[Qemu-devel] [RFC 0/7] KVM PCI/MSI passthrough with mach-virt

[Eric Auger <eric.auger@linaro.org>]

This series enables KVM PCI/MSI passthrough with mach-virt.

A new memory region type is introduced (reserved iova). On
vfio_listener_region_add this IOVA region is registered to the kernel with
VFIO_IOMMU_MAP_DMA (using the new VFIO_DMA_MAP_FLAG_MSI_RESERVED_IOVA flag).

The host VFIO PCI driver then can use this IOVA window to map some host
physical addresses, accessed by passthrough'ed PCI devices, through the IOMMU.
The first goal is to map host MSI controller frames (GICv2M, GITS_TRANSLATER).

mach-virt currently instantiates a 16x64kB reserved IOVA window. This
provisions for future usage. Most probably this exceeds MSI binding needs.

The series includes Pranav/Tushar' series:
QEMU, [v2 0/2] Generic PCIe host bridge INTx determination for INTx routing
((https://lists.nongnu.org/archive/html/qemu-devel/2015-04/msg04361.html))

Those patches are not mandated for PCI/MSI passthrough to work but without
those, the following warning is observed and can puzzle the end-user:
"qemu-system-aarch64: PCI: Bug - unimplemented PCI INTx routing (gpex-pcihost)"

If prefered, this series can be maintained separately. I just put them here
for consistency.

Best Regards

Eric

Dependencies:
The series depends on kernel series: "[PATCH 00/10] KVM PCIe/MSI passthrough on
ARM/ARM64", (https://lkml.org/lkml/2016/1/26/371)

Git:
QEMU:
https://git.linaro.org/people/eric.auger/qemu.git/shortlog/refs/heads/v2.5.0-pci-passthrough-rfc

Kernel:
https://git.linaro.org/people/eric.auger/linux.git/shortlog/refs/heads/v4.5-rc1-pcie-passthrough-v1

Testing:
- on ARM64 AMD Overdrive HW with one e1000e PCIe card.

Eric Auger (7):
  linux-headers: partial update for VFIO reserved IOVA registration
  Add a function to determine interrupt number for INTx routing
  Generic PCIe host bridge INTx determination for INTx routing
  hw: vfio: common: introduce vfio_register_reserved_iova
  memory: add reserved_iova region type
  hw: arm: virt: register reserved IOVA region
  hw: vfio: common: adapt vfio_listeners for reserved_iova region

 hw/arm/virt.c              | 14 ++++++++++
 hw/pci-host/gpex.c         | 12 ++++++++
 hw/vfio/common.c           | 68 ++++++++++++++++++++++++++++++++++++----------
 include/exec/memory.h      | 29 ++++++++++++++++++++
 include/hw/arm/virt.h      |  1 +
 include/hw/pci-host/gpex.h |  1 +
 linux-headers/linux/vfio.h | 15 ++++++++--
 memory.c                   | 11 ++++++++
 8 files changed, 134 insertions(+), 17 deletions(-)

-- 
1.9.1