task/schedule: Rename create_kernel_task()

Rename the function to start_kernel_task() to reflect that it puts the new task on the TASKLIST and run-queue and calls schedule(). Also add rust-doc comments for the function. Signed-off-by: Joerg Roedel <[email protected]>
coconut-svsm · Nov 27, 2024 · 5cdac82 · 5cdac82
1 parent 7367154
commit 5cdac82
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Showing 5 changed files with 20 additions and 10 deletions.
diff --git a/kernel/src/cpu/smp.rs b/kernel/src/cpu/smp.rs
@@ -14,7 +14,7 @@ use crate::error::SvsmError;
 use crate::platform::SvsmPlatform;
 use crate::platform::SVSM_PLATFORM;
 use crate::requests::{request_loop, request_processing_main};
-use crate::task::{create_kernel_task, schedule_init};
+use crate::task::{schedule_init, start_kernel_task};
 use crate::utils::immut_after_init::immut_after_init_set_multithreaded;
 
 fn start_cpu(platform: &dyn SvsmPlatform, apic_id: u32) -> Result<(), SvsmError> {
@@ -68,7 +68,7 @@ fn start_ap() {
 
 #[no_mangle]
 pub extern "C" fn ap_request_loop() {
-    create_kernel_task(request_processing_main).expect("Failed to launch request processing task");
+    start_kernel_task(request_processing_main).expect("Failed to launch request processing task");
     request_loop();
     panic!("Returned from request_loop!");
 }
diff --git a/kernel/src/svsm.rs b/kernel/src/svsm.rs
@@ -46,7 +46,7 @@ use svsm::sev::utils::{rmp_adjust, RMPFlags};
 use svsm::sev::{secrets_page, secrets_page_mut};
 use svsm::svsm_paging::{init_page_table, invalidate_early_boot_memory};
 use svsm::task::exec_user;
-use svsm::task::{create_kernel_task, schedule_init};
+use svsm::task::{schedule_init, start_kernel_task};
 use svsm::types::{PageSize, GUEST_VMPL, PAGE_SIZE};
 use svsm::utils::{immut_after_init::ImmutAfterInitCell, zero_mem_region};
 #[cfg(all(feature = "vtpm", not(test)))]
@@ -462,7 +462,7 @@ pub extern "C" fn svsm_main() {
         }
     }
 
-    create_kernel_task(request_processing_main).expect("Failed to launch request processing task");
+    start_kernel_task(request_processing_main).expect("Failed to launch request processing task");
 
     #[cfg(test)]
     crate::test_main();

diff --git a/kernel/src/task/mod.rs b/kernel/src/task/mod.rs
@@ -10,8 +10,8 @@ mod tasks;
 mod waiting;
 
 pub use schedule::{
-    create_kernel_task, create_user_task, current_task, current_task_terminated, is_current_task,
-    schedule, schedule_init, schedule_task, terminate, RunQueue, TASKLIST,
+    create_user_task, current_task, current_task_terminated, is_current_task, schedule,
+    schedule_init, schedule_task, start_kernel_task, terminate, RunQueue, TASKLIST,
 };
 
 pub use tasks::{

diff --git a/kernel/src/task/schedule.rs b/kernel/src/task/schedule.rs
@@ -232,7 +232,17 @@ impl TaskList {
 
 pub static TASKLIST: SpinLock<TaskList> = SpinLock::new(TaskList::new());
 
-pub fn create_kernel_task(entry: extern "C" fn()) -> Result<TaskPointer, SvsmError> {
+/// Creates, initializes and starts a new kernel task. Note that the task has
+/// already started to run before this function returns.
+///
+/// # Arguments
+///
+/// * entry: The function to run as the new tasks main function
+///
+/// # Returns
+///
+/// A new instance of [`TaskPointer`] on success, [`SvsmError`] on failure.
+pub fn start_kernel_task(entry: extern "C" fn()) -> Result<TaskPointer, SvsmError> {
     let cpu = this_cpu();
     let task = Task::create(cpu, entry)?;
     TASKLIST.lock().list().push_back(task.clone());

diff --git a/kernel/src/task/tasks.rs b/kernel/src/task/tasks.rs
@@ -701,7 +701,7 @@ extern "C" fn task_exit() {
 
 #[cfg(test)]
 mod tests {
-    use crate::task::create_kernel_task;
+    use crate::task::start_kernel_task;
     use core::arch::asm;
     use core::arch::global_asm;
 
@@ -792,7 +792,7 @@ mod tests {
     #[test]
     #[cfg_attr(not(test_in_svsm), ignore = "Can only be run inside guest")]
     fn test_fpu_context_switch() {
-        create_kernel_task(task1).expect("Failed to launch request processing task");
+        start_kernel_task(task1).expect("Failed to launch request processing task");
     }
 
     extern "C" fn task1() {
@@ -801,7 +801,7 @@ mod tests {
             asm!("call test_fpu", options(att_syntax));
         }
 
-        create_kernel_task(task2).expect("Failed to launch request processing task");
+        start_kernel_task(task2).expect("Failed to launch request processing task");
 
         unsafe {
             asm!("call check_fpu", out("rax") ret, options(att_syntax));