Add initial support for AArch64 Linux guests on macOS platform

.github/workflows/ci.yml

@@ -58,7 +58,7 @@ jobs:
           key: custom-out-${{ runner.os }}-${{ github.job }}-${{ hashFiles('**/Cargo.lock') }}-${{ hashFiles('**/litebox_syscall_rewriter/**/*.rs') }}
       - run: ./.github/tools/github_actions_run_cargo fmt
       - run: |
-          ./.github/tools/github_actions_run_cargo clippy --all-targets --all-features --workspace --exclude litebox_runner_lvbs --exclude litebox_runner_snp --exclude litebox_runner_optee_on_linux_userland
+          ./.github/tools/github_actions_run_cargo clippy --all-targets --all-features --workspace --exclude litebox_runner_lvbs --exclude litebox_runner_snp --exclude litebox_runner_optee_on_linux_userland --exclude litebox_runner_linux_on_macos_userland
           ./.github/tools/github_actions_run_cargo clippy --all-targets --all-features -p litebox_runner_optee_on_linux_userland
           # We exclude `litebox_runner_lvbs` because it requires a custom target and nightly
           # features. `build_and_test_lvbs` covers it.
@@ -76,7 +76,7 @@ jobs:
           # aren't included in nextest at the moment. See relevant discussion at
           # https://github.com/nextest-rs/nextest/issues/16
       - name: Build documentation (fail on warnings)
-        run: ./.github/tools/github_actions_run_cargo doc --no-deps --all-features --document-private-items --workspace --exclude litebox_runner_lvbs --exclude litebox_runner_snp
+        run: ./.github/tools/github_actions_run_cargo doc --no-deps --all-features --document-private-items --workspace --exclude litebox_runner_lvbs --exclude litebox_runner_snp --exclude litebox_runner_linux_on_macos_userland
 
   build_and_test_arm64:
     name: Build and Test (AArch64)
@@ -138,6 +138,42 @@ jobs:
           RUSTDOCFLAGS: -Dwarnings
         run: ./.github/tools/github_actions_run_cargo doc --no-deps --all-features --document-private-items $AARCH64_CRATES
 
+  build_and_test_macos_arm64:
+    name: Build and Test (macOS AArch64)
+    runs-on: macos-15
+    env:
+      RUSTFLAGS: -Dwarnings
+      MACOS_AARCH64_CRATES: >-
+        -p dev_tests
+        -p litebox
+        -p litebox_common_linux
+        -p litebox_syscall_rewriter
+        -p litebox_platform_macos_userland
+        -p litebox_shim_linux
+        -p litebox_runner_linux_on_macos_userland
+    steps:
+      - name: Check out repo
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - name: Verify AArch64 host
+        run: test "$(uname -m)" = arm64
+      - name: Set up Rust
+        run: |
+          rustup toolchain install $(awk -F'"' '/channel/{print $2}' rust-toolchain.toml) --profile minimal --no-self-update --component rustfmt,clippy
+      - name: Set up Nextest
+        uses: taiki-e/install-action@ba47c86ac325773530516bb756137ac718732518 # v2.86.5
+        with:
+          tool: nextest@${{ env.NEXTEST_VERSION }}
+      - uses: Swatinem/rust-cache@6323deb102c322ba6fcbdcafc7e3dddab59af2b6 # v2.9.2
+      - run: ./.github/tools/github_actions_run_cargo fmt
+      - run: ./.github/tools/github_actions_run_cargo clippy --all-targets --all-features $MACOS_AARCH64_CRATES
+      - run: ./.github/tools/github_actions_run_cargo build $MACOS_AARCH64_CRATES
+      - run: ./.github/tools/github_actions_run_cargo nextest $MACOS_AARCH64_CRATES
+      - run: ./.github/tools/github_actions_run_cargo test --doc $MACOS_AARCH64_CRATES
+      - name: Build documentation (fail on warnings)
+        env:
+          RUSTDOCFLAGS: -Dwarnings
+        run: ./.github/tools/github_actions_run_cargo doc --no-deps --all-features --document-private-items $MACOS_AARCH64_CRATES
+
   build_and_test_lvbs:
     name: Build and Test LVBS
     runs-on: ubuntu-latest
@@ -298,6 +334,9 @@ jobs:
           # - `litebox_platform_linux_userland` is allowed to have `std` access,
           #   since it is a purely-userland implementation.
           #
+          # - `litebox_platform_macos_userland` is allowed to have `std` access,
+          #   since it is a purely-userland implementation.
+          #
           # - `litebox_platform_windows_userland` is allowed to have `std` access,
           #   since it is a purely-userland implementation.
           #
@@ -327,6 +366,9 @@ jobs:
           # - `litebox_platform_lvbs` has a custom target (`no_std`), so it does
           #   not work with the current no_std checker.
           #
+          # - `litebox_runner_linux_on_macos_userland` is allowed to have `std`
+          #   access since it loads files and runs LiteBox on a hosted platform.
+          #
           # - `litebox_runner_linux_on_windows_userland` is allowed to have `std`
           #   access since it needs to actually access the file-system, pull in
           #   relevant files, and then actually trigger LiteBox itself.
@@ -386,7 +428,9 @@ jobs:
             -not -path './litebox_broker_userland/Cargo.toml' \
             -not -path './litebox_egress_proxy/Cargo.toml' \
             -not -path './litebox_platform_linux_userland/Cargo.toml' \
+            -not -path './litebox_platform_macos_userland/Cargo.toml' \
             -not -path './litebox_platform_windows_userland/Cargo.toml' \
+            -not -path './litebox_runner_linux_on_macos_userland/Cargo.toml' \
             -not -path './litebox_runner_linux_on_windows_userland/Cargo.toml' \
             -not -path './litebox_runner_windows_on_linux_userland/Cargo.toml' \
             -not -path './litebox_platform_lvbs/Cargo.toml' \

