arch/arm/kvm/arm.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 <linux/mman.h>
  26 #include <linux/sched.h>
  27 #include <trace/events/kvm.h>
  28
  29 #define CREATE_TRACE_POINTS
  30 #include "trace.h"
  31
  32 #include <asm/unified.h>
  33 #include <asm/uaccess.h>
  34 #include <asm/ptrace.h>
  35 #include <asm/mman.h>
  36 #include <asm/cputype.h>
  37 #include <asm/tlbflush.h>
  38 #include <asm/virt.h>
  39 #include <asm/kvm_arm.h>
  40 #include <asm/kvm_asm.h>
  41 #include <asm/kvm_mmu.h>
  42
  43 #ifdef REQUIRES_VIRT
  44 __asm__(".arch_extension        virt");
  45 #endif
  46
  47 static DEFINE_PER_CPU(unsigned long, kvm_arm_hyp_stack_page);
  48 static struct vfp_hard_struct __percpu *kvm_host_vfp_state;
  49 static unsigned long hyp_default_vectors;
  50
  51
  52 int kvm_arch_hardware_enable(void *garbage)
  53 {
  54         return 0;
  55 }
  56
  57 int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu)
  58 {
  59         return kvm_vcpu_exiting_guest_mode(vcpu) == IN_GUEST_MODE;
  60 }
  61
  62 void kvm_arch_hardware_disable(void *garbage)
  63 {
  64 }
  65
  66 int kvm_arch_hardware_setup(void)
  67 {
  68         return 0;
  69 }
  70
  71 void kvm_arch_hardware_unsetup(void)
  72 {
  73 }
  74
  75 void kvm_arch_check_processor_compat(void *rtn)
  76 {
  77         *(int *)rtn = 0;
  78 }
  79
  80 void kvm_arch_sync_events(struct kvm *kvm)
  81 {
  82 }
  83
  84 int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
  85 {
  86         if (type)
  87                 return -EINVAL;
  88
  89         return 0;
  90 }
  91
  92 int kvm_arch_vcpu_fault(struct kvm_vcpu *vcpu, struct vm_fault *vmf)
  93 {
  94         return VM_FAULT_SIGBUS;
  95 }
  96
  97 void kvm_arch_free_memslot(struct kvm_memory_slot *free,
  98                            struct kvm_memory_slot *dont)
  99 {
 100 }
 101
 102 int kvm_arch_create_memslot(struct kvm_memory_slot *slot, unsigned long npages)
 103 {
 104         return 0;
 105 }
 106
 107 void kvm_arch_destroy_vm(struct kvm *kvm)
 108 {
 109         int i;
 110
 111         for (i = 0; i < KVM_MAX_VCPUS; ++i) {
 112                 if (kvm->vcpus[i]) {
 113                         kvm_arch_vcpu_free(kvm->vcpus[i]);
 114                         kvm->vcpus[i] = NULL;
 115                 }
 116         }
 117 }
 118
 119 int kvm_dev_ioctl_check_extension(long ext)
 120 {
 121         int r;
 122         switch (ext) {
 123         case KVM_CAP_USER_MEMORY:
 124         case KVM_CAP_SYNC_MMU:
 125         case KVM_CAP_DESTROY_MEMORY_REGION_WORKS:
 126         case KVM_CAP_ONE_REG:
 127                 r = 1;
 128                 break;
 129         case KVM_CAP_COALESCED_MMIO:
 130                 r = KVM_COALESCED_MMIO_PAGE_OFFSET;
 131                 break;
 132         case KVM_CAP_NR_VCPUS:
 133                 r = num_online_cpus();
 134                 break;
 135         case KVM_CAP_MAX_VCPUS:
 136                 r = KVM_MAX_VCPUS;
 137                 break;
 138         default:
 139                 r = 0;
 140                 break;
 141         }
 142         return r;
 143 }
 144
 145 long kvm_arch_dev_ioctl(struct file *filp,
 146                         unsigned int ioctl, unsigned long arg)
 147 {
 148         return -EINVAL;
 149 }
 150
 151 int kvm_arch_set_memory_region(struct kvm *kvm,
 152                                struct kvm_userspace_memory_region *mem,
 153                                struct kvm_memory_slot old,
 154                                int user_alloc)
 155 {
 156         return 0;
 157 }
 158
 159 int kvm_arch_prepare_memory_region(struct kvm *kvm,
 160                                    struct kvm_memory_slot *memslot,
 161                                    struct kvm_memory_slot old,
 162                                    struct kvm_userspace_memory_region *mem,
