[Test code] ARM64: Add try_from()/unwrap() in test

Some places in the code don't allow us to re-type values to let the
compiler verify that those conversions are safe, particularly with
length values. Since these are for test code, I don't expect overflows
to happen, so I've just inserted unwraps here.

I've done this in a separate commit because my dev setup doesn't use
ARM. In case something ARM-specific breaks in CI, I'd like to be able to
keep those changes in their own commits so I can debug more easily.

Signed-off-by: Jonathan Browne <[email protected]>

Author: JBYoshi

src/vmm/src/arch/aarch64/fdt.rs

@@ -449,7 +449,7 @@ mod tests {
     }
     // The `load` function from the `device_tree` will mistakenly check the actual size
     // of the buffer with the allocated size. This works around that.
-    fn set_size(buf: &mut [u8], pos: usize, val: usize) {
+    fn set_size(buf: &mut [u8], pos: usize, val: u32) {
         buf[pos] = ((val >> 24) & 0xff) as u8;
         buf[pos + 1] = ((val >> 16) & 0xff) as u8;
         buf[pos + 2] = ((val >> 8) & 0xff) as u8;
@@ -541,7 +541,7 @@ mod tests {
         // }
 
         let pos = 4;
-        let val = layout::FDT_MAX_SIZE;
+        let val = u32::try_from(layout::FDT_MAX_SIZE).unwrap();
         let mut buf = vec![];
         buf.extend_from_slice(saved_dtb_bytes);
 
@@ -604,7 +604,7 @@ mod tests {
         // }
 
         let pos = 4;
-        let val = layout::FDT_MAX_SIZE;
+        let val = u32::try_from(layout::FDT_MAX_SIZE).unwrap();
         let mut buf = vec![];
         buf.extend_from_slice(saved_dtb_bytes);
 

src/vmm/src/arch/aarch64/regs.rs

@@ -779,7 +779,7 @@ mod tests {
         let bytes = 69_u64.to_le_bytes();
         let reg_ref = Aarch64RegisterRef::new(KVM_REG_SIZE_U64, &bytes);
 
-        assert_eq!(reg_ref.size(), 8);
+        assert_eq!(usize::from(reg_ref.size()), 8);
         assert_eq!(reg_ref.value::<u64, 8>(), 69);
     }
 
@@ -808,7 +808,7 @@ mod tests {
         let mut bytes = 69_u64.to_le_bytes();
         let mut reg_ref = Aarch64RegisterRefMut::new(KVM_REG_SIZE_U64, &mut bytes);
 
-        assert_eq!(reg_ref.size(), 8);
+        assert_eq!(usize::from(reg_ref.size()), 8);
         assert_eq!(reg_ref.value::<u64, 8>(), 69);
         reg_ref.set_value(reg_ref.value::<u64, 8>() + 1);
         assert_eq!(reg_ref.value::<u64, 8>(), 70);