Re: [RFC][PATCH 0/6] HVM PCI Passthrough (non-IOMMU)

[John Byrne <john.l.byrne@hp.com>]

Guy,

I tried your patches with a bnx2 NIC on SLES10 and they didn't work.

The first reason was that you mask off the capabilities bit in the PCI
status. If I got rid of this, I could at least get the NIC to configure,
but it didn't work and the dropped packets looked to be random garbage,
so I don't think it was talking to the device properly. (But I
understand almost nothing about PCI device configuration, so I don't
know what to look for.)

I haven't noticed the merge tree springing into existence into on
xenbits, so is there any progress on making into a real feature? It
sounds like most of the work needs to be done between you and Intel, but
I could certainly help with testing.

One thing I am interested in is, with the 1:1 mapping, could we disable
the VT page-fault handling? I've found that the page-fault overhead for
VT is horrible and would probably affect fork-exec benchmarks significantly.

Thanks,

John Byrne