text: /*
   * QEMU KVM support
   *
   * Copyright IBM, Corp. 2008
   *           Red Hat, Inc. 2008
   *
   * Authors:
   *  Anthony Liguori   <aliguori@us.ibm.com>
   *  Glauber Costa     <gcosta@redhat.com>
   *
   * This work is licensed under the terms of the GNU GPL, version 2 or later.
   * See the COPYING file in the top-level directory.
   *
   */
  
  #include <sys/types.h>
  #include <sys/ioctl.h>
  #include <sys/mman.h>
  #include <stdarg.h>
  
  #include <linux/kvm.h>
  
  #include "qemu-common.h"
  #include "qemu/atomic.h"
  #include "qemu/option.h"
  #include "qemu/config-file.h"
  #include "sysemu/sysemu.h"
  #include "hw/hw.h"
  #include "hw/pci/msi.h"
  #include "exec/gdbstub.h"
  #include "sysemu/kvm.h"
  #include "qemu/bswap.h"
  #include "exec/memory.h"
  #include "exec/address-spaces.h"
  #include "qemu/event_notifier.h"
  #include "trace.h"
  
  /* This check must be after config-host.h is included */
  #ifdef CONFIG_EVENTFD
  #include <sys/eventfd.h>
  #endif
  
  #ifdef CONFIG_VALGRIND_H
  #include <valgrind/memcheck.h>
  #endif
  
  /* KVM uses PAGE_SIZE in its definition of COALESCED_MMIO_MAX */
  #define PAGE_SIZE TARGET_PAGE_SIZE
  
  //#define DEBUG_KVM
  
  #ifdef DEBUG_KVM
  #define DPRINTF(fmt, ...) \
      do { fprintf(stderr, fmt, ## __VA_ARGS__); } while (0)
  #else
  #define DPRINTF(fmt, ...) \
      do { } while (0)
  #endif
  
  #define KVM_MSI_HASHTAB_SIZE    256
  
  typedef struct KVMSlot
  {
      hwaddr start_addr;
      ram_addr_t memory_size;
      void *ram;
      int slot;
      int flags;
  } KVMSlot;
  
  typedef struct kvm_dirty_log KVMDirtyLog;
  
  struct KVMState
  {
      KVMSlot slots[32];
      int fd;
      int vmfd;
      int coalesced_mmio;
      struct kvm_coalesced_mmio_ring *coalesced_mmio_ring;
      bool coalesced_flush_in_progress;
      int broken_set_mem_region;
      int migration_log;
      int vcpu_events;
      int robust_singlestep;
      int debugregs;
  #ifdef KVM_CAP_SET_GUEST_DEBUG
      struct kvm_sw_breakpoint_head kvm_sw_breakpoints;
  #endif
      int pit_state2;
      int xsave, xcrs;
      int many_ioeventfds;
      int intx_set_mask;
      /* The man page (and posix) say ioctl numbers are signed int, but
       * they're not.  Linux, glibc and *BSD all treat ioctl numbers as
       * unsigned, and treating them as signed here can break things */
      unsigned irq_set_ioctl;
  #ifdef KVM_CAP_IRQ_ROUTING
      struct kvm_irq_routing *irq_routes;
      int nr_allocated_irq_routes;
      uint32_t *used_gsi_bitmap;
      unsigned int gsi_count;
      QTAILQ_HEAD(msi_hashtab, KVMMSIRoute) msi_hashtab[KVM_MSI_HASHTAB_SIZE];
      bool direct_msi;
  #endif
  };
  
  KVMState *kvm_state;
  bool kvm_kernel_irqchip;
  bool kvm_async_interrupts_allowed;
  bool kvm_halt_in_kernel_allowed;
  bool kvm_irqfds_allowed;
  bool kvm_msi_via_irqfd_allowed;
  bool kvm_gsi_routing_allowed;
  bool kvm_gsi_direct_mapping;
  bool kvm_allowed;
  bool kvm_readonly_mem_allowed;
  
  static const KVMCapabilityInfo kvm_required_capabilites[] = {
      KVM_CAP_INFO(USER_MEMORY),
      KVM_CAP_INFO(DESTROY_MEMORY_REGION_WORKS),
      KVM_CAP_LAST_INFO
  };
  
  static KVMSlot *kvm_alloc_slot(KVMState *s)
  {
      int i;
  
      for (i = 0; i < ARRAY_SIZE(s->slots); i++) {
          if (s->slots[i].memory_size == 0) {
              return &s->slots[i];
          }
      }
  
      fprintf(stderr, "%s: no free slot available\n", __func__);
      abort();
  }
  
  static KVMSlot *kvm_lookup_matching_slot(KVMState *s,
                                           hwaddr start_addr,
                                           hwaddr end_addr)
  {
      int i;
  
      for (i = 0; i < ARRAY_SIZE(s->slots); i++) {
          KVMSlot *mem = &s->slots[i];
  
          if (start_addr == mem->start_addr &&
              end_addr == mem->start_addr + mem->memory_size) {
              return mem;
          }
      }
  
      return NULL;
  }
  
  /*
   * Find overlapping slot with lowest start address
   */
  static KVMSlot *kvm_lookup_overlapping_slot(KVMState *s,
                                              hwaddr start_addr,
                                              hwaddr end_addr)
  {
      KVMSlot *found = NULL;
      int i;
  
      for (i = 0; i < ARRAY_SIZE(s->slots); i++) {
          KVMSlot *mem = &s->slots[i];
  
          if (mem->memory_size == 0 ||
              (found && found->start_addr < mem->start_addr)) {
              continue;
          }
  
          if (end_addr > mem->start_addr &&
              start_addr < mem->start_addr + mem->memory_size) {
              found = mem;
          }
      }
  
      return found;
  }
  
  int kvm_physical_memory_addr_from_host(KVMState *s, void *ram,
                                         hwaddr *phys_addr)
  {
      int i;
  
      for (i = 0; i < ARRAY_SIZE(s->slots); i++) {
          KVMSlot *mem = &s->slots[i];
  
          if (ram >= mem->ram && ram < mem->ram + mem->memory_size) {
              *phys_addr = mem->start_addr + (ram - mem->ram);
              return 1;
          }
      }
  
      return 0;
  }
  
  static int kvm_set_user_memory_region(KVMState *s, KVMSlot *slot)
  {
      struct kvm_userspace_memory_region mem;
  
      mem.slot = slot->slot;
      mem.guest_phys_addr = slot->start_addr;
      mem.userspace_addr = (unsigned long)slot->ram;
      mem.flags = slot->flags;
      if (s->migration_log) {
          mem.flags |= KVM_MEM_LOG_DIRTY_PAGES;
      }
  
      if (slot->memory_size && mem.flags & KVM_MEM_READONLY) {
          /* Set the slot size to 0 before setting the slot to the desired
           * value. This is needed based on KVM commit 75d61fbc. */
          mem.memory_size = 0;
          kvm_vm_ioctl(s, KVM_SET_USER_MEMORY_REGION, &mem);
      }
      mem.memory_size = slot->memory_size;
      return kvm_vm_ioctl(s, KVM_SET_USER_MEMORY_REGION, &mem);
  }
  
  static void kvm_reset_vcpu(void *opaque)
  {
      CPUState *cpu = opaque;
  
      kvm_arch_reset_vcpu(cpu);
  }
  
  int kvm_init_vcpu(CPUState *cpu)
  {
      KVMState *s = kvm_state;
      long mmap_size;
      int ret;
  
      DPRINTF("kvm_init_vcpu\n");
  
      ret = kvm_vm_ioctl(s, KVM_CREATE_VCPU, (void *)kvm_arch_vcpu_id(cpu));
      if (ret < 0) {
          DPRINTF("kvm_create_vcpu failed\n");
          goto err;
      }
  
      cpu->kvm_fd = ret;
      cpu->kvm_state = s;
      cpu->kvm_vcpu_dirty = true;
  
      mmap_size = kvm_ioctl(s, KVM_GET_VCPU_MMAP_SIZE, 0);
      if (mmap_size < 0) {
          ret = mmap_size;
          DPRINTF("KVM_GET_VCPU_MMAP_SIZE failed\n");
          goto err;
      }
  
      cpu->kvm_run = mmap(NULL, mmap_size, PROT_READ | PROT_WRITE, MAP_SHARED,
                          cpu->kvm_fd, 0);
      if (cpu->kvm_run == MAP_FAILED) {
          ret = -errno;
          DPRINTF("mmap'ing vcpu state failed\n");
          goto err;
      }
  
      if (s->coalesced_mmio && !s->coalesced_mmio_ring) {
          s->coalesced_mmio_ring =
              (void *)cpu->kvm_run + s->coalesced_mmio * PAGE_SIZE;
      }
  
      ret = kvm_arch_init_vcpu(cpu);
      if (ret == 0) {
          qemu_register_reset(kvm_reset_vcpu, cpu);
          kvm_arch_reset_vcpu(cpu);
      }
  err:
      return ret;
  }
  
