dm: Add initial device model

The device model is a user mode program which manages VM's life cycles
and handles various vmexits events. The initial version just calls exit()
syscall without doing anything else.

Signed-off-by: Vijay Dhanraj <[email protected]>
Signed-off-by: Chuanxiao Dong <[email protected]>

.github/workflows/rust.yml

@@ -76,7 +76,7 @@ jobs:
         uses: actions-rs/cargo@v1
         with:
           command: clippy
-          args: --workspace --exclude packit --exclude user* --all-features --tests --target=x86_64-unknown-linux-gnu -- -D warnings
+          args: --workspace --exclude packit --exclude user* --exclude dm --all-features --tests --target=x86_64-unknown-linux-gnu -- -D warnings
 
       - name: Check documentation
         run: make doc

Cargo.toml

@@ -23,6 +23,8 @@ members = [
     "user/lib",
     # Init user-space module
     "user/init",
+    # device model module
+    "user/dm",
 ]
 
 
@@ -38,6 +40,7 @@ syscall = { path = "syscall" }
 packit = { path = "packit" }
 userlib = { path = "user/lib" }
 userinit = { path = "user/init" }
+dm = { path = "user/dm" }
 
 # crates.io
 aes-gcm = { version = "0.10.3", default-features = false }

Makefile

@@ -92,7 +92,7 @@ bin/coconut-test-vanadium.igvm: $(IGVMBUILDER) $(IGVMMEASURE) bin/stage1-trampol
 	$(IGVMMEASURE) --check-kvm --native-zero $@ measure
 
 test:
-	cargo test ${CARGO_ARGS} ${SVSM_ARGS_TEST} --workspace --exclude=user* --target=x86_64-unknown-linux-gnu
+	cargo test ${CARGO_ARGS} ${SVSM_ARGS_TEST} --workspace --exclude=user* --exclude=dm --target=x86_64-unknown-linux-gnu
 
 test-igvm: bin/coconut-test-qemu.igvm bin/coconut-test-hyperv.igvm bin/coconut-test-vanadium.igvm
 
@@ -176,9 +176,9 @@ bin/svsm-test.bin: bin/stage1-test
 
 clippy:
 	cargo clippy --workspace --all-features --exclude packit --exclude svsm-fuzz --exclude igvmbuilder --exclude igvmmeasure -- -D warnings
-	cargo clippy --workspace --all-features --exclude packit --exclude svsm-fuzz --exclude svsm --exclude 'user*' --target=x86_64-unknown-linux-gnu -- -D warnings
+	cargo clippy --workspace --all-features --exclude packit --exclude svsm-fuzz --exclude svsm --exclude 'user*' --exclude 'dm' --target=x86_64-unknown-linux-gnu -- -D warnings
 	RUSTFLAGS="--cfg fuzzing" cargo clippy --package svsm-fuzz --all-features --target=x86_64-unknown-linux-gnu -- -D warnings
-	cargo clippy --workspace --all-features --exclude packit --exclude 'user*' --tests --target=x86_64-unknown-linux-gnu -- -D warnings
+	cargo clippy --workspace --all-features --exclude packit --exclude 'user*' --exclude 'dm' --tests --target=x86_64-unknown-linux-gnu -- -D warnings
 
 clean:
 	cargo clean

configs/all-targets.json

@@ -53,6 +53,9 @@
         "modules": {
             "userinit": {
                 "path": "/init"
+            },
+            "dm": {
+                "path": "/dm"
             }
         }
     }

configs/hyperv-target.json

@@ -32,6 +32,9 @@
         "modules": {
             "userinit": {
                 "path": "/init"
+            },
+            "dm": {
+                "path": "/dm"
             }
         }
     }

configs/qemu-target.json

@@ -34,6 +34,9 @@
         "modules": {
             "userinit": {
                 "path": "/init"
+            },
+            "dm": {
+                "path": "/dm"
             }
         }
     }

configs/vanadium-target.json

@@ -35,6 +35,9 @@
         "modules": {
             "userinit": {
                 "path": "/init"
+            },
+            "dm": {
+                "path": "/dm"
             }
         }
     }

user/dm/Cargo.toml

@@ -0,0 +1,11 @@
+[package]
+name = "dm"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+userlib.workspace = true
+syscall = { path = "../../syscall" }
+
+[lints]
+workspace = true

user/dm/build.rs

@@ -0,0 +1,4 @@
+fn main() {
+    println!("cargo:rustc-link-arg=-Tuser/lib/module.lds");
+    println!("cargo:rustc-link-arg=-no-pie");
+}

user/dm/src/main.rs

@@ -0,0 +1,25 @@
+// SPDX-License-Identifier: MIT
+//
+// Copyright (c) 2024 Intel Corporation.
+//
+// Author: Chuanxiao Dong <[email protected]>
+
+#![no_std]
+#![no_main]
+
+use core::panic::PanicInfo;
+use syscall::exit;
+
+fn dm_exit() -> ! {
+    exit(0);
+}
+
+#[no_mangle]
+pub extern "C" fn _start() -> ! {
+    dm_exit();
+}
+
+#[panic_handler]
+fn panic(_info: &PanicInfo<'_>) -> ! {
+    dm_exit();
+}