kvm-all.c

   1 /*
   2  * QEMU KVM support
   3  *
   4  * Copyright IBM, Corp. 2008
   5  *           Red Hat, Inc. 2008
   6  *
   7  * Authors:
   8  *  Anthony Liguori   <aliguori@us.ibm.com>
   9  *  Glauber Costa     <gcosta@redhat.com>
  10  *
  11  * This work is licensed under the terms of the GNU GPL, version 2 or later.
  12  * See the COPYING file in the top-level directory.
  13  *
  14  */
  15
  16 #include <sys/types.h>
  17 #include <sys/ioctl.h>
  18 #include <sys/mman.h>
  19 #include <stdarg.h>
  20
  21 #include <linux/kvm.h>
  22
  23 #include "qemu-common.h"
  24 #include "sysemu.h"
  25 #include "kvm.h"
  26
  27 //#define DEBUG_KVM
  28
  29 #ifdef DEBUG_KVM
  30 #define dprintf(fmt, ...) \
  31     do { fprintf(stderr, fmt, ## __VA_ARGS__); } while (0)
  32 #else
  33 #define dprintf(fmt, ...) \
  34     do { } while (0)
  35 #endif
  36
  37 typedef struct KVMSlot
  38 {
  39     target_phys_addr_t start_addr;
  40     ram_addr_t memory_size;
  41     ram_addr_t phys_offset;
  42     int slot;
  43     int flags;
  44 } KVMSlot;
  45
  46 typedef struct kvm_dirty_log KVMDirtyLog;
  47
  48 int kvm_allowed = 0;
  49
  50 struct KVMState
  51 {
  52     KVMSlot slots[32];
  53     int fd;
  54     int vmfd;
  55 };
  56
  57 static KVMState *kvm_state;
  58
  59 static KVMSlot *kvm_alloc_slot(KVMState *s)
  60 {
  61     int i;
  62
  63     for (i = 0; i < ARRAY_SIZE(s->slots); i++) {
  64         /* KVM private memory slots */
  65         if (i >= 8 && i < 12)
  66             continue;
  67         if (s->slots[i].memory_size == 0)
  68             return &s->slots[i];
  69     }
  70
  71     return NULL;
  72 }
  73
  74 static KVMSlot *kvm_lookup_slot(KVMState *s, target_phys_addr_t start_addr)
  75 {
  76     int i;
  77
  78     for (i = 0; i < ARRAY_SIZE(s->slots); i++) {
  79         KVMSlot *mem = &s->slots[i];
  80
  81         if (start_addr >= mem->start_addr &&
  82             start_addr < (mem->start_addr + mem->memory_size))
  83             return mem;
  84     }
  85
  86     return NULL;
  87 }
  88
  89 static int kvm_set_user_memory_region(KVMState *s, KVMSlot *slot)
  90 {
  91     struct kvm_userspace_memory_region mem;
  92
  93     mem.slot = slot->slot;
  94     mem.guest_phys_addr = slot->start_addr;
  95     mem.memory_size = slot->memory_size;
  96     mem.userspace_addr = (unsigned long)phys_ram_base + slot->phys_offset;
  97     mem.flags = slot->flags;
  98
  99     return kvm_vm_ioctl(s, KVM_SET_USER_MEMORY_REGION, &mem);
 100 }
 101
 102
 103 int kvm_init_vcpu(CPUState *env)
 104 {
 105     KVMState *s = kvm_state;
 106     long mmap_size;
 107     int ret;
 108
 109     dprintf("kvm_init_vcpu\n");
 110
 111     ret = kvm_vm_ioctl(s, KVM_CREATE_VCPU, env->cpu_index);
 112     if (ret < 0) {
 113         dprintf("kvm_create_vcpu failed\n");
 114         goto err;
 115     }
 116
 117     env->kvm_fd = ret;
 118     env->kvm_state = s;
 119
 120     mmap_size = kvm_ioctl(s, KVM_GET_VCPU_MMAP_SIZE, 0);
 121     if (mmap_size < 0) {
 122         dprintf("KVM_GET_VCPU_MMAP_SIZE failed\n");
 123         goto err;
 124     }
 125
 126     env->kvm_run = mmap(NULL, mmap_size, PROT_READ | PROT_WRITE, MAP_SHARED,
 127                         env->kvm_fd, 0);
 128     if (env->kvm_run == MAP_FAILED) {
 129         ret = -errno;
 130         dprintf("mmap'ing vcpu state failed\n");