  /*
   * dirty pages logging control
   */
  
  static int kvm_mem_flags(KVMState *s, bool log_dirty, bool readonly)
  {
      int flags = 0;
      flags = log_dirty ? KVM_MEM_LOG_DIRTY_PAGES : 0;
      if (readonly && kvm_readonly_mem_allowed) {
          flags |= KVM_MEM_READONLY;
      }
      return flags;
  }
  
  static int kvm_slot_dirty_pages_log_change(KVMSlot *mem, bool log_dirty)
  {
      KVMState *s = kvm_state;
      int flags, mask = KVM_MEM_LOG_DIRTY_PAGES;
      int old_flags;
  
      old_flags = mem->flags;
  
      flags = (mem->flags & ~mask) | kvm_mem_flags(s, log_dirty, false);
      mem->flags = flags;
  
      /* If nothing changed effectively, no need to issue ioctl */
      if (s->migration_log) {
          flags |= KVM_MEM_LOG_DIRTY_PAGES;
      }
  
      if (flags == old_flags) {
          return 0;
      }
  
      return kvm_set_user_memory_region(s, mem);
  }
  
  static int kvm_dirty_pages_log_change(hwaddr phys_addr,
                                        ram_addr_t size, bool log_dirty)
  {
      KVMState *s = kvm_state;
      KVMSlot *mem = kvm_lookup_matching_slot(s, phys_addr, phys_addr + size);
  
      if (mem == NULL)  {
          fprintf(stderr, "BUG: %s: invalid parameters " TARGET_FMT_plx "-"
                  TARGET_FMT_plx "\n", __func__, phys_addr,
                  (hwaddr)(phys_addr + size - 1));
          return -EINVAL;
      }
      return kvm_slot_dirty_pages_log_change(mem, log_dirty);
  }
  
  static void kvm_log_start(MemoryListener *listener,
                            MemoryRegionSection *section)
  {
      int r;
  
      r = kvm_dirty_pages_log_change(section->offset_within_address_space,
                                     int128_get64(section->size), true);
      if (r < 0) {
          abort();
      }
  }
  
  static void kvm_log_stop(MemoryListener *listener,
                            MemoryRegionSection *section)
  {
      int r;
  
      r = kvm_dirty_pages_log_change(section->offset_within_address_space,
                                     int128_get64(section->size), false);
      if (r < 0) {
          abort();
      }
  }
  
  static int kvm_set_migration_log(int enable)
  {
      KVMState *s = kvm_state;
      KVMSlot *mem;
      int i, err;
  
      s->migration_log = enable;
  
      for (i = 0; i < ARRAY_SIZE(s->slots); i++) {
          mem = &s->slots[i];
  
          if (!mem->memory_size) {
              continue;
          }
          if (!!(mem->flags & KVM_MEM_LOG_DIRTY_PAGES) == enable) {
              continue;
          }
          err = kvm_set_user_memory_region(s, mem);
          if (err) {
              return err;
          }
      }
      return 0;
  }
  
  /* get kvm's dirty pages bitmap and update qemu's */
  static int kvm_get_dirty_pages_log_range(MemoryRegionSection *section,
                                           unsigned long *bitmap)
  {
      unsigned int i, j;
      unsigned long page_number, c;
      hwaddr addr, addr1;
      unsigned int pages = int128_get64(section->size) / getpagesize();
      unsigned int len = (pages + HOST_LONG_BITS - 1) / HOST_LONG_BITS;
      unsigned long hpratio = getpagesize() / TARGET_PAGE_SIZE;
  
      /*
       * bitmap-traveling is faster than memory-traveling (for addr...)
       * especially when most of the memory is not dirty.
       */
      for (i = 0; i < len; i++) {
          if (bitmap[i] != 0) {
              c = leul_to_cpu(bitmap[i]);
              do {
                  j = ffsl(c) - 1;
                  c &= ~(1ul << j);
                  page_number = (i * HOST_LONG_BITS + j) * hpratio;
                  addr1 = page_number * TARGET_PAGE_SIZE;
                  addr = section->offset_within_region + addr1;
                  memory_region_set_dirty(section->mr, addr,
                                          TARGET_PAGE_SIZE * hpratio);
              } while (c != 0);
          }
      }
      return 0;
  }
  
  #define ALIGN(x, y)  (((x)+(y)-1) & ~((y)-1))
  
  /**
   * kvm_physical_sync_dirty_bitmap - Grab dirty bitmap from kernel space
   * This function updates qemu's dirty bitmap using
   * memory_region_set_dirty().  This means all bits are set
   * to dirty.
   *
   * @start_add: start of logged region.
   * @end_addr: end of logged region.
   */
  static int kvm_physical_sync_dirty_bitmap(MemoryRegionSection *section)
  {
      KVMState *s = kvm_state;
      unsigned long size, allocated_size = 0;
      KVMDirtyLog d;
      KVMSlot *mem;
      int ret = 0;
      hwaddr start_addr = section->offset_within_address_space;
      hwaddr end_addr = start_addr + int128_get64(section->size);
  
      d.dirty_bitmap = NULL;
      while (start_addr < end_addr) {
          mem = kvm_lookup_overlapping_slot(s, start_addr, end_addr);
          if (mem == NULL) {
              break;
          }
  
          /* XXX bad kernel interface alert
           * For dirty bitmap, kernel allocates array of size aligned to
           * bits-per-long.  But for case when the kernel is 64bits and
           * the userspace is 32bits, userspace can't align to the same
           * bits-per-long, since sizeof(long) is different between kernel
           * and user space.  This way, userspace will provide buffer which
           * may be 4 bytes less than the kernel will use, resulting in
           * userspace memory corruption (which is not detectable by valgrind
           * too, in most cases).
           * So for now, let's align to 64 instead of HOST_LONG_BITS here, in
           * a hope that sizeof(long) wont become >8 any time soon.
           */
          size = ALIGN(((mem->memory_size) >> TARGET_PAGE_BITS),
                       /*HOST_LONG_BITS*/ 64) / 8;
          if (!d.dirty_bitmap) {
              d.dirty_bitmap = g_malloc(size);
          } else if (size > allocated_size) {
              d.dirty_bitmap = g_realloc(d.dirty_bitmap, size);
          }
          allocated_size = size;
          memset(d.dirty_bitmap, 0, allocated_size);
  
          d.slot = mem->slot;
  
          if (kvm_vm_ioctl(s, KVM_GET_DIRTY_LOG, &d) == -1) {
              DPRINTF("ioctl failed %d\n", errno);
              ret = -1;
              break;
          }
  
          kvm_get_dirty_pages_log_range(section, d.dirty_bitmap);
          start_addr = mem->start_addr + mem->memory_size;
      }
      g_free(d.dirty_bitmap);
  
      return ret;
  }
  
  static void kvm_coalesce_mmio_region(MemoryListener *listener,
                                       MemoryRegionSection *secion,
                                       hwaddr start, hwaddr size)
  {
      KVMState *s = kvm_state;
  
      if (s->coalesced_mmio) {
          struct kvm_coalesced_mmio_zone zone;
  
          zone.addr = start;
          zone.size = size;
          zone.pad = 0;
  
          (void)kvm_vm_ioctl(s, KVM_REGISTER_COALESCED_MMIO, &zone);
      }
  }
  
  static void kvm_uncoalesce_mmio_region(MemoryListener *listener,
                                         MemoryRegionSection *secion,
                                         hwaddr start, hwaddr size)
  {
      KVMState *s = kvm_state;
  
      if (s->coalesced_mmio) {
          struct kvm_coalesced_mmio_zone zone;
  
          zone.addr = start;
          zone.size = size;
          zone.pad = 0;
  
