Each Partitionable Endpoint (IOMMU group) has an address range on a PCI bus where devices are allowed to do DMA. These ranges are called DMA windows. By default, there is a single DMA window, 1 or 2GB big, mapped at zero on a PCI bus.
PAPR defines a DDW RTAS API which allows pseries guests querying the hypervisor about DDW support and capabilities (page size mask for now). A pseries guest may request an additional (to the default) DMA windows using this RTAS API. The existing pseries Linux guests request an additional window as big as the guest RAM and map the entire guest window which effectively creates direct mapping of the guest memory to a PCI bus. This patchset reworks PPC64 IOMMU code and adds necessary structures to support big windows on pseries. This patchset is based on David's ppc-for-2.7 branch, sha1 8dc2e5e. This patchset does not contain guest view table reallocation as it is not a part of DDW and it depends on "memory: Add MemoryRegionIOMMUOps.notify_started/stopped callbacks" which went to the VFIO tree; will repost spapr part when the prerequisite is merged into David's queue. Please comment. Thanks! Alexey Kardashevskiy (5): memory: Add reporting of supported page sizes vfio: spapr: Add DMA memory preregistering (SPAPR IOMMU v2) vfio: Add host side DMA window capabilities vfio/spapr: Create DMA window dynamically (SPAPR IOMMU v2) spapr_pci/spapr_pci_vfio: Support Dynamic DMA Windows (DDW) hw/ppc/Makefile.objs | 1 + hw/ppc/spapr.c | 7 +- hw/ppc/spapr_iommu.c | 8 ++ hw/ppc/spapr_pci.c | 77 ++++++++--- hw/ppc/spapr_rtas_ddw.c | 295 ++++++++++++++++++++++++++++++++++++++++++ hw/vfio/Makefile.objs | 1 + hw/vfio/common.c | 180 ++++++++++++++++++++------ hw/vfio/spapr.c | 210 ++++++++++++++++++++++++++++++ include/exec/memory.h | 19 ++- include/hw/pci-host/spapr.h | 8 +- include/hw/ppc/spapr.h | 16 ++- include/hw/vfio/vfio-common.h | 20 ++- memory.c | 16 ++- trace-events | 12 ++ 14 files changed, 800 insertions(+), 70 deletions(-) create mode 100644 hw/ppc/spapr_rtas_ddw.c create mode 100644 hw/vfio/spapr.c -- 2.5.0.rc3
