Remove gpu-socket feature

Remove conditional compilation because when multiple crates
that are in thesame workspace set different features,
cargo feature unification already defeats the purpose of
the `gpu-socket` feature flag since cargo merges all the
feature flags specified by dependent crates into a single
set when compiling shared dependencies. for reference see:
[feature-unification](https://doc.rust-lang.org/cargo/reference/features.html#feature-unification)

Fixes: #265

Signed-off-by: Dorinda Bassey <dbassey@redhat.com>

.buildkite/rust-vmm-ci-tests.json

@@ -22,7 +22,7 @@
     },
     {
       "test_name": "unittests-gnu-all-with-xen",
-      "command": "cargo test --workspace --no-default-features --features test-utils,vhost-vsock,vhost-kern,vhost-vdpa,vhost-net,vhost-user,vhost-user-frontend,gpu-socket,vhost-user-backend,xen",
+      "command": "cargo test --workspace --no-default-features --features test-utils,vhost-vsock,vhost-kern,vhost-vdpa,vhost-net,vhost-user,vhost-user-frontend,vhost-user-backend,xen",
       "platform": [
         "x86_64",
         "aarch64"
@@ -30,7 +30,7 @@
     },
     {
       "test_name": "unittests-gnu-all-without-xen",
-      "command": "cargo test --workspace --no-default-features --features test-utils,vhost-vsock,vhost-kern,vhost-vdpa,vhost-net,vhost-user,vhost-user-frontend,gpu-socket,vhost-user-backend,postcopy",
+      "command": "cargo test --workspace --no-default-features --features test-utils,vhost-vsock,vhost-kern,vhost-vdpa,vhost-net,vhost-user,vhost-user-frontend,vhost-user-backend,postcopy",
       "platform": [
         "x86_64",
         "aarch64"
@@ -38,7 +38,7 @@
     },
     {
       "test_name": "unittests-musl-all-with-xen",
-      "command": "cargo test --workspace --target {target_platform}-unknown-linux-musl --no-default-features --features test-utils,vhost-vsock,vhost-kern,vhost-vdpa,vhost-net,vhost-user,vhost-user-frontend,gpu-socket,vhost-user-backend,xen",
+      "command": "cargo test --workspace --target {target_platform}-unknown-linux-musl --no-default-features --features test-utils,vhost-vsock,vhost-kern,vhost-vdpa,vhost-net,vhost-user,vhost-user-frontend,vhost-user-backend,xen",
       "platform": [
         "x86_64",
         "aarch64"
@@ -46,7 +46,7 @@
     },
     {
       "test_name": "unittests-musl-all-without-xen",
-      "command": "cargo test --workspace --target {target_platform}-unknown-linux-musl --no-default-features --features test-utils,vhost-vsock,vhost-kern,vhost-vdpa,vhost-net,vhost-user,vhost-user-frontend,gpu-socket,vhost-user-backend,postcopy",
+      "command": "cargo test --workspace --target {target_platform}-unknown-linux-musl --no-default-features --features test-utils,vhost-vsock,vhost-kern,vhost-vdpa,vhost-net,vhost-user,vhost-user-frontend,vhost-user-backend,postcopy",
