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[173.79.60.52]) by smtp.gmail.com with ESMTPSA id af79cd13be357-939e190f8c3sm78468885a.17.2026.09.10.06.40.29 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 10 Sep 2026 06:40:30 -0700 (PDT) Date: Thu, 10 Sep 2026 09:40:28 -0400 From: Gregory Price To: "David Hildenbrand (Arm)" Cc: 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 Message-ID: References: <20260902194657.79075-1-gourry@gourry.net> <9b67424d-70e5-442b-9ec7-22b1d3db12f4@kernel.org> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <9b67424d-70e5-442b-9ec7-22b1d3db12f4@kernel.org> On Thu, Sep 10, 2026 at 01:30:04PM +0200, David Hildenbrand (Arm) wrote: > On 9/2/26 21:46, Gregory Price wrote: > > guest_memfd allocates its folios through a per-inode shared mempolicy. > > > > Today that policy can only be set after the fact, with mbind() on a host > > mmap of the fd. That requires the fd to be mappable, and it cannot reach > > folios that are only ever guest-faulted. Neither holds for a > > non-mappable (confidential) guest_memfd. > > That looks like an investment into a mechanism we will soon consider legacy, so > I am not convinced this is the right approach? > Hm, I think i've missed recent work in this space / this context. Any suggested reading here? Don't want to eat too much of your time. ~Gregory