[PATCH 0/5] vfio-pci: Add support for mmapping MSI-X table

[Yongji Xie <xyjxie@linux.vnet.ibm.com>]

Current vfio-pci implementation disallows to mmap the page 
containing MSI-X table in case that users can write to MSI-X
table and generate an incorrect MSIs.

However, this will cause some performance issue when there
are some critical device registers in the same page as the 
MSI-X table. We have to handle the mmio access to these 
registers in QEMU emulation rather than in guest.

To solve this issue, this series allows to mmap MSI-X table 
when hardware supports the capability of interrupt remapping 
which can ensure that a given pci device can only shoot the 
MSIs assigned for it. And we introduce a new bus_flags 
PCI_BUS_FLAGS_MSI_REMAP to test this capability on PCI side 
for different archs.

The patch 3 are based on the proposed patchset[1].

[1] http://www.spinics.net/lists/kvm/msg130256.html

Yongji Xie (5):
  PCI: Add a new PCI_BUS_FLAGS_MSI_REMAP flag
  iommu: Set PCI_BUS_FLAGS_MSI_REMAP if IOMMU have capability of IRQ remapping
  PCI: Set PCI_BUS_FLAGS_MSI_REMAP if MSI controller supports IRQ remapping
  pci-ioda: Set PCI_BUS_FLAGS_MSI_REMAP for IODA host bridge
  vfio-pci: Allow to mmap MSI-X table if interrupt remapping is supported

 arch/powerpc/platforms/powernv/pci-ioda.c |    8 ++++++++
 drivers/iommu/iommu.c                     |   15 +++++++++++++++
 drivers/pci/msi.c                         |   12 ++++++++++++
 drivers/pci/probe.c                       |    3 +++
 drivers/vfio/pci/vfio_pci.c               |    7 +++++--
 drivers/vfio/pci/vfio_pci_rdwr.c          |    3 ++-
 include/linux/msi.h                       |    6 +++++-
 include/linux/pci.h                       |    1 +
 8 files changed, 51 insertions(+), 4 deletions(-)

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1.7.9.5