Re: [PATCH 1/6] x86/tdx: Support hypercalls for TDX guests on Hyper-V

From: Kirill A. Shutemov
Date: Mon Nov 21 2022 - 18:53:11 EST


On Mon, Nov 21, 2022 at 12:38:36PM -0800, Dave Hansen wrote:
> On 11/21/22 11:51, Dexuan Cui wrote:
> > __tdx_hypercall() doesn't work for a TDX guest running on Hyper-V,
> > because Hyper-V uses a different calling convention, so add the
> > new function __tdx_ms_hv_hypercall().
>
> Other than R10 being variable here and fixed for __tdx_hypercall(), this
> looks *EXACTLY* the same as __tdx_hypercall(), or at least a strict
> subset of what __tdx_hypercall() can do.
>
> Did I miss something?
>
> Another way of saying this: It seems like you could do this with a new
> version of _tdx_hypercall() (and all in C) instead of a new
> __tdx_hypercall().

+1. There should be a strong reason to add another asm helper.

--
Kiryl Shutsemau / Kirill A. Shutemov