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Date: Wed, 24 Apr 2024 13:42:28 +0300
Message-Id: <D0SAGP6DPKXF.2EHTXI9UH0HQ9@kernel.org>
Cc: =?utf-8?b?5YiY5Y+MKOi9qeWxuSk=?= <ls123674@antgroup.com>, "Chatre,
 Reinette" <reinette.chatre@intel.com>
Subject: Re: [RFC PATCH 1/1] x86/sgx: Explicitly give up the CPU in EDMM's
 ioctl() to avoid softlockup
From: "Jarkko Sakkinen" <jarkko@kernel.org>
To: "Jarkko Sakkinen" <jarkko@kernel.org>, "Bojun Zhu"
 <zhubojun.zbj@antgroup.com>, "Huang, Kai" <kai.huang@intel.com>,
 "linux-sgx@vger.kernel.org" <linux-sgx@vger.kernel.org>,
 "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
 "dave.hansen@linux.intel.com" <dave.hansen@linux.intel.com>
References: <20240423092550.59297-1-zhubojun.zbj@antgroup.com>
 <20240423092550.59297-2-zhubojun.zbj@antgroup.com>
 <02fe00c3b10e4476d500ad7a34024b7eae5e3c97.camel@intel.com>
 <85dfbebc-a2d5-4828-b3b9-f929cd6e30cf@antgroup.com>
 <D0S5S2NL1N5P.3Q0SM01VIZBJX@kernel.org>
In-Reply-To: <D0S5S2NL1N5P.3Q0SM01VIZBJX@kernel.org>

On Wed Apr 24, 2024 at 10:02 AM EEST, Jarkko Sakkinen wrote:
> On Wed Apr 24, 2024 at 9:46 AM EEST, Bojun Zhu wrote:
> > Based on the the discussion among you, Jarkko and Reinette,
> > I will keep the need_resched() and wrap the logic in using sgx_resched(=
),
> > as suggested by Jarkko.
>
> Sounds like a plan :-)

In sgx_ioc_enclave_add_pages() "if (!c)" check might cause possibly
some  confusion.

Reason for it is that in "transaction sense" the operation can
be only meaningfully restarted when no pages have not been added
as MRENCLAVE checksum cannot be reset.

BR, Jarkko