11 Sep
2024
11 Sep
'24
8:19 a.m.
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