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

[Paolo Bonzini]

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. :)

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(-)
> 
> 
>