RE: [Xen-devel] blkfront/back and sector size of 2048 with CDROM's

["James Harper" <james.harper@xxxxxxxxxxxxxxxx>]

> Yes, except that last_sect = 5, because it's an inclusive range.

Yes. :)

> I'm pretty sure you can DMA to/from unaligned buffers (e.g., in this
case
> non-2kB aligned). Certainly blkback doesn't appear to check for it, so
> presumably we found it works!

My buffers are always page aligned anyway. I have no control over the
buffer alignment that windows gives me, so I have to copy the data back
and forth. In a previous version I would check for buffer alignment
first (windows almost always gives you buffers aligned to a page
boundry), but the windows scsi controller interface is really messed
up... you are always called at a really high irq level, and the routines
for mapping buffers to pfn's are not available in that situation.

James

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel