On Wed, Apr 22, 2015 at 15:13:05 +0200, Paolo Bonzini wrote:
> On 21/03/2015 07:25, Emilio G. Cota wrote:
> > Note that this test
> > if (b & ((1 << len) - 1))
> > can be simplified to
> > if (b & 1)
> > , since we know that iff the first bit of a tb is set,
> > all other bits from that tb are set too.
>
> I don't think this optimization is valid, unfortunately. It is possible
> that say a tb starts at 0x12340001 and tb_invalidate_phys_page_fast is
> called for the range starting at 0x12340000 and ending at 0x12340003.
>
> In this case you need the full test that was used before.
Good catch, haven't seen this in my tests but it could possibly happen.
v2 coming up.
Thanks,
Emilio
