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Date:   Mon, 10 May 2021 20:33:09 +0300
From:   Jarkko Sakkinen <jarkko@kernel.org>
To:     Dave Hansen <dave.hansen@intel.com>
Cc:     mtk.manpages@gmail.com, linux-man@vger.kernel.org,
        linux-sgx@vger.kernel.org, dave.hansen@linux.intel.com
Subject: Re: [PATCH v5] sgx.7: New page with overview of Software Guard
 eXtensions (SGX)
Message-ID: <YJluVfQ2TeO1N/KZ@kernel.org>
References: <20210510145235.8056-1-jarkko@kernel.org>
 <3072f586-4200-a0a1-8c85-fca0102e7913@intel.com>
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On Mon, May 10, 2021 at 07:58:27AM -0700, Dave Hansen wrote:
> On 5/10/21 7:52 AM, Jarkko Sakkinen wrote:
> > +This can lead to reserving a large region than required by the payload,
> > +but the address space can be obviously trimmed after the enclave has been
> > +constructed on,
> > +with a sequence of
> > +.BR mmap(MAP_FIXED)
> > +calls.
> 
> Sorry if I missed this previously.
> 
> But, do we really intend to suggest the use of mmap(MAP_FIXED) for this?
>  What's the harm in leaving a non-populated piece of address space of
> mmap()'d /dev/sgx_enclave?

Probably most of the time: not much. Especially since we support 64-bit
only.

Maybe it should be relaxed a bit?

/Jarkko