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 Wed, Jan 05, 2022 at 06:43:11PM +0300, Kirill A. Shutemov wrote:
    > Not encrypted, saved/restored by TDX module. But yes, cannot be exposed
    > (without guest intend).
    >
    > I talk here about *why* the traditional way to handle MMIO -- on VMM side
    > -- doesn't work for TDX. It's not safe with untrusted VMM.

    Lemme see if I understand this correctly: TDX module saves/restores
    guest registers so a malicious hypervisor cannot access them? And that's
    why you can't do the traditional way MMIO is done?

    > readX()/writeX() helpers limit the range of instructions which can trigger
    > MMIO. It makes MMIO instruction emulation feasible. Raw access to MMIO
    > region allows compiler to generate whatever instruction it wants.
    > Supporting all possible instructions is a task of a different scope.

    Yap, please add that to the commit message.

    Thx.

    --
    Regards/Gruss,
    Boris.

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

    \
     
     \ /
      Last update: 2022-01-07 14:47    [W:5.041 / U:1.260 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site