From: Dave Hansen <dave.hansen@intel.com>
To: Reinette Chatre <reinette.chatre@intel.com>,
Jarkko Sakkinen <jarkko@kernel.org>,
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 07:34:33 -0700 [thread overview]
Message-ID: <28d7a4bf-591f-3afa-b9ea-526a14abc587@intel.com> (raw)
In-Reply-To: <ce358ac4-a473-158c-ccce-c50af813fb6d@intel.com>
On 9/12/22 07:31, Reinette Chatre wrote:
>
> On 9/12/2022 3:47 AM, Jarkko Sakkinen wrote:
>> 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.
There's no good pattern.
But, one guideline is that the X86_FEATURE_*'s are for the *kernel*.
They are *not* for userspace. The fact that the features are exposed to
userspace in cpuinfo is unfortunate, but it doesn't change our guideline.
So, if this patch is done only for the benefit of userspace, I don't
think we should apply it.
next prev parent reply other threads:[~2022-09-12 14:35 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
2022-09-12 14:31 ` Reinette Chatre
2022-09-12 14:34 ` Dave Hansen [this message]
2022-09-12 20:54 ` Huang, Kai
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=28d7a4bf-591f-3afa-b9ea-526a14abc587@intel.com \
--to=dave.hansen@intel.com \
--cc=dave.hansen@linux.intel.com \
--cc=jarkko@kernel.org \
--cc=kai.huang@intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-sgx@vger.kernel.org \
--cc=reinette.chatre@intel.com \
--cc=seanjc@google.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox