Not fully traversing iova reservations bug

Not fully traversing iova reservations bug

[Yee Li]

Dear All,

Is there any other method to fix not fully traversing iova reservations bug.

A case:

For multiple devices in the same iommu group, sorted later device (based
on Bus:Dev.Func) have the RMRR.

Sorted earlier device (without RMRR) initialized the iova domain causing
the sorted later device goto done_unlock  in iommu_dma_init_domain.

     if (iovad->start_pfn) {
         if (1UL << order != iovad->granule ||
             base_pfn != iovad->start_pfn) {
             pr_warn("Incompatible range for DMA domain\n");
             ret = -EFAULT;
             goto done_unlock;
         }

         ret = 0;
         goto done_unlock;
     }

Actually RMRR ignored.

The solution patch link(no response so far):

https://lore.kernel.org/lkml/20240819104219.8057-1-LeoLiu-oc@zhaoxin.com/T/