From nobody Thu Jul 3 08:09:57 2025 Delivered-To: importer2@patchew.org Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer2=patchew.org@nongnu.org; dmarc=pass(p=none dis=none) header.from=redhat.com ARC-Seal: i=1; a=rsa-sha256; t=1675354206; cv=none; d=zohomail.com; s=zohoarc; b=dD0GTkoqaDnu/T/y+w3ovrtkrOQk3/kmk0feRIY+GCH7StTv8SNs6cb/VDM6W0CfIxs2gdNFcyNqYDDH40jXQCJpYZEBj1nc3lxjDUP2QcMtkJhZAe98Oz8tLwUavkv6Z1nKgq+RsDhGpJycLK5cydHdIMEVVErkIc/Kz0aIwN0= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1675354206; h=Content-Transfer-Encoding:Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To; bh=DTtSRy6DBbNnmyL3bRVSvZHzrLJgaxvatHJOywuEQV8=; b=GrKEB1IBiceGbpNgHtUEUFDwYqEEDw4Z6kLG969cUt1jeLT5dTFNWBLRYyBNtQJrKYJ0/PnjRsW+3BSJqGCIXWZhMrAs9WXoWD6CBmVRzZgVI+nmW91GcN/CgBWOuIH1keu5/VNEF52h6r9EDqYdPTwcet7j2uEAhxgII+IpAMY= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer2=patchew.org@nongnu.org; dmarc=pass header.from= (p=none dis=none) Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1675354206084604.929349530573; Thu, 2 Feb 2023 08:10:06 -0800 (PST) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pNc8K-0000fA-Rs; Thu, 02 Feb 2023 11:08:20 -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 1pNc8G-0000Th-Fi for qemu-devel@nongnu.org; Thu, 02 Feb 2023 11:08:19 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pNc8E-0005FQ-AV for qemu-devel@nongnu.org; Thu, 02 Feb 2023 11:08:16 -0500 Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-460-deUzZaSUPwqs94_s2bJLGw-1; Thu, 02 Feb 2023 11:08:12 -0500 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 00DBB100F906; Thu, 2 Feb 2023 16:08:12 +0000 (UTC) Received: from secure.mitica (unknown [10.39.192.57]) by smtp.corp.redhat.com (Postfix) with ESMTP id F2EDF51E5; Thu, 2 Feb 2023 16:08:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1675354093; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=DTtSRy6DBbNnmyL3bRVSvZHzrLJgaxvatHJOywuEQV8=; b=SYaL7kt2FUKSB4gAqaeE4nNVvouXS9bD+iOOjWr9ZbxievRnLuaYBLKVZwjXQUecfu7I/8 wTEv8DocSDa531UAd6i7hPOg3EZ1x7LNoDhjjyourVWqlwGIIbGJ7Wj1Etcy8Cxy03Eua+ pOK0b14K1HpXXp5dJ5EYdKBIfV5HYF4= X-MC-Unique: deUzZaSUPwqs94_s2bJLGw-1 From: Juan Quintela To: qemu-devel@nongnu.org Cc: Richard Henderson , "Michael S. Tsirkin" , Laurent Vivier , Ilya Leoshkevich , Halil Pasic , =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= , Coiby Xu , Eric Farman , Alex Williamson , Christian Borntraeger , Stefan Hajnoczi , =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= , Stefan Berger , Eric Blake , Eduardo Habkost , "Dr. David Alan Gilbert" , Thomas Huth , David Hildenbrand , Marcel Apfelbaum , John Snow , Yanan Wang , =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= , Vladimir Sementsov-Ogievskiy , qemu-block@nongnu.org, Paolo Bonzini , Juan Quintela , Fam Zheng , qemu-s390x@nongnu.org, Michal Privoznik , Peter Xu Subject: [PULL 17/26] virtio-mem: Fail if a memory backend with "prealloc=on" is specified Date: Thu, 2 Feb 2023 17:06:31 +0100 Message-Id: <20230202160640.2300-18-quintela@redhat.com> In-Reply-To: <20230202160640.2300-1-quintela@redhat.com> References: <20230202160640.2300-1-quintela@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.1 on 10.11.54.5 Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer2=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=170.10.133.124; envelope-from=quintela@redhat.com; helo=us-smtp-delivery-124.mimecast.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, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, 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+importer2=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer2=patchew.org@nongnu.org X-ZohoMail-DKIM: pass (identity @redhat.com) X-ZM-MESSAGEID: 1675354208069100003 Content-Type: text/plain; charset="utf-8" From: David Hildenbrand "prealloc=3Don" for the memory backend does not work as expected, as virtio-mem will simply discard all preallocated memory immediately again. In the best case, it's an expensive NOP. In the worst case, it's an unexpected allocation error. Instead, "prealloc=3Don" should be specified for the virtio-mem device only, such that virtio-mem will try preallocating memory before plugging memory dynamically to the guest. Fail if such a memory backend is provided. Tested-by: Michal Privoznik Reviewed-by: Dr. David Alan Gilbert Reviewed-by: Peter Xu Reviewed-by: Michael S. Tsirkin Reviewed-by: Juan Quintela S Signed-off-by: David Hildenbrand Signed-off-by: Juan Quintela --- hw/virtio/virtio-mem.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/hw/virtio/virtio-mem.c b/hw/virtio/virtio-mem.c index 1ed1f5a4af..02f7b5469a 100644 --- a/hw/virtio/virtio-mem.c +++ b/hw/virtio/virtio-mem.c @@ -772,6 +772,12 @@ static void virtio_mem_device_realize(DeviceState *dev= , Error **errp) error_setg(errp, "'%s' property specifies an unsupported memdev", VIRTIO_MEM_MEMDEV_PROP); return; + } else if (vmem->memdev->prealloc) { + error_setg(errp, "'%s' property specifies a memdev with preallocat= ion" + " enabled: %s. Instead, specify 'prealloc=3Don' for the" + " virtio-mem device. ", VIRTIO_MEM_MEMDEV_PROP, + object_get_canonical_path_component(OBJECT(vmem->memdev= ))); + return; } =20 if ((nb_numa_nodes && vmem->node >=3D nb_numa_nodes) || --=20 2.39.1