Re: IOVA address range

[Bjorn Helgaas]

[+cc folks from ./scripts/get_maintainer.pl -f drivers/iommu]

On Fri, Oct 27, 2023 at 12:17:17PM -0700, Eric Pilmore wrote:
> Need a little IOVA/IOMMU help.
> 
> Is it correct that the IOVA address range for a device goes from
> address 0x0 up to the dma-mask of the respective device?
> 
> Is it correct to assume that the base of the IOVA address space for a
> device will always be zero (0x0)? Is there any reason to think that
> this has changed in some newer iteration of the kernel, perhaps 5.10,
> and that the base could be non-zero?
> 
> I realize an IOVA itself can be non-zero. I'm trying to verify what
> the base address is of the IOVA space as a whole on a per device
> basis.
> 
> Thanks,
> Eric Pilmore