Re: [Qemu-devel] [PATCH 6/6] kvm: Fix dirty tracking with large kernel page size

[David Gibson]

On Sun, Feb 26, 2012 at 09:41:17PM +0000, Blue Swirl wrote:
> On Fri, Feb 24, 2012 at 00:23, David Gibson <address@hidden> wrote:
> > From: Benjamin Herrenschmidt <address@hidden>
> >
> > If the kernel page size is larger than TARGET_PAGE_SIZE, which
> > happens for example on ppc64 with kernels compiled for 64K pages,
> > the dirty tracking doesn't work.
> 
> I think a better solution would be to push this to memory API and
> underlying exec.c dirty tracking so that they use the same page size
> as kernel (only in this KVM case, in general dirty tracking should
> match TARGET_PAGE_SIZE granularity).

I'm having trouble reconciling the two parts of this comment.  If it
should be in terms of TARGET_PAGE_SIZE generally, why _not_ keep it
that way always, and just do a fixup when we have to send the data to
the host kernel in terms of host kernel page size?

-- 
David Gibson                    | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au  | minimalist, thank you.  NOT _the_ _other_
                                | _way_ _around_!
http://www.ozlabs.org/~dgibson