[Qemu-devel] Re: [PATCH 13/13] blockdev: New -blockdev to define a host block device

[Paolo Bonzini]

On 06/02/2010 06:55 PM, Markus Armbruster wrote:
* Like -drive, -blockdev ignores cache= silently when snapshot=on.  Do
   we really want that?

Yes, the changes are throw-away by definition.  Might as well use 
cache=unsafe.

+    if (snapshot) {
+        /* always use write-back with snapshot */
+        /* FIXME ignores explicit cache= *silently*; really want that? */
+        flags &= ~BDRV_O_CACHE_MASK;
+        flags |= (BDRV_O_SNAPSHOT | BDRV_O_CACHE_WB);
+        flags |= BDRV_O_SNAPSHOT;

Cut and paste?

Paolo