From: Alexander Graf <graf@amazon.com>
Add a machine model to spawn a Nitro Enclave. Unlike the existing -M
nitro-enclave, this machine model works exclusively with the -accel
nitro accelerator to drive real Nitro Enclave creation. It supports
memory allocation, number of CPU selection, both x86_64 as well as
aarch64, implements the Enclave heartbeat logic and debug serial
console.
To use it, create an EIF file and run
$ qemu-system-x86_64 -accel nitro,debug-mode=on -M nitro -nographic \
-kernel test.eif
or
$ qemu-system-aarch64 -accel nitro,debug-mode=on -M nitro -nographic \
-kernel test.eif
Signed-off-by: Alexander Graf <graf@amazon.com>
Link: https://lore.kernel.org/r/20260225220807.33092-9-graf@amazon.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
include/hw/nitro/machine.h | 20 +++++
hw/nitro/machine.c | 161 +++++++++++++++++++++++++++++++++++++
tests/qtest/libqtest.c | 1 +
hw/nitro/Kconfig | 8 ++
hw/nitro/meson.build | 1 +
5 files changed, 191 insertions(+)
create mode 100644 include/hw/nitro/machine.h
create mode 100644 hw/nitro/machine.c
diff --git a/include/hw/nitro/machine.h b/include/hw/nitro/machine.h
new file mode 100644
index 00000000000..d78ba7d6dc3
--- /dev/null
+++ b/include/hw/nitro/machine.h
@@ -0,0 +1,20 @@
+/*
+ * Nitro Enclaves (accel) machine
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#ifndef HW_NITRO_MACHINE_H
+#define HW_NITRO_MACHINE_H
+
+#include "hw/core/boards.h"
+#include "qom/object.h"
+
+#define TYPE_NITRO_MACHINE MACHINE_TYPE_NAME("nitro")
+OBJECT_DECLARE_SIMPLE_TYPE(NitroMachineState, NITRO_MACHINE)
+
+struct NitroMachineState {
+ MachineState parent;
+};
+
+#endif /* HW_NITRO_MACHINE_H */
diff --git a/hw/nitro/machine.c b/hw/nitro/machine.c
new file mode 100644
index 00000000000..e28c8e9bf50
--- /dev/null
+++ b/hw/nitro/machine.c
@@ -0,0 +1,161 @@
+/*
+ * Nitro Enclaves (accel) machine
+ *
+ * Copyright © 2026 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ * Authors:
+ * Alexander Graf <graf@amazon.com>
+ *
+ * Nitro Enclaves machine model for -accel nitro. This machine behaves
+ * like the nitro-enclave machine, but uses the real Nitro Enclaves
+ * backend to launch the virtual machine. It requires use of the -accel
+ * nitro.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/error-report.h"
+#include "qapi/error.h"
+#include "qom/object_interfaces.h"
+#include "chardev/char.h"
+#include "hw/core/boards.h"
+#include "hw/core/cpu.h"
+#include "hw/core/qdev-properties-system.h"
+#include "hw/nitro/heartbeat.h"
+#include "hw/nitro/machine.h"
+#include "hw/nitro/nitro-vsock-bus.h"
+#include "hw/nitro/serial-vsock.h"
+#include "system/address-spaces.h"
+#include "system/hostmem.h"
+#include "system/system.h"
+#include "system/nitro-accel.h"
+#include "qemu/accel.h"
+#include "hw/arm/machines-qom.h"
+
+#define EIF_LOAD_ADDR (8 * 1024 * 1024)
+
+static void nitro_machine_init(MachineState *machine)
+{
+ const char *eif_path = machine->kernel_filename;
+ const char *cpu_type = machine->cpu_type;
+ g_autofree char *eif_data = NULL;
+ gsize eif_size;
+
+ if (!nitro_enabled()) {
+ error_report("The 'nitro' machine requires -accel nitro");
+ exit(1);
+ }
+
+ if (!cpu_type) {
+ ObjectClass *oc = cpu_class_by_name(target_cpu_type(), "host");
+
+ if (!oc) {
+ error_report("nitro: no 'host' CPU available");
+ exit(1);
+ }
+ cpu_type = object_class_get_name(oc);
+ }
+
+ if (!eif_path) {
+ error_report("nitro: -kernel <eif-file> is required");
+ exit(1);
+ }
+
+ /* Expose memory as normal QEMU RAM. Needs to be huge page backed. */
+ memory_region_add_subregion(get_system_memory(), 0, machine->ram);
+
+ /*
+ * Load EIF (-kernel) as raw blob at the EIF_LOAD_ADDR into guest RAM.
+ * The Nitro Hypervisor will extract its contents and bootstrap the
+ * Enclave from it.
