Re: [PATCH v3] x86/pci-dma: add a SWIOTLB_ANY flag to lift the low mem limitation

[Borislav Petkov]

On Wed, Jun 24, 2026 at 01:53:39AM +0000, Miao, Jun wrote:
> Good suggestion and thank you for testing the ADM SEV-SNP.  

I don't think anyone tested it on SNP yet.

> Confidential Virtual Machines (CVMs) include Intel TDX and AMD SEV, SEV-ES, SEV-SNP 
> want to allocate a swiotlb buffer that is not restricted to low memory for

Why do they want that? The "why" is what I am missing in all this text.

> the trusted hypervisor scheme.

What is the "trusted hypervisor scheme"?

> Adding a new flag will be used in swiotlb_memblock_alloc() to allow
> allocation of SWIOTLB memory beyond low memory restriction.

That you don't need to explain - that's visible from the diff.

Thx.

-- 
Regards/Gruss,
    Boris.

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