Re: [Qemu-ppc] [PATCH 0/5] Improve balloon handling of pagesizes other than 4kiB

[David Gibson]

On Thu, Feb 28, 2019 at 08:39:21AM -0500, Michael S. Tsirkin wrote:
> On Thu, Feb 14, 2019 at 03:39:11PM +1100, David Gibson wrote:
> > I posted some RFCs for this back in December, but didn't wrap it up in
> > time for 3.1.  Posting again for inclusion in 4.0.
> > 
> > The virtio-balloon devices was never really thought out for cases
> > other than 4kiB pagesize on both guest and host.  It works in some
> > cases, but in others can be ineffectual or even cause guest memory
> > corruption.
> > 
> > This series makes a handful of preliminary cleanups, then makes a
> > change to safely, though not perfectly, handle cases with non 4kiB
> > pagesizes.
> 
> I'd like to see a version of this that does not depend on patch 1 which
> is not a cleanup nor a bugfix. Could you look into this please?

Ok... the original series is already applied to master, so I'm not
exactly sure what you want me to do here.  Should I try to come up
with a "logical revert" of the first patch?  Or do you intend to
revert the whole series, and I rewrite the series without the first
patch?

> We can then debate merits of patch 1 separately.
> 
> 
> > Changes since RFC:
> >  * Further refinement of when to issue warnings in 5/5
> > 
> > David Gibson (5):
> >   virtio-balloon: Remove unnecessary MADV_WILLNEED on deflate
> >   virtio-balloon: Corrections to address verification
> >   virtio-balloon: Rework ballon_page() interface
> >   virtio-balloon: Use ram_block_discard_range() instead of raw madvise()
> >   virtio-balloon: Safely handle BALLOON_PAGE_SIZE < host page size
> > 
> >  hw/virtio/virtio-balloon.c         | 102 ++++++++++++++++++++++++-----
> >  include/hw/virtio/virtio-balloon.h |   3 +
> >  2 files changed, 89 insertions(+), 16 deletions(-)
> > 
> 

-- 
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

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