Cargo.toml

@@ -20,9 +20,11 @@ members = [
     "litebox_egress_proxy",
     "litebox_platform_linux_kernel",
     "litebox_platform_linux_userland",
+    "litebox_platform_macos_userland",
     "litebox_platform_windows_userland",
     "litebox_platform_lvbs",
     "litebox_runner_linux_userland",
+    "litebox_runner_linux_on_macos_userland",
     "litebox_runner_linux_on_windows_userland",
     "litebox_runner_windows_on_linux_userland",
     "litebox_runner_windows_userland",
@@ -61,6 +63,7 @@ default-members = [
     "litebox_egress_proxy",
     "litebox_platform_linux_kernel",
     "litebox_platform_linux_userland",
+    "litebox_platform_macos_userland",
     "litebox_platform_windows_userland",
     "litebox_platform_lvbs",
     "litebox_runner_linux_userland",

dev_tests/src/boilerplate.rs

@@ -133,6 +133,8 @@ const SKIP_FILES: &[&str] = &[
     "LICENSE",
     "litebox_platform/src/sync/mutex.rs",
     "litebox_platform/src/sync/rwlock.rs",
+    "litebox_runner_linux_on_macos_userland/tests/test-bins/hello_world_dyn",
+    "litebox_runner_linux_on_macos_userland/tests/test-bins/ld-linux-aarch64.so.1",
     "litebox_runner_linux_on_windows_userland/tests/test-bins/hello_exec_nolibc",
     "litebox_runner_linux_on_windows_userland/tests/test-bins/hello_thread",
     "litebox_runner_linux_on_windows_userland/tests/test-bins/hello_thread_static",

dev_tests/src/ratchet.rs

@@ -14,6 +14,7 @@ fn ratchet_transmutes() -> Result<()> {
             ("dev_tests/", 2),
             ("litebox/", 8),
             ("litebox_platform_linux_userland/", 2),
+            ("litebox_platform_macos_userland/", 2),
         ],
         |file| {
             Ok(file
@@ -41,6 +42,7 @@ fn ratchet_globals() -> Result<()> {
             ("litebox_platform/", 2),
             ("litebox_platform_linux_kernel/", 5),
             ("litebox_platform_linux_userland/", 5),
+            ("litebox_platform_macos_userland/", 5),
             ("litebox_platform_lvbs/", 21),
             ("litebox_platform_windows_userland/", 8),
             ("litebox_runner_lvbs/", 8),
@@ -77,6 +79,7 @@ fn ratchet_maybe_uninit() -> Result<()> {
             ("litebox/", 1),
             ("litebox_broker_transport_linux_userland/", 3),
             ("litebox_platform_linux_userland/", 2),
+            ("litebox_platform_macos_userland/", 2),
         ],
         |file| {
             Ok(file

litebox/src/mm/exception_table.rs

@@ -34,6 +34,14 @@ macro_rules! ex_table_section {
     };
 }
 
+#[cfg(target_os = "macos")]
+macro_rules! ex_table_section {
+    () => {
+        // Regular data; retain entries even when the linker cannot see their users.
+        "__DATA,__ex_table,regular,no_dead_strip"
+    };
+}
+
 macro_rules! ex_table_entry {
     ($start:tt, $stop:tt, $recover:tt) => {
         concat!(
@@ -302,14 +310,17 @@ struct ExceptionTableEntry {
 
