arch/arm/kvm/guest.c

   1 /*
   2  * Copyright (C) 2012 - Virtual Open Systems and Columbia University
   3  * Author: Christoffer Dall <c.dall@virtualopensystems.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License, version 2, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  17  */
  18
  19 #include <linux/errno.h>
  20 #include <linux/err.h>
  21 #include <linux/kvm_host.h>
  22 #include <linux/module.h>
  23 #include <linux/vmalloc.h>
  24 #include <linux/fs.h>
  25 #include <asm/cputype.h>
  26 #include <asm/uaccess.h>
  27 #include <asm/kvm.h>
  28 #include <asm/kvm_asm.h>
  29 #include <asm/kvm_emulate.h>
  30 #include <asm/kvm_coproc.h>
  31
  32 #define VM_STAT(x) { #x, offsetof(struct kvm, stat.x), KVM_STAT_VM }
  33 #define VCPU_STAT(x) { #x, offsetof(struct kvm_vcpu, stat.x), KVM_STAT_VCPU }
  34
  35 struct kvm_stats_debugfs_item debugfs_entries[] = {
  36         { NULL }
  37 };
  38
  39 int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)
  40 {
  41         return 0;
  42 }
  43
  44 static u64 core_reg_offset_from_id(u64 id)
  45 {
  46         return id & ~(KVM_REG_ARCH_MASK | KVM_REG_SIZE_MASK | KVM_REG_ARM_CORE);
  47 }
  48
  49 static int get_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
  50 {
  51         u32 __user *uaddr = (u32 __user *)(long)reg->addr;
  52         struct kvm_regs *regs = &vcpu->arch.regs;
  53         u64 off;
  54
  55         if (KVM_REG_SIZE(reg->id) != 4)
  56                 return -ENOENT;
  57
  58         /* Our ID is an index into the kvm_regs struct. */
  59         off = core_reg_offset_from_id(reg->id);
  60         if (off >= sizeof(*regs) / KVM_REG_SIZE(reg->id))
  61                 return -ENOENT;
  62
  63         return put_user(((u32 *)regs)[off], uaddr);
  64 }
  65
  66 static int set_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
  67 {
  68         u32 __user *uaddr = (u32 __user *)(long)reg->addr;
  69         struct kvm_regs *regs = &vcpu->arch.regs;
  70         u64 off, val;
  71
  72         if (KVM_REG_SIZE(reg->id) != 4)
  73                 return -ENOENT;
  74
  75         /* Our ID is an index into the kvm_regs struct. */
  76         off = core_reg_offset_from_id(reg->id);
  77         if (off >= sizeof(*regs) / KVM_REG_SIZE(reg->id))
  78                 return -ENOENT;
  79
  80         if (get_user(val, uaddr) != 0)
  81                 return -EFAULT;
  82
  83         if (off == KVM_REG_ARM_CORE_REG(usr_regs.ARM_cpsr)) {
  84                 unsigned long mode = val & MODE_MASK;
  85                 switch (mode) {
  86                 case USR_MODE:
  87                 case FIQ_MODE:
  88                 case IRQ_MODE:
  89                 case SVC_MODE:
  90                 case ABT_MODE:
  91                 case UND_MODE:
  92                         break;
  93                 default:
  94                         return -EINVAL;
  95                 }
  96         }
  97