 131         goto err;
 132     }
 133
 134     ret = kvm_arch_init_vcpu(env);
 135
 136 err:
 137     return ret;
 138 }
 139
 140 /*
 141  * dirty pages logging control
 142  */
 143 static int kvm_dirty_pages_log_change(target_phys_addr_t phys_addr, target_phys_addr_t end_addr,
 144                                       unsigned flags,
 145                                       unsigned mask)
 146 {
 147     KVMState *s = kvm_state;
 148     KVMSlot *mem = kvm_lookup_slot(s, phys_addr);
 149     if (mem == NULL)  {
 150             dprintf("invalid parameters %llx-%llx\n", phys_addr, end_addr);
 151             return -EINVAL;
 152     }
 153
 154     flags = (mem->flags & ~mask) | flags;
 155     /* Nothing changed, no need to issue ioctl */
 156     if (flags == mem->flags)
 157             return 0;
 158
 159     mem->flags = flags;
 160
 161     return kvm_set_user_memory_region(s, mem);
 162 }
 163
 164 int kvm_log_start(target_phys_addr_t phys_addr, target_phys_addr_t end_addr)
 165 {
 166         return kvm_dirty_pages_log_change(phys_addr, end_addr,
 167                                           KVM_MEM_LOG_DIRTY_PAGES,
 168                                           KVM_MEM_LOG_DIRTY_PAGES);
 169 }
 170
 171 int kvm_log_stop(target_phys_addr_t phys_addr, target_phys_addr_t end_addr)
 172 {
 173         return kvm_dirty_pages_log_change(phys_addr, end_addr,
 174                                           0,
 175                                           KVM_MEM_LOG_DIRTY_PAGES);
 176 }
 177
 178 /**
 179  * kvm_physical_sync_dirty_bitmap - Grab dirty bitmap from kernel space
 180  * This function updates qemu's dirty bitmap using cpu_physical_memory_set_dirty().
 181  * This means all bits are set to dirty.
 182  *
 183  * @start_add: start of logged region. This is what we use to search the memslot
 184  * @end_addr: end of logged region.
 185  */
 186 void kvm_physical_sync_dirty_bitmap(target_phys_addr_t start_addr, target_phys_addr_t end_addr)
 187 {
 188     KVMState *s = kvm_state;
 189     KVMDirtyLog d;
 190     KVMSlot *mem = kvm_lookup_slot(s, start_addr);
 191     unsigned long alloc_size;
 192     ram_addr_t addr;
 193     target_phys_addr_t phys_addr = start_addr;
 194
 195     dprintf("sync addr: %llx into %lx\n", start_addr, mem->phys_offset);
 196     if (mem == NULL) {
 197             fprintf(stderr, "BUG: %s: invalid parameters\n", __func__);
 198             return;
 199     }
 200
 201     alloc_size = mem->memory_size >> TARGET_PAGE_BITS / sizeof(d.dirty_bitmap);
 202     d.dirty_bitmap = qemu_mallocz(alloc_size);
 203
 204     if (d.dirty_bitmap == NULL) {
 205         dprintf("Could not allocate dirty bitmap\n");
 206         return;
 207     }
 208
 209     d.slot = mem->slot;
 210     dprintf("slot %d, phys_addr %llx, uaddr: %llx\n",
 211             d.slot, mem->start_addr, mem->phys_offset);
 212
 213     if (kvm_vm_ioctl(s, KVM_GET_DIRTY_LOG, &d) == -1) {
 214         dprintf("ioctl failed %d\n", errno);
 215         goto out;
 216     }
 217
 218     phys_addr = start_addr;
 219     for (addr = mem->phys_offset; phys_addr < end_addr; phys_addr+= TARGET_PAGE_SIZE, addr += TARGET_PAGE_SIZE) {
 220         unsigned long *bitmap = (unsigned long *)d.dirty_bitmap;
 221         unsigned nr = (phys_addr - start_addr) >> TARGET_PAGE_BITS;
 222         unsigned word = nr / (sizeof(*bitmap) * 8);
