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 00/13] 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. Please comment. Thanks! Changes: 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 (17): qom: Make object_child_foreach safe for objects removal spapr_iommu: Disable in-kernel IOMMU tables for >4GB windows 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 spapr_rtas: Reserve DDW RTAS token numbers spapr_pci: Define DDW callbacks spapr_pci: Add windows counter spapr_rtas: Add Dynamic DMA windows (DDW) RTAS calls support spapr_pci: Enable DDW spapr_pci_vfio: Call spapr_pci::reset on reset linux headers update for SPAPR (DDW + EEH) spapr_pci_vfio: Enable DDW vfio: Enable DDW ioctls to VFIO IOMMU driver spapr: Add pseries-2.2 machine David Gibson (1): spapr: Make machine naming conventions closer to those for PC hw/misc/vfio.c | 2 + hw/ppc/Makefile.objs | 3 + hw/ppc/spapr.c | 29 +++++- hw/ppc/spapr_iommu.c | 18 +++- hw/ppc/spapr_pci.c | 127 +++++++++++++++++++++--- hw/ppc/spapr_pci_vfio.c | 78 ++++++++++++++- hw/ppc/spapr_rtas_ddw.c | 234 ++++++++++++++++++++++++++++++++++++++++++++ hw/ppc/spapr_vio.c | 2 +- include/hw/pci-host/spapr.h | 30 ++++++ include/hw/ppc/spapr.h | 13 ++- linux-headers/linux/vfio.h | 58 ++++++++++- qom/object.c | 4 +- trace-events | 3 + 13 files changed, 569 insertions(+), 32 deletions(-) create mode 100644 hw/ppc/spapr_rtas_ddw.c -- 2.0.0