  98         ((u32 *)regs)[off] = val;
  99         return 0;
 100 }
 101
 102 int kvm_arch_vcpu_ioctl_get_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
 103 {
 104         return -EINVAL;
 105 }
 106
 107 int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
 108 {
 109         return -EINVAL;
 110 }
 111
 112 #ifndef CONFIG_KVM_ARM_TIMER
 113
 114 #define NUM_TIMER_REGS 0
 115
 116 static int copy_timer_indices(struct kvm_vcpu *vcpu, u64 __user *uindices)
 117 {
 118         return 0;
 119 }
 120
 121 static bool is_timer_reg(u64 index)
 122 {
 123         return false;
 124 }
 125
 126 int kvm_arm_timer_set_reg(struct kvm_vcpu *vcpu, u64 regid, u64 value)
 127 {
 128         return 0;
 129 }
 130
 131 u64 kvm_arm_timer_get_reg(struct kvm_vcpu *vcpu, u64 regid)
 132 {
 133         return 0;
 134 }
 135
 136 #else
 137
 138 #define NUM_TIMER_REGS 3
 139
 140 static bool is_timer_reg(u64 index)
 141 {
 142         switch (index) {
 143         case KVM_REG_ARM_TIMER_CTL:
 144         case KVM_REG_ARM_TIMER_CNT:
 145         case KVM_REG_ARM_TIMER_CVAL:
 146                 return true;
 147         }
 148         return false;
 149 }
 150
 151 static int copy_timer_indices(struct kvm_vcpu *vcpu, u64 __user *uindices)
 152 {
 153         if (put_user(KVM_REG_ARM_TIMER_CTL, uindices))
 154                 return -EFAULT;
 155         uindices++;
 156         if (put_user(KVM_REG_ARM_TIMER_CNT, uindices))
 157                 return -EFAULT;
 158         uindices++;
 159         if (put_user(KVM_REG_ARM_TIMER_CVAL, uindices))
 160                 return -EFAULT;
 161
 162         return 0;
 163 }
 164
 165 #endif
 166
 167 static int set_timer_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
 168 {
 169         void __user *uaddr = (void __user *)(long)reg->addr;
 170         u64 val;
 171         int ret;
 172
 173         ret = copy_from_user(&val, uaddr, KVM_REG_SIZE(reg->id));
 174         if (ret != 0)
 175                 return ret;
 176
 177         return kvm_arm_timer_set_reg(vcpu, reg->id, val);
 178 }
 179
 180 static int get_timer_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
 181 {
 182         void __user *uaddr = (void __user *)(long)reg->addr;
 183         u64 val;
 184
 185         val = kvm_arm_timer_get_reg(vcpu, reg->id);
 186         return copy_to_user(uaddr, &val, KVM_REG_SIZE(reg->id));
 187 }
 188
 189 static unsigned long num_core_regs(void)
 190 {
 191         return sizeof(struct kvm_regs) / sizeof(u32);
 192 }
 193
 194 /**
 195  * kvm_arm_num_regs - how many registers do we present via KVM_GET_ONE_REG
 196  *
 197  * This is for all registers.
 198  */
 199 unsigned long kvm_arm_num_regs(struct kvm_vcpu *vcpu)
 200 {
 201         return num_core_regs() + kvm_arm_num_coproc_regs(vcpu)
 202                 + NUM_TIMER_REGS;
 203 }
 204
 205 /**
 206  * kvm_arm_copy_reg_indices - get indices of all registers.
 207  *
 208  * We do core registers right here, then we apppend coproc regs.
