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         vcpu->arch.hcr = HCR_GUEST_MASK;
  42         return 0;
  43 }
  44
  45 static u64 core_reg_offset_from_id(u64 id)
  46 {
  47         return id & ~(KVM_REG_ARCH_MASK | KVM_REG_SIZE_MASK | KVM_REG_ARM_CORE);
  48 }
  49
  50 static int get_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
  51 {
  52         u32 __user *uaddr = (u32 __user *)(long)reg->addr;
  53         struct kvm_regs *regs = &vcpu->arch.regs;
  54         u64 off;
  55
  56         if (KVM_REG_SIZE(reg->id) != 4)
  57                 return -ENOENT;
  58
  59         /* Our ID is an index into the kvm_regs struct. */
  60         off = core_reg_offset_from_id(reg->id);
  61         if (off >= sizeof(*regs) / KVM_REG_SIZE(reg->id))
  62                 return -ENOENT;
  63
  64         return put_user(((u32 *)regs)[off], uaddr);
  65 }
  66
  67 static int set_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
  68 {
  69         u32 __user *uaddr = (u32 __user *)(long)reg->addr;
  70         struct kvm_regs *regs = &vcpu->arch.regs;
  71         u64 off, val;
  72
  73         if (KVM_REG_SIZE(reg->id) != 4)
  74                 return -ENOENT;
  75
  76         /* Our ID is an index into the kvm_regs struct. */
  77         off = core_reg_offset_from_id(reg->id);
  78         if (off >= sizeof(*regs) / KVM_REG_SIZE(reg->id))
  79                 return -ENOENT;
  80
  81         if (get_user(val, uaddr) != 0)
  82                 return -EFAULT;
  83
  84         if (off == KVM_REG_ARM_CORE_REG(usr_regs.ARM_cpsr)) {
  85                 unsigned long mode = val & MODE_MASK;
  86                 switch (mode) {
  87                 case USR_MODE:
  88                 case FIQ_MODE:
  89                 case IRQ_MODE:
  90                 case SVC_MODE:
  91                 case ABT_MODE:
  92                 case UND_MODE:
  93                         break;
  94                 default:
  95                         return -EINVAL;
  96                 }
  97         }
  98
  99         ((u32 *)regs)[off] = val;
 100         return 0;
 101 }
 102
 103 int kvm_arch_vcpu_ioctl_get_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
 104 {
 105         return -EINVAL;
 106 }
 107
 108 int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
 109 {
 110         return -EINVAL;
 111 }
 112
 113 #ifndef CONFIG_KVM_ARM_TIMER
 114
 115 #define NUM_TIMER_REGS 0
 116
 117 static int copy_timer_indices(struct kvm_vcpu *vcpu, u64 __user *uindices)
 118 {
 119         return 0;
 120 }
 121
 122 static bool is_timer_reg(u64 index)
 123 {
 124         return false;
 125 }
 126
 127 int kvm_arm_timer_set_reg(struct kvm_vcpu *vcpu, u64 regid, u64 value)
 128 {
 129         return 0;
 130 }
 131
 132 u64 kvm_arm_timer_get_reg(struct kvm_vcpu *vcpu, u64 regid)
 133 {
 134         return 0;
 135 }
 136
 137 #else
 138
 139 #define NUM_TIMER_REGS 3
 140
 141 static bool is_timer_reg(u64 index)
 142 {
 143         switch (index) {
 144         case KVM_REG_ARM_TIMER_CTL:
 145         case KVM_REG_ARM_TIMER_CNT:
 146         case KVM_REG_ARM_TIMER_CVAL:
 147                 return true;
 148         }
 149         return false;
 150 }
 151
 152 static int copy_timer_indices(struct kvm_vcpu *vcpu, u64 __user *uindices)
 153 {
 154         if (put_user(KVM_REG_ARM_TIMER_CTL, uindices))
 155                 return -EFAULT;
 156         uindices++;
 157         if (put_user(KVM_REG_ARM_TIMER_CNT, uindices))
 158                 return -EFAULT;
 159         uindices++;
 160         if (put_user(KVM_REG_ARM_TIMER_CVAL, uindices))
 161                 return -EFAULT;
 162
 163         return 0;
 164 }
 165
 166 #endif
 167
 168 static int set_timer_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
 169 {
 170         void __user *uaddr = (void __user *)(long)reg->addr;
 171         u64 val;
 172         int ret;
 173
 174         ret = copy_from_user(&val, uaddr, KVM_REG_SIZE(reg->id));
 175         if (ret != 0)
 176                 return ret;
 177
 178         return kvm_arm_timer_set_reg(vcpu, reg->id, val);
 179 }
 180
 181 static int get_timer_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
 182 {
 183         void __user *uaddr = (void __user *)(long)reg->addr;
 184         u64 val;
 185
 186         val = kvm_arm_timer_get_reg(vcpu, reg->id);
 187         return copy_to_user(uaddr, &val, KVM_REG_SIZE(reg->id));
 188 }
 189
 190 static unsigned long num_core_regs(void)
 191 {
 192         return sizeof(struct kvm_regs) / sizeof(u32);
 193 }
 194
 195 /**
 196  * kvm_arm_num_regs - how many registers do we present via KVM_GET_ONE_REG
 197  *
 198  * This is for all registers.
