temp2

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

Author: Jonathan Woollett-Light

src/cpuid/src/cpuid_ffi.rs

@@ -3,6 +3,8 @@
 use std::alloc::{GlobalAlloc, Layout, System};
 use std::ops::Index;
 use std::{fmt, mem};
+use std::convert::TryFrom;
+use std::mem::{MaybeUninit,size_of};
 /// A rusty mimic of
 /// [`kvm_cpuid`](https://elixir.bootlin.com/linux/v5.10.129/source/arch/x86/include/uapi/asm/kvm.h#L226)
 /// .
@@ -16,10 +18,11 @@ use std::{fmt, mem};
 #[derive(Debug)]
 #[repr(C)]
 pub struct RawCpuid {
-    /// Number of entries
+    /// Number of entries.
     pub nent: u32,
-    padding: u32,
-    // Pointer to entries
+    /// Padding.
+    pub padding: Padding<{ size_of::<u32>() }>,
+    /// Pointer to entries.
     pub entries: *mut RawCpuidEntry,
 }
 impl RawCpuid {
@@ -48,7 +51,7 @@ impl RawCpuid {
     /// On allocation failure.
     pub fn push(&mut self, entry: RawCpuidEntry) {
         unsafe {
-            let layout = Layout::array::<RawCpuidEntry>(self.nent.try_into().unwrap()).unwrap();
+            let layout = Layout::array::<RawCpuidEntry>(usize::try_from(self.nent).unwrap()).unwrap();
             let new_ptr = System.realloc(
                 self.entries.cast(),
                 layout,
@@ -57,7 +60,7 @@ impl RawCpuid {
             assert!(!new_ptr.is_null(), "Allocation failure");
             self.entries = new_ptr.cast();
             self.nent += 1;
-            *self.entries.add(self.nent.try_into().unwrap()) = entry;
+            *self.entries.add(usize::try_from(self.nent).unwrap()) = entry;
         }
     }
 }
@@ -106,6 +109,7 @@ impl From<RawCpuid> for kvm_bindings::CpuId {
         kvm_bindings::CpuId::from_entries(kvm_bindings_slice).unwrap()
     }
 }
+/// Structure used to iterate cross CPUID entries.
 pub struct RawCpuidIter<'a> {
     cpuid: &'a RawCpuid,
     count: usize,
@@ -126,41 +130,42 @@ impl<'a> Iterator for RawCpuidIter<'a> {
         rtn
     }
 }
+/// A structure for owning unused memory for padding.
+#[derive(Debug,Clone)]
+#[repr(C)]
+pub struct Padding<const N:usize>(MaybeUninit<[u8;N]>);
+impl<const N:usize> Default for Padding<N> {
+    fn default() -> Self {
+        Self(MaybeUninit::uninit())
+    }
+}
+impl<const N:usize> PartialEq for Padding<N> {
+    fn eq(&self, _other: &Self) -> bool {
+        true
+    }
+}
+impl<const N:usize> Eq for Padding<N> {}
+
+/// CPUID entry (a mimic of <https://elixir.bootlin.com/linux/v5.10.129/source/arch/x86/include/uapi/asm/kvm.h#L232>).
 #[derive(Debug, Clone, Eq, PartialEq)]
 #[repr(C)]
 pub struct RawCpuidEntry {
+    /// CPUID function (leaf).
     pub function: u32,
+    /// CPUID index (subleaf).
     pub index: u32,
+    /// TODO
     pub flags: u32,
+    /// EAX register.
     pub eax: u32,
+    /// EBX register.
     pub ebx: u32,
+    /// ECX register.
     pub ecx: u32,
+    /// EDX register.
     pub edx: u32,
-    padding: [u32; 3],
-}
-impl RawCpuidEntry {
-    #[must_use]
-    #[allow(clippy::similar_names)]
-    pub fn new(
-        function: u32,
-        index: u32,
-        flags: u32,
-        eax: u32,
-        ebx: u32,
-        ecx: u32,
-        edx: u32,
-    ) -> Self {
-        Self {
-            function,
-            index,
-            flags,
-            eax,
-            ebx,
-            ecx,
-            edx,
-            padding: Default::default(),
-        }
-    }
+    /// CPUID entry padding.
+    pub padding: Padding<{ size_of::<[u32; 3]>() }>,
 }
 impl From<RawCpuidEntry> for (u32, u32, u32, u32) {
     fn from(this: RawCpuidEntry) -> Self {