feat(virtq): use virtq for capi ret error

Signed-off-by: Tomasz Andrzejak <andreiltd@gmail.com>

Author: andreiltd

src/hyperlight_guest/src/virtq/context.rs

@@ -313,7 +313,7 @@ impl GuestContext {
         self.generation
     }
 
-    fn try_send(
+    fn try_send_readonly(
         &mut self,
         header: &[u8],
         payload: &[u8],

src/hyperlight_guest_capi/src/error.rs

@@ -19,7 +19,6 @@ use core::ffi::{CStr, c_char};
 use flatbuffers::FlatBufferBuilder;
 use hyperlight_common::flatbuffer_wrappers::function_types::FunctionCallResult;
 use hyperlight_common::flatbuffer_wrappers::guest_error::{ErrorCode, GuestError};
-use hyperlight_guest_bin::GUEST_HANDLE;
 
 use crate::alloc::borrow::ToOwned;
 
@@ -35,12 +34,11 @@ pub extern "C" fn hl_set_error(err: ErrorCode, message: *const c_char) {
     let fcr = FunctionCallResult::new(guest_error);
     let mut builder = FlatBufferBuilder::new();
     let data = fcr.encode(&mut builder);
-    unsafe {
-        #[allow(static_mut_refs)] // we are single threaded
-        GUEST_HANDLE
-            .push_shared_output_data(data)
-            .expect("Failed to set error")
-    }
+
+    hyperlight_guest::virtq::with_context(|ctx| {
+        ctx.send_h2g_result(data)
+            .expect("Failed to send error via virtq");
+    });
 }
 
 #[unsafe(no_mangle)]