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References: <20210721190250.26095-1-fmdefrancesco@gmail.com>
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From:   Joel Fernandes <joel@joelfernandes.org>
Date:   Fri, 23 Jul 2021 00:38:30 -0400
Message-ID: <CAEXW_YR4bgaLHMDd_e83bQANqfvk=4a_7H3NJUHzG4K7sRetiw@mail.gmail.com>
Subject: Re: [PATCH] admin-guide/hw-vuln: Rephrase a section of core-scheduling.rst
To:     "Fabio M. De Francesco" <fmdefrancesco@gmail.com>
Cc:     Jonathan Corbet <corbet@lwn.net>,
        Vineeth Pillai <Vineeth.Pillai@microsoft.com>,
        "Peter Zijlstra (Intel)" <peterz@infradead.org>,
        "open list:DOCUMENTATION" <linux-doc@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>
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On Wed, Jul 21, 2021 at 3:02 PM Fabio M. De Francesco
<fmdefrancesco@gmail.com> wrote:
>
> Rephrase the "For MDS" section in core-scheduling.rst for the purpose of
> making it clearer what is meant by "kernel memory is still considered
> untrusted".
>
> Suggested-by: Vineeth Pillai <Vineeth.Pillai@microsoft.com>
> Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>

Reviewed-by: Joel Fernandes (Google) <joelaf@google.com>

thanks,

 - Joel


> ---
>  Documentation/admin-guide/hw-vuln/core-scheduling.rst | 9 +++++----
>  1 file changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/Documentation/admin-guide/hw-vuln/core-scheduling.rst b/Documentation/admin-guide/hw-vuln/core-scheduling.rst
> index 7b410aef9c5c..e6b5ceb219ec 100644
> --- a/Documentation/admin-guide/hw-vuln/core-scheduling.rst
> +++ b/Documentation/admin-guide/hw-vuln/core-scheduling.rst
> @@ -181,10 +181,11 @@ Open cross-HT issues that core scheduling does not solve
>  --------------------------------------------------------
>  1. For MDS
>  ~~~~~~~~~~
> -Core scheduling cannot protect against MDS attacks between an HT running in
> -user mode and another running in kernel mode. Even though both HTs run tasks
> -which trust each other, kernel memory is still considered untrusted. Such
> -attacks are possible for any combination of sibling CPU modes (host or guest mode).
> +Core scheduling cannot protect against MDS attacks between the siblings running in
> +user mode and the others running in kernel mode. Even though all siblings run tasks
> +which trust each other, when the kernel is executing code on behalf of a task, it
> +cannot trust the code running in the sibling. Such attacks are possible for any
> +combination of sibling CPU modes (host or guest mode).
>
>  2. For L1TF
>  ~~~~~~~~~~~
> --
> 2.32.0
>