Introduce "xen-save-devices-state"

- add an "is_ram" flag to SaveStateEntry;

- register_savevm_live sets is_ram for live_savevm devices;

- introduce a "xen-save-devices-state" QAPI command that can be used to save
the state of all devices, but not the RAM or the block devices of the
VM.

Changes in v8:

- rename save-devices-state to xen-save-devices-state.

Changes in v7:

- rename save_devices to save-devices-state.

Changes in v6:

- remove the is_ram parameter from register_savevm_live and sets is_ram
if the device is a live_savevm device;

- introduce save_devices as a QAPI command, write a better description
for it;

- fix CODING_STYLE;

- introduce a new doc to explain the save format used by save_devices.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Anthony Liguori <aliguori@us.ibm.com>
Acked-by: Luiz Capitulino <lcapitulino@redhat.com>

1 files changed, 27 insertions, 0 deletions

diff --git a/qmp-commands.hx b/qmp-commands.hx
index 705f704021..dbb623677c 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -444,6 +444,33 @@ Note: inject-nmi is only supported for x86 guest currently, it will
 EQMP
 
     {
+        .name       = "xen-save-devices-state",
+        .args_type  = "filename:F",
+    .mhandler.cmd_new = qmp_marshal_input_xen_save_devices_state,
+    },
+
+SQMP
+xen-save-devices-state
+-------
+
+Save the state of all devices to file. The RAM and the block devices
+of the VM are not saved by this command.
+
+Arguments:
+
+- "filename": the file to save the state of the devices to as binary
+data. See xen-save-devices-state.txt for a description of the binary
+format.
+
+Example:
+
+-> { "execute": "xen-save-devices-state",
+     "arguments": { "filename": "/tmp/save" } }
+<- { "return": {} }
+
+EQMP
+
+    {
         .name       = "migrate",
         .args_type  = "detach:-d,blk:-b,inc:-i,uri:s",
         .params     = "[-d] [-b] [-i] uri",