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

   1 /*
   2  * VGIC: KVM DEVICE API
   3  *
   4  * Copyright (C) 2015 ARM Ltd.
   5  * Author: Marc Zyngier <marc.zyngier@arm.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  */
  16 #include <linux/kvm_host.h>
  17 #include <kvm/arm_vgic.h>
  18 #include <linux/uaccess.h>
  19 #include <asm/kvm_mmu.h>
  20 #include "vgic.h"
  21
  22 /* common helpers */
  23
  24 int vgic_check_ioaddr(struct kvm *kvm, phys_addr_t *ioaddr,
  25                       phys_addr_t addr, phys_addr_t alignment)
  26 {
  27         if (addr & ~KVM_PHYS_MASK)
  28                 return -E2BIG;
  29
  30         if (!IS_ALIGNED(addr, alignment))
  31                 return -EINVAL;
  32
  33         if (!IS_VGIC_ADDR_UNDEF(*ioaddr))
  34                 return -EEXIST;
  35
  36         return 0;
  37 }
  38
  39 /**
  40  * kvm_vgic_addr - set or get vgic VM base addresses
  41  * @kvm:   pointer to the vm struct
  42  * @type:  the VGIC addr type, one of KVM_VGIC_V[23]_ADDR_TYPE_XXX
  43  * @addr:  pointer to address value
  44  * @write: if true set the address in the VM address space, if false read the
  45  *          address
  46  *
  47  * Set or get the vgic base addresses for the distributor and the virtual CPU
  48  * interface in the VM physical address space.  These addresses are properties
  49  * of the emulated core/SoC and therefore user space initially knows this
  50  * information.
  51  * Check them for sanity (alignment, double assignment). We can't check for
  52  * overlapping regions in case of a virtual GICv3 here, since we don't know
  53  * the number of VCPUs yet, so we defer this check to map_resources().
  54  */
  55 int kvm_vgic_addr(struct kvm *kvm, unsigned long type, u64 *addr, bool write)
  56 {
  57         int r = 0;
  58         struct vgic_dist *vgic = &kvm->arch.vgic;
  59         int type_needed;
  60         phys_addr_t *addr_ptr, alignment;
  61
  62         mutex_lock(&kvm->lock);
  63         switch (type) {
  64         case KVM_VGIC_V2_ADDR_TYPE_DIST:
  65                 type_needed = KVM_DEV_TYPE_ARM_VGIC_V2;
  66                 addr_ptr = &vgic->vgic_dist_base;
  67                 alignment = SZ_4K;
  68                 break;
  69         case KVM_VGIC_V2_ADDR_TYPE_CPU:
  70                 type_needed = KVM_DEV_TYPE_ARM_VGIC_V2;
  71                 addr_ptr = &vgic->vgic_cpu_base;
  72                 alignment = SZ_4K;
  73                 break;
  74         case KVM_VGIC_V3_ADDR_TYPE_DIST:
  75                 type_needed = KVM_DEV_TYPE_ARM_VGIC_V3;
  76                 addr_ptr = &vgic->vgic_dist_base;
  77                 alignment = SZ_64K;
  78                 break;
  79         case KVM_VGIC_V3_ADDR_TYPE_REDIST:
  80                 type_needed = KVM_DEV_TYPE_ARM_VGIC_V3;
  81                 addr_ptr = &vgic->vgic_redist_base;
  82                 alignment = SZ_64K;
  83                 break;
  84         default:
  85                 r = -ENODEV;
  86                 goto out;
  87         }
  88
  89         if (vgic->vgic_model != type_needed) {
  90                 r = -ENODEV;
  91                 goto out;
  92         }
  93
  94         if (write) {
  95                 r = vgic_check_ioaddr(kvm, addr_ptr, *addr, alignment);
  96                 if (!r)
  97                         *addr_ptr = *addr;
  98         } else {
  99                 *addr = *addr_ptr;
 100         }
 101
 102 out:
 103         mutex_unlock(&kvm->lock);
 104         return r;
 105 }
 106
 107 static int vgic_set_common_attr(struct kvm_device *dev,
 108                                 struct kvm_device_attr *attr)
 109 {
 110         int r;
 111
 112         switch (attr->group) {
 113         case KVM_DEV_ARM_VGIC_GRP_ADDR: {
 114                 u64 __user *uaddr = (u64 __user *)(long)attr->addr;
 115                 u64 addr;
 116                 unsigned long type = (unsigned long)attr->attr;
 117
 118                 if (copy_from_user(&addr, uaddr, sizeof(addr)))
