refactor(adapter): split trap/page_table/smp/entry by concern; trim comments

crates/hw-virtio/src/gpu.rs

@@ -75,7 +75,7 @@ pub fn resource_flush(mmio: &impl MmioAccess, queue: &VirtioQueue, dma: &GpuDmaA
 fn write_cmd_header(cmd_va: VirtualAddress, cmd_type: u32) {
     unsafe {
         let p = cmd_va.raw() as *mut u8;
-        // Use volatile writes to zero the buffer — ensures device sees the zeros
+        // Volatile so the device sees the zeros.
         for i in 0..128 {
             core::ptr::write_volatile((p as *mut u32).add(i), 0);
         }