From: Jarkko Sakkinen <jarkko@kernel.org>
To: Kai Huang <kai.huang@intel.com>
Cc: linux-sgx@vger.kernel.org, dave.hansen@linux.intel.com,
seanjc@google.com, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] x86/intel: Clear SGX bit if both SGX driver and KVM SGX are not enabled
Date: Mon, 12 Sep 2022 13:47:40 +0300 [thread overview]
Message-ID: <Yx8OTDwhqbgvGp4p@kernel.org> (raw)
In-Reply-To: <20220909080853.547058-1-kai.huang@intel.com>
On Fri, Sep 09, 2022 at 08:08:53PM +1200, Kai Huang wrote:
> Currently on platform which has SGX enabled, if CONFIG_X86_SGX is not
> enabled, the X86_FEATURE_SGX is not cleared, resulting in /proc/cpuinfo
> shows "sgx" feature. This is not desired.
>
> Clear SGX feature bit if both SGX driver and KVM SGX are not enabled in
> init_ia32_feat_ctl().
>
> Signed-off-by: Kai Huang <kai.huang@intel.com>
Is it a pattern that flags are cleared when they are disabled by the
kernel? I don't know the answer for this.
I could imagine that sometimes you might want to know whether the CPU
supports a feature, even if e.g. your distribution kernel does not.
There's of course other ways to answer such qeustion, e.g. by using
cpuid utility.
BR, Jarkko
next prev parent reply other threads:[~2022-09-12 10:47 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-09 8:08 [PATCH] x86/intel: Clear SGX bit if both SGX driver and KVM SGX are not enabled Kai Huang
2022-09-09 11:05 ` Huang, Kai
2022-09-09 12:11 ` Dave Hansen
2022-09-12 3:09 ` Huang, Kai
2022-09-12 10:47 ` Jarkko Sakkinen [this message]
2022-09-12 14:31 ` Reinette Chatre
2022-09-12 14:34 ` Dave Hansen
2022-09-12 20:54 ` Huang, Kai
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