       "platform": [
         "x86_64",
         "aarch64"
@@ -54,7 +54,7 @@
     },
     {
       "test_name": "clippy-all-with-xen",
-      "command": "cargo clippy --workspace --bins --examples --benches --all-targets --no-default-features --features test-utils,vhost-vsock,vhost-kern,vhost-vdpa,vhost-net,vhost-user,vhost-user-frontend,gpu-socket,vhost-user-backend,xen -- -D warnings -D clippy::undocumented_unsafe_blocks",
+      "command": "cargo clippy --workspace --bins --examples --benches --all-targets --no-default-features --features test-utils,vhost-vsock,vhost-kern,vhost-vdpa,vhost-net,vhost-user,vhost-user-frontend,vhost-user-backend,xen -- -D warnings -D clippy::undocumented_unsafe_blocks",
       "platform": [
         "x86_64",
         "aarch64"
@@ -62,7 +62,7 @@
     },
     {
       "test_name": "clippy-all-without-xen",
-      "command": "cargo clippy --workspace --bins --examples --benches --all-targets --no-default-features --features test-utils,vhost-vsock,vhost-kern,vhost-vdpa,vhost-net,vhost-user,vhost-user-frontend,gpu-socket,vhost-user-backend,postcopy -- -D warnings -D clippy::undocumented_unsafe_blocks",
+      "command": "cargo clippy --workspace --bins --examples --benches --all-targets --no-default-features --features test-utils,vhost-vsock,vhost-kern,vhost-vdpa,vhost-net,vhost-user,vhost-user-frontend,vhost-user-backend,postcopy -- -D warnings -D clippy::undocumented_unsafe_blocks",
       "platform": [
         "x86_64",
         "aarch64"
@@ -70,7 +70,7 @@
     },
     {
       "test_name": "check-warnings-all-with-xen",
-      "command": "RUSTFLAGS=\"-D warnings\" cargo check --all-targets --workspace --no-default-features --features test-utils,vhost-vsock,vhost-kern,vhost-vdpa,vhost-net,vhost-user,vhost-user-frontend,gpu-socket,vhost-user-backend,xen",
+      "command": "RUSTFLAGS=\"-D warnings\" cargo check --all-targets --workspace --no-default-features --features test-utils,vhost-vsock,vhost-kern,vhost-vdpa,vhost-net,vhost-user,vhost-user-frontend,vhost-user-backend,xen",
       "platform": [
         "x86_64",
         "aarch64"
@@ -78,7 +78,7 @@
     },
     {
       "test_name": "check-warnings-all-without-xen",
-      "command": "RUSTFLAGS=\"-D warnings\" cargo check --all-targets --workspace --no-default-features --features test-utils,vhost-vsock,vhost-kern,vhost-vdpa,vhost-net,vhost-user,vhost-user-frontend,gpu-socket,vhost-user-backend,postcopy",
+      "command": "RUSTFLAGS=\"-D warnings\" cargo check --all-targets --workspace --no-default-features --features test-utils,vhost-vsock,vhost-kern,vhost-vdpa,vhost-net,vhost-user,vhost-user-frontend,vhost-user-backend,postcopy",
       "platform": [
         "x86_64",
         "aarch64"

