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When the new kernel wants to > > do DMA it will replace the STE with a new, clean VMID, and there is no > > problem. > > I see. I assume the reserved VMID for the kdump kernel will be a > clean VMID (!=0). That should guarantee different cache tags. You will also have to change things to allocate the kernel global vmid from the IDR, it will usually be 0 but not for kdump. Then you have to find all the places where the 0 is implicitly placed and put in the actual value. > But, do we have to scan CDs for ASID? I wonder if we could limit > to ARM_SMMU_FEAT_TRANS_S2 only, as this series does not memremap > CDs at all.. Yeah, I would limit to S2 for now Jason