Re: [PATCH v5 08/22] x86/virt/tdx: Shut down TDX module in case of error

From: Kai Huang
Date: Mon Jun 27 2022 - 20:11:49 EST


On Mon, 2022-06-27 at 17:03 -0700, Dave Hansen wrote:
> On 6/27/22 16:59, Kai Huang wrote:
> > If so, in the assembly, I think we can just XOR TDX_SW_ERROR to the %rax and
> > return %rax:
> >
> > 2:
> > /*
> > * SEAMCALL caused #GP or #UD. By reaching here %eax contains
> > * the trap number. Convert trap number to TDX error code by setting
> > * TDX_SW_ERROR to the high 32-bits of %rax.
> > */
> > xorq $TDX_SW_ERROR, %rax
> >
> > How does this look?
>
> I guess it doesn't matter if you know the things being masked together
> are padded correctly, but I probably would have done a straight OR, not XOR.
>
> Otherwise, I think that looks OK. Simplifies the assembly for sure.

Right straight OR is better. Thanks.

--
Thanks,
-Kai