Dear Tom,
Am 11.10.21 um 15:27 schrieb Tom Lendacky:
On 10/11/21 8:11 AM, Borislav Petkov wrote:
On Mon, Oct 11, 2021 at 03:05:33PM +0200, Paul Menzel wrote:
I think, the IOMMU is enabled on the MSI B350M MORTAR, but otherwise,
yes
this looks fine. The help text could also be updated to mention problems
with AMD Raven devices.
This is not only about Raven GPUs but, as Alex explained, pretty much
about every device which doesn't support a 48 bit DMA mask. I'll expand
that aspect in the changelog.
In general, non-GPU devices that don't support a 48-bit DMA mask work
fine (assuming they have set their DMA mask appropriately). It really
depends on whether SWIOTLB will be able to satisfy the memory
requirements of the driver when the IOMMU is not enabled or in
passthrough mode. Since GPU devices need/use a lot of memory, that
becomes a problem.
How can I check that?
Kind regards,
Paul
