Re: [Qemu-devel] [RFC PATCH 00/15] spapr: add support for PHB hotplug

[Michael Roth <mdroth@linux.vnet.ibm.com>]

Quoting Paolo Bonzini (2015-04-30 09:10:30)
> 
> 
> On 29/04/2015 21:20, Michael Roth wrote:
> > These patches are based on latest spapr-hotplug-pci patches, and
> > can also be obtained from:
> > 
> >   https://github.com/mdroth/qemu/commits/spapr-hotplug-phb
> > 
> > These patches implement support for hotplug/unplug of PCI host-bridges.
> > The main use cases are:
> > 
> >  - allowing for VFIO PCI hotplug for host kernels that still require a
> >    1:1 mapping between guest PHB/TCE table and an iommu group (a
> >    requirement that will be relaxed with Alexey Kardashevskiy's VFIO
> >    rework for DDW support)
> >  - allocating new PHBs/TCE tables for hotplugging/distributing VFIO
> >    devices that have different NUMA affinities associated with them
> >    for performance reason
> >  - expanding hotplug capacity for passthrough/emulated PCI devices
> > 
> > With these patches we support the following:
> > 
> > (qemu) device_add spapr-pci-host-bridge,index=2,id=phb2
> > (qemu) device_add virtio-net-pci,id=hp2.0,bus=phb2.0
> > (qemu) device_del hp2.0
> > (qemu) device_del phb2
> > 
> > Automatic add/remove of PHBs based on EPOW event mechanism require
> > updated versions of powerpc-utils, rtas_errd, and librtas. Patches
> > are forthcoming and will be available in future versions, but for now
> > we can add them manually by executing the following in the guest
> > after/before hotplug/unplug, respectively:
> > 
> >   # add PHB
> >   drmgr -c PHB -s "PHB 2" -a -n
> > 
> >   # remove PHB
> >   drmgr -c PHB -s "PHB 2" -r -n
> > 
> > Feedback/comments are very much appreciated.
> 
> I reviewed the QOM/qdev/memory parts.  Don't know much about the rest,
> sorry. :)

No problem, those seemed to be the scarier bits for me :) Thanks!

> 
> Paolo
> 
> >  hw/core/qdev.c              |  24 ++++++++++++------
> >  hw/pci/pci.c                |  33 +++++++++++++++++++++++++
> >  hw/ppc/spapr.c              | 183 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
> >  hw/ppc/spapr_drc.c          |   1 +
> >  hw/ppc/spapr_events.c       |   5 ++++
> >  hw/ppc/spapr_iommu.c        |   1 +
> >  hw/ppc/spapr_pci.c          |  66 ++++++++++++++++++++++++++++++++++++++++++++++---
> >  include/hw/pci-host/spapr.h |   3 ++-
> >  include/hw/pci/pci.h        |   3 +++
> >  include/hw/ppc/spapr.h      |   1 +
> >  include/hw/qdev-core.h      |   3 +++
> >  11 files changed, 310 insertions(+), 13 deletions(-)
> > 
> > 
> > 
>