test: Add support for running tests inside stage2

In the same way that support was added for running tests inside the svsm
kernel, add tests that run inside stage2. This is useful for
stage2-specific componenets such as the stage 2 #VC handler.

Signed-off-by: Adam Dunlap <acdunlap@google.com>

.github/workflows/rust.yml

@@ -32,7 +32,8 @@ jobs:
       # ld to work, so build all the objects without performing the
       # final linking step.
       - name: Build
-        run: make FEATURES="default,enable-gdb" stage1/kernel.elf stage1/stage1.o stage1/reset.o
+        run: make FEATURES="default,enable-gdb" stage1/kernel.elf stage1/test-kernel.elf stage1/stage2.bin stage1/test-stage2.bin stage1/stage1.o stage1/reset.o
+
 
       - name: Run tests
         run: make test

Makefile

@@ -15,6 +15,7 @@ CARGO_ARGS += -vv
 endif
 
 STAGE2_ELF = "target/x86_64-unknown-none/${TARGET_PATH}/stage2"
+TEST_STAGE2_ELF = target/x86_64-unknown-none/${TARGET_PATH}/stage2-test
 KERNEL_ELF = "target/x86_64-unknown-none/${TARGET_PATH}/svsm"
 TEST_KERNEL_ELF = target/x86_64-unknown-none/${TARGET_PATH}/svsm-test
 FS_FILE ?= none
@@ -23,12 +24,15 @@ C_BIT_POS ?= 51
 
 STAGE1_OBJS = stage1/stage1.o stage1/reset.o
 
-all: stage1/kernel.elf svsm.bin
+all: stage1/kernel.elf stage1/stage2.bin svsm.bin
 
 test:
 	cargo test --target=x86_64-unknown-linux-gnu
 
-test-in-svsm: utils/cbit stage1/test-kernel.elf svsm.bin
+test-in-svsm: utils/cbit stage1/stage2.bin stage1/test-kernel.elf svsm.bin
+	./scripts/test-in-svsm.sh
+
+test-in-stage2: utils/cbit stage1/test-stage2.bin stage1/kernel.elf svsm.bin
 	./scripts/test-in-svsm.sh
 
 doc:
@@ -50,6 +54,10 @@ stage1/stage2.bin:
 	cargo build ${CARGO_ARGS} --bin stage2
 	objcopy -O binary ${STAGE2_ELF} $@
 
+stage1/test-stage2.bin:
+	LINK_STAGE2_TEST=1 cargo +nightly test --config 'target.x86_64-unknown-none.runner=["sh", "-c", "cp $$0 ${TEST_STAGE2_ELF}"]'
+	objcopy -O binary ${TEST_STAGE2_ELF} stage1/stage2.bin
+
 stage1/kernel.elf:
 	cargo build ${CARGO_ARGS} --bin svsm
 	objcopy -O elf64-x86-64 --strip-unneeded ${KERNEL_ELF} $@
@@ -64,7 +72,7 @@ ifneq ($(FS_FILE), none)
 endif
 	touch stage1/svsm-fs.bin
 
-stage1/stage1.o: stage1/stage1.S stage1/stage2.bin stage1/svsm-fs.bin
+stage1/stage1.o: stage1/stage1.S stage1/svsm-fs.bin
 	cc -c -o $@ stage1/stage1.S
 
 stage1/reset.o:  stage1/reset.S stage1/meta.bin
@@ -79,4 +87,4 @@ clean:
 	cargo clean
 	rm -f stage1/stage2.bin svsm.bin stage1/meta.bin stage1/kernel.elf stage1/stage1 stage1/svsm-fs.bin ${STAGE1_OBJS} utils/gen_meta utils/print-meta
 
-.PHONY: stage1/stage2.bin stage1/kernel.elf stage1/test-kernel.elf svsm.bin clean stage1/svsm-fs.bin test test-in-svsm
+.PHONY: stage1/stage2.bin stage1/test-stage2.bin stage1/kernel.elf stage1/test-kernel.elf svsm.bin clean stage1/svsm-fs.bin test test-in-svsm

build.rs

@@ -18,7 +18,7 @@ fn main() {
     println!("cargo:rustc-link-arg-bin=svsm=-Tsvsm.lds");
     println!("cargo:rustc-link-arg-bin=svsm=-no-pie");
 
