+namespace simgrid::s4u {
+xbt::signal<void(VirtualMachine&)> VirtualMachine::on_vm_creation;
+xbt::signal<void(VirtualMachine const&)> VirtualMachine::on_start;
+xbt::signal<void(VirtualMachine const&)> VirtualMachine::on_started;
+xbt::signal<void(VirtualMachine const&)> VirtualMachine::on_shutdown;
+xbt::signal<void(VirtualMachine const&)> VirtualMachine::on_suspend;
+xbt::signal<void(VirtualMachine const&)> VirtualMachine::on_resume;
+xbt::signal<void(VirtualMachine const&)> VirtualMachine::on_migration_start;
+xbt::signal<void(VirtualMachine const&)> VirtualMachine::on_migration_end;
+xbt::signal<void(VirtualMachine const&)> VirtualMachine::on_vm_destruction;
+
+xbt::Extension<Host, VmHostExt> VmHostExt::EXTENSION_ID;
+
+void VmHostExt::ensureVmExtInstalled()
+{
+ if (not EXTENSION_ID.valid())
+ EXTENSION_ID = Host::extension_create<VmHostExt>();
+}
+
+VirtualMachine::VirtualMachine(kernel::resource::VirtualMachineImpl* impl)
+ : Host(impl), pimpl_vm_(dynamic_cast<kernel::resource::VirtualMachineImpl*>(Host::get_impl()))
+{
+}
+
+void VirtualMachine::start()
+{
+ kernel::actor::simcall_answered([this]() { pimpl_vm_->start(); });
+}
+
+void VirtualMachine::suspend()
+{
+ const kernel::actor::ActorImpl* issuer = kernel::actor::ActorImpl::self();
+ kernel::actor::simcall_answered([this, issuer]() { pimpl_vm_->suspend(issuer); });
+}
+
+void VirtualMachine::resume()
+{
+ pimpl_vm_->resume();
+}
+
+void VirtualMachine::shutdown()
+{
+ kernel::actor::ActorImpl* issuer = kernel::actor::ActorImpl::self();
+ kernel::actor::simcall_answered([this, issuer]() { pimpl_vm_->shutdown(issuer); });
+}
+
+void VirtualMachine::destroy()
+{
+ auto destroy_code = [this]() {
+ /* First, terminate all processes on the VM if necessary */
+ shutdown();
+
+ XBT_DEBUG("destroy %s", get_cname());
+ on_vm_destruction(*this);
+ on_this_vm_destruction(*this);
+ /* Then, destroy the VM object */
+ kernel::actor::simcall_answered(
+ [this]() { get_vm_impl()->get_physical_host()->get_impl()->destroy_vm(get_name()); });
+ };
+
+ if (not this_actor::is_maestro() && this_actor::get_host() == this) {
+ XBT_VERB("Launch another actor on physical host %s to destroy my own VM: %s", get_pm()->get_cname(), get_cname());
+ simgrid::s4u::Actor::create(get_name() + "-vm_destroy", get_pm(), destroy_code);
+ simgrid::s4u::this_actor::yield();
+ XBT_CRITICAL("I should be dead now!");
+ DIE_IMPOSSIBLE;
+ }
+
+ destroy_code();
+}
+
+simgrid::s4u::Host* VirtualMachine::get_pm() const
+{
+ return pimpl_vm_->get_physical_host();
+}
+
+VirtualMachine* VirtualMachine::set_pm(simgrid::s4u::Host* pm)
+{
+ kernel::actor::simcall_answered([this, pm]() { pimpl_vm_->set_physical_host(pm); });
+ return this;
+}
+
+VirtualMachine::State VirtualMachine::get_state() const
+{
+ return kernel::actor::simcall_answered([this]() { return pimpl_vm_->get_state(); });
+}
+
+size_t VirtualMachine::get_ramsize() const
+{
+ return pimpl_vm_->get_ramsize();
+}
+
+VirtualMachine* VirtualMachine::set_ramsize(size_t ramsize)
+{
+ pimpl_vm_->set_ramsize(ramsize);
+ return this;
+}
+/** @brief Set a CPU bound for a given VM.
+ * @ingroup msg_VMs
+ *
+ * 1. Note that in some cases sg_exec_set_bound() may not intuitively work for VMs.
+ *
+ * For example,
+ * On PM0, there are Task1 and VM0.
+ * On VM0, there is Task2.
+ * Now we bound 75% to Task1\@PM0 and bound 25% to Task2\@VM0.
+ * Then,
+ * Task1\@PM0 gets 50%.
+ * Task2\@VM0 gets 25%.
+ * This is NOT 75% for Task1\@PM0 and 25% for Task2\@VM0, respectively.
+ *
+ * This is because a VM has the dummy CPU action in the PM layer. Putting a task on the VM does not affect the bound of
+ * the dummy CPU action. The bound of the dummy CPU action is unlimited.
+ *
+ * There are some solutions for this problem. One option is to update the bound of the dummy CPU action automatically.
+ * It should be the sum of all tasks on the VM. But, this solution might be costly, because we have to scan all tasks
+ * on the VM in share_resource() or we have to trap both the start and end of task execution.
+ *
+ * The current solution is to use set_bound(), which allows us to directly set the bound of the dummy CPU action.
+ *
+ * 2. Note that bound == 0 means no bound (i.e., unlimited). But, if a host has multiple CPU cores, the CPU share of a
+ * computation task (or a VM) never exceeds the capacity of a CPU core.
+ */
+VirtualMachine* VirtualMachine::set_bound(double bound)
+{
+ kernel::actor::simcall_answered([this, bound]() { pimpl_vm_->set_bound(bound); });
+ return this;
+}
+
+void VirtualMachine::start_migration() const
+{
+ pimpl_vm_->start_migration();
+}
+
+void VirtualMachine::end_migration() const
+{
+ pimpl_vm_->end_migration();
+}
+
+} // namespace simgrid::s4u
+
+/* **************************** Public C interface *************************** */
+
+/** @brief Create a new VM object with the default parameters
+ * A VM is treated as a host. The name of the VM must be unique among all hosts.
+ */
+sg_vm_t sg_vm_create_core(sg_host_t pm, const char* name)
+{
+ return sg_vm_create_multicore(pm, name, 1);
+}
+/** @brief Create a new VM object with the default parameters, but with a specified amount of cores
+ * A VM is treated as a host. The name of the VM must be unique among all hosts.
+ */
+sg_vm_t sg_vm_create_multicore(sg_host_t pm, const char* name, int coreAmount)
+{
+ return pm->create_vm(name, coreAmount);
+}
+
+const char* sg_vm_get_name(const_sg_vm_t vm)
+{
+ return vm->get_cname();
+}
+
+/** @brief Get the physical host of a given VM. */
+sg_host_t sg_vm_get_pm(const_sg_vm_t vm)
+{
+ return vm->get_pm();
+}
+
+void sg_vm_set_ramsize(sg_vm_t vm, size_t size)
+{
+ vm->set_ramsize(size);
+}
+
+size_t sg_vm_get_ramsize(const_sg_vm_t vm)
+{
+ return vm->get_ramsize();
+}
+
+void sg_vm_set_bound(sg_vm_t vm, double bound)
+{
+ vm->set_bound(bound);
+}
+
+/** @brief Returns whether the given VM has just created, not running. */
+int sg_vm_is_created(const_sg_vm_t vm)
+{
+ return vm->get_state() == simgrid::s4u::VirtualMachine::State::CREATED;
+}
+
+/** @brief Returns whether the given VM is currently running */
+int sg_vm_is_running(const_sg_vm_t vm)