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AHgh+Roju6GNA8npUhYIlxYnxTmD+qX4IPjDr3ZJZiFLp4QDTaVql8yV34CLCLKtpTJAnh2DJnEij7o=@lists.linux.dev X-Gm-Message-State: AOJu0YzyZY4fGYFQhEPn2hOwWoOKlK1q0xpe/Ypt8PM22wIlwSnnusSn Cls2Y6z3LhWdhwR3/c+azJv52kQxrhPMfNpFTlwx2qh5qY7dGtHg4zk+24rp+TxfAwf/7US2Zsi GY/W+KQ== X-Received: from plkb4.prod.google.com ([2002:a17:903:fa4:b0:2c0:a516:2c2]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a17:902:fdad:b0:2bf:9760:b94d with SMTP id d9443c01a7336-2d0ca7fd072mr611571635ad.15.1786404192685; Mon, 10 Aug 2026 16:23:12 -0700 (PDT) Date: Mon, 10 Aug 2026 16:23:12 -0700 In-Reply-To: <20260728121138.1103610-5-tarunsahu@google.com> Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260728121138.1103610-1-tarunsahu@google.com> <20260728121138.1103610-5-tarunsahu@google.com> Message-ID: Subject: Re: [PATCH v4 04/11] KVM: Track weak reference to vm_file in struct kvm 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" On Tue, Jul 28, 2026, Tarun Sahu wrote: > - Add a weak reference 'vm_file' in struct kvm under "vm_file" is effectively already claimed by vm_area_struct.vm_file. *If* we go this route, I would very strongly prefer to take a dependency on "vfio: Use file-based reference counting for KVM"[*]. I'll poke that thread, we really should land that one particular patch long before the s390-is-arm64 insanity. Empashish on "if" because this all feels backwards. It's not at all clear to me why liveupdate goes directly to guest_memfd, but then requires a token associated with the VM. https://lore.kernel.org/all/20260731130902.654679-2-seiden@linux.ibm.com