On Tue, 18 Aug 2020 19:11:26 -0300, Thiago Jung Bauermann wrote:
> POWER secure guests (i.e., guests which use the Protection Execution
> Facility) need to use SWIOTLB to be able to do I/O with the hypervisor, but
> they don't need the SWIOTLB memory to be in low addresses since the
> hypervisor doesn't have any addressing limitation.
>
> This solves a SWIOTLB initialization problem we are seeing in secure guests
> with 128 GB of RAM: they are configured with 4 GB of crashkernel reserved
> memory, which leaves no space for SWIOTLB in low addresses.
>
> [...]
Applied to powerpc/next.
[1/1] powerpc/pseries/svm: Allocate SWIOTLB buffer anywhere in memory
https://git.kernel.org/powerpc/c/eae9eec476d13fad9af6da1f44a054ee02b7b161
cheers
