[PATCH 4/5] migration: Teach QEMUFile to be QIOChannel-aware

[Peter Xu]

migration uses QIOChannel typed qemufiles.  In follow up patches, we'll need
the capability to identify this fact, so that we can get the backing QIOChannel
from a QEMUFile.

We can also define types for QEMUFile but so far since we only need to be able
to identify QIOChannel, introduce a boolean which is simpler.

No functional change.

Signed-off-by: Peter Xu <pet...@redhat.com>
---
 migration/qemu-file-channel.c | 4 ++--
 migration/qemu-file.c         | 5 ++++-
 migration/qemu-file.h         | 2 +-
 migration/ram.c               | 2 +-
 migration/savevm.c            | 4 ++--
 5 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/migration/qemu-file-channel.c b/migration/qemu-file-channel.c
index 867a5ed0c3..2f8b1fcd46 100644
--- a/migration/qemu-file-channel.c
+++ b/migration/qemu-file-channel.c
@@ -187,11 +187,11 @@ static const QEMUFileOps channel_output_ops = {
 QEMUFile *qemu_fopen_channel_input(QIOChannel *ioc)
 {
     object_ref(OBJECT(ioc));
-    return qemu_fopen_ops(ioc, &channel_input_ops);
+    return qemu_fopen_ops(ioc, &channel_input_ops, true);
 }
 
 QEMUFile *qemu_fopen_channel_output(QIOChannel *ioc)
 {
     object_ref(OBJECT(ioc));
-    return qemu_fopen_ops(ioc, &channel_output_ops);
+    return qemu_fopen_ops(ioc, &channel_output_ops, true);
 }
diff --git a/migration/qemu-file.c b/migration/qemu-file.c
index 1eacf9e831..ada58c94dd 100644
--- a/migration/qemu-file.c
+++ b/migration/qemu-file.c
@@ -55,6 +55,8 @@ struct QEMUFile {
     Error *last_error_obj;
     /* has the file has been shutdown */
     bool shutdown;
+    /* Whether opaque points to a QIOChannel */
+    bool has_ioc;
 };
 
 /*
@@ -101,7 +103,7 @@ bool qemu_file_mode_is_not_valid(const char *mode)
     return false;
 }
 
-QEMUFile *qemu_fopen_ops(void *opaque, const QEMUFileOps *ops)
+QEMUFile *qemu_fopen_ops(void *opaque, const QEMUFileOps *ops, bool has_ioc)
 {
     QEMUFile *f;
 
@@ -109,6 +111,7 @@ QEMUFile *qemu_fopen_ops(void *opaque, const QEMUFileOps 
*ops)
 
     f->opaque = opaque;
     f->ops = ops;
+    f->has_ioc = has_ioc;
     return f;
 }
 
diff --git a/migration/qemu-file.h b/migration/qemu-file.h
index a9b6d6ccb7..80d0e79fd1 100644
--- a/migration/qemu-file.h
+++ b/migration/qemu-file.h
@@ -119,7 +119,7 @@ typedef struct QEMUFileHooks {
     QEMURamSaveFunc *save_page;
 } QEMUFileHooks;
 
-QEMUFile *qemu_fopen_ops(void *opaque, const QEMUFileOps *ops);
+QEMUFile *qemu_fopen_ops(void *opaque, const QEMUFileOps *ops, bool has_ioc);
 void qemu_file_set_hooks(QEMUFile *f, const QEMUFileHooks *hooks);
 int qemu_get_fd(QEMUFile *f);
 int qemu_fclose(QEMUFile *f);
diff --git a/migration/ram.c b/migration/ram.c
index b5fc454b2f..f2a86f9971 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -550,7 +550,7 @@ static int compress_threads_save_setup(void)
         /* comp_param[i].file is just used as a dummy buffer to save data,
          * set its ops to empty.
          */
-        comp_param[i].file = qemu_fopen_ops(NULL, &empty_ops);
+        comp_param[i].file = qemu_fopen_ops(NULL, &empty_ops, false);
         comp_param[i].done = true;
         comp_param[i].quit = false;
         qemu_mutex_init(&comp_param[i].mutex);
diff --git a/migration/savevm.c b/migration/savevm.c
index 72848b946c..96b5e5d639 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -168,9 +168,9 @@ static const QEMUFileOps bdrv_write_ops = {
 static QEMUFile *qemu_fopen_bdrv(BlockDriverState *bs, int is_writable)
 {
     if (is_writable) {
-        return qemu_fopen_ops(bs, &bdrv_write_ops);
+        return qemu_fopen_ops(bs, &bdrv_write_ops, false);
     }
-    return qemu_fopen_ops(bs, &bdrv_read_ops);
+    return qemu_fopen_ops(bs, &bdrv_read_ops, false);
 }
 
 
-- 
2.31.1