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To:     "Jarkko Sakkinen" <jarkko@kernel.org>
Cc:     "Reinette Chatre" <reinette.chatre@intel.com>,
        "Dhanraj, Vijay" <vijay.dhanraj@intel.com>,
        "dave.hansen@linux.intel.com" <dave.hansen@linux.intel.com>,
        "tglx@linutronix.de" <tglx@linutronix.de>,
        "bp@alien8.de" <bp@alien8.de>,
        "Lutomirski, Andy" <luto@kernel.org>,
        "mingo@redhat.com" <mingo@redhat.com>,
        "linux-sgx@vger.kernel.org" <linux-sgx@vger.kernel.org>,
        "x86@kernel.org" <x86@kernel.org>,
        "Christopherson,, Sean" <seanjc@google.com>,
        "Huang, Kai" <kai.huang@intel.com>,
        "Zhang, Cathy" <cathy.zhang@intel.com>,
        "Xing, Cedric" <cedric.xing@intel.com>,
        "Huang, Haitao" <haitao.huang@intel.com>,
        "Shanahan, Mark" <mark.shanahan@intel.com>,
        "hpa@zytor.com" <hpa@zytor.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        nathaniel@profian.com
Subject: Re: [PATCH V2 16/32] x86/sgx: Support restricting of enclave page
 permissions
References: <DM8PR11MB55917F499CDF4CC7D426B0A7F63C9@DM8PR11MB5591.namprd11.prod.outlook.com> <YimWaAqEnXHbLdjh@iki.fi> <op.1itu5vkewjvjmi@hhuan26-mobl1.mshome.net> <Yis8LV99mORcLYs6@iki.fi> <Yis9rA8uC/0bmWCF@iki.fi> <97565fed-dc67-bab1-28d4-c40201c9f055@intel.com> <Yi6tPLLt9Q+ailQ3@iki.fi> <Yi6tinbF+Y7a66eQ@iki.fi> <Yi6va4dCaljiQ1WQ@iki.fi> <op.1i01q9s0wjvjmi@hhuan26-mobl1.mshome.net> <YjK7BppjPCio0xv7@iki.fi>
Date:   Thu, 17 Mar 2022 09:47:36 -0500
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From:   "Haitao Huang" <haitao.huang@linux.intel.com>
Organization: Intel Corp
Message-ID: <op.1i6jdmnqwjvjmi@hhuan26-mobl1.mshome.net>
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On Wed, 16 Mar 2022 23:37:26 -0500, Jarkko Sakkinen <jarkko@kernel.org>  
wrote:

> On Mon, Mar 14, 2022 at 10:39:36AM -0500, Haitao Huang wrote:
>> I also see this model as consistent to what kernel does for regular  
>> memory
>> mappings: adding physical pages on #PF or pre-fault and changing PTE
>> permissions only after mprotect is called.
>
> And you were against this in EAUG's case. As in the EAUG's case
> EMODPR could be done as part of the mprotect() flow.
>

I preferred not automatic/unconditional EAUG during mmap.
Here I think automatic/unconditional EMODPR(PROT_READ) on #PF would not  
work for all cases. See my reply to your other email.

Thanks
Haitao