 223         unsigned bit = nr % (sizeof(*bitmap) * 8);
 224         if ((bitmap[word] >> bit) & 1)
 225             cpu_physical_memory_set_dirty(addr);
 226     }
 227 out:
 228     qemu_free(d.dirty_bitmap);
 229 }
 230
 231 int kvm_init(int smp_cpus)
 232 {
 233     KVMState *s;
 234     int ret;
 235     int i;
 236
 237     if (smp_cpus > 1)
 238         return -EINVAL;
 239
 240     s = qemu_mallocz(sizeof(KVMState));
 241     if (s == NULL)
 242         return -ENOMEM;
 243
 244     for (i = 0; i < ARRAY_SIZE(s->slots); i++)
 245         s->slots[i].slot = i;
 246
 247     s->vmfd = -1;
 248     s->fd = open("/dev/kvm", O_RDWR);
 249     if (s->fd == -1) {
 250         fprintf(stderr, "Could not access KVM kernel module: %m\n");
 251         ret = -errno;
 252         goto err;
 253     }
 254
 255     ret = kvm_ioctl(s, KVM_GET_API_VERSION, 0);
 256     if (ret < KVM_API_VERSION) {
 257         if (ret > 0)
 258             ret = -EINVAL;
 259         fprintf(stderr, "kvm version too old\n");
 260         goto err;
 261     }
 262
 263     if (ret > KVM_API_VERSION) {
 264         ret = -EINVAL;
 265         fprintf(stderr, "kvm version not supported\n");
 266         goto err;
 267     }
 268
 269     s->vmfd = kvm_ioctl(s, KVM_CREATE_VM, 0);
 270     if (s->vmfd < 0)
 271         goto err;
 272
 273     /* initially, KVM allocated its own memory and we had to jump through
 274      * hooks to make phys_ram_base point to this.  Modern versions of KVM
 275      * just use a user allocated buffer so we can use phys_ram_base
 276      * unmodified.  Make sure we have a sufficiently modern version of KVM.
 277      */
 278     ret = kvm_ioctl(s, KVM_CHECK_EXTENSION, KVM_CAP_USER_MEMORY);
 279     if (ret <= 0) {
 280         if (ret == 0)
 281             ret = -EINVAL;
 282         fprintf(stderr, "kvm does not support KVM_CAP_USER_MEMORY\n");
 283         goto err;
 284     }
 285
 286     ret = kvm_arch_init(s, smp_cpus);
 287     if (ret < 0)
 288         goto err;
 289
 290     kvm_state = s;
 291
 292     return 0;
 293
 294 err:
 295     if (s) {
 296         if (s->vmfd != -1)
 297             close(s->vmfd);
 298         if (s->fd != -1)
 299             close(s->fd);
 300     }
 301     qemu_free(s);
 302
 303     return ret;
 304 }
 305
 306 static int kvm_handle_io(CPUState *env, uint16_t port, void *data,
 307                          int direction, int size, uint32_t count)
 308 {
 309     int i;
 310     uint8_t *ptr = data;
 311
 312     for (i = 0; i < count; i++) {
 313         if (direction == KVM_EXIT_IO_IN) {
 314             switch (size) {
 315             case 1:
 316                 stb_p(ptr, cpu_inb(env, port));
 317                 break;
 318             case 2:
 319                 stw_p(ptr, cpu_inw(env, port));
 320                 break;
 321             case 4:
 322                 stl_p(ptr, cpu_inl(env, port));
 323                 break;
 324             }
 325         } else {
 326             switch (size) {
 327             case 1:
 328                 cpu_outb(env, port, ldub_p(ptr));
 329                 break;
 330             case 2:
 331                 cpu_outw(env, port, lduw_p(ptr));
 332                 break;
 333             case 4:
 334                 cpu_outl(env, port, ldl_p(ptr));
 335                 break;
 336             }
 337         }
 338
 339         ptr += size;
 340     }
 341
