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Date:   Fri, 21 Oct 2022 16:18:14 +0000
From:   Sean Christopherson <seanjc@google.com>
To:     Chao Peng <chao.p.peng@linux.intel.com>
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Subject: Re: [PATCH v8 1/8] mm/memfd: Introduce userspace inaccessible memfd
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References: <20220915142913.2213336-1-chao.p.peng@linux.intel.com>
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On Fri, Oct 21, 2022, Chao Peng wrote:
> > 
> > In the context of userspace inaccessible memfd, what would be a
> > suggested way to enforce NUMA memory policy for physical memory
> > allocation? mbind[1] won't work here in absence of virtual address
> > range.
> 
> How about set_mempolicy():
> https://www.man7.org/linux/man-pages/man2/set_mempolicy.2.html

Andy Lutomirski brought this up in an off-list discussion way back when the whole
private-fd thing was first being proposed.

  : The current Linux NUMA APIs (mbind, move_pages) work on virtual addresses.  If
  : we want to support them for TDX private memory, we either need TDX private
  : memory to have an HVA or we need file-based equivalents. Arguably we should add
  : fmove_pages and fbind syscalls anyway, since the current API is quite awkward
  : even for tools like numactl.