vhost-user-backend/Cargo.toml

@@ -11,7 +11,6 @@ license = "Apache-2.0"
 [features]
 xen = ["vm-memory/xen", "vhost/xen"]
 postcopy = ["vhost/postcopy", "userfaultfd"]
-gpu-socket = ["vhost/gpu-socket"]
 
 [dependencies]
 libc = "0.2.39"

vhost-user-backend/src/backend.rs

@@ -31,7 +31,6 @@ use vm_memory::bitmap::Bitmap;
 use vmm_sys_util::epoll::EventSet;
 use vmm_sys_util::eventfd::EventFd;
 
-#[cfg(feature = "gpu-socket")]
 use vhost::vhost_user::GpuBackend;
 
 use super::vring::VringT;
@@ -87,7 +86,6 @@ pub trait VhostUserBackend: Send + Sync {
     /// function.
     fn set_backend_req_fd(&self, _backend: Backend) {}
 
-    #[cfg(feature = "gpu-socket")]
     /// Set handler for communicating with the frontend by the gpu specific backend communication
     /// channel.
     ///
@@ -205,7 +203,6 @@ pub trait VhostUserBackendMut: Send + Sync {
     /// function.
     fn set_backend_req_fd(&mut self, _backend: Backend) {}
 
-    #[cfg(feature = "gpu-socket")]
     /// Set handler for communicating with the frontend by the gpu specific backend communication
     /// channel.
     ///
@@ -318,7 +315,6 @@ impl<T: VhostUserBackend> VhostUserBackend for Arc<T> {
         self.deref().set_backend_req_fd(backend)
     }
 
-    #[cfg(feature = "gpu-socket")]
     fn set_gpu_socket(&self, gpu_backend: GpuBackend) {
         self.deref().set_gpu_socket(gpu_backend)
     }
@@ -400,7 +396,6 @@ impl<T: VhostUserBackendMut> VhostUserBackend for Mutex<T> {
         self.lock().unwrap().set_backend_req_fd(backend)
     }
 
-    #[cfg(feature = "gpu-socket")]
     fn set_gpu_socket(&self, gpu_backend: GpuBackend) {
         self.lock().unwrap().set_gpu_socket(gpu_backend)
     }
@@ -485,7 +480,6 @@ impl<T: VhostUserBackendMut> VhostUserBackend for RwLock<T> {
         self.write().unwrap().set_backend_req_fd(backend)
     }
 
-    #[cfg(feature = "gpu-socket")]
     fn set_gpu_socket(&self, gpu_backend: GpuBackend) {
         self.write().unwrap().set_gpu_socket(gpu_backend)
     }
@@ -610,7 +604,6 @@ pub mod tests {
 
         fn set_backend_req_fd(&mut self, _backend: Backend) {}
 
-        #[cfg(feature = "gpu-socket")]
         fn set_gpu_socket(&mut self, _gpu_backend: GpuBackend) {}
 
         fn queues_per_thread(&self) -> Vec<u64> {

vhost-user-backend/src/handler.rs

@@ -21,7 +21,6 @@ use vhost::vhost_user::message::{
     VhostUserMemoryRegion, VhostUserProtocolFeatures, VhostUserSingleMemoryRegion,
     VhostUserVirtioFeatures, VhostUserVringAddrFlags, VhostUserVringState,
 };
-#[cfg(feature = "gpu-socket")]
 use vhost::vhost_user::GpuBackend;
 use vhost::vhost_user::{
     Backend, Error as VhostUserError, Result as VhostUserResult, VhostUserBackendReqHandlerMut,
@@ -556,7 +555,6 @@ where
         self.backend.set_backend_req_fd(backend);
     }
 
-    #[cfg(feature = "gpu-socket")]
     fn set_gpu_socket(&mut self, gpu_backend: GpuBackend) {
         self.backend.set_gpu_socket(gpu_backend);
     }

vhost-user-backend/tests/vhost-user-server.rs

@@ -10,7 +10,6 @@ use std::thread;
 use vhost::vhost_user::message::{
     VhostUserConfigFlags, VhostUserHeaderFlag, VhostUserInflight, VhostUserProtocolFeatures,
 };
-#[cfg(feature = "gpu-socket")]
 use vhost::vhost_user::GpuBackend;
 use vhost::vhost_user::{Backend, Frontend, Listener, VhostUserFrontend};
 use vhost::{VhostBackend, VhostUserMemoryRegionInfo, VringConfigData};
@@ -79,7 +78,6 @@ impl VhostUserBackendMut for MockVhostBackend {
         Ok(())
     }
 
-    #[cfg(feature = "gpu-socket")]
     fn set_gpu_socket(&mut self, _gpu_backend: GpuBackend) {}
 
     fn update_memory(&mut self, atomic_mem: GuestMemoryAtomic<GuestMemoryMmap>) -> Result<()> {

vhost/Cargo.toml

@@ -23,7 +23,6 @@ vhost-net = ["vhost-kern"]
 vhost-user = []
 vhost-user-frontend = ["vhost-user"]
 vhost-user-backend = ["vhost-user"]
-gpu-socket = ["vhost-user"]
 xen = ["vm-memory/xen"]
 postcopy = []
 

vhost/src/vhost_user/backend_req_handler.rs

@@ -12,7 +12,6 @@ use vm_memory::ByteValued;
 
