[PATCH 14/14] migration: Drop rs->f

[Peter Xu <peterx@redhat.com>]

Now with rs->pss we can already cache channels in pss->pss_channels.  That
pss_channel contains more infromation than rs->f because it's per-channel.
So rs->f could be replaced by rss->pss[RAM_CHANNEL_PRECOPY].pss_channel,
while rs->f itself is a bit vague now.

Note that vanilla postcopy still send pages via pss[RAM_CHANNEL_PRECOPY],
that's slightly confusing but it reflects the reality.

Then, after the replacement we can safely drop rs->f.

Signed-off-by: Peter Xu <peterx@redhat.com>
---
 migration/ram.c | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/migration/ram.c b/migration/ram.c
index f42efe02fc..03bf2324ab 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -345,8 +345,6 @@ struct RAMSrcPageRequest {
 
 /* State of RAM for migration */
 struct RAMState {
-    /* QEMUFile used for this migration */
-    QEMUFile *f;
     /*
      * PageSearchStatus structures for the channels when send pages.
      * Protected by the bitmap_mutex.
@@ -2555,8 +2553,6 @@ static int ram_find_and_save_block(RAMState *rs)
         }
 
         if (found) {
-            /* Cache rs->f in pss_channel (TODO: remove rs->f) */
-            pss->pss_channel = rs->f;
             pages = ram_save_host_page(rs, pss);
         }
     } while (!pages && again);
@@ -3112,7 +3108,7 @@ static void ram_state_resume_prepare(RAMState *rs, QEMUFile *out)
     ram_state_reset(rs);
 
     /* Update RAMState cache of output QEMUFile */
-    rs->f = out;
+    rs->pss[RAM_CHANNEL_PRECOPY].pss_channel = out;
 
     trace_ram_state_resume_prepare(pages);
 }
@@ -3203,7 +3199,7 @@ static int ram_save_setup(QEMUFile *f, void *opaque)
             return -1;
         }
     }
-    (*rsp)->f = f;
+    (*rsp)->pss[RAM_CHANNEL_PRECOPY].pss_channel = f;
 
     WITH_RCU_READ_LOCK_GUARD() {
         qemu_put_be64(f, ram_bytes_total_common(true) | RAM_SAVE_FLAG_MEM_SIZE);
@@ -3338,7 +3334,7 @@ static int ram_save_iterate(QEMUFile *f, void *opaque)
 out:
     if (ret >= 0
         && migration_is_setup_or_active(migrate_get_current()->state)) {
-        ret = multifd_send_sync_main(rs->f);
+        ret = multifd_send_sync_main(rs->pss[RAM_CHANNEL_PRECOPY].pss_channel);
         if (ret < 0) {
             return ret;
         }
@@ -3406,7 +3402,7 @@ static int ram_save_complete(QEMUFile *f, void *opaque)
         return ret;
     }
 
-    ret = multifd_send_sync_main(rs->f);
+    ret = multifd_send_sync_main(rs->pss[RAM_CHANNEL_PRECOPY].pss_channel);
     if (ret < 0) {
         return ret;
     }
-- 
2.32.0