 163                                    int user_alloc)
 164 {
 165         return 0;
 166 }
 167
 168 void kvm_arch_commit_memory_region(struct kvm *kvm,
 169                                    struct kvm_userspace_memory_region *mem,
 170                                    struct kvm_memory_slot old,
 171                                    int user_alloc)
 172 {
 173 }
 174
 175 void kvm_arch_flush_shadow_all(struct kvm *kvm)
 176 {
 177 }
 178
 179 void kvm_arch_flush_shadow_memslot(struct kvm *kvm,
 180                                    struct kvm_memory_slot *slot)
 181 {
 182 }
 183
 184 struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm, unsigned int id)
 185 {
 186         int err;
 187         struct kvm_vcpu *vcpu;
 188
 189         vcpu = kmem_cache_zalloc(kvm_vcpu_cache, GFP_KERNEL);
 190         if (!vcpu) {
 191                 err = -ENOMEM;
 192                 goto out;
 193         }
 194
 195         err = kvm_vcpu_init(vcpu, kvm, id);
 196         if (err)
 197                 goto free_vcpu;
 198
 199         return vcpu;
 200 free_vcpu:
 201         kmem_cache_free(kvm_vcpu_cache, vcpu);
 202 out:
 203         return ERR_PTR(err);
 204 }
 205
 206 int kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu)
 207 {
 208         return 0;
 209 }
 210
 211 void kvm_arch_vcpu_free(struct kvm_vcpu *vcpu)
 212 {
 213 }
 214
 215 void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu)
 216 {
 217         kvm_arch_vcpu_free(vcpu);
 218 }
 219
 220 int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu)
 221 {
 222         return 0;
 223 }
 224
 225 int __attribute_const__ kvm_target_cpu(void)
 226 {
 227         unsigned long implementor = read_cpuid_implementor();
 228         unsigned long part_number = read_cpuid_part_number();
 229
 230         if (implementor != ARM_CPU_IMP_ARM)
 231                 return -EINVAL;
 232
 233         switch (part_number) {
 234         case ARM_CPU_PART_CORTEX_A15:
 235                 return KVM_ARM_TARGET_CORTEX_A15;
 236         default:
 237                 return -EINVAL;
 238         }
 239 }
 240
 241 int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
 242 {
 243         return 0;
 244 }
 245
 246 void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu)
 247 {
 248 }
 249
 250 void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 251 {
 252 }
 253
 254 void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
 255 {
 256 }
 257
 258 int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu,
 259                                         struct kvm_guest_debug *dbg)
 260 {
 261         return -EINVAL;
 262 }
 263
 264
 265 int kvm_arch_vcpu_ioctl_get_mpstate(struct kvm_vcpu *vcpu,
 266                                     struct kvm_mp_state *mp_state)
 267 {
 268         return -EINVAL;
 269 }
 270
 271 int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu,
 272                                     struct kvm_mp_state *mp_state)
 273 {
 274         return -EINVAL;
 275 }
 276
 277 int kvm_arch_vcpu_runnable(struct kvm_vcpu *v)
 278 {
 279         return 0;
 280 }
 281
 282 int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
 283 {
 284         return -EINVAL;
 285 }
 286
 287 long kvm_arch_vcpu_ioctl(struct file *filp,
 288                          unsigned int ioctl, unsigned long arg)
 289 {
 290         struct kvm_vcpu *vcpu = filp->private_data;
 291         void __user *argp = (void __user *)arg;
 292
 293         switch (ioctl) {
 294         case KVM_ARM_VCPU_INIT: {
 295                 struct kvm_vcpu_init init;
 296
 297                 if (copy_from_user(&init, argp, sizeof(init)))
 298                         return -EFAULT;
 299
 300                 return kvm_vcpu_set_target(vcpu, &init);
 301
 302         }
 303         case KVM_SET_ONE_REG:
 304         case KVM_GET_ONE_REG: {
