93c65b47a6
This patch allows the use a host_device as the destination for "qemu-img convert". I added a ->bdrv_create function host_device. It merely verifies that the device exists and is large enough. A check is needed in the qemu-img convert loop to ensure that we write out all 0 sectors to the host_device. Otherwise they end up with stale garbage where all zero sectors were expected. I also made the check against bdrv_is_allocated enabled for everything _except_ host devices, since there is no point in making the block backend write a bunch of zeros just so that we can memcmp them immediately afterwards. Host devices can't benefit from this because there is no way to differentiate between a sector being unallocated because it was never written, or because it was written with all zeros and then made a trip through qemu-img convert. Finally, there is an unrelated fix for a typo in the error message printed if the destination device does not support ->bdrv_create. Signed-off-by: Nolan Leake <nolan <at> sigbus.net> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com> git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6978 c046a42c-6fe2-441c-8c8c-71466251a162
Read the documentation in qemu-doc.html. Fabrice Bellard.