From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id D155ACD98F2 for ; Mon, 22 Jun 2026 18:49:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type:Cc:To:From: Subject:Message-ID:References:Mime-Version:In-Reply-To:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=3NnqtfMpo6SzkdI4Y/HSdjjWo3N5TymmoO6c1c+A8Gw=; b=Khr6Vaon4wb+BBI6y1g/k+siuZ uvASB1Key8BHZ8rvnntZrrTt+mMDlaO5rmBs1F4YfPFZi2CvoP8dVCUDt0fk4WYdBzGwxEYIkm2OM fI4eyJ/Kf9dIp8oavJ/+cpeOl9JKL8SYooHTazjm9zTLuYycTPdk/XzjBpcqBqmdhU/vCDZqqY6EB ErgRm4iGPdabePacPlcpK4zbG+NIPXpt9CaNANIajMMz8ccaF6xYrWPM2/2xBorGJWv8veDy+aMPY Sp0KD6wsROTZYQmw8YxfdrR17L8WoZUkNPAdHhLXYk5rw5dVKEN0tzyy5iU972sT+5BOFZaMjNAA/ gg74+BIQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wbjhi-00000005JH2-2eLS; Mon, 22 Jun 2026 18:49:06 +0000 Received: from mail-ej1-x64a.google.com ([2a00:1450:4864:20::64a]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wbjhg-00000005JFh-2aS2 for kexec@lists.infradead.org; Mon, 22 Jun 2026 18:49:05 +0000 Received: by mail-ej1-x64a.google.com with SMTP id a640c23a62f3a-bf481a6e4e6so524557166b.3 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=lists.infradead.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=fevgS2C6lctM3jBXiFbnvhBKN//FozzL/zemOAmZKXY2UAcbzV0R+SurCcbnCmEpLD iwsx4Y0AK4MOvivkEnxQTGxV7jLfLy9zxT4QgQ22EpKXGkoiS1713mvLjYuVA3StBV3c tt6zxhh9gAbfNFNRGtBHURIPq0MMXHR61RXcG743AyIbrrvtuUc+S46yttASWLlgAtuZ TaYH/5yA375SElrtEYXpg1YiFK9zQ/gaPPYYyQeA+WskGeZAbvCNSsuA0RYvGu/jWRnv ulsc7xboKA7sIcGmqa+7MS2CzB/Ku+IJekfwaHgMntR3DV8nbNdTfXjaVPAklxOMeRxm TqoQ== 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=el9Dw800359MNU0PDRcZObvbuDiKsisakv1HXCKZd7C/jyrNMLZflNgMGBfD4+1Z2r izncpAbPQjlfhz07FFvMEoUCNC/NNN9lj1Cc5Cui/l81tWfkaYcCjX3iEn6MmQxqgHMr RatfGMKdQx/bUJ/dI3IRbqja0EvosKVn59a8AGrGysKVHn8a0nKIQDAompuElIuZyTb/ hCoLFUJcpvgXlEIWxMQdoHNuA0rZqcmWpN2yYl9kwljLGjbkwG3fcutbEE6DGLZBtiUY NazKDz1Ghk3x+yYtwCLyoNk0YZ37UiYCe/r+ym18vdiliKNLV66/4R87ZZaqx79dzbSv C5bA== X-Forwarded-Encrypted: i=1; AFNElJ9sd52j33cS2l8Bb+zMIqVPl9Roztb/Wm7/oCsinlnWq+Ov2Z88r+FuqixCs03wTGpdHEJ8Uw==@lists.infradead.org X-Gm-Message-State: AOJu0Yyd6bq9USgsRRKDjTH0v3XvrICEj0UH+0KXPIcVK8JWmCby3BlX FPKNN1WpllQozGbtMwYlhizTQ/4rkD0mrebNXUCSzvRT9qJvGExFEyqvcKwdib+4qtf3tDUmguR jQhelgy2LP4Lb6rMeGw== 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> 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" X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260622_114904_658827_0FE9E1B3 X-CRM114-Status: UNSURE ( 9.13 ) 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 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