Re: [PATCH RFC v6 13/26] nova-core: mm: Add unified page table entry wrapper enums

On Tue, 20 Jan 2026 15:42:50 -0500
Joel Fernandes [off-list ref] wrote:

Add unified Pte, Pde, and DualPde wrapper enums that abstract over
MMU v2 and v3 page table entry formats. These enums allow the page
table walker and VMM to work with both MMU versions.

snip

+impl DualPde {
+    /// Create a [`DualPde`] from raw 128-bit value (two `u64`s) for
the given MMU version.
+    pub(crate) fn new(version: MmuVersion, big: u64, small: u64) ->
Self {
+        match version {
+            MmuVersion::V2 => Self::V2(ver2::DualPde::new(big, small)),
+            MmuVersion::V3 => Self::V3(ver3::DualPde::new(big, small)),
+        }
+    }
+
+    /// Create a [`DualPde`] with only the small page table pointer set.
+    pub(crate) fn new_small(version: MmuVersion, table_pfn: Pfn) ->
Self {
+        match version {
+            MmuVersion::V2 =>
Self::V2(ver2::DualPde::new_small(table_pfn)),
+            MmuVersion::V3 =>
Self::V3(ver3::DualPde::new_small(table_pfn)),
+        }
+    }
+
+    /// Check if the small page table pointer is valid.
+    pub(crate) fn has_small(&self) -> bool {
+        match self {
+            Self::V2(d) => d.has_small(),
+            Self::V3(d) => d.has_small(),
+        }
+    }
+

Should we also have a has_big here as well?

Z.

+    /// Get the small page table VRAM address.
+    pub(crate) fn small_vram_address(&self) -> VramAddress {
+        match self {
+            Self::V2(d) => d.small.table_vram_address(),
+            Self::V3(d) => d.small.table_vram_address(),
+        }
+    }
+
+    /// Get the raw `u64` value of the big PDE.
+    pub(crate) fn big_raw_u64(&self) -> u64 {
+        match self {
+            Self::V2(d) => d.big.raw_u64(),
+            Self::V3(d) => d.big.raw_u64(),
+        }
+    }
+
+    /// Get the raw `u64` value of the small PDE.
+    pub(crate) fn small_raw_u64(&self) -> u64 {
+        match self {
+            Self::V2(d) => d.small.raw_u64(),
+            Self::V3(d) => d.small.raw_u64(),
+        }
+    }
+}