Messages in this thread | | | Subject | Re: `AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT=y` causes AMDGPU to fail on Ryzen: amdgpu: SME is not compatible with RAVEN | From | Paul Menzel <> | Date | Mon, 11 Oct 2021 16:21:55 +0200 |
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Dear Tom,
Am 11.10.21 um 15:58 schrieb Tom Lendacky: > On 10/11/21 8:52 AM, Paul Menzel wrote:
>> 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? > > How can you check what? 32-bit DMA devices? GPUs? I need a bit more > information...
How can I check, why MEM_ENCRYPT is not working on my device despite the IOMMU being enabled.
Kind regards,
Paul
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