          (void)kvm_vm_ioctl(s, KVM_UNREGISTER_COALESCED_MMIO, &zone);
      }
  }
  
  int kvm_check_extension(KVMState *s, unsigned int extension)
  {
      int ret;
  
      ret = kvm_ioctl(s, KVM_CHECK_EXTENSION, extension);
      if (ret < 0) {
          ret = 0;
      }
  
      return ret;
  }
  
  static int kvm_set_ioeventfd_mmio(int fd, uint32_t addr, uint32_t val,
                                    bool assign, uint32_t size, bool datamatch)
  {
      int ret;
      struct kvm_ioeventfd iofd;
  
      iofd.datamatch = datamatch ? val : 0;
      iofd.addr = addr;
      iofd.len = size;
      iofd.flags = 0;
      iofd.fd = fd;
  
      if (!kvm_enabled()) {
          return -ENOSYS;
      }
  
      if (datamatch) {
          iofd.flags |= KVM_IOEVENTFD_FLAG_DATAMATCH;
      }
      if (!assign) {
          iofd.flags |= KVM_IOEVENTFD_FLAG_DEASSIGN;
      }
  
      ret = kvm_vm_ioctl(kvm_state, KVM_IOEVENTFD, &iofd);
  
      if (ret < 0) {
          return -errno;
      }
  
      return 0;
  }
  
  static int kvm_set_ioeventfd_pio(int fd, uint16_t addr, uint16_t val,
                                   bool assign, uint32_t size, bool datamatch)
  {
      struct kvm_ioeventfd kick = {
          .datamatch = datamatch ? val : 0,
          .addr = addr,
          .flags = KVM_IOEVENTFD_FLAG_PIO,
          .len = size,
          .fd = fd,
      };
      int r;
      if (!kvm_enabled()) {
          return -ENOSYS;
      }
      if (datamatch) {
          kick.flags |= KVM_IOEVENTFD_FLAG_DATAMATCH;
      }
      if (!assign) {
          kick.flags |= KVM_IOEVENTFD_FLAG_DEASSIGN;
      }
      r = kvm_vm_ioctl(kvm_state, KVM_IOEVENTFD, &kick);
      if (r < 0) {
          return r;
      }
      return 0;
  }
  
  
  static int kvm_check_many_ioeventfds(void)
  {
      /* Userspace can use ioeventfd for io notification.  This requires a host
       * that supports eventfd(2) and an I/O thread; since eventfd does not
       * support SIGIO it cannot interrupt the vcpu.
       *
       * Older kernels have a 6 device limit on the KVM io bus.  Find out so we
       * can avoid creating too many ioeventfds.
       */
  #if defined(CONFIG_EVENTFD)
      int ioeventfds[7];
      int i, ret = 0;
      for (i = 0; i < ARRAY_SIZE(ioeventfds); i++) {
          ioeventfds[i] = eventfd(0, EFD_CLOEXEC);
          if (ioeventfds[i] < 0) {
              break;
          }
          ret = kvm_set_ioeventfd_pio(ioeventfds[i], 0, i, true, 2, true);
          if (ret < 0) {
              close(ioeventfds[i]);
              break;
          }
      }
  
      /* Decide whether many devices are supported or not */
      ret = i == ARRAY_SIZE(ioeventfds);
  
      while (i-- > 0) {
          kvm_set_ioeventfd_pio(ioeventfds[i], 0, i, false, 2, true);
          close(ioeventfds[i]);
      }
      return ret;
  #else
      return 0;
  #endif
  }
  
  static const KVMCapabilityInfo *
  kvm_check_extension_list(KVMState *s, const KVMCapabilityInfo *list)
  {
      while (list->name) {
          if (!kvm_check_extension(s, list->value)) {
              return list;
          }
          list++;
      }
      return NULL;
  }
  
  static void kvm_set_phys_mem(MemoryRegionSection *section, bool add)
  {
      KVMState *s = kvm_state;
      KVMSlot *mem, old;
      int err;
      MemoryRegion *mr = section->mr;
      bool log_dirty = memory_region_is_logging(mr);
      bool writeable = !mr->readonly && !mr->rom_device;
      bool readonly_flag = mr->readonly || memory_region_is_romd(mr);
      hwaddr start_addr = section->offset_within_address_space;
      ram_addr_t size = int128_get64(section->size);
      void *ram = NULL;
      unsigned delta;
  
      /* kvm works in page size chunks, but the function may be called
         with sub-page size and unaligned start address. */
      delta = TARGET_PAGE_ALIGN(size) - size;
      if (delta > size) {
          return;
      }
      start_addr += delta;
      size -= delta;
      size &= TARGET_PAGE_MASK;
      if (!size || (start_addr & ~TARGET_PAGE_MASK)) {
          return;
      }
  
      if (!memory_region_is_ram(mr)) {
          if (writeable || !kvm_readonly_mem_allowed) {
              return;
          } else if (!mr->romd_mode) {
              /* If the memory device is not in romd_mode, then we actually want
               * to remove the kvm memory slot so all accesses will trap. */
              add = false;
          }
      }
  
      ram = memory_region_get_ram_ptr(mr) + section->offset_within_region + delta;
  
      while (1) {
          mem = kvm_lookup_overlapping_slot(s, start_addr, start_addr + size);
          if (!mem) {
              break;
          }
  
          if (add && start_addr >= mem->start_addr &&
              (start_addr + size <= mem->start_addr + mem->memory_size) &&
              (ram - start_addr == mem->ram - mem->start_addr)) {
              /* The new slot fits into the existing one and comes with
               * identical parameters - update flags and done. */
              kvm_slot_dirty_pages_log_change(mem, log_dirty);
              return;
          }
  
          old = *mem;
  
          if (mem->flags & KVM_MEM_LOG_DIRTY_PAGES) {
              kvm_physical_sync_dirty_bitmap(section);
          }
  
          /* unregister the overlapping slot */
          mem->memory_size = 0;
          err = kvm_set_user_memory_region(s, mem);
          if (err) {
              fprintf(stderr, "%s: error unregistering overlapping slot: %s\n",
                      __func__, strerror(-err));
              abort();
          }
  
          /* Workaround for older KVM versions: we can't join slots, even not by
           * unregistering the previous ones and then registering the larger
           * slot. We have to maintain the existing fragmentation. Sigh.
           *
           * This workaround assumes that the new slot starts at the same
           * address as the first existing one. If not or if some overlapping
           * slot comes around later, we will fail (not seen in practice so far)
           * - and actually require a recent KVM version. */
          if (s->broken_set_mem_region &&
              old.start_addr == start_addr && old.memory_size < size && add) {
              mem = kvm_alloc_slot(s);
              mem->memory_size = old.memory_size;
              mem->start_addr = old.start_addr;
              mem->ram = old.ram;
              mem->flags = kvm_mem_flags(s, log_dirty, readonly_flag);
  
              err = kvm_set_user_memory_region(s, mem);
              if (err) {
                  fprintf(stderr, "%s: error updating slot: %s\n", __func__,
                          strerror(-err));
                  abort();
              }
  
              start_addr += old.memory_size;
              ram += old.memory_size;
              size -= old.memory_size;
              continue;
          }
  
          /* register prefix slot */
          if (old.start_addr < start_addr) {
              mem = kvm_alloc_slot(s);
              mem->memory_size = start_addr - old.start_addr;
              mem->start_addr = old.start_addr;
              mem->ram = old.ram;
              mem->flags =  kvm_mem_flags(s, log_dirty, readonly_flag);
  
              err = kvm_set_user_memory_region(s, mem);
              if (err) {
                  fprintf(stderr, "%s: error registering prefix slot: %s\n",
                          __func__, strerror(-err));
  #ifdef TARGET_PPC
                  fprintf(stderr, "%s: This is probably because your kernel's " \
                                  "PAGE_SIZE is too big. Please try to use 4k " \
                                  "PAGE_SIZE!\n", __func__);
  #endif
                  abort();
              }
          }
  
