diff --git a/src/xenia/core/memory.cc b/src/xenia/core/memory.cc
index 015c34144..4cfadea0f 100644
--- a/src/xenia/core/memory.cc
+++ b/src/xenia/core/memory.cc
@@ -19,11 +19,11 @@
 #define USE_LOCKS               0
 #define USE_DL_PREFIX           1
 #define HAVE_MORECORE           0
-#define HAVE_MMAP               0
 #define HAVE_MREMAP             0
 #define malloc_getpagesize      4096
 #define DEFAULT_GRANULARITY     64 * 1024
 #define DEFAULT_TRIM_THRESHOLD  MAX_SIZE_T
+#define MALLOC_ALIGNMENT        32
 #include <third_party/dlmalloc/malloc.c.h>
 
 
@@ -45,6 +45,8 @@
 struct xe_memory {
   xe_ref_t ref;
 
+  size_t      system_page_size;
+
   size_t      length;
   void*       ptr;
 
@@ -60,6 +62,14 @@ xe_memory_ref xe_memory_create(xe_memory_options_t options) {
   xe_memory_ref memory = (xe_memory_ref)xe_calloc(sizeof(xe_memory));
   xe_ref_init((xe_ref)memory);
 
+#if XE_PLATFORM(WIN32)
+  SYSTEM_INFO si;
+  GetSystemInfo(&si);
+  memory->system_page_size = si.dwPageSize;
+#else
+#error need to implement page size retrieval
+#endif  // WIN32
+
   memory->length = 0xC0000000;
 
 #if XE_PLATFORM(WIN32)
@@ -155,9 +165,6 @@ uint32_t xe_memory_search_aligned(xe_memory_ref memory, size_t start,
 
 uint32_t xe_memory_heap_alloc(xe_memory_ref memory, uint32_t base_addr,
                               uint32_t size, uint32_t flags) {
-  if (base_addr) {
-    return base_addr;
-  }
   XEASSERT(base_addr == 0);
   XEASSERT(flags == 0);
 
diff --git a/src/xenia/kernel/modules/xboxkrnl/xboxkrnl_memory.cc b/src/xenia/kernel/modules/xboxkrnl/xboxkrnl_memory.cc
index d3ccc5596..9150e884f 100644
--- a/src/xenia/kernel/modules/xboxkrnl/xboxkrnl_memory.cc
+++ b/src/xenia/kernel/modules/xboxkrnl/xboxkrnl_memory.cc
@@ -69,6 +69,14 @@ X_STATUS xeNtAllocateVirtualMemory(
   uint32_t adjusted_size = *region_size_ptr;
   // TODO(benvanik): adjust based on page size flags/etc?
 
+  // TODO(benvanik): support different allocation types.
+  // Right now we treat everything as a commit and ignore allocations that have
+  // already happened.
+  if (*base_addr_ptr) {
+    // Having a pointer already means that this is likely a follow-on COMMIT.
+    return X_STATUS_SUCCESS;
+  }
+
   // Allocate.
   uint32_t flags = 0;
   uint32_t addr = xe_memory_heap_alloc(
@@ -86,7 +94,6 @@ X_STATUS xeNtAllocateVirtualMemory(
 }
 
 
-// TODO(benvanik): remove state parameter.
 SHIM_CALL NtAllocateVirtualMemory_shim(
     xe_ppc_state_t* ppc_state, KernelState* state) {
   uint32_t base_addr_ptr      = SHIM_GET_ARG_32(0);
diff --git a/src/xenia/types.h b/src/xenia/types.h
index a3542eed2..047580e36 100644
--- a/src/xenia/types.h
+++ b/src/xenia/types.h
@@ -104,6 +104,8 @@ typedef XECACHEALIGN volatile void xe_aligned_void_t;
 #define XEBITMASK(a, b) (((unsigned) -1 >> (31 - (b))) & ~((1U << (a)) - 1))
 #define XESELECTBITS(value, a, b) ((value & XEBITMASK(a, b)) >> a)
 
+#define XEROUNDUP(v, multiple)  ((v) + (multiple) - 1 - ((v) - 1) % (multiple))
+
 #define XESUCCEED()             goto XECLEANUP
 #define XEFAIL()                goto XECLEANUP
 #define XEEXPECT(expr)          if (!(expr)         ) { goto XECLEANUP; }