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Date:   Mon, 14 Mar 2022 08:20:57 -0700
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To:     Oscar Salvador <osalvador@suse.de>,
        "Huang, Ying" <ying.huang@intel.com>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        Dave Hansen <dave.hansen@linux.intel.com>,
        Abhishek Goel <huntbag@linux.vnet.ibm.com>,
        Baolin Wang <baolin.wang@linux.alibaba.com>,
        linux-mm@kvack.org, linux-kernel@vger.kernel.org
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From:   Dave Hansen <dave.hansen@intel.com>
Subject: Re: [PATCH v2] mm: Only re-generate demotion targets when a numa node
 changes its N_CPU state
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On 3/14/22 08:13, Oscar Salvador wrote:
> On Mon, Mar 14, 2022 at 09:03:59AM +0800, Huang, Ying wrote:
>> Oscar Salvador <osalvador@suse.de> writes:
>> On host machine, PMEM is always exposed via memory hotplug.  But later
>> on, we found that for guest system it's possible for PMEM to be exposed
>> as normal memory.
> Could you please elaborate on that? How is it done? I would love to hear the
> details.

Qemu, for instance, has a "mem-path" argument.  It's typically used for
using hugetlbfs as guest memory.  But, there's nothing stopping you from
pointing it to a DAX device or a file on a DAX filesystem that's backed
by pmem.