2021-06-08 16:32:47

by Dan Williams

[permalink] [raw]
Subject: Re: [RFC v2-fix-v2 3/3] x86/tdx: Handle port I/O

On Tue, Jun 8, 2021 at 8:40 AM Kuppuswamy Sathyanarayanan
<[email protected]> wrote:
>
> From: "Kirill A. Shutemov" <[email protected]>
>
> TDX hypervisors cannot emulate instructions directly. This
> includes port IO which is normally emulated in the hypervisor.
> All port IO instructions inside TDX trigger the #VE exception
> in the guest and would be normally emulated there.
>
> Also string I/O is not supported in TDX guest. So, unroll the
> string I/O operation into a loop operating on one element at
> a time. This method is similar to AMD SEV, so just extend the
> support for TDX guest platform.
>
> Co-developed-by: Kuppuswamy Sathyanarayanan <[email protected]>
> Signed-off-by: Kuppuswamy Sathyanarayanan <[email protected]>
> Signed-off-by: Kirill A. Shutemov <[email protected]>
> Reviewed-by: Andi Kleen <[email protected]>
> ---
> Changes since RFC v2-fix-v1:
> * Fixed commit log to adapt to decompression support code split.

Looks good to me:

Reviewed-by: Dan Williams <[email protected]>