Hi, Neil,
Please see my comments embedded.
2008年5月13日 Neil Turton <nturton@xxxxxxxxxxxxxx>:
> I tried the latest unstable tree on a NIC which supports both MSI and
> MSI-X. When the driver was configured to use MSI mode, everything
> worked fine but when it was configured to use MSI-X, the call to
> pci_enable_msix succeeded but the interrupt didn't work. Have these
> patches been seen to work on an MSI-X device?
I have tested the patch using a NIC with both MSI-X and MSX
capabilities. I can successfully enable MSI-X for the NIC both in dom0
and in domU. The drivers I used for test is igb from
e1000.sourceforge.net.
Can you tell me how to reproduce your problem? Maybe there are some
pathes that I do not take care of. So that I can fix the problem.
>
> In msix_capability_init (drivers/pci/msi-xen.c), there's a loop which
> unmaps the old pirqs. Shouldn't there be some similar code in
> msi_capability_init? I can't see any reason for the inconsistency
> between the two functions.
Agree. I will add that.
>
> Would it be possible to extend this code so that a PV backend driver
> could map different MSI-X entries on a PCI device into different guests?
> We already have frontend/backend drivers which allow multiple guests to
> securely access the PCI memory of a single NIC and would like to extend
> those drivers to map MSI-X interrupts directly to guests. I
> still don't understand enough about the new hypercalls to see how that
> would work.
Do you mean your MSI-X capable NIC is owned simultaneously by multi
guests? Actually, I have not thought of this usage model. Currently,
we rely on pcibackend to provide the owner of the device. Yes, all
MSI-X interrupts are mapped to the same domain to which the device
belongs. But I think by properly set the dom_id for hypercall
PHYSDEVOP_map_pirq, it can cope wth such situations.
>
> Cheers, Neil.
>
>
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@xxxxxxxxxxxxxxxxxxx
> http://lists.xensource.com/xen-devel 
>
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel