lkml.org 
[lkml]   [2022]   [Jan]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 08/26] x86/tdx: Handle in-kernel MMIO
On Fri, Jan 07, 2022 at 08:49:26PM +0300, Kirill A. Shutemov wrote:
> To emulate an instruction the emulator needs two things:
>
> - R/W access to the register file to read/modify instruction arguments
> and see RIP of the faulted instruction.
>
> - Read access to memory where instruction is placed to see what to
> emualte. In this case it is guest kernel text.
>
> Both of them are not available to VMM in TDX environment:
>
> - Register file is never exposed to VMM. When a TD exits to the module,
> it saves registers into the state-save area allocated for that TD.
> The module then scrubs these registers before returning execution
> control to the VMM, to help prevent leakage of TD state.
>
> - Memory is encrypted TD-private key. The CPU disallows software other
> than the TDX module and TDs from making memory accesses using the
> private key.

Thanks, that's very helpful info. It would be nice to have it in the
commit message.

--
Regards/Gruss,
Boris.

https://people.kernel.org/tglx/notes-about-netiquette

\
 
 \ /
  Last update: 2022-01-07 20:07    [W:0.153 / U:0.048 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site