          /* register suffix slot */
          if (old.start_addr + old.memory_size > start_addr + size) {
              ram_addr_t size_delta;
  
              mem = kvm_alloc_slot(s);
              mem->start_addr = start_addr + size;
              size_delta = mem->start_addr - old.start_addr;
              mem->memory_size = old.memory_size - size_delta;
              mem->ram = old.ram + size_delta;
              mem->flags = kvm_mem_flags(s, log_dirty, readonly_flag);
  
              err = kvm_set_user_memory_region(s, mem);
              if (err) {
                  fprintf(stderr, "%s: error registering suffix slot: %s\n",
                          __func__, strerror(-err));
                  abort();
              }
          }
      }
  
      /* in case the KVM bug workaround already "consumed" the new slot */
      if (!size) {
          return;
      }
      if (!add) {
          return;
      }
      mem = kvm_alloc_slot(s);
      mem->memory_size = size;
      mem->start_addr = start_addr;
      mem->ram = ram;
      mem->flags = kvm_mem_flags(s, log_dirty, readonly_flag);
  
      err = kvm_set_user_memory_region(s, mem);
      if (err) {
          fprintf(stderr, "%s: error registering slot: %s\n", __func__,
                  strerror(-err));
          abort();
      }
  }
  
  static void kvm_region_add(MemoryListener *listener,
                             MemoryRegionSection *section)
  {
      memory_region_ref(section->mr);
      kvm_set_phys_mem(section, true);
  }
  
  static void kvm_region_del(MemoryListener *listener,
                             MemoryRegionSection *section)
  {
      kvm_set_phys_mem(section, false);
      memory_region_unref(section->mr);
  }
  
  static void kvm_log_sync(MemoryListener *listener,
                           MemoryRegionSection *section)
  {
      int r;
  
      r = kvm_physical_sync_dirty_bitmap(section);
      if (r < 0) {
          abort();
      }
  }
  
  static void kvm_log_global_start(struct MemoryListener *listener)
  {
      int r;
  
      r = kvm_set_migration_log(1);
      assert(r >= 0);
  }
  
  static void kvm_log_global_stop(struct MemoryListener *listener)
  {
      int r;
  
      r = kvm_set_migration_log(0);
      assert(r >= 0);
  }
  
  static void kvm_mem_ioeventfd_add(MemoryListener *listener,
                                    MemoryRegionSection *section,
                                    bool match_data, uint64_t data,
                                    EventNotifier *e)
  {
      int fd = event_notifier_get_fd(e);
      int r;
  
      r = kvm_set_ioeventfd_mmio(fd, section->offset_within_address_space,
                                 data, true, int128_get64(section->size),
                                 match_data);
      if (r < 0) {
          fprintf(stderr, "%s: error adding ioeventfd: %s\n",
                  __func__, strerror(-r));
          abort();
      }
  }
  
  static void kvm_mem_ioeventfd_del(MemoryListener *listener,
                                    MemoryRegionSection *section,
                                    bool match_data, uint64_t data,
                                    EventNotifier *e)
  {
      int fd = event_notifier_get_fd(e);
      int r;
  
      r = kvm_set_ioeventfd_mmio(fd, section->offset_within_address_space,
                                 data, false, int128_get64(section->size),
                                 match_data);
      if (r < 0) {
          abort();
      }
  }
  
  static void kvm_io_ioeventfd_add(MemoryListener *listener,
                                   MemoryRegionSection *section,
                                   bool match_data, uint64_t data,
                                   EventNotifier *e)
  {
      int fd = event_notifier_get_fd(e);
      int r;
  
      r = kvm_set_ioeventfd_pio(fd, section->offset_within_address_space,
                                data, true, int128_get64(section->size),
                                match_data);
      if (r < 0) {
          fprintf(stderr, "%s: error adding ioeventfd: %s\n",
                  __func__, strerror(-r));
          abort();
      }
  }
  
  static void kvm_io_ioeventfd_del(MemoryListener *listener,
                                   MemoryRegionSection *section,
                                   bool match_data, uint64_t data,
                                   EventNotifier *e)
  
  {
      int fd = event_notifier_get_fd(e);
      int r;
  
      r = kvm_set_ioeventfd_pio(fd, section->offset_within_address_space,
                                data, false, int128_get64(section->size),
                                match_data);
      if (r < 0) {
          abort();
      }
  }
  
  static MemoryListener kvm_memory_listener = {
      .region_add = kvm_region_add,
      .region_del = kvm_region_del,
      .log_start = kvm_log_start,
      .log_stop = kvm_log_stop,
      .log_sync = kvm_log_sync,
      .log_global_start = kvm_log_global_start,
      .log_global_stop = kvm_log_global_stop,
      .eventfd_add = kvm_mem_ioeventfd_add,
      .eventfd_del = kvm_mem_ioeventfd_del,
      .coalesced_mmio_add = kvm_coalesce_mmio_region,
      .coalesced_mmio_del = kvm_uncoalesce_mmio_region,
      .priority = 10,
  };
  
  static MemoryListener kvm_io_listener = {
      .eventfd_add = kvm_io_ioeventfd_add,
      .eventfd_del = kvm_io_ioeventfd_del,
      .priority = 10,
  };
  
  static void kvm_handle_interrupt(CPUState *cpu, int mask)
  {
      cpu->interrupt_request |= mask;
  
      if (!qemu_cpu_is_self(cpu)) {
          qemu_cpu_kick(cpu);
      }
  }
  
  int kvm_set_irq(KVMState *s, int irq, int level)
  {
      struct kvm_irq_level event;
      int ret;
  
      assert(kvm_async_interrupts_enabled());
  
      event.level = level;
      event.irq = irq;
      ret = kvm_vm_ioctl(s, s->irq_set_ioctl, &event);
      if (ret < 0) {
          perror("kvm_set_irq");
          abort();
      }
  
      return (s->irq_set_ioctl == KVM_IRQ_LINE) ? 1 : event.status;
  }
  
  #ifdef KVM_CAP_IRQ_ROUTING
  typedef struct KVMMSIRoute {
      struct kvm_irq_routing_entry kroute;
      QTAILQ_ENTRY(KVMMSIRoute) entry;
  } KVMMSIRoute;
  
  static void set_gsi(KVMState *s, unsigned int gsi)
  {
      s->used_gsi_bitmap[gsi / 32] |= 1U << (gsi % 32);
  }
  
  static void clear_gsi(KVMState *s, unsigned int gsi)
  {
      s->used_gsi_bitmap[gsi / 32] &= ~(1U << (gsi % 32));
  }
  
  void kvm_init_irq_routing(KVMState *s)
  {
      int gsi_count, i;
  
      gsi_count = kvm_check_extension(s, KVM_CAP_IRQ_ROUTING);
      if (gsi_count > 0) {
          unsigned int gsi_bits, i;
  
          /* Round up so we can search ints using ffs */
          gsi_bits = ALIGN(gsi_count, 32);
          s->used_gsi_bitmap = g_malloc0(gsi_bits / 8);
          s->gsi_count = gsi_count;
  
          /* Mark any over-allocated bits as already in use */
          for (i = gsi_count; i < gsi_bits; i++) {
              set_gsi(s, i);
          }
      }
  
      s->irq_routes = g_malloc0(sizeof(*s->irq_routes));
      s->nr_allocated_irq_routes = 0;
  
      if (!s->direct_msi) {
          for (i = 0; i < KVM_MSI_HASHTAB_SIZE; i++) {
              QTAILQ_INIT(&s->msi_hashtab[i]);
          }
      }
  
      kvm_arch_init_irq_routing(s);
  }
  
  void kvm_irqchip_commit_routes(KVMState *s)
  {
      int ret;
  
      s->irq_routes->flags = 0;
      ret = kvm_vm_ioctl(s, KVM_SET_GSI_ROUTING, s->irq_routes);
      assert(ret == 0);
  }
  
  static void kvm_add_routing_entry(KVMState *s,
                                    struct kvm_irq_routing_entry *entry)
  {
      struct kvm_irq_routing_entry *new;
      int n, size;
  
      if (s->irq_routes->nr == s->nr_allocated_irq_routes) {
          n = s->nr_allocated_irq_routes * 2;
          if (n < 64) {
              n = 64;
          }
          size = sizeof(struct kvm_irq_routing);
          size += n * sizeof(*new);
          s->irq_routes = g_realloc(s->irq_routes, size);
          s->nr_allocated_irq_routes = n;
      }
      n = s->irq_routes->nr++;
      new = &s->irq_routes->entries[n];
  
