[PATCH 2/2] exec: Ensure variable page size is only used with TARGET_PAGE_BITS_VARY

[Philippe Mathieu-Daudé]

If TARGET_PAGE_BITS_VARY is not supported, machines should not
intent to modify the target page size.
As set_preferred_target_page_bits() is supposed to return 'false'
on failure (documented in "qemu-common.h"), return false to
indicate failure if this ever happens.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
 include/qemu-common.h | 4 +++-
 exec-vary.c           | 4 +++-
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/include/qemu-common.h b/include/qemu-common.h
index fda7dc6ca77..3ea616d4567 100644
--- a/include/qemu-common.h
+++ b/include/qemu-common.h
@@ -70,7 +70,9 @@ void cpu_exec_step_atomic(CPUState *cpu);
  * size may be smaller than any given CPU's preference).
  * Returns true on success, false on failure (which can only happen
  * if this is called after the system has already finalized its
- * choice of page size and the requested page size is smaller than that).
+ * choice of page size and the requested page size is smaller than
+ * that). Only target supporting variable page size should set a
+ * preferred target page size.
  */
 bool set_preferred_target_page_bits(int bits);
 
diff --git a/exec-vary.c b/exec-vary.c
index ff905f2a8fb..4b0b7f193af 100644
--- a/exec-vary.c
+++ b/exec-vary.c
@@ -86,8 +86,10 @@ bool set_preferred_target_page_bits(int bits)
         }
         init_target_page.bits = bits;
     }
-#endif
     return true;
+#else
+    return false;
+#endif
 }
 
 void finalize_target_page_bits(void)
-- 
2.26.2