page-vary: Build set_preferred_target_page_bits as common code

Use target_info->page_bits_vary to merge
set_preferred_target_page_bits_common into
set_preferred_target_page_bits in page-vary-common.c.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-ID: <20260217095106.598486-5-richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>

include/exec/page-vary.h

@@ -41,7 +41,6 @@ typedef struct {
 } TargetPageBits;
 
 #ifdef IN_PAGE_VARY
-bool set_preferred_target_page_bits_common(int bits);
 void finalize_target_page_bits_common(int min);
 #endif
 

page-vary-common.c

@@ -20,25 +20,32 @@
 #define IN_PAGE_VARY 1
 
 #include "qemu/osdep.h"
+#include "qemu/target-info-impl.h"
 #include "exec/page-vary.h"
 
 /* WARNING: This file must *not* be complied with -flto. */
 
 TargetPageBits target_page;
 
-bool set_preferred_target_page_bits_common(int bits)
+bool set_preferred_target_page_bits(int bits)
 {
-    /*
-     * The target page size is the lowest common denominator for all
-     * the CPUs in the system, so we can only make it smaller, never
-     * larger. And we can't make it smaller once we've committed to
-     * a particular size.
-     */
-    if (target_page.bits == 0 || target_page.bits > bits) {
-        if (target_page.decided) {
-            return false;
+    const TargetInfo *ti = target_info();
+
+    assert(bits >= TARGET_PAGE_BITS_MIN);
+    if (ti->page_bits_vary) {
+
+        /*
+         * The target page size is the lowest common denominator for all
+         * the CPUs in the system, so we can only make it smaller, never
+         * larger. And we can't make it smaller once we've committed to
+         * a particular size.
+         */
+        if (target_page.bits == 0 || target_page.bits > bits) {
+            if (target_page.decided) {
+                return false;
+            }
+            target_page.bits = bits;
         }
-        target_page.bits = bits;
     }
     return true;
 }

page-vary-target.c

@@ -39,16 +39,6 @@ int migration_legacy_page_bits(void)
 }
 #endif
 
-bool set_preferred_target_page_bits(int bits)
-{
-    assert(bits >= TARGET_PAGE_BITS_MIN);
-#ifdef TARGET_PAGE_BITS_VARY
-    return set_preferred_target_page_bits_common(bits);
-#else
-    return true;
-#endif
-}
-
 void finalize_target_page_bits(void)
 {
 #ifndef TARGET_PAGE_BITS_VARY