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Date:   Thu, 3 Mar 2022 13:44:14 -0800
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To:     Reinette Chatre <reinette.chatre@intel.com>,
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From:   Dave Hansen <dave.hansen@intel.com>
Subject: Re: [PATCH V2 16/32] x86/sgx: Support restricting of enclave page
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On 3/3/22 13:23, Reinette Chatre wrote:
> Unfortunately MAP_POPULATE is not supported by SGX VMAs because of their
> VM_IO and VM_PFNMAP flags. When VMAs with such flags obtain this capability
> then I believe that SGX would benefit.

Some Intel folks asked for this quite a while ago.  I think it's
entirely doable: add a new vm_ops->populate() function that will allow
ignoring VM_IO|VM_PFNMAP if present.

Or, if nobody wants to waste all of the vm_ops space, just add an
arch_vma_populate() or something which can call over into SGX.

I'll happily review the patches if anyone can put such a beast together.