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 static 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 #ifdef CONFIG_KVM_ARM_VGIC_V3
  75         case KVM_VGIC_V3_ADDR_TYPE_DIST:
  76                 type_needed = KVM_DEV_TYPE_ARM_VGIC_V3;
  77                 addr_ptr = &vgic->vgic_dist_base;
  78                 alignment = SZ_64K;
  79                 break;
  80         case KVM_VGIC_V3_ADDR_TYPE_REDIST:
  81                 type_needed = KVM_DEV_TYPE_ARM_VGIC_V3;
  82                 addr_ptr = &vgic->vgic_redist_base;
  83                 alignment = SZ_64K;
  84                 break;
  85 #endif
  86         default:
  87                 r = -ENODEV;
  88                 goto out;
  89         }
  90
  91         if (vgic->vgic_model != type_needed) {
  92                 r = -ENODEV;
  93                 goto out;
  94         }
  95
  96         if (write) {
  97                 r = vgic_check_ioaddr(kvm, addr_ptr, *addr, alignment);
  98                 if (!r)
  99                         *addr_ptr = *addr;
 100         } else {
 101                 *addr = *addr_ptr;
 102         }
 103
 104 out:
 105         mutex_unlock(&kvm->lock);
 106         return r;
 107 }
 108
 109 static int vgic_set_common_attr(struct kvm_device *dev,
 110                                 struct kvm_device_attr *attr)
 111 {
 112         int r;
 113
 114         switch (attr->group) {
 115         case KVM_DEV_ARM_VGIC_GRP_ADDR: {
 116                 u64 __user *uaddr = (u64 __user *)(long)attr->addr;
 117                 u64 addr;
 118                 unsigned long type = (unsigned long)attr->attr;
 119
 120                 if (copy_from_user(&addr, uaddr, sizeof(addr)))
 121                         return -EFAULT;
 122
 123                 r = kvm_vgic_addr(dev->kvm, type, &addr, true);
 124                 return (r == -ENODEV) ? -ENXIO : r;
 125         }
 126         case KVM_DEV_ARM_VGIC_GRP_NR_IRQS: {
 127                 u32 __user *uaddr = (u32 __user *)(long)attr->addr;
 128                 u32 val;
 129                 int ret = 0;
 130
 131                 if (get_user(val, uaddr))
 132                         return -EFAULT;
 133
 134                 /*
 135                  * We require:
 136                  * - at least 32 SPIs on top of the 16 SGIs and 16 PPIs
 137                  * - at most 1024 interrupts
 138                  * - a multiple of 32 interrupts
 139                  */
 140                 if (val < (VGIC_NR_PRIVATE_IRQS + 32) ||
 141                     val > VGIC_MAX_RESERVED ||
 142                     (val & 31))
 143                         return -EINVAL;
 144
 145                 mutex_lock(&dev->kvm->lock);
 146
 147                 if (vgic_ready(dev->kvm) || dev->kvm->arch.vgic.nr_spis)
 148                         ret = -EBUSY;
 149                 else
 150                         dev->kvm->arch.vgic.nr_spis =
 151                                 val - VGIC_NR_PRIVATE_IRQS;
 152
 153                 mutex_unlock(&dev->kvm->lock);
 154
 155                 return ret;
 156         }
 157         case KVM_DEV_ARM_VGIC_GRP_CTRL: {
 158                 switch (attr->attr) {
 159                 case KVM_DEV_ARM_VGIC_CTRL_INIT:
 160                         mutex_lock(&dev->kvm->lock);
 161                         r = vgic_init(dev->kvm);
 162                         mutex_unlock(&dev->kvm->lock);
 163                         return r;
 164                 }
 165                 break;
 166         }
 167         }
 168
 169         return -ENXIO;
 170 }
 171
 172 static int vgic_get_common_attr(struct kvm_device *dev,
 173                                 struct kvm_device_attr *attr)
 174 {
 175         int r = -ENXIO;
 176
 177         switch (attr->group) {
 178         case KVM_DEV_ARM_VGIC_GRP_ADDR: {
 179                 u64 __user *uaddr = (u64 __user *)(long)attr->addr;
 180                 u64 addr;
 181                 unsigned long type = (unsigned long)attr->attr;
 182
 183                 r = kvm_vgic_addr(dev->kvm, type, &addr, false);
 184                 if (r)
 185                         return (r == -ENODEV) ? -ENXIO : r;