 342     return 1;
 343 }
 344
 345 int kvm_cpu_exec(CPUState *env)
 346 {
 347     struct kvm_run *run = env->kvm_run;
 348     int ret;
 349
 350     dprintf("kvm_cpu_exec()\n");
 351
 352     do {
 353         kvm_arch_pre_run(env, run);
 354
 355         if ((env->interrupt_request & CPU_INTERRUPT_EXIT)) {
 356             dprintf("interrupt exit requested\n");
 357             ret = 0;
 358             break;
 359         }
 360
 361         ret = kvm_vcpu_ioctl(env, KVM_RUN, 0);
 362         kvm_arch_post_run(env, run);
 363
 364         if (ret == -EINTR || ret == -EAGAIN) {
 365             dprintf("io window exit\n");
 366             ret = 0;
 367             break;
 368         }
 369
 370         if (ret < 0) {
 371             dprintf("kvm run failed %s\n", strerror(-ret));
 372             abort();
 373         }
 374
 375         ret = 0; /* exit loop */
 376         switch (run->exit_reason) {
 377         case KVM_EXIT_IO:
 378             dprintf("handle_io\n");
 379             ret = kvm_handle_io(env, run->io.port,
 380                                 (uint8_t *)run + run->io.data_offset,
 381                                 run->io.direction,
 382                                 run->io.size,
 383                                 run->io.count);
 384             break;
 385         case KVM_EXIT_MMIO:
 386             dprintf("handle_mmio\n");
 387             cpu_physical_memory_rw(run->mmio.phys_addr,
 388                                    run->mmio.data,
 389                                    run->mmio.len,
 390                                    run->mmio.is_write);
 391             ret = 1;
 392             break;
 393         case KVM_EXIT_IRQ_WINDOW_OPEN:
 394             dprintf("irq_window_open\n");
 395             break;
 396         case KVM_EXIT_SHUTDOWN:
 397             dprintf("shutdown\n");
 398             qemu_system_reset_request();
 399             ret = 1;
 400             break;
 401         case KVM_EXIT_UNKNOWN:
 402             dprintf("kvm_exit_unknown\n");
 403             break;
 404         case KVM_EXIT_FAIL_ENTRY:
 405             dprintf("kvm_exit_fail_entry\n");
 406             break;
 407         case KVM_EXIT_EXCEPTION:
 408             dprintf("kvm_exit_exception\n");
 409             break;
 410         case KVM_EXIT_DEBUG:
 411             dprintf("kvm_exit_debug\n");
 412             break;
 413         default:
 414             dprintf("kvm_arch_handle_exit\n");
 415             ret = kvm_arch_handle_exit(env, run);
 416             break;
 417         }
 418     } while (ret > 0);
 419
 420     if ((env->interrupt_request & CPU_INTERRUPT_EXIT)) {
 421         env->interrupt_request &= ~CPU_INTERRUPT_EXIT;
 422         env->exception_index = EXCP_INTERRUPT;
 423     }
 424
 425     return ret;
 426 }
 427
 428 void kvm_set_phys_mem(target_phys_addr_t start_addr,
 429                       ram_addr_t size,
 430                       ram_addr_t phys_offset)
 431 {
 432     KVMState *s = kvm_state;
 433     ram_addr_t flags = phys_offset & ~TARGET_PAGE_MASK;
 434     KVMSlot *mem;
 435
 436     /* KVM does not support read-only slots */
 437     phys_offset &= ~IO_MEM_ROM;
 438
 439     mem = kvm_lookup_slot(s, start_addr);
 440     if (mem) {
 441         if ((flags == IO_MEM_UNASSIGNED) || (flags >= TLB_MMIO)) {
 442             mem->memory_size = 0;
 443             mem->start_addr = start_addr;