 119                         return -EFAULT;
 120
 121                 r = kvm_vgic_addr(dev->kvm, type, &addr, true);
 122                 return (r == -ENODEV) ? -ENXIO : r;
 123         }
 124         case KVM_DEV_ARM_VGIC_GRP_NR_IRQS: {
 125                 u32 __user *uaddr = (u32 __user *)(long)attr->addr;
 126                 u32 val;
 127                 int ret = 0;
 128
 129                 if (get_user(val, uaddr))
 130                         return -EFAULT;
 131
 132                 /*
 133                  * We require:
 134                  * - at least 32 SPIs on top of the 16 SGIs and 16 PPIs
 135                  * - at most 1024 interrupts
 136                  * - a multiple of 32 interrupts
 137                  */
 138                 if (val < (VGIC_NR_PRIVATE_IRQS + 32) ||
 139                     val > VGIC_MAX_RESERVED ||
 140                     (val & 31))
 141                         return -EINVAL;
 142
 143                 mutex_lock(&dev->kvm->lock);
 144
 145                 if (vgic_ready(dev->kvm) || dev->kvm->arch.vgic.nr_spis)
 146                         ret = -EBUSY;
 147                 else
 148                         dev->kvm->arch.vgic.nr_spis =
 149                                 val - VGIC_NR_PRIVATE_IRQS;
 150
 151                 mutex_unlock(&dev->kvm->lock);
 152
 153                 return ret;
 154         }
 155         case KVM_DEV_ARM_VGIC_GRP_CTRL: {
 156                 switch (attr->attr) {
 157                 case KVM_DEV_ARM_VGIC_CTRL_INIT:
 158                         mutex_lock(&dev->kvm->lock);
 159                         r = vgic_init(dev->kvm);
 160                         mutex_unlock(&dev->kvm->lock);
 161                         return r;
 162                 }
 163                 break;
 164         }
 165         }
 166
 167         return -ENXIO;
 168 }
 169
 170 static int vgic_get_common_attr(struct kvm_device *dev,
 171                                 struct kvm_device_attr *attr)
 172 {
 173         int r = -ENXIO;
 174
 175         switch (attr->group) {
 176         case KVM_DEV_ARM_VGIC_GRP_ADDR: {
 177                 u64 __user *uaddr = (u64 __user *)(long)attr->addr;
 178                 u64 addr;
 179                 unsigned long type = (unsigned long)attr->attr;
 180
 181                 r = kvm_vgic_addr(dev->kvm, type, &addr, false);
 182                 if (r)
 183                         return (r == -ENODEV) ? -ENXIO : r;
 184
 185                 if (copy_to_user(uaddr, &addr, sizeof(addr)))
 186                         return -EFAULT;
 187                 break;
 188         }
 189         case KVM_DEV_ARM_VGIC_GRP_NR_IRQS: {
 190                 u32 __user *uaddr = (u32 __user *)(long)attr->addr;
 191
 192                 r = put_user(dev->kvm->arch.vgic.nr_spis +
 193                              VGIC_NR_PRIVATE_IRQS, uaddr);
 194                 break;
 195         }
 196         }
 197
 198         return r;
 199 }
 200
 201 static int vgic_create(struct kvm_device *dev, u32 type)
 202 {
 203         return kvm_vgic_create(dev->kvm, type);
 204 }
 205
 206 static void vgic_destroy(struct kvm_device *dev)
 207 {
 208         kfree(dev);
 209 }
 210
 211 int kvm_register_vgic_device(unsigned long type)
 212 {
 213         int ret = -ENODEV;
 214
 215         switch (type) {
 216         case KVM_DEV_TYPE_ARM_VGIC_V2:
 217                 ret = kvm_register_device_ops(&kvm_arm_vgic_v2_ops,
 218                                               KVM_DEV_TYPE_ARM_VGIC_V2);
 219                 break;
 220         case KVM_DEV_TYPE_ARM_VGIC_V3:
 221                 ret = kvm_register_device_ops(&kvm_arm_vgic_v3_ops,
 222                                               KVM_DEV_TYPE_ARM_VGIC_V3);
 223
 224                 if (ret)
 225                         break;
 226                 ret = kvm_vgic_register_its_device();
 227                 break;
 228         }
 229
 230         return ret;
 231 }
 232
 233 struct vgic_reg_attr {
 234         struct kvm_vcpu *vcpu;
