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

[Michael S. Tsirkin]

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?
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(-)
> 
> -- 
> 2.20.1