On Wed, Oct 12, 2022 at 10:34:23AM +0000, Radovanovic, Aleksandar wrote: > For the MSI EventID, the HW interrupt logic assumes the MSI write value is > equal to the MSI vector number. However, the vector number is programmable > for most (all) of the interrupt sources, which isn't exactly the same as saying > EventID is programmable for a vector number, but can be used to emulate the > desired behaviour, with a translation table in firmware. If you do this stuff wrong you will eventually run into situations that don't work. Like VFIO/VMs and things. > As for GITS_TRANSLATER, we can take up to 4 different IOVAs, which limits us > to 4 CDX devices (should be sufficient for current HW use-cases). Also, it means > that the address part must be the same for all vectors within a single CDX > device. I'm assuming this is OK as it is going to be a single interrupt and IOMMU > domain anyway. This is not at all how MSI is supposed to work. Jason
