Linux Virtualization - Sep 2012 - miscalculated vring size in virtio-0.9.5.pdf?

Hi,

the vring_size() formula in section 2.3 seems to miss

(a) "vring_avail.used_event" in the first ALIGN(), and

(b) "vring_used.flags", "vring_used.idx",
"vring_used.avail_event" in
the second ALIGN().

vring_size() in Appendix A fixes (b) (no rounding up to page size
though), but (a) is wrong there too, I believe.

Thanks,
Laszlo

Laszlo Ersek <lersek at redhat.com> writes:
> Hi,
>
> the vring_size() formula in section 2.3 seems to miss
>
> (a) "vring_avail.used_event" in the first ALIGN(), and
>
> (b) "vring_used.flags", "vring_used.idx",
"vring_used.avail_event" in
> the second ALIGN().
>
> vring_size() in Appendix A fixes (b) (no rounding up to page size
> though), but (a) is wrong there too, I believe.
Hi Laszlo,

        The effect is the same, due to ALIGN().  However, the latest
copy of the spec on github should be consistent.  Indeed, I cleaned up
the header in the Appendix so it actually compiles...

Cheers,
Rusty.