From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ed1-f73.google.com (mail-ed1-f73.google.com [209.85.208.73]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 49781346FDA for ; Mon, 22 Jun 2026 18:49:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.208.73 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782154145; cv=none; b=rg5bMThPtYdHSOzzdMquK71p8alDwegGI3sZfGlqEYCyFQXTAEVj6DfFMtUMm7nIG0NpRyGYtncOyy1nN2g8Bey95HAGj87n27/BPJHNVlXLglSSLmCmvkfNoJzM2KdmjtP0TpBV5ci7EUvzgs3LUvsvPlSZFG+QBTbZmT/DL0c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782154145; c=relaxed/simple; bh=/ll0ethd+Y+ejhMqnBHdeN5CKETZ/XI2FbZX/MXGx/Y=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=Qp4gFJLpO3OXYYfK9TkaNQLqgiObih1mEPpD/aRgtUCmWnyURST+Oj0VNSuJ0SXERfZCKnEQ86ED7HPYl7GRO+fmsv1eCKW8euaqRqy0AjEFZuipF/FK0Gs9r/HsCLIoX87CBeUh81lQ8i1Ggd+3lcEQYlOPYjW4I96u66R86TI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--tarunsahu.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=lWnEmNUW; arc=none smtp.client-ip=209.85.208.73 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--tarunsahu.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="lWnEmNUW" Received: by mail-ed1-f73.google.com with SMTP id 4fb4d7f45d1cf-69576b83dc2so4274930a12.1 for ; Mon, 22 Jun 2026 11:49:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1782154142; x=1782758942; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=3NnqtfMpo6SzkdI4Y/HSdjjWo3N5TymmoO6c1c+A8Gw=; b=lWnEmNUWgiAJuCJ2psJandvmHOGoljVXEmEv3OYvw0DxJprLApw1qjEYX09tdZRrhX oUJ24G+STJzQ9IKjsXcX/JbP35nXiyq/igPt8ZrYY5xjK4T083/Z+uU+vArbD1e4ZLPj kqjjLTD+pIZQb6fvbRiI5DGMRhxL3gdvAqu5KsHpFhdJhbttdal2xMNMccXTK+Nnj6Aa IhplV7KRdWlu3elvPgyiz8fBwedc83mISwlZ5/YoGlSHiXgSqv0BSQxym96tDcSjObay /gm3KfITuRGwTY7SKcyHQqN7FKS9SINMc1GvgOfUrGvdTnCACxEiaWQ15STUAeh7CJev mQfg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1782154142; x=1782758942; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=3NnqtfMpo6SzkdI4Y/HSdjjWo3N5TymmoO6c1c+A8Gw=; b=WNqWfN6GQIEcvoymHD6lkxIYPIBTE9jP/iyzrzxa3I0vfT/mJpjy5kQRKyFrFHaE7a 9AhIlXf8FYDufAzgoG3y4WjYFilXEmfUZAJg1o85RATJ2Wj/t8roxQ9I+ubUkhQvUXJ9 pPVZOoF775lZ9nyY9/v4QEU2HNrNN6a6q69EExqNgfjemITkBLJEbO8j26h8A0hr3pw+ aJHHpItykWbjCN/tEe0aKcycyFLp60gVbeOJTCzhh28t9upH7KYFCVad0n0k6qtxOfpR 0eASxTxgI6z3Wh7TqjLikQ2D2TUW0554lzun1fhZ1HYldYiTnQfKVpUmHqTYUjNweIzK PuRA== X-Forwarded-Encrypted: i=1; AFNElJ+MJy0EVnSKa1ZGsgoiHIcrOy3PzyfbxEDHlIculCVcu08Okbpv+S3i8kJKWJ1t7DfSJcXDQO7C1CQ=@vger.kernel.org X-Gm-Message-State: AOJu0Yw08iDc6stmhuwMVgNbARLBDOlwnmyOsXnFLpUXN6mNPJT1coeA I4fBlfHwXsBKmFdy0IsCZ3KRzHG+d6ZLh6CMNf1oj7XPxdogwtt1x+MBc4SIov1lelnt254dxLm kiII5nu5GNHenIwRT3w== X-Received: from edh3.prod.google.com ([2002:a05:6402:5043:b0:697:8dab:813a]) (user=tarunsahu job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6402:3548:b0:695:837d:529f with SMTP id 4fb4d7f45d1cf-696e5221662mr7941415a12.20.1782154141503; Mon, 22 Jun 2026 11:49:01 -0700 (PDT) Date: Mon, 22 Jun 2026 18:48:43 +0000 In-Reply-To: <20260622184851.2309827-1-tarunsahu@google.com> Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260622184851.2309827-1-tarunsahu@google.com> X-Mailer: git-send-email 2.55.0.rc0.786.g65d90a0328-goog Message-ID: <20260622184851.2309827-2-tarunsahu@google.com> Subject: [PATCH v3 1/9] liveupdate: Add LIVEUPDATE_GUEST_MEMFD config option From: Tarun Sahu To: Jonathan Corbet , Mike Rapoport , Paolo Bonzini , Alexander Graf , Shuah Khan , Pratyush Yadav , Tarun Sahu , Pasha Tatashin Cc: kvm@vger.kernel.org, linux-mm@kvack.org, kexec@lists.infradead.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" 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 and pre-faulted. Signed-off-by: Tarun Sahu --- kernel/liveupdate/Kconfig | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/kernel/liveupdate/Kconfig b/kernel/liveupdate/Kconfig index c13af38..2490f9a 100644 --- a/kernel/liveupdate/Kconfig +++ b/kernel/liveupdate/Kconfig @@ -86,4 +86,19 @@ config LIVEUPDATE_MEMFD If unsure, say N. +config LIVEUPDATE_GUEST_MEMFD + bool "Live update support for guest_memfd" + depends on LIVEUPDATE + depends on KVM_GUEST_MEMFD + default LIVEUPDATE + help + Enable live update support for KVM guest_memfd files. This allows + preserving VM Memory backed by guest_memfd file across kernel live + updates. + + This can only be used for the guest_memfd that are fully-shared + and pre-faulted. + + If unsure, say N. + endmenu -- 2.55.0.rc0.786.g65d90a0328-goog