[v2,0/2] pcie: Add simple ACS "support" to the generic PCIe root port

Message

Knut Omang Jan. 24, 2019, 10:12 a.m. UTC

These two patches together implements a PCIe capability
config space header for Access Control Services (ACS) for the
new Qemu specific generic root port. ACS support in the
associated root port is a prerequisite to be able to pass
individual functions of a device populating the port through to
an L2 guest from an unmodified kernel.

Without this, the IOMMU group the device belongs to will also
include the root port itself, and all functions the device provides.

It is necessary to support SR/IOV where the primary
purpose is to be able to share out individual VFs to different
guests, which will not be permitted by VFIO or the Windows Hyper-V equivalent
unless ACS is supported by the root port.

These patches can also be found as part of an updated version of
my SR/IOV emulation patch set at

  https://github.com/knuto/qemu/tree/sriov_patches_v10

Changes from v1:
----------------
Incorporated feedback from Alex Williamson:

- Make commit messages reflect a more correct understanding of how this
  affects VFIO operation.
- Implemented the CTRL register properly (reset callback + making non-implemented
  capabilities RO, default value 0)
- removed the egress ctrl vector parameter to the init function
- Fixed some whitespace issues

Knut Omang (2):
  pcie: Add a simple PCIe ACS (Access Control Services) helper function
  gen_pcie_root_port: Add ACS (Access Control Services) capability

 hw/pci-bridge/gen_pcie_root_port.c |  2 ++
 hw/pci-bridge/pcie_root_port.c     |  4 ++++
 hw/pci/pcie.c                      | 21 +++++++++++++++++++++
 include/hw/pci/pcie.h              |  6 ++++++
 include/hw/pci/pcie_port.h         |  1 +
 include/hw/pci/pcie_regs.h         |  4 ++++
 6 files changed, 38 insertions(+)

base-commit: a8d2b0685681e2f291faaa501efbbd76875f8ec8