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

From: Yongji Xie
Date: Wed Apr 27 2016 - 08:46:58 EST


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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