[Qemu-devel] [PATCH 43/55] savevm: Include writable devices with removable media

[Markus Armbruster]

savevm and loadvm silently ignore block devices with removable media,
such as floppies and SD cards.  Rolling back a VM to a previous
checkpoint will *not* roll back writes to block devices with removable
media.

Moreover, bdrv_is_removable() is a confused mess, and wrong in at
least one case: it considers "-drive if=xen,media=cdrom -M xenpv"
removable.  It'll be cleaned up later in this series.

Read-only block devices are also ignored, but that's okay.

Fix by ignoring only read-only block devices and empty block devices.

Signed-off-by: Markus Armbruster <address@hidden>
---
 block.c  |    2 +-
 savevm.c |    4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/block.c b/block.c
index f233062..9591c8a 100644
--- a/block.c
+++ b/block.c
@@ -1958,7 +1958,7 @@ void bdrv_debug_event(BlockDriverState *bs, BlkDebugEvent 
event)
 int bdrv_can_snapshot(BlockDriverState *bs)
 {
     BlockDriver *drv = bs->drv;
-    if (!drv || bdrv_is_removable(bs) || bdrv_is_read_only(bs)) {
+    if (!drv || !bdrv_is_inserted(bs) || bdrv_is_read_only(bs)) {
         return 0;
     }
 
diff --git a/savevm.c b/savevm.c
index 8139bc7..1f03987 100644
--- a/savevm.c
+++ b/savevm.c
@@ -1913,7 +1913,7 @@ void do_savevm(Monitor *mon, const QDict *qdict)
     bs = NULL;
     while ((bs = bdrv_next(bs))) {
 
-        if (bdrv_is_removable(bs) || bdrv_is_read_only(bs)) {
+        if (!bdrv_is_inserted(bs) || bdrv_is_read_only(bs)) {
             continue;
         }
 
@@ -2033,7 +2033,7 @@ int load_vmstate(const char *name)
     bs = NULL;
     while ((bs = bdrv_next(bs))) {
 
-        if (bdrv_is_removable(bs) || bdrv_is_read_only(bs)) {
+        if (!bdrv_is_inserted(bs) || bdrv_is_read_only(bs)) {
             continue;
         }
 
-- 
1.7.2.3