> From: Jason Gunthorpe <jgg@xxxxxxxxxx> > Sent: Wednesday, May 22, 2024 2:25 AM > > On Tue, May 14, 2024 at 06:59:07PM -0700, Nicolin Chen wrote: > > So, you want a proxy S1 domain for a device to attach, in case > > of a stage-2 only setup, because an S2 domain will no longer has > > a VMID, since it's shared among viommus. In the SMMU driver case, > > an arm_smmu_domain won't have an smmu pointer, so a device can't > > attach to an S2 domain but always an nested S1 domain, right? > > That seems like a simple solution to the VMID lifetime, but it means > the kernel has to decode more types of vSTE. > why does ATC invalidation need to know about VMID? Or is above talking about beyond the discussion between DEV_INVALIDATE vs. VIOMMU_INVALIDATE?
