Re: [Qemu-devel] [v2][PATCH 4/8] xen, gfx passthrough: reserve 00:02.0 for INTEL IGD

[Chen, Tiejun]

> -----Original Message-----
> From: Gerd Hoffmann [mailto:address@hidden
> Sent: Thursday, May 22, 2014 2:45 PM
> To: Chen, Tiejun
> Cc: Anthony PERARD; Daniel P. Berrange; address@hidden;
> address@hidden; address@hidden;
> address@hidden; Kay, Allen M; address@hidden;
> address@hidden; Zhang, Yang Z; address@hidden
> Subject: Re: [Qemu-devel] [v2][PATCH 4/8] xen, gfx passthrough: reserve
> 00:02.0 for INTEL IGD
> 
>   Hi,
> 
> > > Another useful thing would be to not create the xen platform device
> > > in case "-nodefaults" was specified on the command line (that switch
> > > turns off a bunch of other devices present by default: vga, nic, cdrom, 
> > > ...).
> >
> > Currently looks 'xen-platform' itself can't be created, not those devices
> existed on that.
> 
> The error message looks more like libxl tries to hot-unplug the xen platform
> device.
> 
> Attached patch (untested!) hooks up the xen platform device to the default
> device code we have in qemu.  Two effects:
> 
>   (1) As mentioned above the device will not be created in case
>       -nodefaults  is specified on the command line.
>   (2) Autocreating the device is also turned off in case xen-platform
>       is added manually via -device.
> 
> With the patch applied you should be able to move the xen-platform device to
> some other place with a simple 'qemu -device xen-platform,addr=$slot'.
> 

Gerd,

Sorry, I may misunderstand what you mean previously then have a wrong test.

So this still doesn't work actually. 

After applied your patch, 'xen-platform' is always disabled by default, right? 
So 00:02.0 is left naturally to be assigned to IGD as we expect like this,

address@hidden:~$ lspci
00:00.0 Host bridge: Intel Corporation 4th Gen Core Processor DRAM Controller 
(rev 06)
00:01.0 ISA bridge: Intel Corporation 82371SB PIIX3 ISA [Natoma/Triton II]
00:01.1 IDE interface: Intel Corporation 82371SB PIIX3 IDE [Natoma/Triton II]
00:01.3 Bridge: Intel Corporation 82371AB/EB/MB PIIX4 ACPI (rev 03)
00:02.0 VGA compatible controller: Intel Corporation Xeon E3-1200 v3/4th Gen 
Core Processor Integrated Graphics Controller (rev 06)
00:03.0 USB controller: Intel Corporation 8 Series/C220 Series Chipset Family 
USB EHCI #2 (rev 04)
00:1f.0 ISA bridge: Intel Corporation Q87 Express LPC Controller (rev 04)

Then this is fine but if you intend to add a 'qemu -device 
xen-platform,addr=$slot', this doesn't work well. In my case,

gfx_passthru=1
pci=["00:address@hidden", "00:1a.0"]
xen_platform_pci=0
device_model_args_hvm = ['-device', 'xen-platform,addr=0x3']

address@hidden:~/workspace$ sudo xl cr domu-cfg
Parsing config from domu-cfg
libxl: error: libxl_qmp.c:287:qmp_handle_error_response: received an error 
message from QMP server: Unsupported bus. Bus doesn't have property 
'acpi-pcihp-bsel' set
libxl: error: libxl_create.c:1277:domcreate_attach_pci: libxl_device_pci_add 
failed: -3

Thanks
Tiejun