 186
 187                 if (copy_to_user(uaddr, &addr, sizeof(addr)))
 188                         return -EFAULT;
 189                 break;
 190         }
 191         case KVM_DEV_ARM_VGIC_GRP_NR_IRQS: {
 192                 u32 __user *uaddr = (u32 __user *)(long)attr->addr;
 193
 194                 r = put_user(dev->kvm->arch.vgic.nr_spis +
 195                              VGIC_NR_PRIVATE_IRQS, uaddr);
 196                 break;
 197         }
 198         }
 199
 200         return r;
 201 }
 202
 203 static int vgic_create(struct kvm_device *dev, u32 type)
 204 {
 205         return kvm_vgic_create(dev->kvm, type);
 206 }
 207
 208 static void vgic_destroy(struct kvm_device *dev)
 209 {
 210         kfree(dev);
 211 }
 212
 213 void kvm_register_vgic_device(unsigned long type)
 214 {
 215         switch (type) {
 216         case KVM_DEV_TYPE_ARM_VGIC_V2:
 217                 kvm_register_device_ops(&kvm_arm_vgic_v2_ops,
 218                                         KVM_DEV_TYPE_ARM_VGIC_V2);
 219                 break;
 220 #ifdef CONFIG_KVM_ARM_VGIC_V3
 221         case KVM_DEV_TYPE_ARM_VGIC_V3:
 222                 kvm_register_device_ops(&kvm_arm_vgic_v3_ops,
 223                                         KVM_DEV_TYPE_ARM_VGIC_V3);
 224                 break;
 225 #endif
 226         }
 227 }
 228
 229 /** vgic_attr_regs_access: allows user space to read/write VGIC registers
 230  *
 231  * @dev: kvm device handle
 232  * @attr: kvm device attribute
 233  * @reg: address the value is read or written
 234  * @is_write: write flag
 235  *
 236  */
 237 static int vgic_attr_regs_access(struct kvm_device *dev,
 238                                  struct kvm_device_attr *attr,
 239                                  u32 *reg, bool is_write)
 240 {
 241         gpa_t addr;
 242         int cpuid, ret, c;
 243         struct kvm_vcpu *vcpu, *tmp_vcpu;
 244         int vcpu_lock_idx = -1;
 245
 246         cpuid = (attr->attr & KVM_DEV_ARM_VGIC_CPUID_MASK) >>
 247                  KVM_DEV_ARM_VGIC_CPUID_SHIFT;
 248         vcpu = kvm_get_vcpu(dev->kvm, cpuid);
 249         addr = attr->attr & KVM_DEV_ARM_VGIC_OFFSET_MASK;
 250
 251         mutex_lock(&dev->kvm->lock);
 252
 253         ret = vgic_init(dev->kvm);
 254         if (ret)
 255                 goto out;
 256
 257         if (cpuid >= atomic_read(&dev->kvm->online_vcpus)) {
 258                 ret = -EINVAL;
 259                 goto out;
 260         }
 261
 262         /*
 263          * Any time a vcpu is run, vcpu_load is called which tries to grab the
 264          * vcpu->mutex.  By grabbing the vcpu->mutex of all VCPUs we ensure
 265          * that no other VCPUs are run and fiddle with the vgic state while we
 266          * access it.
 267          */
 268         ret = -EBUSY;
 269         kvm_for_each_vcpu(c, tmp_vcpu, dev->kvm) {
 270                 if (!mutex_trylock(&tmp_vcpu->mutex))
 271                         goto out;
 272                 vcpu_lock_idx = c;
 273         }
 274
 275         switch (attr->group) {
 276         case KVM_DEV_ARM_VGIC_GRP_CPU_REGS:
 277                 ret = vgic_v2_cpuif_uaccess(vcpu, is_write, addr, reg);
 278                 break;
 279         case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
 280                 ret = vgic_v2_dist_uaccess(vcpu, is_write, addr, reg);
 281                 break;
 282         default:
 283                 ret = -EINVAL;
 284                 break;
 285         }
 286
 287 out:
 288         for (; vcpu_lock_idx >= 0; vcpu_lock_idx--) {
 289                 tmp_vcpu = kvm_get_vcpu(dev->kvm, vcpu_lock_idx);
 290                 mutex_unlock(&tmp_vcpu->mutex);
 291         }
 292
 293         mutex_unlock(&dev->kvm->lock);
 294         return ret;
 295 }
 296
 297 /* V2 ops */
 298
 299 static int vgic_v2_set_attr(struct kvm_device *dev,
 300                             struct kvm_device_attr *attr)
 301 {
 302         int ret;
 303
 304         ret = vgic_set_common_attr(dev, attr);
 305         if (ret != -ENXIO)
 306                 return ret;
 307
 308         switch (attr->group) {
