[trace-host] remove unused OutBAction::TraceRecordStack

- The guest side does not use this type of OutBAction
- The stack unwinding is done either way when the mem_profile feature is enabled

Signed-off-by: Doru Blânzeanu <[email protected]>

Author: dblnz

src/hyperlight_common/src/outb.rs

@@ -90,7 +90,6 @@ impl TryFrom<u8> for Exception {
 /// - CallFunction: makes a call to a host function,
 /// - Abort: aborts the execution of the guest,
 /// - DebugPrint: prints a message to the host
-/// - TraceRecordStack: records the stack trace of the guest
 /// - TraceMemoryAlloc: records memory allocation events
 /// - TraceMemoryFree: records memory deallocation events
 /// - TraceRecord: records a trace event in the guest
@@ -99,14 +98,12 @@ pub enum OutBAction {
     CallFunction = 101,
     Abort = 102,
     DebugPrint = 103,
-    #[cfg(feature = "mem_profile")]
-    TraceRecordStack = 104,
+    #[cfg(feature = "trace_guest")]
+    TraceRecord = 104,
     #[cfg(feature = "mem_profile")]
     TraceMemoryAlloc = 105,
     #[cfg(feature = "mem_profile")]
     TraceMemoryFree = 106,
-    #[cfg(feature = "trace_guest")]
-    TraceRecord = 107,
 }
 
 impl TryFrom<u16> for OutBAction {
@@ -117,14 +114,12 @@ impl TryFrom<u16> for OutBAction {
             101 => Ok(OutBAction::CallFunction),
             102 => Ok(OutBAction::Abort),
             103 => Ok(OutBAction::DebugPrint),
-            #[cfg(feature = "mem_profile")]
-            104 => Ok(OutBAction::TraceRecordStack),
+            #[cfg(feature = "trace_guest")]
+            104 => Ok(OutBAction::TraceRecord),
             #[cfg(feature = "mem_profile")]
             105 => Ok(OutBAction::TraceMemoryAlloc),
             #[cfg(feature = "mem_profile")]
             106 => Ok(OutBAction::TraceMemoryFree),
-            #[cfg(feature = "trace_guest")]
-            107 => Ok(OutBAction::TraceRecord),
             _ => Err(anyhow::anyhow!("Invalid OutBAction value: {}", val)),
         }
     }

src/hyperlight_host/src/sandbox/outb.rs

@@ -302,15 +302,6 @@ pub(crate) fn handle_outb(
             Ok(())
         }
         #[cfg(feature = "mem_profile")]
-        OutBAction::TraceRecordStack => {
-            let Ok(stack) = unwind(_hv, mem_mgr, _hv.trace_info_as_ref()) else {
-                return Ok(());
-            };
-            record_trace_frame(_hv.trace_info_as_ref(), 1u64, |f| {
-                write_stack(f, &stack);
-            })
-        }
-        #[cfg(feature = "mem_profile")]
         OutBAction::TraceMemoryAlloc => {
             use crate::hypervisor::regs::CommonRegisters;