 /// Returns the exception table, found by linker-defined symbols marking the
 /// start and end of the section.
-#[cfg(any(target_os = "linux", target_os = "none"))]
+#[cfg(any(target_os = "linux", target_os = "none", target_os = "macos"))]
 fn exception_table() -> &'static [ExceptionTableEntry] {
     // SAFETY: the linker automatically defines these symbols when the section
     // is non-empty.
     unsafe extern "C" {
-        #[link_name = "__start_ex_table"]
+        // \x01 suppresses Mach-O's leading underscore.
+        #[cfg_attr(target_os = "macos", link_name = "\x01section$start$__DATA$__ex_table")]
+        #[cfg_attr(not(target_os = "macos"), link_name = "__start_ex_table")]
         static START_EX_TABLE: [ExceptionTableEntry; 0];
-        #[link_name = "__stop_ex_table"]
+        #[cfg_attr(target_os = "macos", link_name = "\x01section$end$__DATA$__ex_table")]
+        #[cfg_attr(not(target_os = "macos"), link_name = "__stop_ex_table")]
         static STOP_EX_TABLE: [ExceptionTableEntry; 0];
     }
 

litebox/src/mm/linux.rs

@@ -17,7 +17,12 @@ use crate::platform::page_mgmt::AllocationError;
 use crate::platform::page_mgmt::FixedAddressBehavior;
 use crate::platform::page_mgmt::MemoryRegionPermissions;
 
-/// Page size in bytes
+/// Host page size in bytes on Apple Silicon macOS.
+#[cfg(all(target_os = "macos", target_arch = "aarch64"))]
+pub const PAGE_SIZE: usize = 16384;
+
+/// Page size in bytes.
+#[cfg(not(all(target_os = "macos", target_arch = "aarch64")))]
 pub const PAGE_SIZE: usize = 4096;
 
 bitflags::bitflags! {
@@ -660,6 +665,9 @@ impl<Platform: PageManagementProvider<ALIGN> + 'static, const ALIGN: usize> Vmem
             } {
                 Ok(_) => {}
                 Err(AllocationError::OutOfMemory) => return Err(VmemResizeError::OutOfMemory),
+                Err(AllocationError::PermissionDenied) => {
+                    return Err(VmemResizeError::PermissionDenied);
+                }
                 Err(
                     AllocationError::AddressInUse
                     | AllocationError::AddressInUseByPlatform
@@ -979,6 +987,8 @@ pub(super) enum VmemResizeError {
     InvalidAddr { range: Range<usize>, addr: usize },
     #[error("range {0:?} is already (partially) occupied")]
     RangeOccupied(Range<usize>),
+    #[error("requested page permissions are denied")]
+    PermissionDenied,
     #[error("out of memory")]
     OutOfMemory,
 }

litebox/src/mm/mod.rs

@@ -442,6 +442,7 @@ where
             Err(linux::VmemResizeError::NotExist(_)) => Err(RemapError::AlreadyUnallocated),
             Err(linux::VmemResizeError::InvalidAddr { .. }) => Err(RemapError::AlreadyAllocated),
             Err(linux::VmemResizeError::OutOfMemory) => Err(RemapError::OutOfMemory),
+            Err(linux::VmemResizeError::PermissionDenied) => Err(RemapError::PermissionDenied),
         }
     }
 

litebox/src/mm/tests.rs

@@ -36,6 +36,10 @@ impl crate::platform::PageManagementProvider<PAGE_SIZE> for DummyVmemBackend {
     const TASK_ADDR_MAX: usize = 0x7FFF_FFFF_F000; // (1 << 47) - PAGE_SIZE;
     #[cfg(all(target_arch = "aarch64", target_os = "linux"))]
     const TASK_ADDR_MAX: usize = 0xFFFF_FFFF_F000; // 48-bit VA space
+    #[cfg(all(target_arch = "aarch64", target_os = "macos"))]
+    const TASK_ADDR_MIN: usize = 0x1_0000; // Vmem unit-test bound
+    #[cfg(all(target_arch = "aarch64", target_os = "macos"))]
+    const TASK_ADDR_MAX: usize = 0x7FFF_FE00_0000; // MACH_VM_MAX_ADDRESS
 
