migration: remove the QEMUFileOps 'get_buffer' callback

This directly implements the get_buffer logic using QIOChannel APIs.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
  dgilbert: Fixup len = *-*EIO as spotted by Peter Xu

1 files changed, 16 insertions, 2 deletions

diff --git a/migration/qemu-file.c b/migration/qemu-file.c
index 74f919de67..2f46873efd 100644
--- a/migration/qemu-file.c
+++ b/migration/qemu-file.c
@@ -377,8 +377,22 @@ static ssize_t qemu_fill_buffer(QEMUFile *f)
         return 0;
     }
 
-    len = f->ops->get_buffer(f->ioc, f->buf + pending, f->total_transferred,
-                             IO_BUF_SIZE - pending, &local_error);
+    do {
+        len = qio_channel_read(f->ioc,
+                               (char *)f->buf + pending,
+                               IO_BUF_SIZE - pending,
+                               &local_error);
+        if (len == QIO_CHANNEL_ERR_BLOCK) {
+            if (qemu_in_coroutine()) {
+                qio_channel_yield(f->ioc, G_IO_IN);
+            } else {
+                qio_channel_wait(f->ioc, G_IO_IN);
+            }
+        } else if (len < 0) {
+            len = -EIO;
+        }
+    } while (len == QIO_CHANNEL_ERR_BLOCK);
+
     if (len > 0) {
         f->buf_size += len;
         f->total_transferred += len;