[RFC] Make mmap_unix and mmap_xen compatible

.buildkite/custom-tests.json

@@ -1,61 +1,9 @@
 {
   "tests": [
-    {
-      "test_name": "build-gnu-mmap",
-      "command": "cargo build --release --features=xen",
-      "platform": ["x86_64", "aarch64"]
-    },
-    {
-      "test_name": "build-gnu-mmap-no-xen",
-      "command": "cargo build --release --features=backend-mmap",
-      "platform": ["x86_64", "aarch64"]
-    },
-    {
-      "test_name": "build-musl-mmap",
-      "command": "cargo build --release --features=xen --target {target_platform}-unknown-linux-musl",
-      "platform": ["x86_64", "aarch64"]
-    },
-    {
-      "test_name": "build-musl-mmap-no-xen",
-      "command": "cargo build --release --features=backend-mmap --target {target_platform}-unknown-linux-musl",
-      "platform": ["x86_64", "aarch64"]
-    },
     {
       "test_name": "miri",
       "command": "RUST_BACKTRACE=1 MIRIFLAGS='-Zmiri-disable-isolation -Zmiri-backtrace=full' cargo +nightly miri test --features backend-mmap,backend-bitmap",
       "platform": ["x86_64", "aarch64"]
-    },
-    {
-      "test_name": "unittests-gnu-no-xen",
-      "command": "cargo test --features 'backend-bitmap backend-mmap backend-atomic' --workspace",
-      "platform": [
-        "x86_64",
-        "aarch64"
-      ]
-    },
-    {
-      "test_name": "unittests-musl-no-xen",
-      "command": "cargo test  --features 'backend-bitmap backend-mmap backend-atomic' --workspace --target {target_platform}-unknown-linux-musl",
-      "platform": [
-        "x86_64",
-        "aarch64"
-      ]
-    },
-    {
-      "test_name": "clippy-no-xen",
-      "command": "cargo clippy --workspace --bins --examples --benches  --features 'backend-bitmap backend-mmap backend-atomic' --all-targets -- -D warnings -D clippy::undocumented_unsafe_blocks",
-      "platform": [
-        "x86_64",
-        "aarch64"
-      ]
-    },
-    {
-      "test_name": "check-warnings-no-xen",
-      "command": "RUSTFLAGS=\"-D warnings\" cargo check --all-targets  --features 'backend-bitmap backend-mmap backend-atomic' --workspace",
-      "platform": [
-        "x86_64",
-        "aarch64"
-      ]
     }
   ]
 }

CHANGELOG.md

@@ -20,6 +20,9 @@
   and `GuestRegionMmap::from_range` to be separate from the error type returned by `GuestRegionCollection` functions.
   Change return type of `GuestRegionMmap::new` from `Result` to `Option`.
 - \[#324](https:////github.com/rust-vmm/vm-memory/pull/324)\] `GuestMemoryRegion::bitmap()` now returns a `BitmapSlice`. Accessing the full bitmap is now possible only if the type of the memory region is know, for example with `MmapRegion::bitmap()`.
+- \[[#317](https://github.com/rust-vmm/vm-memory/pull/317)\]: Make `xen` feature additive, meaning enabling it
+  no longer disables the `mmap_unix` module at compile time. For this, various Xen-related structs had to be
+  renamed due to naming conflicts.
 
 ### Removed
 

coverage_config_x86_64.json

@@ -1,5 +1,5 @@
 {
   "coverage_score": 91.78,
   "exclude_path": "mmap_windows.rs",
-  "crate_features": "backend-mmap,backend-atomic,backend-bitmap"
+  "crate_features": "backend-mmap,backend-atomic,backend-bitmap,xen"
 }

src/bitmap/mod.rs

@@ -219,7 +219,7 @@ pub(crate) mod tests {
     // them to test the mmap-based backend implementations for now. Going forward, the generic
     // test functions defined here can be placed in a separate module (i.e. `test_utilities`)
     // which is gated by a feature and can be used for testing purposes by other crates as well.
-    #[cfg(feature = "backend-mmap")]
+    #[cfg(all(feature = "backend-mmap", target_family = "unix"))]
     fn test_guest_memory_region<R: GuestMemoryRegion>(region: &R) {
         let dirty_addr = MemoryRegionAddress(0x0);
         let val = 123u64;
@@ -253,7 +253,7 @@ pub(crate) mod tests {
         );
     }
 
-    #[cfg(feature = "backend-mmap")]
+    #[cfg(all(feature = "backend-mmap", target_family = "unix"))]
     // Assumptions about M generated by f ...
     pub fn test_guest_memory_and_region<M, F>(f: F)
     where

src/bytes.rs

@@ -330,7 +330,7 @@ pub trait Bytes<A> {
     /// * Read bytes from /dev/urandom (uses the `backend-mmap` feature)
     ///
     /// ```
-    /// # #[cfg(all(feature = "backend-mmap", feature = "rawfd"))]
+    /// # #[cfg(all(feature = "backend-mmap", feature = "rawfd", target_family = "unix"))]
     /// # {
     /// # use vm_memory::{Address, GuestMemory, Bytes, GuestAddress, GuestMemoryMmap};
     /// # use std::fs::File;