 235         gpa_t addr;
 236 };
 237
 238 static int parse_vgic_v2_attr(struct kvm_device *dev,
 239                               struct kvm_device_attr *attr,
 240                               struct vgic_reg_attr *reg_attr)
 241 {
 242         int cpuid;
 243
 244         cpuid = (attr->attr & KVM_DEV_ARM_VGIC_CPUID_MASK) >>
 245                  KVM_DEV_ARM_VGIC_CPUID_SHIFT;
 246
 247         if (cpuid >= atomic_read(&dev->kvm->online_vcpus))
 248                 return -EINVAL;
 249
 250         reg_attr->vcpu = kvm_get_vcpu(dev->kvm, cpuid);
 251         reg_attr->addr = attr->attr & KVM_DEV_ARM_VGIC_OFFSET_MASK;
 252
 253         return 0;
 254 }
 255
 256 /* unlocks vcpus from @vcpu_lock_idx and smaller */
 257 static void unlock_vcpus(struct kvm *kvm, int vcpu_lock_idx)
 258 {
 259         struct kvm_vcpu *tmp_vcpu;
 260
 261         for (; vcpu_lock_idx >= 0; vcpu_lock_idx--) {
 262                 tmp_vcpu = kvm_get_vcpu(kvm, vcpu_lock_idx);
 263                 mutex_unlock(&tmp_vcpu->mutex);
 264         }
 265 }
 266
 267 static void unlock_all_vcpus(struct kvm *kvm)
 268 {
 269         unlock_vcpus(kvm, atomic_read(&kvm->online_vcpus) - 1);
 270 }
 271
 272 /* Returns true if all vcpus were locked, false otherwise */
 273 static bool lock_all_vcpus(struct kvm *kvm)
 274 {
 275         struct kvm_vcpu *tmp_vcpu;
 276         int c;
 277
 278         /*
 279          * Any time a vcpu is run, vcpu_load is called which tries to grab the
 280          * vcpu->mutex.  By grabbing the vcpu->mutex of all VCPUs we ensure
 281          * that no other VCPUs are run and fiddle with the vgic state while we
 282          * access it.
 283          */
 284         kvm_for_each_vcpu(c, tmp_vcpu, kvm) {
 285                 if (!mutex_trylock(&tmp_vcpu->mutex)) {
 286                         unlock_vcpus(kvm, c - 1);
 287                         return false;
 288                 }
 289         }
 290
 291         return true;
 292 }
 293
 294 /**
 295  * vgic_attr_regs_access_v2 - allows user space to access VGIC v2 state
 296  *
 297  * @dev:      kvm device handle
 298  * @attr:     kvm device attribute
 299  * @reg:      address the value is read or written
 300  * @is_write: true if userspace is writing a register
 301  */
 302 static int vgic_attr_regs_access_v2(struct kvm_device *dev,
 303                                     struct kvm_device_attr *attr,
 304                                     u32 *reg, bool is_write)
 305 {
 306         struct vgic_reg_attr reg_attr;
 307         gpa_t addr;
 308         struct kvm_vcpu *vcpu;
 309         int ret;
 310
 311         ret = parse_vgic_v2_attr(dev, attr, &reg_attr);
 312         if (ret)
 313                 return ret;
 314
 315         vcpu = reg_attr.vcpu;
 316         addr = reg_attr.addr;
 317
 318         mutex_lock(&dev->kvm->lock);
 319
 320         ret = vgic_init(dev->kvm);
 321         if (ret)
 322                 goto out;
 323
 324         if (!lock_all_vcpus(dev->kvm)) {
 325                 ret = -EBUSY;
 326                 goto out;
 327         }
 328
 329         switch (attr->group) {
 330         case KVM_DEV_ARM_VGIC_GRP_CPU_REGS:
 331                 ret = vgic_v2_cpuif_uaccess(vcpu, is_write, addr, reg);
 332                 break;
 333         case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
 334                 ret = vgic_v2_dist_uaccess(vcpu, is_write, addr, reg);
 335                 break;
 336         default:
 337                 ret = -EINVAL;
 338                 break;
 339         }
 340
 341         unlock_all_vcpus(dev->kvm);
 342 out:
 343         mutex_unlock(&dev->kvm->lock);
 344         return ret;
 345 }
 346
 347 static int vgic_v2_set_attr(struct kvm_device *dev,
 348                             struct kvm_device_attr *attr)
 349 {
 350         int ret;
 351
 352         ret = vgic_set_common_attr(dev, attr);
 353         if (ret != -ENXIO)
 354                 return ret;
 355
 356         switch (attr->group) {
