fixup! amd64: move processor control structures to snapshot region

Remove the useless `round_up_to` helper function, and replace it with
standard library `next_multiple_of` integer methods.

Signed-off-by: Lucy Menon <168595099+syntactically@users.noreply.github.com>

Author: syntactically

src/hyperlight_common/src/lib.rs

@@ -36,9 +36,6 @@ pub mod mem;
 /// cbindgen:ignore
 pub mod outb;
 
-// cbindgen:ignore
-pub mod util;
-
 /// cbindgen:ignore
 pub mod resource;
 

src/hyperlight_common/src/util.rs

@@ -62,7 +62,6 @@ use std::fmt::Debug;
 use std::mem::{offset_of, size_of};
 
 use hyperlight_common::mem::{GuestMemoryRegion, HyperlightPEB, PAGE_SIZE_USIZE};
-use hyperlight_common::util::round_up_to;
 use tracing::{Span, instrument};
 
 #[cfg(feature = "init-paging")]
@@ -208,7 +207,7 @@ impl SandboxMemoryLayout {
     ) -> Result<Self> {
         let guest_code_offset = 0;
         // The following offsets are to the fields of the PEB struct itself!
-        let peb_offset = round_up_to(code_size, PAGE_SIZE_USIZE);
+        let peb_offset = code_size.next_multiple_of(PAGE_SIZE_USIZE);
         let peb_guest_dispatch_function_ptr_offset =
             peb_offset + offset_of!(HyperlightPEB, guest_function_dispatch_ptr);
         let peb_input_data_offset = peb_offset + offset_of!(HyperlightPEB, input_stack);
@@ -220,22 +219,17 @@ impl SandboxMemoryLayout {
         // which are written to PEB struct
         let peb_address = Self::BASE_ADDRESS + peb_offset;
         // make sure input data buffer starts at 4K boundary
-        let input_data_buffer_offset = round_up_to(
-            peb_heap_data_offset + size_of::<GuestMemoryRegion>(),
-            PAGE_SIZE_USIZE,
-        );
-        let output_data_buffer_offset = round_up_to(
-            input_data_buffer_offset + cfg.get_input_data_size(),
-            PAGE_SIZE_USIZE,
-        );
+        let input_data_buffer_offset = (peb_heap_data_offset + size_of::<GuestMemoryRegion>())
+            .next_multiple_of(PAGE_SIZE_USIZE);
+        let output_data_buffer_offset = (input_data_buffer_offset + cfg.get_input_data_size())
+            .next_multiple_of(PAGE_SIZE_USIZE);
         // make sure heap buffer starts at 4K boundary
-        let guest_heap_buffer_offset = round_up_to(
-            output_data_buffer_offset + cfg.get_output_data_size(),
-            PAGE_SIZE_USIZE,
-        );
+        let guest_heap_buffer_offset = (output_data_buffer_offset + cfg.get_output_data_size())
+            .next_multiple_of(PAGE_SIZE_USIZE);
         // make sure init data starts at 4K boundary
-        let init_data_offset = round_up_to(guest_heap_buffer_offset + heap_size, PAGE_SIZE_USIZE);
-        let pt_offset = round_up_to(init_data_offset + init_data_size, PAGE_SIZE_USIZE);
+        let init_data_offset =
+            (guest_heap_buffer_offset + heap_size).next_multiple_of(PAGE_SIZE_USIZE);
+        let pt_offset = (init_data_offset + init_data_size).next_multiple_of(PAGE_SIZE_USIZE);
 
         Ok(Self {
             peb_offset,
@@ -640,38 +634,20 @@ mod tests {
 
     use super::*;
 
-    #[test]
-    fn test_round_up() {
-        assert_eq!(0, round_up_to(0, 4));
-        assert_eq!(4, round_up_to(1, 4));
-        assert_eq!(4, round_up_to(2, 4));
-        assert_eq!(4, round_up_to(3, 4));
-        assert_eq!(4, round_up_to(4, 4));
-        assert_eq!(8, round_up_to(5, 4));
-        assert_eq!(8, round_up_to(6, 4));
-        assert_eq!(8, round_up_to(7, 4));
-        assert_eq!(8, round_up_to(8, 4));
-        assert_eq!(PAGE_SIZE_USIZE, round_up_to(44, PAGE_SIZE_USIZE));
-        assert_eq!(PAGE_SIZE_USIZE, round_up_to(4095, PAGE_SIZE_USIZE));
-        assert_eq!(PAGE_SIZE_USIZE, round_up_to(4096, PAGE_SIZE_USIZE));
-        assert_eq!(PAGE_SIZE_USIZE * 2, round_up_to(4097, PAGE_SIZE_USIZE));
-        assert_eq!(PAGE_SIZE_USIZE * 2, round_up_to(8191, PAGE_SIZE_USIZE));
-    }
-
     // helper func for testing
     fn get_expected_memory_size(layout: &SandboxMemoryLayout) -> usize {
         let cfg = layout.sandbox_memory_config;
         let mut expected_size = 0;
         // in order of layout
         expected_size += layout.code_size;
 
-        expected_size += round_up_to(size_of::<HyperlightPEB>(), PAGE_SIZE_USIZE);
+        expected_size += size_of::<HyperlightPEB>().next_multiple_of(PAGE_SIZE_USIZE);
 
-        expected_size += round_up_to(cfg.get_input_data_size(), PAGE_SIZE_USIZE);
+        expected_size += cfg.get_input_data_size().next_multiple_of(PAGE_SIZE_USIZE);
 
-        expected_size += round_up_to(cfg.get_output_data_size(), PAGE_SIZE_USIZE);
+        expected_size += cfg.get_output_data_size().next_multiple_of(PAGE_SIZE_USIZE);
 
-        expected_size += round_up_to(layout.heap_size, PAGE_SIZE_USIZE);
+        expected_size += layout.heap_size.next_multiple_of(PAGE_SIZE_USIZE);
 
         expected_size
     }