                VGIC_ACCESS_32bit),
 414        REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_ENABLE_CLEAR,
 415                vgic_mmio_read_enable, vgic_mmio_write_cenable, NULL, NULL, 1,
 416                VGIC_ACCESS_32bit),
 417        REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_PENDING_SET,
 418                vgic_mmio_read_pending, vgic_mmio_write_spending, NULL, NULL, 1,
 419                VGIC_ACCESS_32bit),
 420        REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_PENDING_CLEAR,
 421                vgic_mmio_read_pending, vgic_mmio_write_cpending, NULL, NULL, 1,
 422                VGIC_ACCESS_32bit),
 423        REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_ACTIVE_SET,
 424                vgic_mmio_read_active, vgic_mmio_write_sactive,
 425                NULL, vgic_mmio_uaccess_write_sactive, 1,
 426                VGIC_ACCESS_32bit),
 427        REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_ACTIVE_CLEAR,
 428                vgic_mmio_read_active, vgic_mmio_write_cactive,
 429                NULL, vgic_mmio_uaccess_write_cactive, 1,
 430                VGIC_ACCESS_32bit),
 431        REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_PRI,
 432                vgic_mmio_read_priority, vgic_mmio_write_priority, NULL, NULL,
 433                8, VGIC_ACCESS_32bit | VGIC_ACCESS_8bit),
 434        REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_TARGET,
 435                vgic_mmio_read_target, vgic_mmio_write_target, NULL, NULL, 8,
 436                VGIC_ACCESS_32bit | VGIC_ACCESS_8bit),
 437        REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_CONFIG,
 438                vgic_mmio_read_config, vgic_mmio_write_config, NULL, NULL, 2,
 439                VGIC_ACCESS_32bit),
 440        REGISTER_DESC_WITH_LENGTH(GIC_DIST_SOFTINT,
 441                vgic_mmio_read_raz, vgic_mmio_write_sgir, 4,
 442                VGIC_ACCESS_32bit),
 443        REGISTER_DESC_WITH_LENGTH(GIC_DIST_SGI_PENDING_CLEAR,
 444                vgic_mmio_read_sgipend, vgic_mmio_write_sgipendc, 16,
 445                VGIC_ACCESS_32bit | VGIC_ACCESS_8bit),
 446        REGISTER_DESC_WITH_LENGTH(GIC_DIST_SGI_PENDING_SET,
 447                vgic_mmio_read_sgipend, vgic_mmio_write_sgipends, 16,
 448                VGIC_ACCESS_32bit | VGIC_ACCESS_8bit),
 449};
 450
 451static const struct vgic_register_region vgic_v2_cpu_registers[] = {
 452        REGISTER_DESC_WITH_LENGTH(GIC_CPU_CTRL,
 453                vgic_mmio_read_vcpuif, vgic_mmio_write_vcpuif, 4,
 454                VGIC_ACCESS_32bit),
 455        REGISTER_DESC_WITH_LENGTH(GIC_CPU_PRIMASK,
 456                vgic_mmio_read_vcpuif, vgic_mmio_write_vcpuif, 4,
 457                VGIC_ACCESS_32bit),
 458        REGISTER_DESC_WITH_LENGTH(GIC_CPU_BINPOINT,
 459                vgic_mmio_read_vcpuif, vgic_mmio_write_vcpuif, 4,
 460                VGIC_ACCESS_32bit),
 461        REGISTER_DESC_WITH_LENGTH(GIC_CPU_ALIAS_BINPOINT,
 462                vgic_mmio_read_vcpuif, vgic_mmio_write_vcpuif, 4,
 463                VGIC_ACCESS_32bit),
 464        REGISTER_DESC_WITH_LENGTH(GIC_CPU_ACTIVEPRIO,
 465                vgic_mmio_read_apr, vgic_mmio_write_apr, 16,
 466                VGIC_ACCESS_32bit),
 467        REGISTER_DESC_WITH_LENGTH(GIC_CPU_IDENT,
 468                vgic_mmio_read_vcpuif, vgic_mmio_write_vcpuif, 4,
 469                VGIC_ACCESS_32bit),
 470};
 471
 472unsigned int vgic_v2_init_dist_iodev(struct vgic_io_device *dev)
 473{
 474        dev->regions = vgic_v2_dist_registers;
 475        dev->nr_regions = ARRAY_SIZE(vgic_v2_dist_registers);
 476
 477        kvm_iodevice_init(&dev->dev, &kvm_io_gic_ops);
 478
 479        return SZ_4K;
 480}
 481
 482int vgic_v2_has_attr_regs(struct kvm_device *dev, struct kvm_device_attr *attr)
 483{
 484        const struct vgic_register_region *region;
 485        struct vgic_io_device iodev;
 486        struct vgic_reg_attr reg_attr;
 487        struct kvm_vcpu *vcpu;
 488        gpa_t addr;
 489        int ret;
 490
 491        ret = vgic_v2_parse_attr(dev, attr, &reg_attr);
 492        if (ret)
 493                return ret;
 494
 495        vcpu = reg_attr.vcpu;
 496        addr = reg_attr.addr;
 497
 498        switch (attr->group) {
 499        case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
 500                iodev.regions = vgic_v2_dist_registers;
 501                iodev.nr_regions = ARRAY_SIZE(vgic_v2_dist_registers);
 502                iodev.base_addr = 0;
 503                break;
 504        case KVM_DEV_ARM_VGIC_GRP_CPU_REGS:
 505                iodev.regions = vgic_v2_cpu_registers;
 506                iodev.nr_regions = ARRAY_SIZE(vgic_v2_cpu_registers);
 507                iodev.base_addr = 0;
 508                break;
 509        default:
 510                return -ENXIO;
 511        }
 512
 513        /* We only support aligned 32-bit accesses. */
 514        if (addr & 3)
 515                return -ENXIO;
 516
 517        region = vgic_get_mmio_region(vcpu, &iodev, addr, sizeof(u32));
 518        if (!region)
 519                return -ENXIO;
 520
 521        return 0;
 522}
 523
 524int vgic_v2_cpuif_uaccess(struct kvm_vcpu *vcpu, bool is_write,
 525                          int offset, u32 *val)
 526{
 527        struct vgic_io_device dev = {
 528                .regions = vgic_v2_cpu_registers,
 529                .nr_regions = ARRAY_SIZE(vgic_v2_cpu_registers),
 530                .iodev_type = IODEV_CPUIF,
 531        };
 532
 533        return vgic_uaccess(vcpu, &dev, is_write, offset, val);
 534}
 535
 536int vgic_v2_dist_uaccess(struct kvm_vcpu *vcpu, bool is_write,
 537                         int offset, u32 *val)
 538{
 539        struct vgic_io_device dev = {
 540                .regions = vgic_v2_dist_registers,
 541                .nr_regions = ARRAY_SIZE(vgic_v2_dist_registers),
 542                .iodev_type = IODEV_DIST,
 543        };
 544
 545        return vgic_uaccess(vcpu, &dev, is_write, offset, val);
 546}
 547