[pvmfw] Extract a library to support various hypervisor backends
This cl extracts a library libhyp from pvmfw to support
various hypervisor backends including kvm.
Bug: 272226230
Test: m pvmfw_img
Change-Id: I5307cb5d6cccc7a01af6bc9c46ae7111c0d51e93
diff --git a/libs/hyp/src/mmio_guard.rs b/libs/hyp/src/mmio_guard.rs
new file mode 100644
index 0000000..512eb88
--- /dev/null
+++ b/libs/hyp/src/mmio_guard.rs
@@ -0,0 +1,69 @@
+// Copyright 2022, 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.
+
+//! Safe MMIO_GUARD support.
+
+use crate::hypervisor::{mmio_guard_enroll, mmio_guard_info, mmio_guard_map, mmio_guard_unmap};
+use crate::util::{page_address, SIZE_4KB};
+use core::{fmt, result};
+
+/// MMIO guard error.
+#[derive(Debug, Clone)]
+pub enum Error {
+ /// Failed the necessary MMIO_GUARD_ENROLL call.
+ EnrollFailed(smccc::Error),
+ /// Failed to obtain the MMIO_GUARD granule size.
+ InfoFailed(smccc::Error),
+ /// Failed to MMIO_GUARD_MAP a page.
+ MapFailed(smccc::Error),
+ /// Failed to MMIO_GUARD_UNMAP a page.
+ UnmapFailed(smccc::Error),
+ /// The MMIO_GUARD granule used by the hypervisor is not supported.
+ UnsupportedGranule(usize),
+}
+
+impl fmt::Display for Error {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ match self {
+ Self::EnrollFailed(e) => write!(f, "Failed to enroll into MMIO_GUARD: {e}"),
+ Self::InfoFailed(e) => write!(f, "Failed to get the MMIO_GUARD granule: {e}"),
+ Self::MapFailed(e) => write!(f, "Failed to MMIO_GUARD map: {e}"),
+ Self::UnmapFailed(e) => write!(f, "Failed to MMIO_GUARD unmap: {e}"),
+ Self::UnsupportedGranule(g) => write!(f, "Unsupported MMIO_GUARD granule: {g}"),
+ }
+ }
+}
+
+/// Result type with mmio_guard::Error.
+pub type Result<T> = result::Result<T, Error>;
+
+/// Initializes the hypervisor by enrolling a MMIO guard and checking the memory granule size.
+pub fn init() -> Result<()> {
+ mmio_guard_enroll().map_err(Error::EnrollFailed)?;
+ let mmio_granule = mmio_guard_info().map_err(Error::InfoFailed)? as usize;
+ if mmio_granule != SIZE_4KB {
+ return Err(Error::UnsupportedGranule(mmio_granule));
+ }
+ Ok(())
+}
+
+/// Maps a memory address to the hypervisor MMIO guard.
+pub fn map(addr: usize) -> Result<()> {
+ mmio_guard_map(page_address(addr)).map_err(Error::MapFailed)
+}
+
+/// Unmaps a memory address from the hypervisor MMIO guard.
+pub fn unmap(addr: usize) -> Result<()> {
+ mmio_guard_unmap(page_address(addr)).map_err(Error::UnmapFailed)
+}