On Wed, Dec 16, 2015 at 12:38 PM, Alex Williamson <alex.williamson at redhat.com> wrote: > > So it works. Is it acceptable? Useful? Sufficiently complete? Does > it imply deprecating the uio interface? I believe the feature that > started this discussion was support for MSI/X interrupts so that VFs > can support some kind of interrupt (uio only supports INTx since it > doesn't allow DMA). Implementing that would be the ultimate test of > whether this provides dpdk with not only a more consistent interface, > but the feature dpdk wants that's missing in uio. Thanks, > Hi Alex,
Sorry for jumping in. Just being curious, how does VFIO No-IOMMU mode support DMA from userspace drivers? If I understand correctly, due to the absence of IOMMU, pcidev has to use physaddr to start a DMA transaction, but how it is supposed to get physaddr from userspace drivers, /proc/<pid>/pagemap or something else? -- Thanks, Jike