From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:47887) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TBpGF-0007C8-72 for qemu-devel@nongnu.org; Wed, 12 Sep 2012 11:54:00 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TBpGB-0007jY-31 for qemu-devel@nongnu.org; Wed, 12 Sep 2012 11:53:55 -0400 Received: from cantor2.suse.de ([195.135.220.15]:58565 helo=mx2.suse.de) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TBpGA-0007jP-Jg for qemu-devel@nongnu.org; Wed, 12 Sep 2012 11:53:50 -0400 Message-ID: <5050B005.9080500@suse.de> Date: Wed, 12 Sep 2012 17:53:41 +0200 From: Alexander Graf MIME-Version: 1.0 References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] Enablig DLPAR capacity on QEMU pSeries List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Erlon Cruz Cc: qemu-devel@nongnu.org, David Gibson On 09/12/2012 04:54 PM, Erlon Cruz wrote: > Hi all, > > We are planning to implement DLPAR capacity on QEMU pSeries. As we What is DLPAR? Hotplug support? > lack of experience in the internals of the arch we would like you guys > to give us some design directions > and confirm if we going in the right direction. Our first idea is: > > 1 - to patch 'spapr.c' so it can dynamically insert/remove basic > items into the device tree. What exactly would you like to patch into it? We already do have support for dynamic dt creation with the spapr target. > 2 - create a host side device that will be used with a guest side > driver to perform guest side operations and communicate changes from > host to the guest (like DynamicRM does in PowerVM LPARs). We are not Why not just use hypercalls? > planning to use powerpc-tools and want to make resource management > transparent (i.e. no need to run daemons or userspace programs in the > guest, only this kernel driver). > 3 - create bindings to support adding/removal ibmvscsi devices > 4 - create bindings to support adding/removal ibmveth devices > 5 - create bindings to support adding/removal PCI devices > 6 - create bindings to support adding/removal of memory This is going to be the hardest part. I don't think QEMU supports memory hotplug yet. > - Do we need to do this the way PowerVM does? We have tested > virtio ballooning and it can works with a few endiannes corrections. I don't know how PowerVM works. But if normal ballooning is all you need, you should certainly just enable virtio-balloon. > 7 - create bindings to support adding/removal CPUs > - is SMP supported already? I tried to run SMP in a x86 host > and the guest stuck when SMP is enabled SMP should work just fine, yes. Where exactly does it get stuck? > - would be possible to work on this without a P7 baremetal > machine? At least for device hotplug, it should be perfectly possible to use an old G5 with PR KVM. I haven't gotten around to patch all the pieces of the puzzle to make -M pseries work with PR KVM when it's running on top of pHyp yet, so that won't work. > We have a P7 8205-E6B, is that possible to kick PHYP out? Ben? > Any ideia on how much effort (time/people) the hole thing would take? > Any consideration about this is much appreciated :) Phew. It's hard to tell. Depends heavily on how good your people are :). Alex