 305                 struct kvm_one_reg reg;
 306                 if (copy_from_user(&reg, argp, sizeof(reg)))
 307                         return -EFAULT;
 308                 if (ioctl == KVM_SET_ONE_REG)
 309                         return kvm_arm_set_reg(vcpu, &reg);
 310                 else
 311                         return kvm_arm_get_reg(vcpu, &reg);
 312         }
 313         case KVM_GET_REG_LIST: {
 314                 struct kvm_reg_list __user *user_list = argp;
 315                 struct kvm_reg_list reg_list;
 316                 unsigned n;
 317
 318                 if (copy_from_user(&reg_list, user_list, sizeof(reg_list)))
 319                         return -EFAULT;
 320                 n = reg_list.n;
 321                 reg_list.n = kvm_arm_num_regs(vcpu);
 322                 if (copy_to_user(user_list, &reg_list, sizeof(reg_list)))
 323                         return -EFAULT;
 324                 if (n < reg_list.n)
 325                         return -E2BIG;
 326                 return kvm_arm_copy_reg_indices(vcpu, user_list->reg);
 327         }
 328         default:
 329                 return -EINVAL;
 330         }
 331 }
 332
 333 int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log)
 334 {
 335         return -EINVAL;
 336 }
 337
 338 long kvm_arch_vm_ioctl(struct file *filp,
 339                        unsigned int ioctl, unsigned long arg)
 340 {
 341         return -EINVAL;
 342 }
 343
 344 static void cpu_init_hyp_mode(void *vector)
 345 {
 346         unsigned long long pgd_ptr;
 347         unsigned long pgd_low, pgd_high;
 348         unsigned long hyp_stack_ptr;
 349         unsigned long stack_page;
 350         unsigned long vector_ptr;
 351
 352         /* Switch from the HYP stub to our own HYP init vector */
 353         __hyp_set_vectors((unsigned long)vector);
 354
 355         pgd_ptr = (unsigned long long)kvm_mmu_get_httbr();
 356         pgd_low = (pgd_ptr & ((1ULL << 32) - 1));
 357         pgd_high = (pgd_ptr >> 32ULL);
 358         stack_page = __get_cpu_var(kvm_arm_hyp_stack_page);
 359         hyp_stack_ptr = stack_page + PAGE_SIZE;
 360         vector_ptr = (unsigned long)__kvm_hyp_vector;
 361
 362         /*
 363          * Call initialization code, and switch to the full blown
 364          * HYP code. The init code doesn't need to preserve these registers as
 365          * r1-r3 and r12 are already callee save according to the AAPCS.
 366          * Note that we slightly misuse the prototype by casing the pgd_low to
 367          * a void *.
 368          */
 369         kvm_call_hyp((void *)pgd_low, pgd_high, hyp_stack_ptr, vector_ptr);
 370 }
 371
 372 /**
 373  * Inits Hyp-mode on all online CPUs
 374  */
 375 static int init_hyp_mode(void)
 376 {
 377         phys_addr_t init_phys_addr;
 378         int cpu;
 379         int err = 0;
 380
 381         /*
 382          * Allocate Hyp PGD and setup Hyp identity mapping
 383          */
 384         err = kvm_mmu_init();
 385         if (err)
 386                 goto out_err;
 387
 388         /*
 389          * It is probably enough to obtain the default on one
 390          * CPU. It's unlikely to be different on the others.
 391          */
 392         hyp_default_vectors = __hyp_get_vectors();
 393
 394         /*
 395          * Allocate stack pages for Hypervisor-mode
 396          */
 397         for_each_possible_cpu(cpu) {
 398                 unsigned long stack_page;
 399
 400                 stack_page = __get_free_page(GFP_KERNEL);
 401                 if (!stack_page) {
 402                         err = -ENOMEM;
 403                         goto out_free_stack_pages;
 404                 }
 405
 406                 per_cpu(kvm_arm_hyp_stack_page, cpu) = stack_page;
 407         }
 408
 409         /*
 410          * Execute the init code on each CPU.
