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

From: Dave Hansen
Date: Mon Jun 27 2022 - 20:05:01 EST


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.