Messages in this thread | | | Date | Thu, 14 Jun 2018 16:59:42 +0200 | From | Christoph Hellwig <> | Subject | Re: Requirement to get BAR pci_bus_address in user space |
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On Thu, Jun 14, 2018 at 08:50:15AM -0600, Alex Williamson wrote: > I don't understand the CQ vs CMB, but I think I gather that there's some > sort of buffer that's allocated from within the devices MMIO BAR and > some programming of the device needs to reference that buffer. > Wouldn't you therefore use the vfio type1 IOMMU MAP_DMA ioctl to map > the BAR into the IOVA address space and you can then use the IOVA + > offset into the BAR for the device to reference the buffer? It seems > this is the same way we'd setup a peer-to-peer mapping, but we're using > it for the device to reference itself effectively. Thanks,
That's exactly what I meant..
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