Re: [Xen-devel] [xen-unstable test] 16788: regressions - FAIL

[Tim Deegan <tim@xxxxxxx>]

At 11:29 +0000 on 04 Mar (1362396574), Jan Beulich wrote:
> >>> On 04.03.13 at 12:12, Tim Deegan <tim@xxxxxxx> wrote:
> > At 10:57 +0000 on 04 Mar (1362394626), Jan Beulich wrote:
> >> Question - is there really no better way than this to deal with
> >> cross page emulated writes?
> > 
> > There probably is -- all that's wanted here is two mappings that are
> > guaranteed to be contiguous in virtual address.  The LDT slots were
> > available; it would have been better to document this use where
> > LDT_VIRT_START is defined, though.
> > 
> > AFAICT, we'll need to:
> >  - cause some equivalent pair of PTEs to be available (either per-cpu or
> >    per-vcpu); or
> >  - add a map_two_domain_pages() function to use the mapcache for this; or
> 
> Would vmap() do? Or do we expect this code path to be performance
> sensitive?

I can't really tell what vmap() is for, since it seems to have no
documentation, and the checkin description just says "implement vmap()".
But it looks plausible, and emulating page-crossing writes oughtn't to
be performance-sensitive.

Tim.

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel