[Qemu-devel] [PATCH v4 00/18] spapr: vfio: Enable Dynamic DMA windows (DDW)

[Alexey Kardashevskiy]

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, posted earlier today as:
[PATCH v3 00/24] powerpc/iommu/vfio: Enable Dynamic DMA windows

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.


This does not contain PCI 64bit BAR support and VIO-TCE-bypass rework, these
are required for this to work but they have been posted separately today.


Please comment. Thanks!

Changes:
v4:
* (!) reimplemented the whole thing
* machine reset and ddw-reset RTAS call both remove all TCE tables and
create the default one
* IOMMU group id is not needed to use VFIO PHB anymore, multiple groups
are supported on the same VFIO container and virtual PHB

v3:
* removed "reset" from API now
* reworked machine versions
* applied multiple comments
* includes David's machine QOM rework as this patchset adds a new machine type

v2:
* tested on emulated PHB
* removed "ddw" machine property, now it is PHB property
* disabled by default
* defined "pseries-2.2" machine which enables DDW by default
* fixed reset() and reference counting




Alexey Kardashevskiy (18):
  spapr_iommu: Disable in-kernel IOMMU tables for >4GB windows
  spapr_iommu: Make H_PUT_TCE_INDIRECT endian-safe
  spapr_pci: Introduce a liobn number generating macros
  spapr_vio: Introduce a liobn number generating macros
  spapr_pci: Make find_phb()/find_dev() public
  spapr_iommu: Make spapr_tce_find_by_liobn() public
  spapr_iommu: Implement free_table() helper
  vfio: Add DMA memory registering
  spapr_rtas: Reserve DDW RTAS token numbers
  spapr_pci: Define DDW callbacks
  spapr_pci/spapr_pci_vfio: Support Dynamic DMA Windows (DDW)
  spapr_rtas: Add Dynamic DMA windows (DDW) RTAS handlers
  spapr_pci: Advertise dynamic DMA windows to guest
  vfio: Enable DDW ioctls to VFIO IOMMU driver
  spapr_pci_vfio: Enable multiple groups per container
  spapr_rtas_ddw: Workaround broken LE guests
  target-ppc: kvm: make use of KVM_CREATE_SPAPR_TCE_64
  vfio: Enable in-kernel acceleration via VFIO KVM device

 hw/ppc/Makefile.objs          |   3 +
 hw/ppc/spapr.c                |   5 +
 hw/ppc/spapr_iommu.c          |  23 ++-
 hw/ppc/spapr_pci.c            | 209 ++++++++++++++++++++------
 hw/ppc/spapr_pci_vfio.c       | 108 +++++++++-----
 hw/ppc/spapr_rtas.c           |  29 ++++
 hw/ppc/spapr_rtas_ddw.c       | 337 ++++++++++++++++++++++++++++++++++++++++++
 hw/ppc/spapr_vio.c            |   2 +-
 hw/vfio/common.c              | 167 ++++++++++++++++++---
 include/hw/pci-host/spapr.h   |  38 ++++-
 include/hw/ppc/spapr.h        |  15 +-
 include/hw/vfio/vfio-common.h |   3 +-
 include/hw/vfio/vfio.h        |   6 +-
 target-ppc/kvm.c              |  48 ++++--
 target-ppc/kvm_ppc.h          |  10 +-
 trace-events                  |   4 +
 16 files changed, 881 insertions(+), 126 deletions(-)
 create mode 100644 hw/ppc/spapr_rtas_ddw.c

-- 
2.0.0