Add a enable_write_cache flag in the block driver state, and use it to
decide if we claim to have a volatile write cache that needs controlled
flushing from the guest. The flag is off if cache=writethrough is
defined because O_DSYNC guarantees that every write goes to stable
storage, and it is on for cache=none and cache=writeback.
Both scsi-disk and ide now use the new flage, changing from their
defaults of always off (ide) or always on (scsi-disk).
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
8baf73adf6 (qdev/isa: convert fdc)
breaks MIPS Malta:
Tried to create isa device isa-fdc with no isa bus present
Fix this by creating an isa bus for piix4.
This change also requires some more qdev related changes
(similar changes were applied to pc.c) and allows
cleaning of piix3/piix4 code.
Thanks to Gerd Hoffmann for his hints.
Signed-off-by: Stefan Weil <weil@mail.berlios.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
These variables are per bus, not per drive. Lets move them and
cleanup things a bit. And fix the cmd migration bug for real.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