 411          *
 412          * Note: The stack is not mapped yet, so don't do anything else than
 413          * initializing the hypervisor mode on each CPU using a local stack
 414          * space for temporary storage.
 415          */
 416         init_phys_addr = virt_to_phys(__kvm_hyp_init);
 417         for_each_online_cpu(cpu) {
 418                 smp_call_function_single(cpu, cpu_init_hyp_mode,
 419                                          (void *)(long)init_phys_addr, 1);
 420         }
 421
 422         /*
 423          * Unmap the identity mapping
 424          */
 425         kvm_clear_hyp_idmap();
 426
 427         /*
 428          * Map the Hyp-code called directly from the host
 429          */
 430         err = create_hyp_mappings(__kvm_hyp_code_start, __kvm_hyp_code_end);
 431         if (err) {
 432                 kvm_err("Cannot map world-switch code\n");
 433                 goto out_free_mappings;
 434         }
 435
 436         /*
 437          * Map the Hyp stack pages
 438          */
 439         for_each_possible_cpu(cpu) {
 440                 char *stack_page = (char *)per_cpu(kvm_arm_hyp_stack_page, cpu);
 441                 err = create_hyp_mappings(stack_page, stack_page + PAGE_SIZE);
 442
 443                 if (err) {
 444                         kvm_err("Cannot map hyp stack\n");
 445                         goto out_free_mappings;
 446                 }
 447         }
 448
 449         /*
 450          * Map the host VFP structures
 451          */
 452         kvm_host_vfp_state = alloc_percpu(struct vfp_hard_struct);
 453         if (!kvm_host_vfp_state) {
 454                 err = -ENOMEM;
 455                 kvm_err("Cannot allocate host VFP state\n");
 456                 goto out_free_mappings;
 457         }
 458
 459         for_each_possible_cpu(cpu) {
 460                 struct vfp_hard_struct *vfp;
 461
 462                 vfp = per_cpu_ptr(kvm_host_vfp_state, cpu);
 463                 err = create_hyp_mappings(vfp, vfp + 1);
 464
 465                 if (err) {
 466                         kvm_err("Cannot map host VFP state: %d\n", err);
 467                         goto out_free_vfp;
 468                 }
 469         }
 470
 471         kvm_info("Hyp mode initialized successfully\n");
 472         return 0;
 473 out_free_vfp:
 474         free_percpu(kvm_host_vfp_state);
 475 out_free_mappings:
 476         free_hyp_pmds();
 477 out_free_stack_pages:
 478         for_each_possible_cpu(cpu)
 479                 free_page(per_cpu(kvm_arm_hyp_stack_page, cpu));
 480 out_err:
 481         kvm_err("error initializing Hyp mode: %d\n", err);
 482         return err;
 483 }
 484
 485 /**
 486  * Initialize Hyp-mode and memory mappings on all CPUs.
 487  */
 488 int kvm_arch_init(void *opaque)
 489 {
 490         int err;
 491
 492         if (!is_hyp_mode_available()) {
 493                 kvm_err("HYP mode not available\n");
 494                 return -ENODEV;
 495         }
 496
 497         if (kvm_target_cpu() < 0) {
 498                 kvm_err("Target CPU not supported!\n");
 499                 return -ENODEV;
 500         }
 501
 502         err = init_hyp_mode();
 503         if (err)
 504                 goto out_err;
 505
 506         return 0;
 507 out_err:
 508         return err;
 509 }
 510
 511 /* NOP: Compiling as a module not supported */
 512 void kvm_arch_exit(void)
 513 {
 514 }
 515
 516 static int arm_init(void)
 517 {
 518         int rc = kvm_init(NULL, sizeof(struct kvm_vcpu), 0, THIS_MODULE);
 519         return rc;
 520 }
 521
 522 module_init(arm_init);