page-vary: Build migration_legacy_page_bits as common code

Use target_info->page_bits_init to implement
migration_legacy_page_bits.  Because this is the last
function within the file, rename page-vary-target.c
to page-vary-system.c and build once for system mode.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-ID: <20260217095106.598486-7-richard.henderson@linaro.org>
[PMD: Update MAINTAINERS]
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>

MAINTAINERS

diff --git a/MAINTAINERS b/MAINTAINERS
index 8da0b35..606b167 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -159,7 +159,7 @@
 R: Paolo Bonzini <pbonzini@redhat.com>
 S: Maintained
 F: system/watchpoint.c
-F: page-vary-target.c
+F: page-vary-system.c
 F: page-vary-common.c
 F: accel/tcg/
 F: accel/stubs/tcg-stub.c

meson.build

diff --git a/meson.build b/meson.build
index d9a17ee..3cd1d8d 100644
--- a/meson.build
+++ b/meson.build
@@ -3833,7 +3833,7 @@
   pagevary = declare_dependency(link_with: pagevary)
 endif
 common_ss.add(pagevary)
-specific_ss.add(files('page-vary-target.c'))
+system_ss.add(files('page-vary-system.c'))
 
 common_ss.add(files('target-info.c'))
 system_ss.add(files('target-info-qom.c'))

page-vary-system.c

diff --git a/page-vary-target.c b/page-vary-system.c
similarity index 73%
rename from page-vary-target.c
rename to page-vary-system.c
index bc4d893..6c49c10 100644
--- a/page-vary-target.c
+++ b/page-vary-system.c
@@ -1,5 +1,5 @@
 /*
- * Variable page size handling -- target specific part.
+ * Variable page size handling -- system specific part.
  *
  *  Copyright (c) 2003 Fabrice Bellard
  *
@@ -17,24 +17,17 @@
  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  */
 
-#define IN_PAGE_VARY 1
-
 #include "qemu/osdep.h"
 #include "exec/page-vary.h"
-#include "exec/target_page.h"
-
-#ifndef CONFIG_USER_ONLY
 #include "exec/tlb-flags.h"
+#include "qemu/target-info-impl.h"
 
 QEMU_BUILD_BUG_ON(TLB_FLAGS_MASK & ((1u < TARGET_PAGE_BITS_MIN) - 1));
 
 int migration_legacy_page_bits(void)
 {
-#ifdef TARGET_PAGE_BITS_VARY
-    QEMU_BUILD_BUG_ON(TARGET_PAGE_BITS_LEGACY < TARGET_PAGE_BITS_MIN);
-    return TARGET_PAGE_BITS_LEGACY;
-#else
-    return TARGET_PAGE_BITS;
-#endif
+    const TargetInfo *ti = target_info();
+
+    assert(ti->page_bits_init >= TARGET_PAGE_BITS_MIN);
+    return ti->page_bits_init;
 }
-#endif