 357         case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
 358         case KVM_DEV_ARM_VGIC_GRP_CPU_REGS: {
 359                 u32 __user *uaddr = (u32 __user *)(long)attr->addr;
 360                 u32 reg;
 361
 362                 if (get_user(reg, uaddr))
 363                         return -EFAULT;
 364
 365                 return vgic_attr_regs_access_v2(dev, attr, &reg, true);
 366         }
 367         }
 368
 369         return -ENXIO;
 370 }
 371
 372 static int vgic_v2_get_attr(struct kvm_device *dev,
 373                             struct kvm_device_attr *attr)
 374 {
 375         int ret;
 376
 377         ret = vgic_get_common_attr(dev, attr);
 378         if (ret != -ENXIO)
 379                 return ret;
 380
 381         switch (attr->group) {
 382         case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
 383         case KVM_DEV_ARM_VGIC_GRP_CPU_REGS: {
 384                 u32 __user *uaddr = (u32 __user *)(long)attr->addr;
 385                 u32 reg = 0;
 386
 387                 ret = vgic_attr_regs_access_v2(dev, attr, &reg, false);
 388                 if (ret)
 389                         return ret;
 390                 return put_user(reg, uaddr);
 391         }
 392         }
 393
 394         return -ENXIO;
 395 }
 396
 397 static int vgic_v2_has_attr(struct kvm_device *dev,
 398                             struct kvm_device_attr *attr)
 399 {
 400         switch (attr->group) {
 401         case KVM_DEV_ARM_VGIC_GRP_ADDR:
 402                 switch (attr->attr) {
 403                 case KVM_VGIC_V2_ADDR_TYPE_DIST:
 404                 case KVM_VGIC_V2_ADDR_TYPE_CPU:
 405                         return 0;
 406                 }
 407                 break;
 408         case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
 409         case KVM_DEV_ARM_VGIC_GRP_CPU_REGS:
 410                 return vgic_v2_has_attr_regs(dev, attr);
 411         case KVM_DEV_ARM_VGIC_GRP_NR_IRQS:
 412                 return 0;
 413         case KVM_DEV_ARM_VGIC_GRP_CTRL:
 414                 switch (attr->attr) {
 415                 case KVM_DEV_ARM_VGIC_CTRL_INIT:
 416                         return 0;
 417                 }
 418         }
 419         return -ENXIO;
 420 }
 421
 422 struct kvm_device_ops kvm_arm_vgic_v2_ops = {
 423         .name = "kvm-arm-vgic-v2",
 424         .create = vgic_create,
 425         .destroy = vgic_destroy,
 426         .set_attr = vgic_v2_set_attr,
 427         .get_attr = vgic_v2_get_attr,
 428         .has_attr = vgic_v2_has_attr,
 429 };
 430
 431 static int vgic_v3_set_attr(struct kvm_device *dev,
 432                             struct kvm_device_attr *attr)
 433 {
 434         return vgic_set_common_attr(dev, attr);
 435 }
 436
 437 static int vgic_v3_get_attr(struct kvm_device *dev,
 438                             struct kvm_device_attr *attr)
 439 {
 440         return vgic_get_common_attr(dev, attr);
 441 }
 442
 443 static int vgic_v3_has_attr(struct kvm_device *dev,
 444                             struct kvm_device_attr *attr)
 445 {
 446         switch (attr->group) {
 447         case KVM_DEV_ARM_VGIC_GRP_ADDR:
 448                 switch (attr->attr) {
 449                 case KVM_VGIC_V3_ADDR_TYPE_DIST:
 450                 case KVM_VGIC_V3_ADDR_TYPE_REDIST:
 451                         return 0;
 452                 }
 453                 break;
 454         case KVM_DEV_ARM_VGIC_GRP_NR_IRQS:
 455                 return 0;
 456         case KVM_DEV_ARM_VGIC_GRP_CTRL:
 457                 switch (attr->attr) {
 458                 case KVM_DEV_ARM_VGIC_CTRL_INIT:
 459                         return 0;
 460                 }
 461         }
 462         return -ENXIO;
 463 }
 464
 465 struct kvm_device_ops kvm_arm_vgic_v3_ops = {
 466         .name = "kvm-arm-vgic-v3",
 467         .create = vgic_create,
 468         .destroy = vgic_destroy,
 469         .set_attr = vgic_v3_set_attr,
 470         .get_attr = vgic_v3_get_attr,
 471         .has_attr = vgic_v3_has_attr,
 472 };