• Alexey Kardashevskiy's avatar
    powerpc/vfio: Enable on PowerNV platform · 4e13c1ac
    Alexey Kardashevskiy authored
    This initializes IOMMU groups based on the IOMMU configuration
    discovered during the PCI scan on POWERNV (POWER non virtualized)
    platform.  The IOMMU groups are to be used later by the VFIO driver,
    which is used for PCI pass through.
    It also implements an API for mapping/unmapping pages for
    guest PCI drivers and providing DMA window properties.
    This API is going to be used later by QEMU-VFIO to handle
    h_put_tce hypercalls from the KVM guest.
    The iommu_put_tce_user_mode() does only a single page mapping
    as an API for adding many mappings at once is going to be
    added later.
    Although this driver has been tested only on the POWERNV
    platform, it should work on any platform which supports
    TCE tables.  As h_put_tce hypercall is received by the host
    kernel and processed by the QEMU (what involves calling
    the host kernel again), performance is not the best -
    circa 220MB/s on 10Gb ethernet network.
    To enable VFIO on POWER, enable SPAPR_TCE_IOMMU config
    option and configure VFIO as required.
    Cc: David Gibson <david@gibson.dropbear.id.au>
    Signed-off-by: default avatarAlexey Kardashevskiy <aik@ozlabs.ru>
    Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
    Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
pci.c 16 KB