Am 20.07.2010 17:40, schrieb Anthony Liguori: > On 07/20/2010 10:17 AM, jes.soren...@redhat.com wrote: >> From: Jes Sorensen<jes.soren...@redhat.com> >> >> O_DIRECT (cache=none) requires sector alignment, however the physical >> sector size of CDROM/DVD drives is 2048, as opposed to most disk >> devices which use 512. QEMU is hard coding 512 all over the place, so >> allowing O_DIRECT for CDROM/DVD devices does not work. >> >> Signed-off-by: Jes Sorensen<jes.soren...@redhat.com> >> > > Wouldn't a better solution be to have a cdrom_read/cdrom_write hook that > did the appropriate bouncing?
We already have code that does some bouncing, we'd just need to teach it to use different sizes than 512. Duplicating everything wouldn't be a nice solution. > Silently disabling something a user explicitly asked for is not a good > option. In the very least, it should error out entirely. Yeah, that's probably better. Kevin
