quoted

-     u32 msiir_offset; /* Offset of MSIIR, relative to start of CCSR */
+     dma_addr_t msiir; /* MSIIR Address in CCSR */

Are you sure dma_addr_t is right here, versus phys_addr_t?  It implies
that it's the output of the DMA API, but I don't think the DMA API is
used in the MSI driver.  Perhaps it should be, but we still want the raw
physical address to pass on to VFIO.

I don't know what "msiir" is used for, but if it's an address you
program into a PCI device, then it's a dma_addr_t even if you didn't
get it from the DMA API.  Maybe "bus_addr_t" would have been a more
suggestive name than "dma_addr_t".  That said, I have no idea how this
relates to VFIO.

Bjorn