From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33446) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZjCJR-0002Yv-Bs for qemu-devel@nongnu.org; Mon, 05 Oct 2015 16:24:46 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZjCJM-0007Tk-FB for qemu-devel@nongnu.org; Mon, 05 Oct 2015 16:24:45 -0400 Received: from mx1.redhat.com ([209.132.183.28]:52828) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZjCJM-0007TS-9d for qemu-devel@nongnu.org; Mon, 05 Oct 2015 16:24:40 -0400 Date: Mon, 5 Oct 2015 23:24:33 +0300 From: "Michael S. Tsirkin" Message-ID: <20151005232244-mutt-send-email-mst@redhat.com> References: <1444034124-28747-1-git-send-email-bharata@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1444034124-28747-1-git-send-email-bharata@linux.vnet.ibm.com> Subject: Re: [Qemu-devel] [RFC v0 0/2] Enforce gaps between DIMMs List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Bharata B Rao Cc: imammedo@redhat.com, qemu-devel@nongnu.org, david@gibson.dropbear.id.au 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 >