Re: [Qemu-devel] [RFC v0 0/2] Enforce gaps between DIMMs

[Michael S. Tsirkin]

On Mon, Oct 05, 2015 at 02:05:22PM +0530, Bharata B Rao wrote:
> The suggested way to work around the virtio bug reported here
> 
> http://lists.nongnu.org/archive/html/qemu-devel/2015-08/msg00522.html
> 
> is to introduce gaps between DIMMs. Igor's patchset changes the pc-dimm
> auto-address assignment to introduce gaps and ues the same from pc memhp.
> This patchset does the same for sPAPR PowerPC.
> 
> Before introducing the gap, ensure that memory hotplug region has enough
> room for alignment adjustment. We accommodate a max alignment of 256MB for
> each slot since sPAPR memory hotplug enforces an alignment requirement of
> 256MB on RAM size, maxmem and NUMA node mem sizes.
> 
> This applies on David's spapr-next branch + Igor's patchset applied.
> 
> This has been very lightly tested and intention is to get feedback
> on the correctness aspect of this.
> 
> Bharata B Rao (2):
>   spapr: Accommadate alignment gaps in hotplug memory region
>   spapr: Force gaps between DIMM's GPA

PC needs this, PPC needs this ... I don't see why would this not
apply everywhere. Isn't it time we just converted everyone?
Drop the gap flag, set it unconditionally for new machine types.

Thoughts?


>  hw/ppc/spapr.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> -- 
> 2.1.0
>