diff options
| -rw-r--r-- | virt/kvm/kvm_main.c | 24 |
1 files changed, 16 insertions, 8 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index e21bac7ed5d3..a83c186cefc1 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -506,11 +506,6 @@ static struct kvm_memslots *kvm_alloc_memslots(void) if (!slots) return NULL; - /* - * Init kvm generation close to the maximum to easily test the - * code of handling generation number wrap-around. - */ - slots->generation = -150; for (i = 0; i < KVM_MEM_SLOTS_NUM; i++) slots->id_to_index[i] = slots->memslots[i].id = i; @@ -641,9 +636,16 @@ static struct kvm *kvm_create_vm(unsigned long type) r = -ENOMEM; for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) { - kvm->memslots[i] = kvm_alloc_memslots(); - if (!kvm->memslots[i]) + struct kvm_memslots *slots = kvm_alloc_memslots(); + if (!slots) goto out_err_no_srcu; + /* + * Generations must be different for each address space. + * Init kvm generation close to the maximum to easily test the + * code of handling generation number wrap-around. + */ + slots->generation = i * 2 - 150; + rcu_assign_pointer(kvm->memslots[i], slots); } if (init_srcu_struct(&kvm->srcu)) @@ -870,8 +872,14 @@ static struct kvm_memslots *install_new_memslots(struct kvm *kvm, * Increment the new memslot generation a second time. This prevents * vm exits that race with memslot updates from caching a memslot * generation that will (potentially) be valid forever. + * + * Generations must be unique even across address spaces. We do not need + * a global counter for that, instead the generation space is evenly split + * across address spaces. For example, with two address spaces, address + * space 0 will use generations 0, 4, 8, ... while * address space 1 will + * use generations 2, 6, 10, 14, ... */ - slots->generation++; + slots->generation += KVM_ADDRESS_SPACE_NUM * 2 - 1; kvm_arch_memslots_updated(kvm, slots); |