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From: Thomas Gleixner <tglx@linutronix.de>
To: Josh Poimboeuf <jpoimboe@redhat.com>, "Singh\,
	Balbir" <sblbir@amazon.com>
Cc: "linux-kernel\@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"tony.luck\@intel.com" <tony.luck@intel.com>,
	"keescook\@chromium.org" <keescook@chromium.org>,
	"benh\@kernel.crashing.org" <benh@kernel.crashing.org>,
	"x86\@kernel.org" <x86@kernel.org>,
	"dave.hansen\@intel.com" <dave.hansen@intel.com>
Subject: Re: [PATCH 0/3] arch/x86: Optionally flush L1D on context switch
Date: Thu, 02 Apr 2020 23:45:01 +0200	[thread overview]
Message-ID: <875zehmujm.fsf@nanos.tec.linutronix.de> (raw)
In-Reply-To: <20200402204749.33ulub5jx66dktxg@treble>

Josh Poimboeuf <jpoimboe@redhat.com> writes:
> On Thu, Apr 02, 2020 at 08:35:46PM +0000, Singh, Balbir wrote:
>> Yes, that CVE the motivation, the mitigation for CVE-2020-0550 does suggest
>> flushing the cache on context switch. But in general, as we begin to find more
>> ways of evicting data or snopping data, a generic mechanism is more useful and
>> that is why I am making it an opt-in.
>
> Ok.  I think it would be a good idea to expand on that justification
> more precisely in the commit message.  That would help both reviewers of
> the code and users of the new option understand what level of paranoia
> they're opting in to :-)

The commit message is mostly useful for reviewers and people who have to
do code archeaology. 

Documentation/admin-guide/hw-vuln/ has plenty of space to host a
document with explanations. paranoia.rst comes to my mind. :)

Thanks,

        tglx
 

  reply	other threads:[~2020-04-02 21:45 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-04-02  6:23 [PATCH 0/3] arch/x86: Optionally flush L1D on context switch Balbir Singh
2020-04-02  6:23 ` [PATCH 1/3] arch/x86/kvm: Refactor l1d flush lifecycle management Balbir Singh
2020-04-02  6:24 ` [PATCH 2/3] arch/x86: Refactor tlbflush and l1d flush Balbir Singh
2020-04-02  6:24 ` [PATCH 3/3] arch/x86: Optionally flush L1D on context switch Balbir Singh
2020-04-02 22:11   ` Borislav Petkov
2020-04-02 22:18     ` Singh, Balbir
2020-04-02 20:13 ` [PATCH 0/3] " Josh Poimboeuf
2020-04-02 20:35   ` Singh, Balbir
2020-04-02 20:47     ` Josh Poimboeuf
2020-04-02 21:45       ` Thomas Gleixner [this message]
2020-04-02 22:23         ` Singh, Balbir

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