Add boot mode support

qubes/ext/core_features.py

@@ -104,6 +104,86 @@ async def qubes_features_request(self, vm, event, untrusted_features):
             untrusted_value = untrusted_features["qubes-agent-version"]
             if _version_re.fullmatch(untrusted_value):
                 vm.features["qubes-agent-version"] = untrusted_value
+
+        # handle boot mode advertisement
+        old_bootmode_info = {}
+        for feature_key, feature_val in vm.features.items():
+            if feature_key.startswith(
+                "boot-mode.kernelopts."
+            ) or feature_key.startswith("boot-mode.name."):
+                old_bootmode_info[feature_key] = feature_val
+        new_bootmode_info = {}
+        new_bootmode_names = []
+        for (
+            untrusted_feature_key,
+            untrusted_feature_value,
+        ) in untrusted_features.items():
+            if untrusted_feature_key.startswith("boot-mode.kernelopts."):
+                bootmode_key_parts = untrusted_feature_key.split(".")
+                if len(bootmode_key_parts) != 3:
+                    # Boot mode key contains unexpected data, reject it
+                    continue
+                bootmode_name = bootmode_key_parts[2]
+                if bootmode_name == "":
+                    continue
+                if bootmode_name == "default":
+                    # "default" is reserved, cannot set kernelopts for it
+                    continue
+                bootmode_feature = untrusted_feature_key
+                bootmode_value = untrusted_feature_value
+                new_bootmode_info[bootmode_feature] = bootmode_value
+        for (
+            untrusted_feature_key,
+            untrusted_feature_value,
+        ) in untrusted_features.items():
+            if untrusted_feature_key.startswith("boot-mode.name."):
+                bootmode_key_parts = untrusted_feature_key.split(".")
+                if len(bootmode_key_parts) != 3:
+                    # Boot mode key contains unexpected data, reject it
+                    continue
+                bootmode_name = bootmode_key_parts[2]
+                if bootmode_name == "":
+                    continue
+                if (
+                    f"boot-mode.kernelopts.{bootmode_name}"
+                    not in new_bootmode_info
+                ) and bootmode_name != "default":
+                    continue
+                bootmode_feature = untrusted_feature_key
+                bootmode_value = untrusted_feature_value
+                new_bootmode_info[bootmode_feature] = bootmode_value
+                new_bootmode_names.append(bootmode_value)
+        if (
+            # Disallow duplicate boot mode names
+            len(new_bootmode_names) == len(set(new_bootmode_names))
+            # Don't allow more than 64 boot modes
+            and len(new_bootmode_info) <= 64
+            # Don't allow wiping all boot modes
+            and len(new_bootmode_info) > 0
+        ):
+            for feature_key in old_bootmode_info:
+                if feature_key not in new_bootmode_info:
+                    del vm.features[feature_key]
+            for feature_key, feature_val in new_bootmode_info.items():
+                vm.features[feature_key] = feature_val
+        if "boot-mode.active" in untrusted_features:
+            untrusted_feature_value = untrusted_features["boot-mode.active"]
+            if (
+                f"boot-mode.kernelopts.{untrusted_feature_value}" in vm.features
+                or untrusted_feature_value == "default"
+            ):
+                bootmode_value = untrusted_feature_value
+                vm.features["boot-mode.active"] = bootmode_value
+        if "boot-mode.appvm-default" in untrusted_features:
+            untrusted_feature_value = untrusted_features[
+                "boot-mode.appvm-default"
+            ]
+            if (
+                f"boot-mode.kernelopts.{untrusted_feature_value}" in vm.features
+                or untrusted_feature_value == "default"
+            ) and hasattr(vm, "appvm_default_bootmode"):
+                bootmode_value = untrusted_feature_value
+                vm.features["boot-mode.appvm-default"] = bootmode_value
         del untrusted_features
 
         # default user for qvm-run etc