Fix: CRN API did not expose CPU features for trusted computing

Trusted computing requires CPU features such as `sev`, `sev_es` and `sev_snp`.

This adds the field `properties.cpu.features` `/about/usage/system` as a list of CPU features.

Currently, only SEV related features are present, but more can be added, for example `avx2`, `fma` and `f16c`. Adding them will require ensuring that they are actually active and not just present on the CPU via `/proc/cpuinfo`.

This work is based on a proposal to add the relevant field on aleph-message: aleph-im/aleph-message#100

pyproject.toml

@@ -29,7 +29,7 @@ dependencies = [
   "aiodns==3.1.0",
   "setproctitle==1.3.3",
   "pyyaml==6.0.1",
-  "aleph-message==0.4.4",
+  "aleph-message @ git+https://github.com/aleph-im/aleph-message@hoh-add-cpu-features#egg=aleph-message",
   "eth-account~=0.10",
   "sentry-sdk==1.31.0",
   "aioredis==1.3.1",

src/aleph/vm/conf.py

@@ -16,7 +16,12 @@
 from pydantic.env_settings import DotenvType, env_file_sentinel
 from pydantic.typing import StrPath
 
-from aleph.vm.utils import check_system_module, file_hashes_differ, is_command_available
+from aleph.vm.utils import (
+    check_amd_sev_es_supported,
+    check_amd_sev_supported,
+    file_hashes_differ,
+    is_command_available,
+)
 
 logger = logging.getLogger(__name__)
 
@@ -384,11 +389,11 @@ def check(self):
             ), "Command `qemu-system-x86_64` not found, run `apt install qemu-system-x86`"
 
         if self.ENABLE_CONFIDENTIAL_COMPUTING:
-            assert check_system_module("kvm_amd/parameters/sev") == "Y", "SEV feature isn't enabled, enable it in BIOS"
-            assert (
-                check_system_module("kvm_amd/parameters/sev_es") == "Y"
-            ), "SEV-ES feature isn't enabled, enable it in BIOS"
             assert self.SEV_CTL_PATH.is_file(), f"File not found {self.SEV_CTL_PATH}"
+            assert check_amd_sev_supported(), "SEV feature isn't enabled, enable it in BIOS"
+            assert check_amd_sev_es_supported(), "SEV-ES feature isn't enabled, enable it in BIOS"
+            # Not available on the test machine yet
+            # assert check_amd_sev_snp_supported(), "SEV-SNP feature isn't enabled, enable it in BIOS"
             assert self.ENABLE_QEMU_SUPPORT, "Qemu Support is needed for confidential computing and it's disabled, "
             "enable it setting the env variable `ENABLE_QEMU_SUPPORT=True` in configuration"
 

src/aleph/vm/orchestrator/resources.py

@@ -12,7 +12,12 @@
 
 from aleph.vm.conf import settings
 from aleph.vm.sevclient import SevClient
-from aleph.vm.utils import cors_allow_all
+from aleph.vm.utils import (
+    check_amd_sev_es_supported,
+    check_amd_sev_snp_supported,
+    check_amd_sev_supported,
+    cors_allow_all,
+)
 
 
 class Period(BaseModel):
@@ -90,6 +95,16 @@ def get_machine_properties() -> MachineProperties:
         cpu=CpuProperties(
             architecture=cpu_info.get("raw_arch_string", cpu_info.get("arch_string_raw")),
             vendor=cpu_info.get("vendor_id", cpu_info.get("vendor_id_raw")),
+            features=list(
+                filter(
+                    None,
+                    (
+                        "sev" if check_amd_sev_supported() else None,
+                        "sev_es" if check_amd_sev_es_supported() else None,
+                        "sev_snp" if check_amd_sev_snp_supported() else None,
+                    ),
+                )
+            ),
         ),
     )
 

src/aleph/vm/utils.py

@@ -137,6 +137,34 @@ def check_system_module(module_path: str) -> Optional[str]:
     return p.read_text().strip()
 
 
+def check_amd_sev_supported() -> bool:
+    """Check if AMD SEV is supported on the system.
+
+    AMD Secure Encrypted Virtualization (SEV)
+    Uses one key per virtual machine to isolate guests and the hypervisor from one another.
+    """
+    return check_system_module("kvm_amd/parameters/sev") == "Y"
+
+
+def check_amd_sev_es_supported() -> bool:
+    """Check if AMD SEV-ES is supported on the system.
+
+    AMD Secure Encrypted Virtualization-Encrypted State (SEV-ES)
+    Encrypts all CPU register contents when a VM stops running.
+    """
+    return check_system_module("kvm_amd/parameters/sev_es") == "Y"
+
+
+def check_amd_sev_snp_supported() -> bool:
+    """Check if AMD SEV-SNP is supported on the system.
+
+    AMD Secure Encrypted Virtualization-Secure Nested Paging (SEV-SNP)
+    Adds strong memory integrity protection to help prevent malicious hypervisor-based attacks like data replay,
+    memory re-mapping, and more in order to create an isolated execution environment.
+    """
+    return check_system_module("kvm_amd/parameters/sev_snp") == "Y"
+
+
 def fix_message_validation(message: dict) -> dict:
     """Patch a fake message program to pass validation."""
     message["item_content"] = json.dumps(message["content"])

tests/supervisor/test_utils.py

@@ -1,6 +1,11 @@
 from unittest import mock
 
-from aleph.vm.utils import check_system_module
+from aleph.vm.utils import (
+    check_amd_sev_es_supported,
+    check_amd_sev_snp_supported,
+    check_amd_sev_supported,
+    check_system_module,
+)
 
 
 def test_check_system_module_enabled():
@@ -17,3 +22,18 @@ def test_check_system_module_enabled():
 
             output = check_system_module("kvm_amd/parameters/sev_enp")
             assert output == expected_value
+
+            assert check_amd_sev_supported() is True
+            assert check_amd_sev_es_supported() is True
+            assert check_amd_sev_snp_supported() is True
+
+        with mock.patch(
+            "pathlib.Path.open",
+            mock.mock_open(read_data="N"),
+        ):
+            output = check_system_module("kvm_amd/parameters/sev_enp")
+            assert output is None
+
+            assert check_amd_sev_supported() is False
+            assert check_amd_sev_es_supported() is False
+            assert check_amd_sev_snp_supported() is False