return NULL;
}
-static KVMSlot *kvm_lookup_slot(KVMState *s, target_phys_addr_t start_addr)
+/*
+ * Find overlapping slot with lowest start address
+ */
+static KVMSlot *kvm_lookup_overlapping_slot(KVMState *s,
+ target_phys_addr_t start_addr,
+ target_phys_addr_t end_addr)
{
+ KVMSlot *found = NULL;
int i;
for (i = 0; i < ARRAY_SIZE(s->slots); i++) {
KVMSlot *mem = &s->slots[i];
- if (start_addr >= mem->start_addr &&
- start_addr < (mem->start_addr + mem->memory_size))
- return mem;
+ 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 NULL;
+ return found;
}
static int kvm_set_user_memory_region(KVMState *s, KVMSlot *slot)
return ret;
}
+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;
+}
+
int kvm_init(int smp_cpus)
{
KVMState *s;
int ret;
int i;
- if (smp_cpus > 1)
+ if (smp_cpus > 1) {
+ fprintf(stderr, "No SMP KVM support, use '-smp 1'\n");
return -EINVAL;
+ }
s = qemu_mallocz(sizeof(KVMState));
* just use a user allocated buffer so we can use regular pages
* unmodified. Make sure we have a sufficiently modern version of KVM.
*/
- ret = kvm_ioctl(s, KVM_CHECK_EXTENSION, KVM_CAP_USER_MEMORY);
- if (ret <= 0) {
- if (ret == 0)
- ret = -EINVAL;
+ if (!kvm_check_extension(s, KVM_CAP_USER_MEMORY)) {
+ ret = -EINVAL;
fprintf(stderr, "kvm does not support KVM_CAP_USER_MEMORY\n");
goto err;
}
/* There was a nasty bug in < kvm-80 that prevents memory slots from being
* destroyed properly. Since we rely on this capability, refuse to work
* with any kernel without this capability. */
- ret = kvm_ioctl(s, KVM_CHECK_EXTENSION,
- KVM_CAP_DESTROY_MEMORY_REGION_WORKS);
- if (ret <= 0) {
- if (ret == 0)
- ret = -EINVAL;
+ if (!kvm_check_extension(s, KVM_CAP_DESTROY_MEMORY_REGION_WORKS)) {
+ ret = -EINVAL;
fprintf(stderr,
"KVM kernel module broken (DESTROY_MEMORY_REGION)\n"
goto err;
}
- s->coalesced_mmio = 0;
#ifdef KVM_CAP_COALESCED_MMIO
- ret = kvm_ioctl(s, KVM_CHECK_EXTENSION, KVM_CAP_COALESCED_MMIO);
- if (ret > 0)
- s->coalesced_mmio = ret;
+ s->coalesced_mmio = kvm_check_extension(s, KVM_CAP_COALESCED_MMIO);
+#else
+ s->coalesced_mmio = 0;
#endif
ret = kvm_arch_init(s, smp_cpus);
{
KVMState *s = kvm_state;
ram_addr_t flags = phys_offset & ~TARGET_PAGE_MASK;
- KVMSlot *mem;
+ KVMSlot *mem, old;
+ int err;
if (start_addr & ~TARGET_PAGE_MASK) {
- fprintf(stderr, "Only page-aligned memory slots supported\n");
+ if (flags >= IO_MEM_UNASSIGNED) {
+ if (!kvm_lookup_overlapping_slot(s, start_addr,
+ start_addr + size)) {
+ return;
+ }
+ fprintf(stderr, "Unaligned split of a KVM memory slot\n");
+ } else {
+ fprintf(stderr, "Only page-aligned memory slots supported\n");
+ }
abort();
}
/* KVM does not support read-only slots */
phys_offset &= ~IO_MEM_ROM;
- mem = kvm_lookup_slot(s, start_addr);
- if (mem) {
- if (flags >= IO_MEM_UNASSIGNED) {
- mem->memory_size = 0;
- mem->start_addr = start_addr;
- mem->phys_offset = 0;
+ while (1) {
+ mem = kvm_lookup_overlapping_slot(s, start_addr, start_addr + size);
+ if (!mem) {
+ break;
+ }
+
+ if (flags < IO_MEM_UNASSIGNED && start_addr >= mem->start_addr &&
+ (start_addr + size <= mem->start_addr + mem->memory_size) &&
+ (phys_offset - start_addr == mem->phys_offset - mem->start_addr)) {
+ /* The new slot fits into the existing one and comes with
