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Mon, 10 Aug 2026 15:58:20 -0700 (PDT) Date: Mon, 10 Aug 2026 15:58:20 -0700 In-Reply-To: <20260728121138.1103610-2-tarunsahu@google.com> Mime-Version: 1.0 References: <20260728121138.1103610-1-tarunsahu@google.com> <20260728121138.1103610-2-tarunsahu@google.com> Message-ID: Subject: Re: [PATCH v4 01/11] liveupdate: Add LIVEUPDATE_GUEST_MEMFD config option From: Sean Christopherson To: Tarun Sahu Cc: ackerleytng@google.com, fuad.tabba@linux.dev, Andrew Morton , dmatlack@google.com, Shuah Khan , Jonathan Corbet , david@redhat.com, Pasha Tatashin , Pratyush Yadav , sagis@google.com, Paolo Bonzini , Mike Rapoport , Alexander Graf , linux-kselftest@vger.kernel.org, andre.przywara@arm.com, michael.roth@amd.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, will@kernel.org, vannapurve@google.com, maz@kernel.org, fvdl@google.com, kvm@vger.kernel.org, oliver.upton@linux.dev, kvmarm@lists.linux.dev, alexandru.elisei@arm.com, skhawaja@google.com, aneesh.kumar@kernel.org, linux-doc@vger.kernel.org, David Hildenbrand , yan.y.zhao@intel.com, kexec@lists.infradead.org, suzuki.poulose@arm.com Content-Type: text/plain; charset="us-ascii" X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260810_155822_664648_58B56844 X-CRM114-Status: UNSURE ( 9.81 ) X-CRM114-Notice: Please train this message. X-BeenThere: kexec@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "kexec" Errors-To: kexec-bounces+kexec=archiver.kernel.org@lists.infradead.org On Tue, Jul 28, 2026, Tarun Sahu wrote: > Introduce the LIVEUPDATE_GUEST_MEMFD Kconfig option. This option > enables live update support for KVM guest_memfd files, enabling > guest_memfd-backed memory preservation across kernel upgrades. > > Currently this support only guest_memfd files that are full-shared > (INIT_SHARED and no support for private_mem). Why? Specifically, why do we need/want a separate Kconfig for guest_memfd liveupdate versus KVM liveupdate? I can _maybe_ see a KVM-wide Kconfig, but even that seems like a stretch given that (AFAIK) hypervisors are the one and only use-case for liveupdate.