[Qemu-devel] [RFC v2 0/4] Add Generic PCI host device update

[Alvise Rigo]

This patch series is based on the previous work [1] and [2] by Rob
Herring and on [3] by myself.  For sake of readability and since this is
still a RFC, these patches come as a stand alone work, so there's no
need to apply first [1][2][3].  it tries to enhance this work on these
points:

Improvements from v1:

- The code should be general enough to allow the use of the controller
  with other platforms, not only with mach-virt.  The only assumption
  made is that a GIC v2 is used at guest side (the interrupt-map
  property describes the parent interrupts using the three cells
  format).
- The interrupt-map node generation has been enhanced in the following
  aspects:
  - support of multi-function PCI device has been added
  - a PCI device can now use an interrupt pin different from #INTA

Since some other works like [4] require to modify the device tree only
when all the devices have been instantiated, the PATCH[1/4] proposes a
solution for mach-virt to allow multiple agents (e.g., generic-pci,
VFIO) to modify the device tree. The approach in simple: a global list
is kept to store all the routines that perform the modification of the
device tree. Eventually, when the machine is completed, all these
routines are sequentially executed and the kernel is loaded to the guest
by mean of a machine_init_done_notifier.
In the context of this patch, here are some questions:
Rather than postponing the arm_load_kernel call as this patch does,
should we use instead the modify_dtb call provided by arm_boot_info to
modify the device tree?
If so, shouldn't modify_dtb be used to modify only *user* provided
device trees?

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. Due to a lack of devices, this part is a bit hard to
  accomplish at the moment.

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] [RFC PATCH 0/8] Add Generic PCI host device update"
https://lists.gnu.org/archive/html/qemu-devel/2014-07/msg01957.html
[4]
http://lists.nongnu.org/archive/html/qemu-devel/2014-10/msg03816.html

Alvise Rigo (4):
  hw/arm/virt: Allow multiple agents to modify dt
  hw/arm/virt: find_machine_info: handle NULL value
  hw/pci-host: Add a generic PCI host controller for virtual platforms
  hw/arm/virt: Add generic-pci device support

 hw/arm/virt.c                     | 114 +++++++++++++++-
 hw/pci-host/Makefile.objs         |   2 +-
 hw/pci-host/generic-pci.c         | 280 ++++++++++++++++++++++++++++++++++++++
 include/hw/pci-host/generic-pci.h |  74 ++++++++++
 4 files changed, 468 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