-    // Extra linker args for tests.
+    // Extra linker args for svsm kernel tests.
     println!("cargo:rerun-if-env-changed=LINK_TEST");
     if std::env::var("LINK_TEST").is_ok() {
         println!("cargo:rustc-cfg=test_in_svsm");
@@ -28,4 +28,14 @@ fn main() {
         println!("cargo:rustc-link-arg=-Tsvsm.lds");
         println!("cargo:rustc-link-arg=-no-pie");
     }
+
+    // Extra linker args for stage2 tests.
+    println!("cargo:rerun-if-env-changed=LINK_STAGE2_TEST");
+    if std::env::var("LINK_STAGE2_TEST").is_ok() {
+        println!("cargo:rustc-cfg=test_in_stage2");
+        println!("cargo:rustc-link-arg=-nostdlib");
+        println!("cargo:rustc-link-arg=--build-id=none");
+        println!("cargo:rustc-link-arg=-Tstage2.lds");
+        println!("cargo:rustc-link-arg=-no-pie");
+    }
 }

src/lib.rs

@@ -7,10 +7,19 @@
 #![no_std]
 #![deny(missing_copy_implementations)]
 #![deny(missing_debug_implementations)]
-#![cfg_attr(all(test, test_in_svsm), no_main)]
-#![cfg_attr(all(test, test_in_svsm), feature(custom_test_frameworks))]
-#![cfg_attr(all(test, test_in_svsm), test_runner(crate::testing::svsm_test_runner))]
-#![cfg_attr(all(test, test_in_svsm), reexport_test_harness_main = "test_main")]
+#![cfg_attr(all(test, any(test_in_svsm, test_in_stage2)), no_main)]
+#![cfg_attr(
+    all(test, any(test_in_svsm, test_in_stage2)),
+    feature(custom_test_frameworks)
+)]
+#![cfg_attr(
+    all(test, any(test_in_svsm, test_in_stage2)),
+    test_runner(crate::testing::svsm_test_runner)
+)]
+#![cfg_attr(
+    all(test, any(test_in_svsm, test_in_stage2)),
+    reexport_test_harness_main = "test_main"
+)]
 
 pub mod acpi;
 pub mod address;
@@ -48,8 +57,14 @@ fn test_nop() {}
 #[path = "svsm.rs"]
 pub mod svsm_bin;
 // The kernel expects to access this crate as svsm, so reexport.
-#[cfg(all(test, test_in_svsm))]
+#[cfg(all(test, any(test_in_svsm, test_in_stage2)))]
 extern crate self as svsm;
 // Include a module containing the test runner.
-#[cfg(all(test, test_in_svsm))]
+#[cfg(all(test, any(test_in_svsm, test_in_stage2)))]
 pub mod testing;
+
+// When running tests inside the SVSM:
+// Build the kernel entrypoint.
+#[cfg(all(test, test_in_stage2))]
+#[path = "stage2.rs"]
+pub mod stage2_bin;

src/stage2.rs

@@ -4,8 +4,8 @@
 //
 // Author: Joerg Roedel <jroedel@suse.de>
 
-#![no_std]
-#![no_main]
+#![cfg_attr(not(test), no_std)]
+#![cfg_attr(not(test), no_main)]
 
 pub mod boot_stage2;
 
@@ -142,7 +142,7 @@ fn map_and_validate(vaddr: VirtAddr, paddr: PhysAddr, len: usize) {
 // Launch info from stage1, usually at the bottom of the stack
 // The layout has to match the order in which the parts are pushed to the stack
 // in stage1/stage1.S
-#[derive(Default, Debug)]
+#[derive(Default, Debug, Clone, Copy)]
 #[repr(C, packed)]
 pub struct Stage1LaunchInfo {
     kernel_elf_start: u32,
@@ -297,6 +297,9 @@ pub extern "C" fn stage2_main(launch_info: &Stage1LaunchInfo) {
     let kernel_entry = kernel_elf.get_entry(kernel_vaddr_alloc_base);
     let valid_bitmap = valid_bitmap_addr();
 
+    #[cfg(test)]
+    crate::test_main();
+
     // Shut down the GHCB
     shutdown_percpu();