+ * identical parameters - nothing to be done. */
+ return;
+ }
+
+ old = *mem;
+
+ /* 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 (old.start_addr == start_addr && old.memory_size < size &&
+ flags < IO_MEM_UNASSIGNED) {
+ mem = kvm_alloc_slot(s);
+ mem->memory_size = old.memory_size;
+ mem->start_addr = old.start_addr;
+ mem->phys_offset = old.phys_offset;
mem->flags = 0;
- kvm_set_user_memory_region(s, mem);
- } else if (start_addr >= mem->start_addr &&
- (start_addr + size) <= (mem->start_addr +
- mem->memory_size)) {
- KVMSlot slot;
- target_phys_addr_t mem_start;
- ram_addr_t mem_size, mem_offset;
-
- /* Not splitting */
- if ((phys_offset - (start_addr - mem->start_addr)) ==
- mem->phys_offset)
- return;
+ err = kvm_set_user_memory_region(s, mem);
+ if (err) {
+ fprintf(stderr, "%s: error updating slot: %s\n", __func__,
+ strerror(-err));
+ abort();
+ }
- /* unregister whole slot */
- memcpy(&slot, mem, sizeof(slot));
- mem->memory_size = 0;
- kvm_set_user_memory_region(s, mem);
+ start_addr += old.memory_size;
+ phys_offset += old.memory_size;
+ size -= old.memory_size;
+ continue;
+ }
- /* register prefix slot */
- mem_start = slot.start_addr;
- mem_size = start_addr - slot.start_addr;
- mem_offset = slot.phys_offset;
- if (mem_size)
- kvm_set_phys_mem(mem_start, mem_size, mem_offset);
+ /* 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->phys_offset = old.phys_offset;
+ mem->flags = 0;
- /* register new slot */
- kvm_set_phys_mem(start_addr, size, phys_offset);
+ err = kvm_set_user_memory_region(s, mem);
+ if (err) {
+ fprintf(stderr, "%s: error registering prefix slot: %s\n",
+ __func__, strerror(-err));
+ abort();
+ }
+ }
- /* register suffix slot */
- mem_start = start_addr + size;
- mem_offset += mem_size + size;
- mem_size = slot.memory_size - mem_size - size;
- if (mem_size)
- kvm_set_phys_mem(mem_start, mem_size, mem_offset);
+ /* register suffix slot */
+ if (old.start_addr + old.memory_size > start_addr + size) {
+ ram_addr_t size_delta;
- return;
- } else {
- printf("Registering overlapping slot\n");
- abort();
+ 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->phys_offset = old.phys_offset + size_delta;
+ mem->flags = 0;
+
+ 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;
+
/* KVM does not need to know about this memory */
if (flags >= IO_MEM_UNASSIGNED)
return;
mem->phys_offset = phys_offset;
mem->flags = 0;
- kvm_set_user_memory_region(s, mem);
- /* FIXME deal with errors */
+ err = kvm_set_user_memory_region(s, mem);
+ if (err) {
+ fprintf(stderr, "%s: error registering slot: %s\n", __func__,
+ strerror(-err));
+ abort();
+ }
}
int kvm_ioctl(KVMState *s, int type, ...)
#ifdef KVM_CAP_SYNC_MMU
KVMState *s = kvm_state;
- if (kvm_ioctl(s, KVM_CHECK_EXTENSION, KVM_CAP_SYNC_MMU) > 0)
- return 1;
+ return kvm_check_extension(s, KVM_CAP_SYNC_MMU);
+#else
+ return 0;
#endif
+}
- return 0;
+void kvm_setup_guest_memory(void *start, size_t size)
+{
+ if (!kvm_has_sync_mmu()) {
+#ifdef MADV_DONTFORK
+ int ret = madvise(start, size, MADV_DONTFORK);
+
+ if (ret) {
+ perror("madvice");
+ exit(1);
+ }
+#else
+ fprintf(stderr,
+ "Need MADV_DONTFORK in absence of synchronous KVM MMU\n");
+ exit(1);
+#endif
+ }
}
#ifdef KVM_CAP_SET_GUEST_DEBUG
projects / qemu / blobdiff