On Mon, 2014-06-16 at 17:21 +0200, Joerg Roedel wrote: > On Mon, Jun 16, 2014 at 04:13:29PM +0100, Will Deacon wrote: > > MSIs look just like memory accesses made by the device, so the SMMU > > will translate them to point at the GIC ITS (doorbell). The ITS then > > has tables to work out how to route the MSI. > > > > So, if IOMMU_CAP_INTR_REMAP is simply supposed to indicate that the > > SMMU can translate MSIs to point somewhere else, then the ARM SMMU can > > always do it. If it's supposed to indicate that the actual MSI > > payload can be filtered/routed, then that requires the GIC ITS. > > > > The part I'm unsure of is how VFIO knows where to map the MSIs to. > > That requires knowledge of the physical and virtual doorbell pages -- > > is that discoverable in the API? > > VFIO does not care about the actual routing, it only cares that the > device can not send interrupts it is not allowed to send (e.g. > interrupts to vectors used by other devices or, on x86, exception vectors). > If that is guaranteed by the SMMU or the GIC ITS hardware and driver > then it is fine to set this flag. Yep, I agree. Thanks, Alex -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
