migration/ram: Expose ramblock_is_ignored() as migrate_ram_is_ignored()

virtio-mem wants to know whether it should not mess with the RAMBlock
content (e.g., discard RAM, preallocate memory) on incoming migration.

So let's expose that function as migrate_ram_is_ignored() in
migration/misc.h

Message-ID: <20230706075612.67404-4-david@redhat.com>
Acked-by: Peter Xu <peterx@redhat.com>
Tested-by: Mario Casquero <mcasquer@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>

include/migration/misc.h

@@ -40,6 +40,7 @@ int precopy_notify(PrecopyNotifyReason reason, Error **errp);
 
 void ram_mig_init(void);
 void qemu_guest_free_page_hint(void *addr, size_t len);
+bool migrate_ram_is_ignored(RAMBlock *block);
 
 /* migration/block.c */
 

migration/postcopy-ram.c

@@ -408,7 +408,7 @@ bool postcopy_ram_supported_by_host(MigrationIncomingState *mis, Error **errp)
     /*
      * We don't support postcopy with some type of ramblocks.
      *
-     * NOTE: we explicitly ignored ramblock_is_ignored() instead we checked
+     * NOTE: we explicitly ignored migrate_ram_is_ignored() instead we checked
      * all possible ramblocks.  This is because this function can be called
      * when creating the migration object, during the phase RAM_MIGRATABLE
      * is not even properly set for all the ramblocks.

migration/ram.c

@@ -194,7 +194,7 @@ static bool postcopy_preempt_active(void)
     return migrate_postcopy_preempt() && migration_in_postcopy();
 }
 
-bool ramblock_is_ignored(RAMBlock *block)
+bool migrate_ram_is_ignored(RAMBlock *block)
 {
     return !qemu_ram_is_migratable(block) ||
            (migrate_ignore_shared() && qemu_ram_is_shared(block)
@@ -696,7 +696,7 @@ static void pss_find_next_dirty(PageSearchStatus *pss)
     unsigned long size = rb->used_length >> TARGET_PAGE_BITS;
     unsigned long *bitmap = rb->bmap;
 
-    if (ramblock_is_ignored(rb)) {
+    if (migrate_ram_is_ignored(rb)) {
         /* Points directly to the end, so we know no dirty page */
         pss->page = size;
         return;
@@ -780,7 +780,7 @@ unsigned long colo_bitmap_find_dirty(RAMState *rs, RAMBlock *rb,
 
     *num = 0;
 
-    if (ramblock_is_ignored(rb)) {
+    if (migrate_ram_is_ignored(rb)) {
         return size;
     }
 
@@ -2260,7 +2260,7 @@ static int ram_save_host_page(RAMState *rs, PageSearchStatus *pss)
     unsigned long start_page = pss->page;
     int res;
 
-    if (ramblock_is_ignored(pss->block)) {
+    if (migrate_ram_is_ignored(pss->block)) {
         error_report("block %s should not be migrated !", pss->block->idstr);
         return 0;
     }
@@ -3347,7 +3347,7 @@ static inline RAMBlock *ram_block_from_stream(MigrationIncomingState *mis,
         return NULL;
     }
 
-    if (ramblock_is_ignored(block)) {
+    if (migrate_ram_is_ignored(block)) {
         error_report("block %s should not be migrated !", id);
         return NULL;
     }
@@ -3958,7 +3958,7 @@ static int ram_load_precopy(QEMUFile *f)
                     }
                     if (migrate_ignore_shared()) {
                         hwaddr addr = qemu_get_be64(f);
-                        if (ramblock_is_ignored(block) &&
+                        if (migrate_ram_is_ignored(block) &&
                             block->mr->addr != addr) {
                             error_report("Mismatched GPAs for block %s "
                                          "%" PRId64 "!= %" PRId64,
@@ -4254,7 +4254,7 @@ static void ram_mig_ram_block_resized(RAMBlockNotifier *n, void *host,
     RAMBlock *rb = qemu_ram_block_from_host(host, false, &offset);
     Error *err = NULL;
 
-    if (ramblock_is_ignored(rb)) {
+    if (migrate_ram_is_ignored(rb)) {
         return;
     }
 

migration/ram.h

@@ -36,11 +36,10 @@
 extern XBZRLECacheStats xbzrle_counters;
 extern CompressionStats compression_counters;
 
-bool ramblock_is_ignored(RAMBlock *block);
 /* Should be holding either ram_list.mutex, or the RCU lock. */
 #define RAMBLOCK_FOREACH_NOT_IGNORED(block)            \
     INTERNAL_RAMBLOCK_FOREACH(block)                   \
-        if (ramblock_is_ignored(block)) {} else
+        if (migrate_ram_is_ignored(block)) {} else
 
 #define RAMBLOCK_FOREACH_MIGRATABLE(block)             \
     INTERNAL_RAMBLOCK_FOREACH(block)                   \