[hypervisor] Add mmio_guard_init() to Hypervisor trait
Since MMIO guard is currently KVM specific, we can move the details
to hypervisor/kvm.rs. This makes it easier to extend the Hypervisor
trait for the hypervisors that do not support MMIO guard.
Bug: 272226230
Test: atest rialto_test && m pvmfw_img
Change-Id: Ib313130946f7f27968fca79c7954a27bc283d0b5
diff --git a/libs/hyp/src/error.rs b/libs/hyp/src/error.rs
new file mode 100644
index 0000000..20a0cff
--- /dev/null
+++ b/libs/hyp/src/error.rs
@@ -0,0 +1,45 @@
+// Copyright 2023, The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//! Error and Result types for hypervisor.
+
+use core::{fmt, result};
+
+/// Result type with hypervisor error.
+pub type Result<T> = result::Result<T, Error>;
+
+/// Hypervisor error.
+#[derive(Debug, Clone)]
+pub enum Error {
+ /// MMIO guard is not supported.
+ MmioGuardNotsupported,
+ /// Failed to invoke a certain HVC function.
+ HvcError(smccc::Error, u32),
+ /// The MMIO_GUARD granule used by the hypervisor is not supported.
+ UnsupportedMmioGuardGranule(usize),
+}
+
+impl fmt::Display for Error {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ match self {
+ Self::MmioGuardNotsupported => write!(f, "MMIO guard is not supported"),
+ Self::HvcError(e, function_id) => {
+ write!(f, "Failed to invoke the HVC function with function ID {function_id}: {e}")
+ }
+ Self::UnsupportedMmioGuardGranule(g) => {
+ write!(f, "Unsupported MMIO guard granule: {g}")
+ }
+ }
+ }
+}