      *new = *entry;
  
      set_gsi(s, entry->gsi);
  }
  
  static int kvm_update_routing_entry(KVMState *s,
                                      struct kvm_irq_routing_entry *new_entry)
  {
      struct kvm_irq_routing_entry *entry;
      int n;
  
      for (n = 0; n < s->irq_routes->nr; n++) {
          entry = &s->irq_routes->entries[n];
          if (entry->gsi != new_entry->gsi) {
              continue;
          }
  
          if(!memcmp(entry, new_entry, sizeof *entry)) {
              return 0;
          }
  
          *entry = *new_entry;
  
          kvm_irqchip_commit_routes(s);
  
          return 0;
      }
  
      return -ESRCH;
  }
  
  void kvm_irqchip_add_irq_route(KVMState *s, int irq, int irqchip, int pin)
  {
      struct kvm_irq_routing_entry e = {};
  
      assert(pin < s->gsi_count);
  
      e.gsi = irq;
      e.type = KVM_IRQ_ROUTING_IRQCHIP;
      e.flags = 0;
      e.u.irqchip.irqchip = irqchip;
      e.u.irqchip.pin = pin;
      kvm_add_routing_entry(s, &e);
  }
  
  void kvm_irqchip_release_virq(KVMState *s, int virq)
  {
      struct kvm_irq_routing_entry *e;
      int i;
  
      if (kvm_gsi_direct_mapping()) {
          return;
      }
  
      for (i = 0; i < s->irq_routes->nr; i++) {
          e = &s->irq_routes->entries[i];
          if (e->gsi == virq) {
              s->irq_routes->nr--;
              *e = s->irq_routes->entries[s->irq_routes->nr];
          }
      }
      clear_gsi(s, virq);
  }
  
  static unsigned int kvm_hash_msi(uint32_t data)
  {
      /* This is optimized for IA32 MSI layout. However, no other arch shall
       * repeat the mistake of not providing a direct MSI injection API. */
      return data & 0xff;
  }
  
  static void kvm_flush_dynamic_msi_routes(KVMState *s)
  {
      KVMMSIRoute *route, *next;
      unsigned int hash;
  
      for (hash = 0; hash < KVM_MSI_HASHTAB_SIZE; hash++) {
          QTAILQ_FOREACH_SAFE(route, &s->msi_hashtab[hash], entry, next) {
              kvm_irqchip_release_virq(s, route->kroute.gsi);
              QTAILQ_REMOVE(&s->msi_hashtab[hash], route, entry);
              g_free(route);
          }
      }
  }
  
  static int kvm_irqchip_get_virq(KVMState *s)
  {
      uint32_t *word = s->used_gsi_bitmap;
      int max_words = ALIGN(s->gsi_count, 32) / 32;
      int i, bit;
      bool retry = true;
  
  again:
      /* Return the lowest unused GSI in the bitmap */
      for (i = 0; i < max_words; i++) {
          bit = ffs(~word[i]);
          if (!bit) {
              continue;
          }
  
          return bit - 1 + i * 32;
      }
      if (!s->direct_msi && retry) {
          retry = false;
          kvm_flush_dynamic_msi_routes(s);
          goto again;
      }
      return -ENOSPC;
  
  }
  
  static KVMMSIRoute *kvm_lookup_msi_route(KVMState *s, MSIMessage msg)
  {
      unsigned int hash = kvm_hash_msi(msg.data);
      KVMMSIRoute *route;
  
      QTAILQ_FOREACH(route, &s->msi_hashtab[hash], entry) {
          if (route->kroute.u.msi.address_lo == (uint32_t)msg.address &&
              route->kroute.u.msi.address_hi == (msg.address >> 32) &&
              route->kroute.u.msi.data == le32_to_cpu(msg.data)) {
              return route;
          }
      }
      return NULL;
  }
  
  int kvm_irqchip_send_msi(KVMState *s, MSIMessage msg)
  {
      struct kvm_msi msi;
      KVMMSIRoute *route;
  
      if (s->direct_msi) {
          msi.address_lo = (uint32_t)msg.address;
          msi.address_hi = msg.address >> 32;
          msi.data = le32_to_cpu(msg.data);
          msi.flags = 0;
          memset(msi.pad, 0, sizeof(msi.pad));
  
          return kvm_vm_ioctl(s, KVM_SIGNAL_MSI, &msi);
      }
  
      route = kvm_lookup_msi_route(s, msg);
      if (!route) {
          int virq;
  
          virq = kvm_irqchip_get_virq(s);
          if (virq < 0) {
              return virq;
          }
  
          route = g_malloc0(sizeof(KVMMSIRoute));
          route->kroute.gsi = virq;
          route->kroute.type = KVM_IRQ_ROUTING_MSI;
          route->kroute.flags = 0;
          route->kroute.u.msi.address_lo = (uint32_t)msg.address;
          route->kroute.u.msi.address_hi = msg.address >> 32;
          route->kroute.u.msi.data = le32_to_cpu(msg.data);
  
          kvm_add_routing_entry(s, &route->kroute);
          kvm_irqchip_commit_routes(s);
  
          QTAILQ_INSERT_TAIL(&s->msi_hashtab[kvm_hash_msi(msg.data)], route,
                             entry);
      }
  
      assert(route->kroute.type == KVM_IRQ_ROUTING_MSI);
  
      return kvm_set_irq(s, route->kroute.gsi, 1);
  }
  
  int kvm_irqchip_add_msi_route(KVMState *s, MSIMessage msg)
  {
      struct kvm_irq_routing_entry kroute = {};
      int virq;
  
      if (kvm_gsi_direct_mapping()) {
          return msg.data & 0xffff;
      }
  
      if (!kvm_gsi_routing_enabled()) {
          return -ENOSYS;
      }
  
      virq = kvm_irqchip_get_virq(s);
      if (virq < 0) {
          return virq;
      }
  
      kroute.gsi = virq;
      kroute.type = KVM_IRQ_ROUTING_MSI;
      kroute.flags = 0;
      kroute.u.msi.address_lo = (uint32_t)msg.address;
      kroute.u.msi.address_hi = msg.address >> 32;
      kroute.u.msi.data = le32_to_cpu(msg.data);
  
      kvm_add_routing_entry(s, &kroute);
      kvm_irqchip_commit_routes(s);
  
      return virq;
  }
  
  int kvm_irqchip_update_msi_route(KVMState *s, int virq, MSIMessage msg)
  {
      struct kvm_irq_routing_entry kroute = {};
  
      if (kvm_gsi_direct_mapping()) {
          return 0;
      }
  
      if (!kvm_irqchip_in_kernel()) {
          return -ENOSYS;
      }
  
      kroute.gsi = virq;
      kroute.type = KVM_IRQ_ROUTING_MSI;
      kroute.flags = 0;
      kroute.u.msi.address_lo = (uint32_t)msg.address;
      kroute.u.msi.address_hi = msg.address >> 32;
      kroute.u.msi.data = le32_to_cpu(msg.data);
  
      return kvm_update_routing_entry(s, &kroute);
  }
  
  static int kvm_irqchip_assign_irqfd(KVMState *s, int fd, int rfd, int virq,
                                      bool assign)
  {
      struct kvm_irqfd irqfd = {
          .fd = fd,
          .gsi = virq,
          .flags = assign ? 0 : KVM_IRQFD_FLAG_DEASSIGN,
      };
  
      if (rfd != -1) {
          irqfd.flags |= KVM_IRQFD_FLAG_RESAMPLE;
          irqfd.resamplefd = rfd;
      }
  
      if (!kvm_irqfds_enabled()) {
          return -ENOSYS;
      }
  
      return kvm_vm_ioctl(s, KVM_IRQFD, &irqfd);
  }
  
  #else /* !KVM_CAP_IRQ_ROUTING */
  
  void kvm_init_irq_routing(KVMState *s)
  {
  }
  
  void kvm_irqchip_release_virq(KVMState *s, int virq)
  {
  }
  
  int kvm_irqchip_send_msi(KVMState *s, MSIMessage msg)
  {
      abort();
  }
  
  int kvm_irqchip_add_msi_route(KVMState *s, MSIMessage msg)
  {
      return -ENOSYS;
  }
  
