On 2024/9/11 16:17, Tian, Kevin wrote:
If a VMID for an S2 hwpt is valid on physical IOMMU A but has already
been allocated for another purpose on physical IOMMU B, how can it be
shared across both IOMMUs? Or the VMID is allocated globally?
I'm not sure that's a problem. The point is that each vIOMMU object
will get a VMID from the SMMU which it's associated to (assume
one vIOMMU cannot span multiple SMMU). Whether that VMID
is globally allocated or per-SMMU is the policy in the SMMU driver.
It's the driver's responsibility to ensure not using a conflicting VMID
when creating an vIOMMU instance.
Make sense.
Thanks,
baolu
