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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (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 F0691CCF9E3 for ; Tue, 4 Nov 2025 10:54:31 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1vGEfy-0004Q6-QW; Tue, 04 Nov 2025 05:54:10 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1vGEfx-0004Pl-0g for qemu-devel@nongnu.org; Tue, 04 Nov 2025 05:54:09 -0500 Received: from mail-yw1-x1129.google.com ([2607:f8b0:4864:20::1129]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1vGEfv-00063I-GT for qemu-devel@nongnu.org; Tue, 04 Nov 2025 05:54:08 -0500 Received: by mail-yw1-x1129.google.com with SMTP id 00721157ae682-7866aca9e25so21949717b3.3 for ; Tue, 04 Nov 2025 02:54:06 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1762253646; x=1762858446; darn=nongnu.org; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=IzZ7SuZ7t7bfsmmCugQ23TNFJAFSK4U00LSWWPJjhjc=; b=nNsnIqWeMrnqcLaDayZH97oeI298excwzmU/UWBH65HAtsYgdO8w4ZNfyNI3a7vSje ltw4yQO4ZRp9Ru4xOx7Q/949jNHkg9zPxVXQC+GJRWkh5Xe3alhPhyeu8IT/DfrstBKz YHpxwZOTX381AqXp9hCeQtD3leyIV3vil97OIZGUk0udi1/nukI3ualjOFv0M4xARVyn K/FjcOWsjatY2esIOOd9PytmEUEb0/7OW8dFe4DpkFR8c+W1yXhNsuM+9f8DtrNUMvxi G7O9eSSduC5Qzw/8CKaWJp/NHIgWD8Pbib4CClzUpblNJo+gw/HY8DEAZ2L2liwtYWAJ uCiw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1762253646; x=1762858446; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=IzZ7SuZ7t7bfsmmCugQ23TNFJAFSK4U00LSWWPJjhjc=; b=L03+1+YB9CynI9SpDJ7S7/HQVFHCVV+ymATR5CDmlKWi+ohg+wJUVJd/TFMB28TNKk XHLTWFuNjJPRVnC8qWgyydEam3wx9KSks9gXWfkNRlHwaEygILKP482OiBtcjWjETaQr 5PD5daBlPLer+PArMwdYILeBQGFoG9mErvbpNMx5JwX2uo/dc+wOCUCku8+4YFOU7Nch kdnIeDw8okAh39QnQnYsLvrmOmAXf5DFRMHTHNtZHHx9EQahOTM0cBfGnyBNnPfVexs2 pYxpGOH43BEGcs20Ji8qFi/HafFp7T7kW8YQNFKGS4N+43m0NIeDraRQRdNYdMu5PkTA /RnA== X-Gm-Message-State: AOJu0YwrUGoFAP8NeS2P/JUdxZBIXNPRODheP5IXkd56vYoUJ9lAjTCW o+HqzUmM/TVQnE9p2J0AXn7tRmGBmTCAOKymuKRBC7LE03n+LDNq47blm/QECk3691LE5xjKSF2 fl5GmbX52nitJ+/KgVmS5IodZ3jFqQiQ/xZ9di3lhGw== X-Gm-Gg: ASbGncv6je+SDGGdKwkxGgL1beAm9Hy6wQGKeZ2kpZwQPmYbsm52cugVXKouKjxTzR6 Trx5p25OFSWVx23wZnXcxZavo9LGuYU+iUBevBtq7/BbBwGou523FnA/d7xBrtGEJMAIG0Mp1mm hrh6P3Bj7zIwwskMHbuo46J/OXekde/8S9P1uJGBpe2j/xiqCQ8YqiXfuTTI445371dUDdyzyli tBydLlZSZNG5oQ0ZVbO/v65aSOjW2kskFimKK+OoR+KrOlyMdgRgOEPqrawMw== X-Google-Smtp-Source: AGHT+IFoKbTjaPhyVKrWQFRm76sqAsS1X6Y4FZ6s6KnCnDZDLKa92ECOOOtD5Lhdy1D9qR38Q28HI6e40DDz8XMDG30= X-Received: by 2002:a53:d058:0:20b0:63f:ba88:e8f7 with SMTP id 956f58d0204a3-63fba88efb9mr3999881d50.27.1762253646006; Tue, 04 Nov 2025 02:54:06 -0800 (PST) MIME-Version: 1.0 References: <20250129160059.6987-1-farosas@suse.de> <20250129160059.6987-8-farosas@suse.de> In-Reply-To: <20250129160059.6987-8-farosas@suse.de> From: Peter Maydell Date: Tue, 4 Nov 2025 10:53:54 +0000 X-Gm-Features: AWmQ_bkRtRoiabEpvVBWJtsdoKbL2mfDZ9PT7_hnIJ4mbGovYab5w9CPuL2kLhU Message-ID: Subject: Re: [PULL 07/42] machine: aux-ram-share option To: Fabiano Rosas Cc: qemu-devel@nongnu.org, Peter Xu , Steve Sistare Content-Type: text/plain; charset="UTF-8" Received-SPF: pass client-ip=2607:f8b0:4864:20::1129; envelope-from=peter.maydell@linaro.org; helo=mail-yw1-x1129.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Wed, 29 Jan 2025 at 16:03, Fabiano Rosas wrote: > > From: Steve Sistare > > Allocate auxilliary guest RAM as an anonymous file that is shareable > with an external process. This option applies to memory allocated as > a side effect of creating various devices. It does not apply to > memory-backend-objects, whether explicitly specified on the command > line, or implicitly created by the -m command line option. > > This option is intended to support new migration modes, in which the > memory region can be transferred in place to a new QEMU process, by sending > the memfd file descriptor to the process. Memory contents are preserved, > and if the mode also transfers device descriptors, then pages that are > locked in memory for DMA remain locked. This behavior is a pre-requisite > for supporting vfio, vdpa, and iommufd devices with the new modes. Hi; I've just noticed that in this patch: > @@ -1162,6 +1178,12 @@ static void machine_class_init(ObjectClass *oc, void *data) > object_class_property_set_description(oc, "mem-merge", > "Enable/disable memory merge support"); > > +#ifdef CONFIG_POSIX > + object_class_property_add_bool(oc, "aux-ram-share", > + machine_get_aux_ram_share, > + machine_set_aux_ram_share); > +#endif we added a new class property to the machine, but we don't call object_class_property_set_description() to give it any help text (compare how we handle the other properties in this function). > + > object_class_property_add_bool(oc, "usb", > machine_get_usb, machine_set_usb); > object_class_property_set_description(oc, "usb", This means that if you run "qemu-system-x86_64 -M q35,help" you'll see that this option is missing help text: pc-q35-10.2-machine options: acpi= - Enable ACPI append= - Linux kernel command line aux-ram-share= boot= - Boot configuration bus-lock-ratelimit= - Set the ratelimit for the bus locks acquired in VMs confidential-guest-support=> - Set confidential guest scheme to support default-bus-bypass-iommu= [etc] Would somebody like to write a patch to add the missing description ? thanks -- PMM