  static int kvm_irqchip_assign_irqfd(KVMState *s, int fd, int virq, bool assign)
  {
      abort();
  }
  
  int kvm_irqchip_update_msi_route(KVMState *s, int virq, MSIMessage msg)
  {
      return -ENOSYS;
  }
  #endif /* !KVM_CAP_IRQ_ROUTING */
  
  int kvm_irqchip_add_irqfd_notifier(KVMState *s, EventNotifier *n,
                                     EventNotifier *rn, int virq)
  {
      return kvm_irqchip_assign_irqfd(s, event_notifier_get_fd(n),
             rn ? event_notifier_get_fd(rn) : -1, virq, true);
  }
  
  int kvm_irqchip_remove_irqfd_notifier(KVMState *s, EventNotifier *n, int virq)
  {
      return kvm_irqchip_assign_irqfd(s, event_notifier_get_fd(n), -1, virq,
             false);
  }
  
  static int kvm_irqchip_create(KVMState *s)
  {
      int ret;
  
      if (!qemu_opt_get_bool(qemu_get_machine_opts(), "kernel_irqchip", true) ||
          !kvm_check_extension(s, KVM_CAP_IRQCHIP)) {
          return 0;
      }
  
      ret = kvm_vm_ioctl(s, KVM_CREATE_IRQCHIP);
      if (ret < 0) {
          fprintf(stderr, "Create kernel irqchip failed\n");
          return ret;
      }
  
      kvm_kernel_irqchip = true;
      /* If we have an in-kernel IRQ chip then we must have asynchronous
       * interrupt delivery (though the reverse is not necessarily true)
       */
      kvm_async_interrupts_allowed = true;
      kvm_halt_in_kernel_allowed = true;
  
      kvm_init_irq_routing(s);
  
      return 0;
  }
  
  /* Find number of supported CPUs using the recommended
   * procedure from the kernel API documentation to cope with
   * older kernels that may be missing capabilities.
   */
  static int kvm_recommended_vcpus(KVMState *s)
  {
      int ret = kvm_check_extension(s, KVM_CAP_NR_VCPUS);
      return (ret) ? ret : 4;
  }
  
  static int kvm_max_vcpus(KVMState *s)
  {
      int ret = kvm_check_extension(s, KVM_CAP_MAX_VCPUS);
      return (ret) ? ret : kvm_recommended_vcpus(s);
  }
  
  int kvm_init(void)
  {
      static const char upgrade_note[] =
          "Please upgrade to at least kernel 2.6.29 or recent kvm-kmod\n"
          "(see http://sourceforge.net/projects/kvm).\n";
      struct {
          const char *name;
          int num;
      } num_cpus[] = {
          { "SMP",          smp_cpus },
          { "hotpluggable", max_cpus },
          { NULL, }
      }, *nc = num_cpus;
      int soft_vcpus_limit, hard_vcpus_limit;
      KVMState *s;
      const KVMCapabilityInfo *missing_cap;
      int ret;
      int i;
  
      s = g_malloc0(sizeof(KVMState));
  
      /*
       * On systems where the kernel can support different base page
       * sizes, host page size may be different from TARGET_PAGE_SIZE,
       * even with KVM.  TARGET_PAGE_SIZE is assumed to be the minimum
       * page size for the system though.
       */
      assert(TARGET_PAGE_SIZE <= getpagesize());
  
  #ifdef KVM_CAP_SET_GUEST_DEBUG
      QTAILQ_INIT(&s->kvm_sw_breakpoints);
  #endif
      for (i = 0; i < ARRAY_SIZE(s->slots); i++) {
          s->slots[i].slot = i;
      }
      s->vmfd = -1;
      s->fd = qemu_open("/dev/kvm", O_RDWR);
      if (s->fd == -1) {
          fprintf(stderr, "Could not access KVM kernel module: %m\n");
          ret = -errno;
          goto err;
      }
  
      ret = kvm_ioctl(s, KVM_GET_API_VERSION, 0);
      if (ret < KVM_API_VERSION) {
          if (ret > 0) {
              ret = -EINVAL;
          }
          fprintf(stderr, "kvm version too old\n");
          goto err;
      }
  
      if (ret > KVM_API_VERSION) {
          ret = -EINVAL;
          fprintf(stderr, "kvm version not supported\n");
          goto err;
      }
  
      /* check the vcpu limits */
      soft_vcpus_limit = kvm_recommended_vcpus(s);
      hard_vcpus_limit = kvm_max_vcpus(s);
  
      while (nc->name) {
          if (nc->num > soft_vcpus_limit) {
              fprintf(stderr,
                      "Warning: Number of %s cpus requested (%d) exceeds "
                      "the recommended cpus supported by KVM (%d)\n",
                      nc->name, nc->num, soft_vcpus_limit);
  
              if (nc->num > hard_vcpus_limit) {
                  ret = -EINVAL;
                  fprintf(stderr, "Number of %s cpus requested (%d) exceeds "
                          "the maximum cpus supported by KVM (%d)\n",
                          nc->name, nc->num, hard_vcpus_limit);
                  goto err;
              }
          }
          nc++;
      }
  
      s->vmfd = kvm_ioctl(s, KVM_CREATE_VM, 0);
      if (s->vmfd < 0) {
  #ifdef TARGET_S390X
          fprintf(stderr, "Please add the 'switch_amode' kernel parameter to "
                          "your host kernel command line\n");
  #endif
          ret = s->vmfd;
          goto err;
      }
  
      missing_cap = kvm_check_extension_list(s, kvm_required_capabilites);
      if (!missing_cap) {
          missing_cap =
              kvm_check_extension_list(s, kvm_arch_required_capabilities);
      }
      if (missing_cap) {
          ret = -EINVAL;
          fprintf(stderr, "kvm does not support %s\n%s",
                  missing_cap->name, upgrade_note);
          goto err;
      }
  
      s->coalesced_mmio = kvm_check_extension(s, KVM_CAP_COALESCED_MMIO);
  
      s->broken_set_mem_region = 1;
      ret = kvm_check_extension(s, KVM_CAP_JOIN_MEMORY_REGIONS_WORKS);
      if (ret > 0) {
          s->broken_set_mem_region = 0;
      }
  
  #ifdef KVM_CAP_VCPU_EVENTS
      s->vcpu_events = kvm_check_extension(s, KVM_CAP_VCPU_EVENTS);
  #endif
  
      s->robust_singlestep =
          kvm_check_extension(s, KVM_CAP_X86_ROBUST_SINGLESTEP);
  
  #ifdef KVM_CAP_DEBUGREGS
      s->debugregs = kvm_check_extension(s, KVM_CAP_DEBUGREGS);
  #endif
  
  #ifdef KVM_CAP_XSAVE
      s->xsave = kvm_check_extension(s, KVM_CAP_XSAVE);
  #endif
  
  #ifdef KVM_CAP_XCRS
      s->xcrs = kvm_check_extension(s, KVM_CAP_XCRS);
  #endif
  
  #ifdef KVM_CAP_PIT_STATE2
      s->pit_state2 = kvm_check_extension(s, KVM_CAP_PIT_STATE2);
  #endif
  
  #ifdef KVM_CAP_IRQ_ROUTING
      s->direct_msi = (kvm_check_extension(s, KVM_CAP_SIGNAL_MSI) > 0);
  #endif
  
      s->intx_set_mask = kvm_check_extension(s, KVM_CAP_PCI_2_3);
  
      s->irq_set_ioctl = KVM_IRQ_LINE;
      if (kvm_check_extension(s, KVM_CAP_IRQ_INJECT_STATUS)) {
          s->irq_set_ioctl = KVM_IRQ_LINE_STATUS;
      }
  
