Hi
I’ve post a message on xen-users@xxxxxxxxxxxx , according to a member of this list, I’ve decide to post it on xen-devel.
See mailing-list copy above :
This sounds like a question it would be useful to ask on xen-devel.
(Unfortuantely I'm not familiar enough with PCIe-to-PCI bridges to give you a good answer.)
-George
> In my opinion it could be due to the EPT table. In my "xm dmesg" I
> could see "EPT not enable" and "CPU capabilities : EPT table 2Mo",
> but I can't active it (I've try different options in default/grub
> without succes)
>
> (if devices behind the same pci bridges could not be allocated to
> different VMs, it' simply because VT-d use specific interruption
> command call MSI-X in aim to identify a domU, and those interruptions
> commands could be possible only with PCIe, you can have more information in the pdf intel VT-d).
>
> thank you for your help in advance
> Amiard Brice
>> 2012/6/22 amiard brice <perso@xxxxxxxxxxxxxxx>:
>> I want create four domU with 2 PCI device per dom.
>
>> I've bought a backplane ("motherboard extension") with 4 bridges PCIe 1x to PCI
>> directly connected to the PCH (Q67).
>>And I have one domU for each "PCI-e to PCI
>> bridge", so according to the intel_VT-d pdf, it could be possible in
>> my case to have 4 domU (one for each PCIe to PCI bridges).
>>
>> (Moreover PCI card (ethernet card) are composed with a PCI bridge)
>>
>>
>>
>> I've succefuly created 4 domU with bakend devices, with option
>> "pci-backend-strict-check" disable.
>>
>> I’ve try with it but even if all PCI ports behind “PCIe to PCI bridge “
>> appears in pci-list-assignable-devices, domU won’t start, with an
>> error message "device XX:XX.X need to be co-assigned with XX:XX.X,
>> but it's not owned by pci-backend
>>
>>
>>
>> The probleme is : even if my domU are configuer with 1 VCPUs for
>> each of them, when domU acces to I/O devices, VCPUs aren't separated
>> (I've notice this using virt-manager charts). During a basic CPU
>> benchmark on a domU, VCPUs are isolated.
>>
>>
>>
>> I Have attached "lspci-v", "xm dmesg", "xm
>> pci-list-assignable-devices", "default-grub", "xm info" and a “domU
>> cfg file”
>> For example when I transfer some file between
>> a other PC and a domU through the Ethernet card
>> connected using VT-d, VCPU's charts are identical between each
>> domU (it's like if I/O instruction aren't separated between CPU cores,
>> I think XEN can't determine CPU cores assignation for d'I/O,
>>so it execute instruction on each CPU,
>>and after DMA remapping transfer data to the correct domU).
>>
>>
>>
>> A share core is very problematic my RT application
>>
>>
>>
>> thank you for your help in advance