 use super::backend_req::Backend;
 use super::connection::Endpoint;
-#[cfg(feature = "gpu-socket")]
 use super::gpu_backend_req::GpuBackend;
 use super::message::*;
 use super::{take_single_file, Error, Result};
@@ -67,7 +66,6 @@ pub trait VhostUserBackendReqHandler {
     fn get_config(&self, offset: u32, size: u32, flags: VhostUserConfigFlags) -> Result<Vec<u8>>;
     fn set_config(&self, offset: u32, buf: &[u8], flags: VhostUserConfigFlags) -> Result<()>;
     fn set_backend_req_fd(&self, _backend: Backend) {}
-    #[cfg(feature = "gpu-socket")]
     fn set_gpu_socket(&self, gpu_backend: GpuBackend);
     fn get_inflight_fd(&self, inflight: &VhostUserInflight) -> Result<(VhostUserInflight, File)>;
     fn set_inflight_fd(&self, inflight: &VhostUserInflight, file: File) -> Result<()>;
@@ -128,7 +126,6 @@ pub trait VhostUserBackendReqHandlerMut {
     ) -> Result<Vec<u8>>;
     fn set_config(&mut self, offset: u32, buf: &[u8], flags: VhostUserConfigFlags) -> Result<()>;
     fn set_backend_req_fd(&mut self, _backend: Backend) {}
-    #[cfg(feature = "gpu-socket")]
     fn set_gpu_socket(&mut self, _gpu_backend: GpuBackend);
     fn get_inflight_fd(
         &mut self,
@@ -241,7 +238,6 @@ impl<T: VhostUserBackendReqHandlerMut> VhostUserBackendReqHandler for Mutex<T> {
         self.lock().unwrap().set_backend_req_fd(backend)
     }
 
-    #[cfg(feature = "gpu-socket")]
     fn set_gpu_socket(&self, gpu_backend: GpuBackend) {
         self.lock().unwrap().set_gpu_socket(gpu_backend);
     }
@@ -571,7 +567,6 @@ impl<S: VhostUserBackendReqHandler> BackendReqHandler<S> {
                 let res = self.backend.set_inflight_fd(&msg, file);
                 self.send_ack_message(&hdr, res)?;
             }
-            #[cfg(feature = "gpu-socket")]
             Ok(FrontendReq::GPU_SET_SOCKET) => {
                 let res = self.set_gpu_socket(files);
                 self.send_ack_message(&hdr, res)?;
@@ -812,7 +807,6 @@ impl<S: VhostUserBackendReqHandler> BackendReqHandler<S> {
         Ok(())
     }
 
-    #[cfg(feature = "gpu-socket")]
     fn set_gpu_socket(&mut self, files: Option<Vec<File>>) -> Result<()> {
         let file = take_single_file(files).ok_or(Error::InvalidMessage)?;
         // SAFETY: Safe because we have ownership of the files that were

vhost/src/vhost_user/dummy_backend.rs

@@ -259,7 +259,6 @@ impl VhostUserBackendReqHandlerMut for DummyBackendReqHandler {
         Ok(())
     }
 
-    #[cfg(feature = "gpu-socket")]
     fn set_gpu_socket(&mut self, _gpu_backend: GpuBackend) {}
 
     fn get_inflight_fd(

vhost/src/vhost_user/mod.rs

@@ -52,11 +52,8 @@ pub use self::backend_req_handler::{
 mod backend_req;
 #[cfg(feature = "vhost-user-backend")]
 pub use self::backend_req::Backend;
-#[cfg(feature = "gpu-socket")]
 mod gpu_backend_req;
-#[cfg(feature = "gpu-socket")]
 pub mod gpu_message;
-#[cfg(feature = "gpu-socket")]
 pub use self::gpu_backend_req::GpuBackend;
 
 /// Errors for vhost-user operations