  #ifdef KVM_CAP_READONLY_MEM
      kvm_readonly_mem_allowed =
          (kvm_check_extension(s, KVM_CAP_READONLY_MEM) > 0);
  #endif
  
      ret = kvm_arch_init(s);
      if (ret < 0) {
          goto err;
      }
  
      ret = kvm_irqchip_create(s);
      if (ret < 0) {
          goto err;
      }
  
      kvm_state = s;
      memory_listener_register(&kvm_memory_listener, &address_space_memory);
      memory_listener_register(&kvm_io_listener, &address_space_io);
  
      s->many_ioeventfds = kvm_check_many_ioeventfds();
  
      cpu_interrupt_handler = kvm_handle_interrupt;
  
      return 0;
  
  err:
      if (s->vmfd >= 0) {
          close(s->vmfd);
      }
      if (s->fd != -1) {
          close(s->fd);
      }
      g_free(s);
  
      return ret;
  }
  
  static void kvm_handle_io(uint16_t port, void *data, int direction, int size,
                            uint32_t count)
  {
      int i;
      uint8_t *ptr = data;
  
      for (i = 0; i < count; i++) {
          address_space_rw(&address_space_io, port, ptr, size,
                           direction == KVM_EXIT_IO_OUT);
          ptr += size;
      }
  }
  
  static int kvm_handle_internal_error(CPUState *cpu, struct kvm_run *run)
  {
      fprintf(stderr, "KVM internal error.");
      if (kvm_check_extension(kvm_state, KVM_CAP_INTERNAL_ERROR_DATA)) {
          int i;
  
          fprintf(stderr, " Suberror: %d\n", run->internal.suberror);
          for (i = 0; i < run->internal.ndata; ++i) {
              fprintf(stderr, "extra data[%d]: %"PRIx64"\n",
                      i, (uint64_t)run->internal.data[i]);
          }
      } else {
          fprintf(stderr, "\n");
      }
      if (run->internal.suberror == KVM_INTERNAL_ERROR_EMULATION) {
          fprintf(stderr, "emulation failure\n");
          if (!kvm_arch_stop_on_emulation_error(cpu)) {
              cpu_dump_state(cpu, stderr, fprintf, CPU_DUMP_CODE);
              return EXCP_INTERRUPT;
          }
      }
      /* FIXME: Should trigger a qmp message to let management know
       * something went wrong.
       */
      return -1;
  }
  
  void kvm_flush_coalesced_mmio_buffer(void)
  {
      KVMState *s = kvm_state;
  
      if (s->coalesced_flush_in_progress) {
          return;
      }
  
      s->coalesced_flush_in_progress = true;
  
      if (s->coalesced_mmio_ring) {
          struct kvm_coalesced_mmio_ring *ring = s->coalesced_mmio_ring;
          while (ring->first != ring->last) {
              struct kvm_coalesced_mmio *ent;
  
              ent = &ring->coalesced_mmio[ring->first];
  
              cpu_physical_memory_write(ent->phys_addr, ent->data, ent->len);
              smp_wmb();
              ring->first = (ring->first + 1) % KVM_COALESCED_MMIO_MAX;
          }
      }
  
      s->coalesced_flush_in_progress = false;
  }
  
  static void do_kvm_cpu_synchronize_state(void *arg)
  {
      CPUState *cpu = arg;
  
      if (!cpu->kvm_vcpu_dirty) {
          kvm_arch_get_registers(cpu);
          cpu->kvm_vcpu_dirty = true;
      }
  }
  
  void kvm_cpu_synchronize_state(CPUState *cpu)
  {
      if (!cpu->kvm_vcpu_dirty) {
          run_on_cpu(cpu, do_kvm_cpu_synchronize_state, cpu);
      }
  }
  
  void kvm_cpu_synchronize_post_reset(CPUState *cpu)
  {
      kvm_arch_put_registers(cpu, KVM_PUT_RESET_STATE);
      cpu->kvm_vcpu_dirty = false;
  }
  
  void kvm_cpu_synchronize_post_init(CPUState *cpu)
  {
      kvm_arch_put_registers(cpu, KVM_PUT_FULL_STATE);
      cpu->kvm_vcpu_dirty = false;
  }
  
  int kvm_cpu_exec(CPUState *cpu)
  {
      struct kvm_run *run = cpu->kvm_run;
      int ret, run_ret;
  
      DPRINTF("kvm_cpu_exec()\n");
  
      if (kvm_arch_process_async_events(cpu)) {
          cpu->exit_request = 0;
          return EXCP_HLT;
      }
  
      do {
          if (cpu->kvm_vcpu_dirty) {
              kvm_arch_put_registers(cpu, KVM_PUT_RUNTIME_STATE);
              cpu->kvm_vcpu_dirty = false;
          }
  
          kvm_arch_pre_run(cpu, run);
          if (cpu->exit_request) {
              DPRINTF("interrupt exit requested\n");
              /*
               * KVM requires us to reenter the kernel after IO exits to complete
               * instruction emulation. This self-signal will ensure that we
               * leave ASAP again.
               */
              qemu_cpu_kick_self();
          }
          qemu_mutex_unlock_iothread();
  
          run_ret = kvm_vcpu_ioctl(cpu, KVM_RUN, 0);
  
          qemu_mutex_lock_iothread();
          kvm_arch_post_run(cpu, run);
  
          if (run_ret < 0) {
              if (run_ret == -EINTR || run_ret == -EAGAIN) {
                  DPRINTF("io window exit\n");
                  ret = EXCP_INTERRUPT;
                  break;
              }
              fprintf(stderr, "error: kvm run failed %s\n",
                      strerror(-run_ret));
              abort();
          }
  
          trace_kvm_run_exit(cpu->cpu_index, run->exit_reason);
          switch (run->exit_reason) {
          case KVM_EXIT_IO:
              DPRINTF("handle_io\n");
              kvm_handle_io(run->io.port,
                            (uint8_t *)run + run->io.data_offset,
                            run->io.direction,
                            run->io.size,
                            run->io.count);
              ret = 0;
              break;
          case KVM_EXIT_MMIO:
              DPRINTF("handle_mmio\n");
              cpu_physical_memory_rw(run->mmio.phys_addr,
                                     run->mmio.data,
                                     run->mmio.len,
                                     run->mmio.is_write);
              ret = 0;
              break;
          case KVM_EXIT_IRQ_WINDOW_OPEN:
              DPRINTF("irq_window_open\n");
              ret = EXCP_INTERRUPT;
              break;
          case KVM_EXIT_SHUTDOWN:
              DPRINTF("shutdown\n");
              qemu_system_reset_request();
              ret = EXCP_INTERRUPT;
              break;
          case KVM_EXIT_UNKNOWN:
              fprintf(stderr, "KVM: unknown exit, hardware reason %" PRIx64 "\n",
                      (uint64_t)run->hw.hardware_exit_reason);
              ret = -1;
              break;
          case KVM_EXIT_INTERNAL_ERROR:
              ret = kvm_handle_internal_error(cpu, run);
              break;
          default:
              DPRINTF("kvm_arch_handle_exit\n");
              ret = kvm_arch_handle_exit(cpu, run);
              break;
          }
      } while (ret == 0);
  
      if (ret < 0) {
          cpu_dump_state(cpu, stderr, fprintf, CPU_DUMP_CODE);
          vm_stop(RUN_STATE_INTERNAL_ERROR);
      }
  
      cpu->exit_request = 0;
      return ret;
  }
  
  int kvm_ioctl(KVMState *s, int type, ...)
  {
      int ret;
      void *arg;
      va_list ap;
  
      va_start(ap, type);
      arg = va_arg(ap, void *);
      va_end(ap);
  
      trace_kvm_ioctl(type, arg);
      ret = ioctl(s->fd, type, arg);
      if (ret == -1) {
          ret = -errno;
      }
      return ret;
  }
  
  int kvm_vm_ioctl(KVMState *s, int type, ...)
  {
      int ret;
      void *arg;
      va_list ap;
  
      va_start(ap, type);
      arg = va_arg(ap, void *);
      va_end(ap);
  
      trace_kvm_vm_ioctl(type, arg);
      ret = ioctl(s->vmfd, type, arg);
      if (ret == -1) {
          ret = -errno;
      }
      return ret;
  }
  
  int kvm_vcpu_ioctl(CPUState *cpu, int type, ...)
  {
      int ret;
      void *arg;
      va_list ap;
  
      va_start(ap, type);
      arg = va_arg(ap, void *);
      va_end(ap);
  
      trace_kvm_vcpu_ioctl(cpu->cpu_index, type, arg);
      ret = ioctl(cpu->kvm_fd, type, arg);
      if (ret == -1) {
          ret = -errno;
      }
      return ret;
  }
  
