Re: [PATCH v5 16/16] x86/tdx: Add cmdline option to force use of ioremap_host_shared

Michael S. Tsirkin
2021-10-12T21:00:09Z

On Tue, Oct 12, 2021 at 10:55:20AM -0700, Andi Kleen wrote:
>
> > I mean ... it's already wide spread.
>
>
> I meant wide spread usage with confidential guests.
>
> > If we support it with TDX
> > it will be used with TDX.
>
> It has some security trade offs. The main reason to use TDX is security.
> Also when people take the VT-d tradeoffs they might be ok with the BIOS
> trade offs too.
>
> -Andi

Interesting. VT-d tradeoffs ... what are they?
Allowing hypervisor to write into BIOS looks like it will
trivially lead to code execution, won't it?

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MST