 209  */
 210 int kvm_arm_copy_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices)
 211 {
 212         unsigned int i;
 213         const u64 core_reg = KVM_REG_ARM | KVM_REG_SIZE_U32 | KVM_REG_ARM_CORE;
 214         int ret;
 215
 216         for (i = 0; i < sizeof(struct kvm_regs)/sizeof(u32); i++) {
 217                 if (put_user(core_reg | i, uindices))
 218                         return -EFAULT;
 219                 uindices++;
 220         }
 221
 222         ret = copy_timer_indices(vcpu, uindices);
 223         if (ret)
 224                 return ret;
 225         uindices += NUM_TIMER_REGS;
 226
 227         return kvm_arm_copy_coproc_indices(vcpu, uindices);
 228 }
 229
 230 int kvm_arm_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
 231 {
 232         /* We currently use nothing arch-specific in upper 32 bits */
 233         if ((reg->id & ~KVM_REG_SIZE_MASK) >> 32 != KVM_REG_ARM >> 32)
 234                 return -EINVAL;
 235
 236         /* Register group 16 means we want a core register. */
 237         if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_CORE)
 238                 return get_core_reg(vcpu, reg);
 239
 240         if (is_timer_reg(reg->id))
 241                 return get_timer_reg(vcpu, reg);
 242
 243         return kvm_arm_coproc_get_reg(vcpu, reg);
 244 }
 245
 246 int kvm_arm_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
 247 {
 248         /* We currently use nothing arch-specific in upper 32 bits */
 249         if ((reg->id & ~KVM_REG_SIZE_MASK) >> 32 != KVM_REG_ARM >> 32)
 250                 return -EINVAL;
 251
 252         /* Register group 16 means we set a core register. */
 253         if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_CORE)
 254                 return set_core_reg(vcpu, reg);
 255
 256         if (is_timer_reg(reg->id))
 257                 return set_timer_reg(vcpu, reg);
 258
 259         return kvm_arm_coproc_set_reg(vcpu, reg);
 260 }
 261
 262 int kvm_arch_vcpu_ioctl_get_sregs(struct kvm_vcpu *vcpu,
 263                                   struct kvm_sregs *sregs)
 264 {
 265         return -EINVAL;
 266 }
 267
 268 int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
 269                                   struct kvm_sregs *sregs)
 270 {
 271         return -EINVAL;
 272 }
 273
 274 int __attribute_const__ kvm_target_cpu(void)
 275 {
 276         unsigned long implementor = read_cpuid_implementor();
 277         unsigned long part_number = read_cpuid_part_number();
 278
 279         if (implementor != ARM_CPU_IMP_ARM)
 280                 return -EINVAL;
 281
 282         switch (part_number) {
 283         case ARM_CPU_PART_CORTEX_A7:
 284                 return KVM_ARM_TARGET_CORTEX_A7;
 285         case ARM_CPU_PART_CORTEX_A15:
 286                 return KVM_ARM_TARGET_CORTEX_A15;
 287         default:
 288                 return -EINVAL;
 289         }
 290 }
 291
 292 int kvm_vcpu_set_target(struct kvm_vcpu *vcpu,
 293                         const struct kvm_vcpu_init *init)
 294 {
 295         unsigned int i;
 296
 297         /* We can only cope with guest==host and only on A15/A7 (for now). */
 298         if (init->target != kvm_target_cpu())
 299                 return -EINVAL;
 300
 301         vcpu->arch.target = init->target;
 302         bitmap_zero(vcpu->arch.features, KVM_VCPU_MAX_FEATURES);
 303
 304         /* -ENOENT for unknown features, -EINVAL for invalid combinations. */
 305         for (i = 0; i < sizeof(init->features) * 8; i++) {
 306                 if (test_bit(i, (void *)init->features)) {
 307                         if (i >= KVM_VCPU_MAX_FEATURES)
 308                                 return -ENOENT;
 309                         set_bit(i, vcpu->arch.features);
 310                 }
 311         }
 312
 313         /* Now we know what it is, we can reset it. */
 314         return kvm_reset_vcpu(vcpu);
 315 }
 316
 317 int kvm_vcpu_preferred_target(struct kvm_vcpu_init *init)
 318 {
 319         int target = kvm_target_cpu();
 320
 321         if (target < 0)
 322                 return -ENODEV;
 323
 324         memset(init, 0, sizeof(*init));
 325
 326         /*
 327          * For now, we don't return any features.
 328          * In future, we might use features to return target
 329          * specific features available for the preferred
 330          * target type.
 331          */
 332         init->target = (__u32)target;
 333
 334         return 0;
 335 }
 336
 337 int kvm_arch_vcpu_ioctl_get_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
 338 {
 339         return -EINVAL;
 340 }
 341
 342 int kvm_arch_vcpu_ioctl_set_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
 343 {
 344         return -EINVAL;
 345 }
 346
 347 int kvm_arch_vcpu_ioctl_translate(struct kvm_vcpu *vcpu,
 348                                   struct kvm_translation *tr)
 349 {
 350         return -EINVAL;
 351 }