Re: [Qemu-devel] USB PCI host bus adapter hot plug

[Alexey Kardashevskiy]

On 08/11/2014 03:59 PM, Gonglei (Arei) wrote:
> Hi,
> 
>> Subject: [Qemu-devel] USB PCI host bus adapter hot plug
>>
>> Hi!
>>
>> I noticed that QMP's "device_add usb-ehci,id=i2,bus=pci.0" fails on PCI
>> hotplug. The same for pci-ohci and this is because their initfn() do
>> "dc->hotpluggable   = false". So I removed those and now I can hotplug USB
>> hosts but none of them is able to actually work:
>>
>> address@hidden:~# echo 1 >/sys/bus/pci/rescan
>> [   41.143062] ohci-pci 0000:00:01.0: init err (c8700000 0000)
>> [   41.143133] ohci-pci 0000:00:01.0: can't start
>> [   41.143227] ohci-pci 0000:00:01.0: startup error -75
>> [   41.144202] ohci-pci 0000:00:01.0: init 0000:00:01.0 fail, -75
>>
>>
>> address@hidden:~# echo 1 >/sys/bus/pci/rescan
>> [   43.691067] ehci-pci 0000:00:01.0: can't setup: -110
>> [   43.692424] ehci-pci 0000:00:01.0: init 0000:00:01.0 fail, -110
>>
>>
>> Why is that? Is QEMU just missing some bits or there is some fundamental
>> issue which I just do not see? Thanks!
>>
> Cc'ing Gerd.
> 
> Actually I have post a patch serials for supporting usb host adapter 
> hotplugging,
> Which has been involved in Gerd's (the USB mantainer) usb-next tree. Please 
> see:
> https://www.kraxel.org/cgit/qemu/log/?h=rebase/usb-next
> 
> The function of usb host adapter hotplugging is ok. You are welcome to test 
> it.

It does not work for me though. The device appears in the system but the
driver fails to bring it up:

address@hidden ~]# echo 1 >/sys/bus/pci/rescan

[   43.482378] pci 0000:00:01.0: BAR 0: assigned [mem
0x100a0000000-0x100a0000fff]
[   43.488851] ehci-pci 0000:00:01.0: EHCI Host Controller

[   43.490153] ehci-pci 0000:00:01.0: new USB bus registered, assigned bus
number 1
[   43.504957] ehci-pci 0000:00:01.0: can't setup: -110

[   43.505028] ehci-pci 0000:00:01.0: USB bus 1 deregistered

[   43.507660] ehci-pci 0000:00:01.0: init 0000:00:01.0 fail, -110

[   43.507808] ehci-pci: probe of 0000:00:01.0 failed with error -110



> BTW, What's your guest os type?

Fedora20/ppc64 or Ubuntu14/ppc64le.

I tried your tree merged with
https://github.com/mdroth/qemu/tree/spapr-pci-hotplug-ppc-next-cleanup2

I am adding PCIhotplug-on-PPC experts to the thread, may be they have ideas...



-- 
Alexey