diff --git a/pvmfw/src/entry.rs b/pvmfw/src/entry.rs
index fc96e53..5e22bae 100644
--- a/pvmfw/src/entry.rs
+++ b/pvmfw/src/entry.rs
@@ -228,7 +228,7 @@
     MEMORY.lock().replace(MemoryTracker::new(
         page_table,
         crosvm::MEM_START..memory::MAX_ADDR,
-        crosvm::MMIO_START..crosvm::MMIO_END,
+        crosvm::MMIO_RANGE,
         Some(memory::appended_payload_range()),
     ));
 
diff --git a/rialto/src/main.rs b/rialto/src/main.rs
index 9736aa4..3328659 100644
--- a/rialto/src/main.rs
+++ b/rialto/src/main.rs
@@ -29,7 +29,8 @@
 use hyp::get_hypervisor;
 use log::{debug, error, info};
 use vmbase::{
-    layout, main,
+    layout::{self, crosvm},
+    main,
     memory::{PageTable, PAGE_SIZE},
     power::reboot,
 };
@@ -37,7 +38,6 @@
 const SZ_1K: usize = 1024;
 const SZ_64K: usize = 64 * SZ_1K;
 const SZ_1M: usize = 1024 * SZ_1K;
-const SZ_1G: usize = 1024 * SZ_1M;
 
 #[global_allocator]
 static HEAP_ALLOCATOR: LockedHeap<32> = LockedHeap::<32>::new();
@@ -54,8 +54,7 @@
 fn init_page_table() -> Result<()> {
     let mut page_table = PageTable::default();
 
-    // The first 1 GiB of address space is used by crosvm for MMIO.
-    page_table.map_device(&(0..SZ_1G))?;
+    page_table.map_device(&crosvm::MMIO_RANGE)?;
     page_table.map_data(&layout::scratch_range())?;
     page_table.map_data(&layout::stack_range(40 * PAGE_SIZE))?;
     page_table.map_code(&layout::text_range())?;
diff --git a/vmbase/src/layout/crosvm.rs b/vmbase/src/layout/crosvm.rs
index fbeb477..85d1e0b 100644
--- a/vmbase/src/layout/crosvm.rs
+++ b/vmbase/src/layout/crosvm.rs
@@ -16,10 +16,14 @@
 //!
 //! https://crosvm.dev/book/appendix/memory_layout.html#common-layout
 
+use core::ops::Range;
+
 /// The start address of MMIO space.
 pub const MMIO_START: usize = 0x0;
 /// The end address of MMIO space.
 pub const MMIO_END: usize = 0x4000_0000;
+/// MMIO range.
+pub const MMIO_RANGE: Range<usize> = MMIO_START..MMIO_END;
 
 /// The start of the system's contiguous "main" memory.
 pub const MEM_START: usize = 0x8000_0000;