 199  */
 200 unsigned long kvm_arm_num_regs(struct kvm_vcpu *vcpu)
 201 {
 202         return num_core_regs() + kvm_arm_num_coproc_regs(vcpu)
 203                 + NUM_TIMER_REGS;
 204 }
 205
 206 /**
 207  * kvm_arm_copy_reg_indices - get indices of all registers.
 208  *
 209  * We do core registers right here, then we apppend coproc regs.
 210  */
 211 int kvm_arm_copy_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices)
 212 {
 213         unsigned int i;
 214         const u64 core_reg = KVM_REG_ARM | KVM_REG_SIZE_U32 | KVM_REG_ARM_CORE;
 215         int ret;
 216
 217         for (i = 0; i < sizeof(struct kvm_regs)/sizeof(u32); i++) {
 218                 if (put_user(core_reg | i, uindices))
 219                         return -EFAULT;
 220                 uindices++;
 221         }
 222
 223         ret = copy_timer_indices(vcpu, uindices);
 224         if (ret)
 225                 return ret;
 226         uindices += NUM_TIMER_REGS;
 227
 228         return kvm_arm_copy_coproc_indices(vcpu, uindices);
 229 }
 230
 231 int kvm_arm_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
 232 {
 233         /* We currently use nothing arch-specific in upper 32 bits */
 234         if ((reg->id & ~KVM_REG_SIZE_MASK) >> 32 != KVM_REG_ARM >> 32)
 235                 return -EINVAL;
 236
 237         /* Register group 16 means we want a core register. */
 238         if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_CORE)
 239                 return get_core_reg(vcpu, reg);
 240
 241         if (is_timer_reg(reg->id))
 242                 return get_timer_reg(vcpu, reg);
 243
 244         return kvm_arm_coproc_get_reg(vcpu, reg);
 245 }
 246
 247 int kvm_arm_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
 248 {
 249         /* We currently use nothing arch-specific in upper 32 bits */
 250         if ((reg->id & ~KVM_REG_SIZE_MASK) >> 32 != KVM_REG_ARM >> 32)
 251                 return -EINVAL;
 252
 253         /* Register group 16 means we set a core register. */
 254         if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_CORE)
 255                 return set_core_reg(vcpu, reg);
 256
 257         if (is_timer_reg(reg->id))
 258                 return set_timer_reg(vcpu, reg);
 259
 260         return kvm_arm_coproc_set_reg(vcpu, reg);
 261 }
 262
 263 int kvm_arch_vcpu_ioctl_get_sregs(struct kvm_vcpu *vcpu,
 264                                   struct kvm_sregs *sregs)
 265 {
 266         return -EINVAL;
 267 }
 268
 269 int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
 270                                   struct kvm_sregs *sregs)
 271 {
 272         return -EINVAL;
 273 }
 274
 275 int __attribute_const__ kvm_target_cpu(void)
 276 {
 277         switch (read_cpuid_part()) {
 278         case ARM_CPU_PART_CORTEX_A7:
 279                 return KVM_ARM_TARGET_CORTEX_A7;
 280         case ARM_CPU_PART_CORTEX_A15:
 281                 return KVM_ARM_TARGET_CORTEX_A15;
 282         default:
 283                 return -EINVAL;
 284         }
 285 }
 286
 287 int kvm_vcpu_set_target(struct kvm_vcpu *vcpu,
 288                         const struct kvm_vcpu_init *init)
 289 {
 290         unsigned int i;
 291
 292         /* We can only cope with guest==host and only on A15/A7 (for now). */
 293         if (init->target != kvm_target_cpu())
 294                 return -EINVAL;
 295
 296         vcpu->arch.target = init->target;
 297         bitmap_zero(vcpu->arch.features, KVM_VCPU_MAX_FEATURES);
 298
 299         /* -ENOENT for unknown features, -EINVAL for invalid combinations. */
 300         for (i = 0; i < sizeof(init->features) * 8; i++) {
 301                 if (test_bit(i, (void *)init->features)) {
 302                         if (i >= KVM_VCPU_MAX_FEATURES)
 303                                 return -ENOENT;
 304                         set_bit(i, vcpu->arch.features);
 305                 }
 306         }
 307
 308         /* Now we know what it is, we can reset it. */
 309         return kvm_reset_vcpu(vcpu);
 310 }
 311
 312 int kvm_vcpu_preferred_target(struct kvm_vcpu_init *init)
 313 {
 314         int target = kvm_target_cpu();
 315
 316         if (target < 0)
 317                 return -ENODEV;
 318
 319         memset(init, 0, sizeof(*init));
 320
 321         /*
 322          * For now, we don't return any features.
 323          * In future, we might use features to return target
 324          * specific features available for the preferred
 325          * target type.
 326          */
 327         init->target = (__u32)target;
 328
 329         return 0;
 330 }
 331
 332 int kvm_arch_vcpu_ioctl_get_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
 333 {
 334         return -EINVAL;
 335 }
 336
 337 int kvm_arch_vcpu_ioctl_set_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
 338 {
 339         return -EINVAL;
 340 }
 341
 342 int kvm_arch_vcpu_ioctl_translate(struct kvm_vcpu *vcpu,
 343                                   struct kvm_translation *tr)
 344 {
 345         return -EINVAL;
 346 }