[Qemu-devel] buffer alignment for block backends

[Stefano Stabellini <stefano.stabellini@eu.citrix.com>]

Hi all,
I am having an issue with the alignment of the buffers given to the
block backends. In particular, at the moment we are allocating buffers
512 bytes aligned while the backend I am working on (block-vbd) needs
page alignment.
Given that the 512 bytes alignment comes already from the requirements
of a "special case" (linux O_DIRECT, I guess), would you be willing to
make another exception for another special case and page align the buffers?

If you do not want to do that, another possible solution is to create a
new function called "qemu_blockalign" that would be implemented as
qemu_memalign(512, size); so we don't have to write 512 bytes everywhere
but only in one place, thus making life easier to people like me that
have to change the value for a special case.

Thanks in advance for your sympathy :)

Stefano Stabellini