From: Breno Leitao <leitao@debian.org>
To: Borislav Petkov <bp@alien8.de>
Cc: Thomas Gleixner <tglx@linutronix.de>,
pawan.kumar.gupta@linux.intel.com, paul@paul-moore.com,
leit@meta.com, x86@kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] cpu/bugs: Disable CPU mitigations at compilation time
Date: Mon, 12 Jun 2023 06:46:16 -0700 [thread overview]
Message-ID: <ZIchqLWousxkCqyB@gmail.com> (raw)
In-Reply-To: <20230612133230.GJZIcebkHxd8QJs0Dv@fat_crate.local>
On Mon, Jun 12, 2023 at 03:32:30PM +0200, Borislav Petkov wrote:
> On Mon, Jun 12, 2023 at 05:54:56AM -0700, Breno Leitao wrote:
> > 1) We keep consistency with other CONFIG options. Linux already has a
> > CONFIG option to enable/disable mitigations for speculations
> > (CONFIG_SPECULATION_MITIGATIONS), so, this will be a similar one.
>
> So you can get what you want by disabling all those options there,
> right?
This patch proposes creating CONFIG_CPU_MITIGATIONS_DEFAULT_OFF that
will turn all the mitigations off in a binary, which is the same as
passing mitigations=off in the command line when the kernel boots.
Setting CONFIG_SPECULATION_MITIGATIONS=n does *not* disable all the
mitigations, as, there are some mitigations that are *not* disabled when
you pass CONFIG_SPECULATION_MITIGATIONS=n. As an example (from my
memory - need to double check in 6.4), MDS and TAA mitigations are not
disabled when CONFIG_SPECULATION_MITIGATIONS=n. MDS and TAA mitigations
are disabled when `mitigations=off` parameter is passed, tho.
next prev parent reply other threads:[~2023-06-12 13:46 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-03 12:06 [PATCH] cpu/bugs: Disable CPU mitigations at compilation time Breno Leitao
2023-06-09 17:33 ` Borislav Petkov
2023-06-12 11:22 ` David Laight
2023-06-12 11:51 ` Borislav Petkov
2023-06-12 12:16 ` David Laight
2023-06-12 13:27 ` Borislav Petkov
2023-06-10 22:37 ` Thomas Gleixner
2023-06-12 12:54 ` Breno Leitao
2023-06-12 13:32 ` Borislav Petkov
2023-06-12 13:46 ` Breno Leitao [this message]
2023-06-12 13:53 ` Borislav Petkov
2023-06-12 14:16 ` Breno Leitao
2023-06-12 16:08 ` Borislav Petkov
2023-06-12 16:37 ` Breno Leitao
2023-06-12 17:05 ` Borislav Petkov
2023-06-13 16:02 ` Breno Leitao
2023-06-13 16:20 ` Borislav Petkov
2023-06-12 17:26 ` Thomas Gleixner
2023-06-12 18:06 ` Randy Dunlap
2023-06-12 18:13 ` Borislav Petkov
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