 309         case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
 310         case KVM_DEV_ARM_VGIC_GRP_CPU_REGS: {
 311                 u32 __user *uaddr = (u32 __user *)(long)attr->addr;
 312                 u32 reg;
 313
 314                 if (get_user(reg, uaddr))
 315                         return -EFAULT;
 316
 317                 return vgic_attr_regs_access(dev, attr, &reg, true);
 318         }
 319         }
 320
 321         return -ENXIO;
 322 }
 323
 324 static int vgic_v2_get_attr(struct kvm_device *dev,
 325                             struct kvm_device_attr *attr)
 326 {
 327         int ret;
 328
 329         ret = vgic_get_common_attr(dev, attr);
 330         if (ret != -ENXIO)
 331                 return ret;
 332
 333         switch (attr->group) {
 334         case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
 335         case KVM_DEV_ARM_VGIC_GRP_CPU_REGS: {
 336                 u32 __user *uaddr = (u32 __user *)(long)attr->addr;
 337                 u32 reg = 0;
 338
 339                 ret = vgic_attr_regs_access(dev, attr, &reg, false);
 340                 if (ret)
 341                         return ret;
 342                 return put_user(reg, uaddr);
 343         }
 344         }
 345
 346         return -ENXIO;
 347 }
 348
 349 static int vgic_v2_has_attr(struct kvm_device *dev,
 350                             struct kvm_device_attr *attr)
 351 {
 352         switch (attr->group) {
 353         case KVM_DEV_ARM_VGIC_GRP_ADDR:
 354                 switch (attr->attr) {
 355                 case KVM_VGIC_V2_ADDR_TYPE_DIST:
 356                 case KVM_VGIC_V2_ADDR_TYPE_CPU:
 357                         return 0;
 358                 }
 359                 break;
 360         case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
 361         case KVM_DEV_ARM_VGIC_GRP_CPU_REGS:
 362                 return vgic_v2_has_attr_regs(dev, attr);
 363         case KVM_DEV_ARM_VGIC_GRP_NR_IRQS:
 364                 return 0;
 365         case KVM_DEV_ARM_VGIC_GRP_CTRL:
 366                 switch (attr->attr) {
 367                 case KVM_DEV_ARM_VGIC_CTRL_INIT:
 368                         return 0;
 369                 }
 370         }
 371         return -ENXIO;
 372 }
 373
 374 struct kvm_device_ops kvm_arm_vgic_v2_ops = {
 375         .name = "kvm-arm-vgic-v2",
 376         .create = vgic_create,
 377         .destroy = vgic_destroy,
 378         .set_attr = vgic_v2_set_attr,
 379         .get_attr = vgic_v2_get_attr,
 380         .has_attr = vgic_v2_has_attr,
 381 };
 382
 383 /* V3 ops */
 384
 385 #ifdef CONFIG_KVM_ARM_VGIC_V3
 386
 387 static int vgic_v3_set_attr(struct kvm_device *dev,
 388                             struct kvm_device_attr *attr)
 389 {
 390         return vgic_set_common_attr(dev, attr);
 391 }
 392
 393 static int vgic_v3_get_attr(struct kvm_device *dev,
 394                             struct kvm_device_attr *attr)
 395 {
 396         return vgic_get_common_attr(dev, attr);
 397 }
 398
 399 static int vgic_v3_has_attr(struct kvm_device *dev,
 400                             struct kvm_device_attr *attr)
 401 {
 402         switch (attr->group) {
 403         case KVM_DEV_ARM_VGIC_GRP_ADDR:
 404                 switch (attr->attr) {
 405                 case KVM_VGIC_V3_ADDR_TYPE_DIST:
 406                 case KVM_VGIC_V3_ADDR_TYPE_REDIST:
 407                         return 0;
 408                 }
 409                 break;
 410         case KVM_DEV_ARM_VGIC_GRP_NR_IRQS:
 411                 return 0;
 412         case KVM_DEV_ARM_VGIC_GRP_CTRL:
 413                 switch (attr->attr) {
 414                 case KVM_DEV_ARM_VGIC_CTRL_INIT:
 415                         return 0;
 416                 }
 417         }
 418         return -ENXIO;
 419 }
 420
 421 struct kvm_device_ops kvm_arm_vgic_v3_ops = {
 422         .name = "kvm-arm-vgic-v3",
 423         .create = vgic_create,
 424         .destroy = vgic_destroy,
 425         .set_attr = vgic_v3_set_attr,
 426         .get_attr = vgic_v3_get_attr,
 427         .has_attr = vgic_v3_has_attr,
 428 };
 429
 430 #endif /* CONFIG_KVM_ARM_VGIC_V3 */
 431