From: Gregory Price <gourry@gourry.net>
To: "David Hildenbrand (Arm)" <david@kernel.org>
Cc: Ackerley Tng <ackerleytng@google.com>,
linux-mm@kvack.org, kvm@vger.kernel.org,
linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org,
kernel-team@meta.com, pbonzini@redhat.com, seanjc@google.com,
akpm@linux-foundation.org, ziy@nvidia.com,
matthew.brost@intel.com, joshua.hahnjy@gmail.com,
rakie.kim@sk.com, byungchul@sk.com,
ying.huang@linux.alibaba.com, apopple@nvidia.com,
shuah@kernel.org
Subject: Re: [PATCH 0/5] KVM: guest_memfd: bind backing memory to a NUMA node
Date: Thu, 10 Sep 2026 09:39:24 -0400 [thread overview]
Message-ID: <aqKxk2Marnz1HU4G@gourry-fedora-PF4VCD3F> (raw)
In-Reply-To: <0386eb30-0e0c-4d8c-abfe-86161b9e3d1f@kernel.org>
On Thu, Sep 10, 2026 at 01:32:08PM +0200, David Hildenbrand (Arm) wrote:
> >> 3. Why not request the guest_memfd to be mmap-able just to be able to
> >> set a memory policy?
> >
> > the eventual intent is to enable this for fully confidential,
> > host-unmapped guest, isolated to a particular memory device.
> >
> > Requiring a mapping to get node-placement is quite defeating the point.
>
> You only need a VMA, not actually mapped/faulted pages. So I don't immediately
> see the problem?
>
There is no VMA here - only an inode (GMEM_I), which is where the
shared policy hangs off of.
So yeah, if there was a vma, that's i suppose the missing component
needed to hook up userland mempolicy to all of this - but I would have
thought creating a VMA for guest_memfd is hacky and confusing (since its
intent is to basically not have a VMA).
Is there a series I missed that was proposing this?
~Gregory
next prev parent reply other threads:[~2026-09-10 13:39 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-02 19:46 [PATCH 0/5] KVM: guest_memfd: bind backing memory to a NUMA node Gregory Price
2026-09-02 19:46 ` [PATCH 1/5] mm/mempolicy: add mempolicy_create() Gregory Price
2026-09-02 19:46 ` [PATCH 2/5] mm/mempolicy: add mpol_set_shared_policy_range() Gregory Price
2026-09-02 19:46 ` [PATCH 3/5] KVM: guest_memfd: bind backing memory to a NUMA node at creation Gregory Price
2026-09-02 19:46 ` [PATCH 4/5] selftests: KVM: guest_memfd: let the gmem_test() harness bind a node Gregory Price
2026-09-02 19:46 ` [PATCH 5/5] selftests: KVM: guest_memfd: test GUEST_MEMFD_FLAG_BIND_NODE Gregory Price
2026-09-09 22:41 ` [PATCH 0/5] KVM: guest_memfd: bind backing memory to a NUMA node Ackerley Tng
2026-09-09 23:10 ` Gregory Price
2026-09-09 23:23 ` Ackerley Tng
2026-09-09 23:41 ` Gregory Price
2026-09-10 11:32 ` David Hildenbrand (Arm)
2026-09-10 13:39 ` Gregory Price [this message]
2026-09-10 14:00 ` David Hildenbrand (Arm)
2026-09-10 11:30 ` David Hildenbrand (Arm)
2026-09-10 13:40 ` Gregory Price
2026-09-10 14:05 ` David Hildenbrand (Arm)
2026-09-10 14:46 ` Gregory Price
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