  int kvm_has_sync_mmu(void)
  {
      return kvm_check_extension(kvm_state, KVM_CAP_SYNC_MMU);
  }
  
  int kvm_has_vcpu_events(void)
  {
      return kvm_state->vcpu_events;
  }
  
  int kvm_has_robust_singlestep(void)
  {
      return kvm_state->robust_singlestep;
  }
  
  int kvm_has_debugregs(void)
  {
      return kvm_state->debugregs;
  }
  
  int kvm_has_xsave(void)
  {
      return kvm_state->xsave;
  }
  
  int kvm_has_xcrs(void)
  {
      return kvm_state->xcrs;
  }
  
  int kvm_has_pit_state2(void)
  {
      return kvm_state->pit_state2;
  }
  
  int kvm_has_many_ioeventfds(void)
  {
      if (!kvm_enabled()) {
          return 0;
      }
      return kvm_state->many_ioeventfds;
  }
  
  int kvm_has_gsi_routing(void)
  {
  #ifdef KVM_CAP_IRQ_ROUTING
      return kvm_check_extension(kvm_state, KVM_CAP_IRQ_ROUTING);
  #else
      return false;
  #endif
  }
  
  int kvm_has_intx_set_mask(void)
  {
      return kvm_state->intx_set_mask;
  }
  
  void kvm_setup_guest_memory(void *start, size_t size)
  {
  #ifdef CONFIG_VALGRIND_H
      VALGRIND_MAKE_MEM_DEFINED(start, size);
  #endif
      if (!kvm_has_sync_mmu()) {
          int ret = qemu_madvise(start, size, QEMU_MADV_DONTFORK);
  
          if (ret) {
              perror("qemu_madvise");
              fprintf(stderr,
                      "Need MADV_DONTFORK in absence of synchronous KVM MMU\n");
              exit(1);
          }
      }
  }
  
  #ifdef KVM_CAP_SET_GUEST_DEBUG
  struct kvm_sw_breakpoint *kvm_find_sw_breakpoint(CPUState *cpu,
                                                   target_ulong pc)
  {
      struct kvm_sw_breakpoint *bp;
  
      QTAILQ_FOREACH(bp, &cpu->kvm_state->kvm_sw_breakpoints, entry) {
          if (bp->pc == pc) {
              return bp;
          }
      }
      return NULL;
  }
  
  int kvm_sw_breakpoints_active(CPUState *cpu)
  {
      return !QTAILQ_EMPTY(&cpu->kvm_state->kvm_sw_breakpoints);
  }
  
  struct kvm_set_guest_debug_data {
      struct kvm_guest_debug dbg;
      CPUState *cpu;
      int err;
  };
  
  static void kvm_invoke_set_guest_debug(void *data)
  {
      struct kvm_set_guest_debug_data *dbg_data = data;
  
      dbg_data->err = kvm_vcpu_ioctl(dbg_data->cpu, KVM_SET_GUEST_DEBUG,
                                     &dbg_data->dbg);
  }
  
  int kvm_update_guest_debug(CPUState *cpu, unsigned long reinject_trap)
  {
      struct kvm_set_guest_debug_data data;
  
      data.dbg.control = reinject_trap;
  
      if (cpu->singlestep_enabled) {
          data.dbg.control |= KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_SINGLESTEP;
      }
      kvm_arch_update_guest_debug(cpu, &data.dbg);
      data.cpu = cpu;
  
      run_on_cpu(cpu, kvm_invoke_set_guest_debug, &data);
      return data.err;
  }
  
  int kvm_insert_breakpoint(CPUState *cpu, target_ulong addr,
                            target_ulong len, int type)
  {
      struct kvm_sw_breakpoint *bp;
      int err;
  
      if (type == GDB_BREAKPOINT_SW) {
          bp = kvm_find_sw_breakpoint(cpu, addr);
          if (bp) {
              bp->use_count++;
              return 0;
          }
  
          bp = g_malloc(sizeof(struct kvm_sw_breakpoint));
          if (!bp) {
              return -ENOMEM;
          }
  
          bp->pc = addr;
          bp->use_count = 1;
          err = kvm_arch_insert_sw_breakpoint(cpu, bp);
          if (err) {
              g_free(bp);
              return err;
          }
  
          QTAILQ_INSERT_HEAD(&cpu->kvm_state->kvm_sw_breakpoints, bp, entry);
      } else {
          err = kvm_arch_insert_hw_breakpoint(addr, len, type);
          if (err) {
              return err;
          }
      }
  
      CPU_FOREACH(cpu) {
          err = kvm_update_guest_debug(cpu, 0);
          if (err) {
              return err;
          }
      }
      return 0;
  }
  
  int kvm_remove_breakpoint(CPUState *cpu, target_ulong addr,
                            target_ulong len, int type)
  {
      struct kvm_sw_breakpoint *bp;
      int err;
  
      if (type == GDB_BREAKPOINT_SW) {
          bp = kvm_find_sw_breakpoint(cpu, addr);
          if (!bp) {
              return -ENOENT;
          }
  
          if (bp->use_count > 1) {
              bp->use_count--;
              return 0;
          }
  
          err = kvm_arch_remove_sw_breakpoint(cpu, bp);
          if (err) {
              return err;
          }
  
          QTAILQ_REMOVE(&cpu->kvm_state->kvm_sw_breakpoints, bp, entry);
          g_free(bp);
      } else {
          err = kvm_arch_remove_hw_breakpoint(addr, len, type);
          if (err) {
              return err;
          }
      }
  
      CPU_FOREACH(cpu) {
          err = kvm_update_guest_debug(cpu, 0);
          if (err) {
              return err;
          }
      }
      return 0;
  }
  
  void kvm_remove_all_breakpoints(CPUState *cpu)
  {
      struct kvm_sw_breakpoint *bp, *next;
      KVMState *s = cpu->kvm_state;
  
      QTAILQ_FOREACH_SAFE(bp, &s->kvm_sw_breakpoints, entry, next) {
          if (kvm_arch_remove_sw_breakpoint(cpu, bp) != 0) {
              /* Try harder to find a CPU that currently sees the breakpoint. */
              CPU_FOREACH(cpu) {
                  if (kvm_arch_remove_sw_breakpoint(cpu, bp) == 0) {
                      break;
                  }
              }
          }
          QTAILQ_REMOVE(&s->kvm_sw_breakpoints, bp, entry);
          g_free(bp);
      }
      kvm_arch_remove_all_hw_breakpoints();
  
      CPU_FOREACH(cpu) {
          kvm_update_guest_debug(cpu, 0);
      }
  }
  
  #else /* !KVM_CAP_SET_GUEST_DEBUG */
  
  int kvm_update_guest_debug(CPUState *cpu, unsigned long reinject_trap)
  {
      return -EINVAL;
  }
  
  int kvm_insert_breakpoint(CPUState *cpu, target_ulong addr,
                            target_ulong len, int type)
  {
      return -EINVAL;
  }
  
  int kvm_remove_breakpoint(CPUState *cpu, target_ulong addr,
                            target_ulong len, int type)
  {
      return -EINVAL;
  }
  
  void kvm_remove_all_breakpoints(CPUState *cpu)
  {
  }
  #endif /* !KVM_CAP_SET_GUEST_DEBUG */
  
  int kvm_set_signal_mask(CPUState *cpu, const sigset_t *sigset)
  {
      struct kvm_signal_mask *sigmask;
      int r;
  
      if (!sigset) {
          return kvm_vcpu_ioctl(cpu, KVM_SET_SIGNAL_MASK, NULL);
      }
  
      sigmask = g_malloc(sizeof(*sigmask) + sizeof(*sigset));
  
      sigmask->len = 8;
      memcpy(sigmask->sigset, sigset, sizeof(*sigset));
      r = kvm_vcpu_ioctl(cpu, KVM_SET_SIGNAL_MASK, sigmask);
      g_free(sigmask);
  
      return r;
  }
  int kvm_on_sigbus_vcpu(CPUState *cpu, int code, void *addr)
  {
      return kvm_arch_on_sigbus_vcpu(cpu, code, addr);
  }
  
  int kvm_on_sigbus(int code, void *addr)
  {
      return kvm_arch_on_sigbus(code, addr);
  }
  