Re: [Qemu-ppc] [RFC PATCH 00/10] spapr: vfio: Enable Dynamic DMA windows (DDW)

[Alexey Kardashevskiy]

On 08/05/2014 11:30 AM, Alexey Kardashevskiy wrote:
> On 07/31/2014 07:34 PM, Alexey Kardashevskiy wrote:
>> At the moment sPAPR PHB supports only a single 32bit window
>> which is normally 1..2GB which is not enough for high performance devices.
>>
>> PAPR spec enables creating an additional window(s) to support 64bit
>> DMA and bigger page sizes.
>>
>> This patchset adds DDW support for pseries. The host kernel changes are
>> required.
>>
>> This was tested on POWER8 system which allows one additional DMA window
>> which is mapped at 0x800.0000.0000.0000 and supports 16MB pages.
>> Existing guests check for DDW capabilities in PHB's device tree and if it
>> is present, they request for an additional window and map entire guest RAM
>> using H_PUT_TCE/... hypercalls once at boot time and switch to direct DMA
>> operations.
>>
>> TCE tables still may be big enough for guests backed with 64K pages but they
>> are reasonably small for guests backed by 16MB pages.
>>
>> Please comment. Thanks!
> 
> 
> Alexander Graf, ping!


Ping?


> 
> 
> 
>> Alexey Kardashevskiy (10):
>>   qom: Make object_child_foreach safe for objects removal
>>   spapr_iommu: Disable in-kernel IOMMU tables for >4GB windows
>>   spapr_pci: Make find_phb()/find_dev() public
>>   spapr_iommu: Make spapr_tce_find_by_liobn() public
>>   linux headers update for DDW
>>   spapr_rtas: Add Dynamic DMA windows (DDW) RTAS calls support
>>   spapr: Add "ddw" machine option
>>   spapr_pci: Enable DDW
>>   spapr_pci_vfio: Enable DDW
>>   vfio: Enable DDW ioctls to VFIO IOMMU driver
>>
>>  hw/misc/vfio.c              |   4 +
>>  hw/ppc/Makefile.objs        |   3 +
>>  hw/ppc/spapr.c              |  15 +++
>>  hw/ppc/spapr_iommu.c        |   8 +-
>>  hw/ppc/spapr_pci.c          |  87 +++++++++++--
>>  hw/ppc/spapr_pci_vfio.c     |  75 +++++++++++
>>  hw/ppc/spapr_rtas_ddw.c     | 296 
>> ++++++++++++++++++++++++++++++++++++++++++++
>>  include/hw/pci-host/spapr.h |  27 ++++
>>  include/hw/ppc/spapr.h      |   7 +-
>>  linux-headers/linux/vfio.h  |  37 +++++-
>>  qom/object.c                |   4 +-
>>  trace-events                |   4 +
>>  vl.c                        |   4 +
>>  13 files changed, 552 insertions(+), 19 deletions(-)
>>  create mode 100644 hw/ppc/spapr_rtas_ddw.c
>>
> 
> 


-- 
Alexey