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 #else
 128
 129 #define NUM_TIMER_REGS 3
 130
 131 static bool is_timer_reg(u64 index)
 132 {
 133         switch (index) {
 134         case KVM_REG_ARM_TIMER_CTL:
 135         case KVM_REG_ARM_TIMER_CNT:
 136         case KVM_REG_ARM_TIMER_CVAL:
 137                 return true;
 138         }
 139         return false;
 140 }
 141
 142 static int copy_timer_indices(struct kvm_vcpu *vcpu, u64 __user *uindices)
 143 {
 144         if (put_user(KVM_REG_ARM_TIMER_CTL, uindices))
 145                 return -EFAULT;
 146         uindices++;
 147         if (put_user(KVM_REG_ARM_TIMER_CNT, uindices))
 148                 return -EFAULT;
 149         uindices++;
 150         if (put_user(KVM_REG_ARM_TIMER_CVAL, uindices))
 151                 return -EFAULT;
 152
 153         return 0;
 154 }
 155
 156 #endif
 157
 158 static int set_timer_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
 159 {
 160         void __user *uaddr = (void __user *)(long)reg->addr;
 161         u64 val;
 162         int ret;
 163
 164         ret = copy_from_user(&val, uaddr, KVM_REG_SIZE(reg->id));
 165         if (ret != 0)
 166                 return -EFAULT;
 167
 168         return kvm_arm_timer_set_reg(vcpu, reg->id, val);
 169 }
 170
 171 static int get_timer_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
 172 {
 173         void __user *uaddr = (void __user *)(long)reg->addr;
 174         u64 val;
 175
 176         val = kvm_arm_timer_get_reg(vcpu, reg->id);
 177         return copy_to_user(uaddr, &val, KVM_REG_SIZE(reg->id));
 178 }
 179
 180 static unsigned long num_core_regs(void)
 181 {
 182         return sizeof(struct kvm_regs) / sizeof(u32);
 183 }
 184
 185 /**
 186  * kvm_arm_num_regs - how many registers do we present via KVM_GET_ONE_REG
 187  *
 188  * This is for all registers.
 189  */
 190 unsigned long kvm_arm_num_regs(struct kvm_vcpu *vcpu)
 191 {
 192         return num_core_regs() + kvm_arm_num_coproc_regs(vcpu)
 193                 + NUM_TIMER_REGS;
 194 }
 195
 196 /**
 197  * kvm_arm_copy_reg_indices - get indices of all registers.
 198  *
 199  * We do core registers right here, then we apppend coproc regs.
 200  */
 201 int kvm_arm_copy_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices)
 202 {
 203         unsigned int i;
 204         const u64 core_reg = KVM_REG_ARM | KVM_REG_SIZE_U32 | KVM_REG_ARM_CORE;
 205         int ret;
 206
 207         for (i = 0; i < sizeof(struct kvm_regs)/sizeof(u32); i++) {
 208                 if (put_user(core_reg | i, uindices))
 209                         return -EFAULT;
 210                 uindices++;
 211         }
 212
 213         ret = copy_timer_indices(vcpu, uindices);
 214         if (ret)
 215                 return ret;
 216         uindices += NUM_TIMER_REGS;
 217
 218         return kvm_arm_copy_coproc_indices(vcpu, uindices);
 219 }
 220
 221 int kvm_arm_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
 222 {
 223         /* We currently use nothing arch-specific in upper 32 bits */
 224         if ((reg->id & ~KVM_REG_SIZE_MASK) >> 32 != KVM_REG_ARM >> 32)
 225                 return -EINVAL;
 226
 227         /* Register group 16 means we want a core register. */
 228         if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_CORE)
 229                 return get_core_reg(vcpu, reg);
 230
 231         if (is_timer_reg(reg->id))
 232                 return get_timer_reg(vcpu, reg);
 233
 234         return kvm_arm_coproc_get_reg(vcpu, reg);
 235 }
 236
 237 int kvm_arm_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
 238 {
 239         /* We currently use nothing arch-specific in upper 32 bits */
 240         if ((reg->id & ~KVM_REG_SIZE_MASK) >> 32 != KVM_REG_ARM >> 32)
 241                 return -EINVAL;
 242
 243         /* Register group 16 means we set a core register. */
 244         if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_CORE)
 245                 return set_core_reg(vcpu, reg);
 246
 247         if (is_timer_reg(reg->id))
 248                 return set_timer_reg(vcpu, reg);
 249
 250         return kvm_arm_coproc_set_reg(vcpu, reg);
 251 }
 252
 253 int kvm_arch_vcpu_ioctl_get_sregs(struct kvm_vcpu *vcpu,
 254                                   struct kvm_sregs *sregs)
 255 {
 256         return -EINVAL;
 257 }
 258
 259 int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
 260                                   struct kvm_sregs *sregs)
 261 {
 262         return -EINVAL;
 263 }
 264
 265 int __attribute_const__ kvm_target_cpu(void)
 266 {
 267         switch (read_cpuid_part()) {
 268         case ARM_CPU_PART_CORTEX_A7:
 269                 return KVM_ARM_TARGET_CORTEX_A7;
 270         case ARM_CPU_PART_CORTEX_A15:
 271                 return KVM_ARM_TARGET_CORTEX_A15;
 272         default:
 273                 return -EINVAL;
 274         }
 275 }
 276
 277 int kvm_vcpu_set_target(struct kvm_vcpu *vcpu,
 278                         const struct kvm_vcpu_init *init)
 279 {
 280         unsigned int i;
 281
 282         /* We can only cope with guest==host and only on A15/A7 (for now). */
 283         if (init->target != kvm_target_cpu())
 284                 return -EINVAL;
 285
 286         vcpu->arch.target = init->target;
 287         bitmap_zero(vcpu->arch.features, KVM_VCPU_MAX_FEATURES);
 288
 289         /* -ENOENT for unknown features, -EINVAL for invalid combinations. */
 290         for (i = 0; i < sizeof(init->features) * 8; i++) {
 291                 if (test_bit(i, (void *)init->features)) {
 292                         if (i >= KVM_VCPU_MAX_FEATURES)
 293                                 return -ENOENT;
 294                         set_bit(i, vcpu->arch.features);
 295                 }
 296         }
 297
 298         /* Now we know what it is, we can reset it. */
 299         return kvm_reset_vcpu(vcpu);
 300 }
 301
 302 int kvm_vcpu_preferred_target(struct kvm_vcpu_init *init)
 303 {
 304         int target = kvm_target_cpu();
 305
 306         if (target < 0)
 307                 return -ENODEV;
 308
 309         memset(init, 0, sizeof(*init));
 310
 311         /*
 312          * For now, we don't return any features.
 313          * In future, we might use features to return target
 314          * specific features available for the preferred
 315          * target type.
 316          */
 317         init->target = (__u32)target;
 318
 319         return 0;
 320 }
 321
 322 int kvm_arch_vcpu_ioctl_get_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
 323 {
 324         return -EINVAL;
 325 }
 326
 327 int kvm_arch_vcpu_ioctl_set_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
 328 {
 329         return -EINVAL;
 330 }
 331
 332 int kvm_arch_vcpu_ioctl_translate(struct kvm_vcpu *vcpu,
 333                                   struct kvm_translation *tr)
 334 {
 335         return -EINVAL;
 336 }