+ */
+ if (!g_file_get_contents(eif_path, &eif_data, &eif_size, NULL)) {
+ error_report("nitro: failed to read EIF '%s'", eif_path);
+ exit(1);
+ }
+ address_space_write(&address_space_memory, EIF_LOAD_ADDR,
+ MEMTXATTRS_UNSPECIFIED, eif_data, eif_size);
+
+ if (defaults_enabled()) {
+ NitroVsockBridge *bridge = nitro_vsock_bridge_create();
+
+ /* Nitro Enclaves require a heartbeat device. Provide one. */
+ qdev_realize(qdev_new(TYPE_NITRO_HEARTBEAT),
+ BUS(&bridge->bus), &error_fatal);
+
+ /*
+ * In debug mode, Nitro Enclaves expose the guest's serial output via
+ * vsock. When the accel is in debug mode, wire the vsock serial to
+ * the machine's serial port so that -nographic automatically works
+ */
+ if (object_property_get_bool(OBJECT(current_accel()), "debug-mode", NULL)) {
+ Chardev *chr = serial_hd(0);
+
+ if (chr) {
+ DeviceState *dev = qdev_new(TYPE_NITRO_SERIAL_VSOCK);
+
+ qdev_prop_set_chr(dev, "chardev", chr);
+ qdev_realize(dev, BUS(&bridge->bus), &error_fatal);
+ }
+ }
+ }
+}
+
+static bool nitro_create_memfd_backend(MachineState *ms, const char *path,
+ Error **errp)
+{
+ MachineClass *mc = MACHINE_GET_CLASS(ms);
+ Object *root = object_get_objects_root();
+ Object *obj;
+ bool r = false;
+
+ obj = object_new(TYPE_MEMORY_BACKEND_MEMFD);
+
+ /* Nitro Enclaves require huge page backing */
+ if (!object_property_set_int(obj, "size", ms->ram_size, errp) ||
+ !object_property_set_bool(obj, "hugetlb", true, errp)) {
+ goto out;
+ }
+
+ object_property_add_child(root, mc->default_ram_id, obj);
+
+ if (!user_creatable_complete(USER_CREATABLE(obj), errp)) {
+ goto out;
+ }
+ r = object_property_set_link(OBJECT(ms), "memory-backend", obj, errp);
+
+out:
+ object_unref(obj);
+ return r;
+}
+
+static void nitro_machine_class_init(ObjectClass *oc, const void *data)
+{
+ MachineClass *mc = MACHINE_CLASS(oc);
+
+ mc->desc = "Nitro Enclave";
+ mc->init = nitro_machine_init;
+ mc->create_default_memdev = nitro_create_memfd_backend;
+ mc->default_ram_id = "ram";
+ mc->max_cpus = 4096;
+}
+
+static const TypeInfo nitro_machine_info = {
+ .name = TYPE_NITRO_MACHINE,
+ .parent = TYPE_MACHINE,
+ .instance_size = sizeof(NitroMachineState),
+ .class_init = nitro_machine_class_init,
+ .interfaces = (const InterfaceInfo[]) {
+ /* x86_64 and aarch64 only */
+ { TYPE_TARGET_AARCH64_MACHINE },
+ { }
+ },
+};
+
+static void nitro_machine_register(void)
+{
+ type_register_static(&nitro_machine_info);
+}
+
+type_init(nitro_machine_register);
diff --git a/tests/qtest/libqtest.c b/tests/qtest/libqtest.c
index 794d8700857..051faf31e14 100644
--- a/tests/qtest/libqtest.c
+++ b/tests/qtest/libqtest.c
@@ -1815,6 +1815,7 @@ void qtest_cb_for_every_machine(void (*cb)(const char *machine),
g_str_equal("xenpv", machines[i].name) ||
g_str_equal("xenpvh", machines[i].name) ||
g_str_equal("vmapple", machines[i].name) ||
+ g_str_equal("nitro", machines[i].name) ||
g_str_equal("nitro-enclave", machines[i].name)) {
continue;
}
diff --git a/hw/nitro/Kconfig b/hw/nitro/Kconfig
index d3fbc7b683c..cfae85920a0 100644
--- a/hw/nitro/Kconfig
+++ b/hw/nitro/Kconfig
@@ -8,3 +8,11 @@ config NITRO_SERIAL_VSOCK
config NITRO_HEARTBEAT
bool
depends on NITRO_VSOCK_BUS
+
+config NITRO_MACHINE
+ bool
+ default y
+ depends on NITRO
+ select NITRO_VSOCK_BUS
+ select NITRO_HEARTBEAT
+ select NITRO_SERIAL_VSOCK
diff --git a/hw/nitro/meson.build b/hw/nitro/meson.build
index 381c1ee6c15..e3f18958906 100644
--- a/hw/nitro/meson.build
+++ b/hw/nitro/meson.build
@@ -1,3 +1,4 @@
system_ss.add(when: 'CONFIG_NITRO_VSOCK_BUS', if_true: files('nitro-vsock-bus.c'))
system_ss.add(when: 'CONFIG_NITRO_SERIAL_VSOCK', if_true: files('serial-vsock.c'))
system_ss.add(when: 'CONFIG_NITRO_HEARTBEAT', if_true: files('heartbeat.c'))
+system_ss.add(when: 'CONFIG_NITRO_MACHINE', if_true: files('machine.c'))
--
2.53.0