Re: [PATCH 2/2] iommu/amd: Force identity mode for selected GPUs only

On Wed, Aug 12, 2026 at 09:03:58PM +0000, Deucher, Alexander wrote:
> > Sure, but the end result is the GPU and SME are inherently incompatible, we
> > can't really fix it.
> >
> > What's wrong with blowing up at boot with a clear message that Linux must
> > have SME disabled on this HW printed to the UEFI console?
> 
> It's not very user friendly, plus it would break working systems.

Huh? You've explained that SME doesn't work with these GPUs? How are
there any working systems with SME turned on already running Linux?

>  I'm not sure the average user would know what to do.  

Turn off SME in the bios? Doesn't it default to off?

>  You aren't likely to want SME in the first place on one of these
>  laptops.  Why not flip the logic and print a clear message that if
>  the user wants SME they have to explicitly enable it via the kernel
>  command line.

That seems like it would be API breaking for server users that do want
SME

Jason