On Fri, 22 Sep 2017 14:40:31 +0200 Christian Borntraeger <borntrae...@de.ibm.com> wrote:
> On 09/22/2017 02:13 PM, Pierre Morel wrote: > > On 22/09/2017 10:38, Christian Borntraeger wrote: > >> Instead of unconditionally enabling the KVM AIS capability > >> in the kvm arch init function, do this in the flic realize function > >> when we know if migration is available. This requires to initialize > >> flic before the CPUs. > > > > I am not sure to agree. > > > > AIS facility is used for PCI (currently only PCI) > > We want to support PCI emulation and PCI VFIO > > > > > > Not having AIS support in the host kernel or not supporting AISM in the > > host kernel does not affect the emulation. > > Neither virtio-pci nor TCG. > > The only devices, (currently), which can not work without AIS and is not > > migratable without AISM are PCI VFIO devices. > > This patch enable the conditional enablement facility for the KVM host mask. > The cpu model enablement is done > differently for KVM and TCG anyway. > Right now AIS is only enabled for KVM. For TCG AIS is not implemented at all > and disabled. So for whenever this > is fixed in TCG it can be handled then. Yes, that will probably still need quite a bit of work before we are there. > > And for emulated devices under KVM you still need the kernel support - > otherwise migration is really broken for > the nimm/dimm values. Agreed, you need this for any pci device. I have not yet reviewed this (or tested under tcg). I'd like to hear David's opinion, though.