diff --git a/tools/libxc/xc_bitops.h b/tools/libxc/xc_bitops.h
index cd749f4014..3e7a544c9d 100644
--- a/tools/libxc/xc_bitops.h
+++ b/tools/libxc/xc_bitops.h
@@ -6,70 +6,73 @@
 #include <stdlib.h>
 #include <string.h>
 
+/* Needed by several includees, but no longer used for bitops. */
 #define BITS_PER_LONG (sizeof(unsigned long) * 8)
 #define ORDER_LONG (sizeof(unsigned long) == 4 ? 5 : 6)
 
-#define BITMAP_ENTRY(_nr,_bmap) ((_bmap))[(_nr)/BITS_PER_LONG]
-#define BITMAP_SHIFT(_nr) ((_nr) % BITS_PER_LONG)
+#define BITMAP_ENTRY(_nr,_bmap) ((_bmap))[(_nr) / 8]
+#define BITMAP_SHIFT(_nr) ((_nr) % 8)
 
 /* calculate required space for number of longs needed to hold nr_bits */
 static inline int bitmap_size(int nr_bits)
 {
-    int nr_long, nr_bytes;
-    nr_long = (nr_bits + BITS_PER_LONG - 1) >> ORDER_LONG;
-    nr_bytes = nr_long * sizeof(unsigned long);
-    return nr_bytes;
+    return (nr_bits + 7) / 8;
 }
 
-static inline unsigned long *bitmap_alloc(int nr_bits)
+static inline void *bitmap_alloc(int nr_bits)
 {
     return calloc(1, bitmap_size(nr_bits));
 }
 
-static inline void bitmap_set(unsigned long *addr, int nr_bits)
+static inline void bitmap_set(void *addr, int nr_bits)
 {
     memset(addr, 0xff, bitmap_size(nr_bits));
 }
 
-static inline void bitmap_clear(unsigned long *addr, int nr_bits)
+static inline void bitmap_clear(void *addr, int nr_bits)
 {
     memset(addr, 0, bitmap_size(nr_bits));
 }
 
-static inline int test_bit(int nr, unsigned long *addr)
+static inline int test_bit(int nr, const void *_addr)
 {
+    const char *addr = _addr;
     return (BITMAP_ENTRY(nr, addr) >> BITMAP_SHIFT(nr)) & 1;
 }
 
-static inline void clear_bit(int nr, unsigned long *addr)
+static inline void clear_bit(int nr, void *_addr)
 {
+    char *addr = _addr;
     BITMAP_ENTRY(nr, addr) &= ~(1UL << BITMAP_SHIFT(nr));
 }
 
-static inline void set_bit(int nr, unsigned long *addr)
+static inline void set_bit(int nr, void *_addr)
 {
+    char *addr = _addr;
     BITMAP_ENTRY(nr, addr) |= (1UL << BITMAP_SHIFT(nr));
 }
 
-static inline int test_and_clear_bit(int nr, unsigned long *addr)
+static inline int test_and_clear_bit(int nr, void *addr)
 {
     int oldbit = test_bit(nr, addr);
     clear_bit(nr, addr);
     return oldbit;
 }
 
-static inline int test_and_set_bit(int nr, unsigned long *addr)
+static inline int test_and_set_bit(int nr, void *addr)
 {
     int oldbit = test_bit(nr, addr);
     set_bit(nr, addr);
     return oldbit;
 }
 
-static inline void bitmap_or(unsigned long *dst, const unsigned long *other,
+static inline void bitmap_or(void *_dst, const void *_other,
                              int nr_bits)
 {
-    int i, nr_longs = (bitmap_size(nr_bits) / sizeof(unsigned long));
-    for ( i = 0; i < nr_longs; ++i )
+    char *dst = _dst;
+    const char *other = _other;
+    int i;
+    for ( i = 0; i < bitmap_size(nr_bits); ++i )
         dst[i] |= other[i];
 }
 
diff --git a/tools/libxc/xc_misc.c b/tools/libxc/xc_misc.c
index 124537bdc1..7d997d98ad 100644
--- a/tools/libxc/xc_misc.c
+++ b/tools/libxc/xc_misc.c
@@ -99,6 +99,9 @@ xc_cpumap_t xc_cpumap_alloc(xc_interface *xch)
  * byte aligned and so we need byte versions for architectures which do
  * not support misaligned accesses (which is basically everyone
  * but x86, although even on x86 it can be inefficient).
+ *
+ * NOTE: The xc_bitops macros now use byte alignment.
+ * TODO: Clean up the users of this interface.
  */
 #define BITS_PER_CPUMAP(map) (sizeof(*map) * 8)
 #define CPUMAP_ENTRY(cpu, map) ((map))[(cpu) / BITS_PER_CPUMAP(map)]