[Qemu-devel] [RFC 02/13] migration: Allow the migrate command to work on file: urls

[zhanghailiang]

Usage:
(qemu) migrate file:/path/to/vm_statefile

Signed-off-by: zhanghailiang <address@hidden>
Signed-off-by: Benoit Canet <address@hidden>
---
- With this patch, we can easily test memory snapshot
- Rebase on qemu 2.5
---
 include/migration/migration.h |  6 +++++-
 migration/fd.c                | 19 +++++++++++++++++--
 migration/migration.c         |  4 +++-
 3 files changed, 25 insertions(+), 4 deletions(-)

diff --git a/include/migration/migration.h b/include/migration/migration.h
index 4c80939..bf4f8e9 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -193,7 +193,11 @@ void unix_start_outgoing_migration(MigrationState *s, 
const char *path, Error **
 
 void fd_start_incoming_migration(const char *path, Error **errp);
 
-void fd_start_outgoing_migration(MigrationState *s, const char *fdname, Error 
**errp);
+void fd_start_outgoing_migration(MigrationState *s, const char *fdname,
+                                 int outfd, Error **errp);
+
+void file_start_outgoing_migration(MigrationState *s, const char *filename,
+                                   Error **errp);
 
 void rdma_start_outgoing_migration(void *opaque, const char *host_port, Error 
**errp);
 
diff --git a/migration/fd.c b/migration/fd.c
index 3e4bed0..b62161f 100644
--- a/migration/fd.c
+++ b/migration/fd.c
@@ -42,9 +42,10 @@ static bool fd_is_socket(int fd)
     return S_ISSOCK(stat.st_mode);
 }
 
-void fd_start_outgoing_migration(MigrationState *s, const char *fdname, Error 
**errp)
+void fd_start_outgoing_migration(MigrationState *s, const char *fdname,
+                                 int outfd, Error **errp)
 {
-    int fd = monitor_get_fd(cur_mon, fdname, errp);
+    int fd = fdname ? monitor_get_fd(cur_mon, fdname, errp) : outfd;
     if (fd == -1) {
         return;
     }
@@ -58,6 +59,20 @@ void fd_start_outgoing_migration(MigrationState *s, const 
char *fdname, Error **
     migrate_fd_connect(s);
 }
 
+void file_start_outgoing_migration(MigrationState *s, const char *filename,
+                                   Error **errp)
+{
+    int fd;
+
+    fd = qemu_open(filename, O_CREAT | O_TRUNC | O_WRONLY, S_IRUSR | S_IWUSR);
+    if (fd < 0) {
+        error_setg_errno(errp, errno, "Failed to open file: %s", filename);
+        return;
+    }
+    fd_start_outgoing_migration(s, NULL, fd, errp);
+}
+
+
 static void fd_accept_incoming_migration(void *opaque)
 {
     QEMUFile *f = opaque;
diff --git a/migration/migration.c b/migration/migration.c
index c842499..3ec3b85 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -1021,7 +1021,9 @@ void qmp_migrate(const char *uri, bool has_blk, bool blk,
     } else if (strstart(uri, "unix:", &p)) {
         unix_start_outgoing_migration(s, p, &local_err);
     } else if (strstart(uri, "fd:", &p)) {
-        fd_start_outgoing_migration(s, p, &local_err);
+        fd_start_outgoing_migration(s, p, -1, &local_err);
+    } else if (strstart(uri, "file:", &p)) {
+        file_start_outgoing_migration(s, p,  &local_err);
 #endif
     } else {
         error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "uri",
-- 
1.8.3.1