 444             mem->phys_offset = 0;
 445             mem->flags = 0;
 446
 447             kvm_set_user_memory_region(s, mem);
 448         } else if (start_addr >= mem->start_addr &&
 449                    (start_addr + size) <= (mem->start_addr +
 450                                            mem->memory_size)) {
 451             KVMSlot slot;
 452             target_phys_addr_t mem_start;
 453             ram_addr_t mem_size, mem_offset;
 454
 455             /* Not splitting */
 456             if ((phys_offset - (start_addr - mem->start_addr)) ==
 457                 mem->phys_offset)
 458                 return;
 459
 460             /* unregister whole slot */
 461             memcpy(&slot, mem, sizeof(slot));
 462             mem->memory_size = 0;
 463             kvm_set_user_memory_region(s, mem);
 464
 465             /* register prefix slot */
 466             mem_start = slot.start_addr;
 467             mem_size = start_addr - slot.start_addr;
 468             mem_offset = slot.phys_offset;
 469             if (mem_size)
 470                 kvm_set_phys_mem(mem_start, mem_size, mem_offset);
 471
 472             /* register new slot */
 473             kvm_set_phys_mem(start_addr, size, phys_offset);
 474
 475             /* register suffix slot */
 476             mem_start = start_addr + size;
 477             mem_offset += mem_size + size;
 478             mem_size = slot.memory_size - mem_size - size;
 479             if (mem_size)
 480                 kvm_set_phys_mem(mem_start, mem_size, mem_offset);
 481
 482             return;
 483         } else {
 484             printf("Registering overlapping slot\n");
 485             abort();
 486         }
 487     }
 488     /* KVM does not need to know about this memory */
 489     if (flags >= IO_MEM_UNASSIGNED)
 490         return;
 491
 492     mem = kvm_alloc_slot(s);
 493     mem->memory_size = size;
 494     mem->start_addr = start_addr;
 495     mem->phys_offset = phys_offset;
 496     mem->flags = 0;
 497
 498     kvm_set_user_memory_region(s, mem);
 499     /* FIXME deal with errors */
 500 }
 501
 502 int kvm_ioctl(KVMState *s, int type, ...)
 503 {
 504     int ret;
 505     void *arg;
 506     va_list ap;
 507
 508     va_start(ap, type);
 509     arg = va_arg(ap, void *);
 510     va_end(ap);
 511
 512     ret = ioctl(s->fd, type, arg);
 513     if (ret == -1)
 514         ret = -errno;
 515
 516     return ret;
 517 }
 518
 519 int kvm_vm_ioctl(KVMState *s, int type, ...)
 520 {
 521     int ret;
 522     void *arg;
 523     va_list ap;
 524
 525     va_start(ap, type);
 526     arg = va_arg(ap, void *);
 527     va_end(ap);
 528
 529     ret = ioctl(s->vmfd, type, arg);
 530     if (ret == -1)
 531         ret = -errno;
 532
 533     return ret;
 534 }
 535
 536 int kvm_vcpu_ioctl(CPUState *env, int type, ...)
 537 {
 538     int ret;
 539     void *arg;
 540     va_list ap;
 541
 542     va_start(ap, type);
 543     arg = va_arg(ap, void *);
 544     va_end(ap);
 545
 546     ret = ioctl(env->kvm_fd, type, arg);
 547     if (ret == -1)
 548         ret = -errno;
 549
 550     return ret;
 551 }
 552
 553 int kvm_has_sync_mmu(void)
 554 {
 555     KVMState *s = kvm_state;
 556
 557 #ifdef KVM_CAP_SYNC_MMU
 558     if (kvm_ioctl(s, KVM_CHECK_EXTENSION, KVM_CAP_SYNC_MMU) > 0)
 559         return 1;
 560 #endif
 561
 562     return 0;
 563 }