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

[Claudio Fontana]

Another general question about this series use:

why do all these other devices that are unrelated to the virt platform show up?
Here I am running on the guest with just virtio-net, virtio-blk and virtio-rng:

(qemu) info pci
  Bus  0, device   0, function 0:
    Class 2880: PCI device 1b36:1234
      id ""
  Bus  0, device   1, function 0:
    USB controller: PCI device 106b:003f
      IRQ 0.
      BAR0: 32 bit memory at 0xffffffffffffffff [0x000000fe].
      id ""
  Bus  0, device   2, function 0:
    SCSI controller: PCI device 1000:0012
      IRQ 0.
      BAR0: I/O at 0xffffffffffffffff [0x00fe].
      BAR1: 32 bit memory at 0xffffffffffffffff [0x000003fe].
      BAR2: 32 bit memory at 0xffffffffffffffff [0x00001ffe].
      id ""
  Bus  0, device   3, function 0:
    SCSI controller: PCI device 1af4:1001
      IRQ 0.
      BAR0: I/O at 0x0100 [0x013f].
      id "blk0"
  Bus  0, device   4, function 0:
    Class 0255: PCI device 1af4:1005
      IRQ 0.
      BAR0: I/O at 0x0140 [0x015f].
      id ""
  Bus  0, device   5, function 0:
    Ethernet controller: PCI device 1af4:1000
      IRQ 0.
      BAR0: I/O at 0x0160 [0x017f].
      BAR6: 32 bit memory at 0xffffffffffffffff [0x0003fffe].
      id ""

Also what is the BAR6 for the virtio-net device? I am struggling to understand 
where it is coming from...

Thanks,

Claudio

On 21.11.2014 19:07, Alvise Rigo wrote:
> 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
> 


-- 
Claudio Fontana
Server Virtualization Architect
Huawei Technologies Duesseldorf GmbH
Riesstraße 25 - 80992 München

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