     fn allocate_pages(
         &self,

litebox/src/platform/page_mgmt.rs

@@ -112,6 +112,7 @@ pub trait PageManagementProvider<const ALIGN: usize>: RawPointerProvider {
             )
             .map_err(|e| match e {
                 AllocationError::OutOfMemory => RemapError::OutOfMemory,
+                AllocationError::PermissionDenied => RemapError::PermissionDenied,
                 AllocationError::AddressInUse | AllocationError::AddressInUseByPlatform => {
                     RemapError::AlreadyAllocated
                 }
@@ -220,6 +221,8 @@ pub enum AllocationError {
     AboveMaxAddress,
     #[error("out of memory")]
     OutOfMemory,
+    #[error("requested page permissions are denied")]
+    PermissionDenied,
     #[error("provided fixed address range is in use")]
     AddressInUse,
     #[error("provided fixed address range is in use by the platform")]
@@ -250,6 +253,8 @@ pub enum RemapError {
     Overlapping,
     #[error("provided new range is already allocated")]
     AlreadyAllocated,
+    #[error("requested page permissions are denied")]
+    PermissionDenied,
     #[error("out of memory")]
     OutOfMemory,
 }
@@ -262,6 +267,12 @@ pub enum PermissionUpdateError {
     Unaligned,
     #[error("provided range contains unallocated pages")]
     Unallocated,
+    #[error("requested page permissions are denied")]
+    PermissionDenied,
+    #[error("out of memory")]
+    OutOfMemory,
+    #[error("platform failed to update page permissions")]
+    PlatformFailure,
 }
 
 /// Possible errors for [`PageManagementProvider::try_allocate_cow_pages`]

litebox_common_linux/src/errno/mod.rs

@@ -238,6 +238,7 @@ impl From<litebox::platform::page_mgmt::AllocationError> for Errno {
             litebox::platform::page_mgmt::AllocationError::Unaligned
             | litebox::platform::page_mgmt::AllocationError::AboveMaxAddress => Errno::EINVAL,
             litebox::platform::page_mgmt::AllocationError::BelowMinAddress => Errno::EPERM,
+            litebox::platform::page_mgmt::AllocationError::PermissionDenied => Errno::EACCES,
             litebox::platform::page_mgmt::AllocationError::OutOfMemory
             | litebox::platform::page_mgmt::AllocationError::AddressPartiallyInUse
             | litebox::platform::page_mgmt::AllocationError::AddressInUseByPlatform => {
@@ -299,7 +300,8 @@ impl From<litebox::platform::page_mgmt::RemapError> for Errno {
             | litebox::platform::page_mgmt::RemapError::Overlapping => Errno::EINVAL,
             litebox::platform::page_mgmt::RemapError::AlreadyAllocated
             | litebox::platform::page_mgmt::RemapError::AlreadyUnallocated => Errno::EFAULT,
-            litebox::platform::page_mgmt::RemapError::OutOfMemory => Errno::ENOMEM,
+            litebox::platform::page_mgmt::RemapError::OutOfMemory
+            | litebox::platform::page_mgmt::RemapError::PermissionDenied => Errno::ENOMEM,
             _ => unimplemented!(),
         }
     }
@@ -309,7 +311,10 @@ impl From<litebox::platform::page_mgmt::PermissionUpdateError> for Errno {
     fn from(value: litebox::platform::page_mgmt::PermissionUpdateError) -> Self {
         match value {
             litebox::platform::page_mgmt::PermissionUpdateError::Unaligned => Errno::EINVAL,
-            litebox::platform::page_mgmt::PermissionUpdateError::Unallocated => Errno::ENOMEM,
+            litebox::platform::page_mgmt::PermissionUpdateError::Unallocated
+            | litebox::platform::page_mgmt::PermissionUpdateError::OutOfMemory => Errno::ENOMEM,
+            litebox::platform::page_mgmt::PermissionUpdateError::PermissionDenied => Errno::EACCES,
+            litebox::platform::page_mgmt::PermissionUpdateError::PlatformFailure => Errno::EINVAL,
             _ => unimplemented!(),
         }
     }