[Qemu-devel] [RFC v3 0/2] Add Generic PCI host device update

[Alvise Rigo <a.rigo@virtualopensystems.com>]

This is just an update to address the comments received on v2.

This patch series is based on the previous work [1] and [2] by Rob Herring.
This is a stand alone work, but I will not hesitate to split the patches in a
more accurate way if needed.

Changes from [1] and [2]:
- memory topology definition has been revisited
- memory addresses and sizes are now defined as qdev properties
- four system interrupts are swizzled between all the PCI devices and their
  pins
- other minor changes
- removed implicit creation of lsi and pci-ohci devices

Changes from v2:
- Some comments from Peter Maydell have been addressed: the device tree node
  generation is moved back to the mach-virt platform as in the original work.
  For this reason, mach-virt is the only supported machine model at the moment.
  Moreover, the device tree node is statically created at the device init,
  while in the previous versions it was generated according to the PCI devices
  attached to the bus.
- The creation of the device memory regions has been postponed in the realize
  function (thanks to Alexander Graf).
- Various comments from Claudio Fontana have been addressed to better explain
  some crucial points of the adopted PCI specifications (see below).

There are two specifications used by these patches. The first one regards
mainly how to describe a PCI regions inside the dt node "ranges" property. Look
at "PCI Bus binding: IEEE Std 1275-1994" for more details.  The second instead
regards mainly the properties "interrupt-map-mask" and "interrupt-map" that are
described in "Open Firmware Recommended Practice: Interrupt Mapping". This
document propose a way to route PCI interrupts to system interrupts.  All these
specifications have been firstly implemented, in kernel side, by the
host-generic-pci driver.

This work has been tested attaching several PCI devices to the mach-virt
platform using an ARMv7 CPU. The tested devices are: virtio-blk-pci,
virtio-net-pci, lsi53c895a and pci-ohci (all attached at the same time).

TODO:
- Add MSI, MSI-X support
- PCI-E support. For this, you would probably look at Alexander Graf work [3]

Thank you, alvise

[1]
"[Qemu-devel] [RFC PATCH 1/2] hw/pci-host: add a generic PCI host"
http://lists.gnu.org/archive/html/qemu-devel/2014-06/msg03482.html
[2]
"[Qemu-devel] [RFC PATCH 2/2] hw/arm/virt: Add generic PCI host device"
http://lists.gnu.org/archive/html/qemu-devel/2014-06/msg03483.html
[3]
"[Qemu-devel] [PATCH 0/4] ARM: Add support for a generic PCI Express host bridge"
https://www.mail-archive.com/qemu-devel@nongnu.org/msg272648.html



Alvise Rigo (2):
  pci/pci-host: Add generic-pci PCI host controller device
  hw/arm/virt: add generic-pci PCI host controller

 hw/arm/virt.c                     | 112 +++++++++++++++++++++++++++++-
 hw/pci-host/Makefile.objs         |   2 +-
 hw/pci-host/generic-pci.c         | 140 ++++++++++++++++++++++++++++++++++++++
 include/hw/pci-host/generic-pci.h |  45 ++++++++++++
 4 files changed, 297 insertions(+), 2 deletions(-)
 create mode 100644 hw/pci-host/generic-pci.c
 create mode 100644 include/hw/pci-host/generic-pci.h

-- 
2.1.0