03/11/2017 11:44, Jonas Pfefferle1: > Thomas Monjalon <tho...@monjalon.net> wrote on 11/03/2017 11:28:10 AM: > > 03/11/2017 10:56, Jonas Pfefferle1: > > > Thomas Monjalon <tho...@monjalon.net> wrote on 11/02/2017 11:17:10 AM: > > > > > 26/10/2017 14:57, Jonas Pfefferle1: > > > > > > > > > > > > Hi @all > > > > > > > > > > > > I just stumbled upon this patch while testing on POWER. > RTE_IOVA_VA > > > > will > > > > > > not work for the sPAPR code since the dma window size is > currently > > > > > > determined by the physical address only. > > > > > > > > > > Is it affecting POWER8? > > > > > > > > It is. > > > > > > > > > > > > > > > I'm preparing a patch to address this. > > > > > > > > > > Any news? > > > > > Can you use virtual addresses? > > > > > > > > After a long discussion with Alexey (CC) we came to the conclusion > that > > > > with the current sPAPR iommu driver we cannot use virtual addresses > since > > > > the iova is restricted to lay in the DMA window which itself is > > > restricted > > > > to physical RAM addresses resp. with the current code 0 to hotplug > memory > > > > max. However, Alexey is working on a patch to lift this restriction > on > > > the > > > > DMA window size which should allow us to do VA:VA mappings in the > future. > > > > For now we should fall back to PA in the dynamic iova mode check. I > will > > > > send an according patch later today. > > > > > > I looked into this yesterday but I'm not sure what the right solution > is > > > here. > > > At the time rte_pci_get_iommu_class is called we already know which > IOMMU > > > types are supported because vfio_get_container_fd resp. > > > vfio_has_supported_extensions has been called however we do not know > which > > > one is going to be used (Decided later in vfio_setup_device resp. > > > vfio_set_iommu_type). We can choose a iova mode which is supported by > all > > > types but if the modes are exclusive to the types we have to guess > which > > > one is going to be used. Or let the user decide? > > > > You can keep the old behaviour, restricting to physical memory, > > until you support virtual addressing. > > It can be just a #ifdef RTE_ARCH_PPC_64. > > > > Ok but we might want to refine this in the future. IMO It looks much > cleaner > to decide this on the iommu type plus this would also cover the noiommu > case without having this extra check reading the sysfs variable.
You are using the word "this" too many times to help me understand :) Anyway, please send a quick fix today for 17.11. The RC3 will be probably closed before Monday.
