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 0E7E9C369AB for ; Tue, 15 Apr 2025 09:29:07 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1u4cb5-0003dr-Q0; Tue, 15 Apr 2025 05:28:51 -0400 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 1u4caw-0003R8-Gb; Tue, 15 Apr 2025 05:28:42 -0400 Received: from frasgout.his.huawei.com ([185.176.79.56]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1u4cau-0002Y6-KK; Tue, 15 Apr 2025 05:28:42 -0400 Received: from mail.maildlp.com (unknown [172.18.186.216]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4ZcJdQ2h4cz6K9Tv; Tue, 15 Apr 2025 17:24:26 +0800 (CST) Received: from frapeml100008.china.huawei.com (unknown [7.182.85.131]) by mail.maildlp.com (Postfix) with ESMTPS id 564571406AD; Tue, 15 Apr 2025 17:28:37 +0800 (CST) Received: from frapeml500008.china.huawei.com (7.182.85.71) by frapeml100008.china.huawei.com (7.182.85.131) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.39; Tue, 15 Apr 2025 11:28:37 +0200 Received: from frapeml500008.china.huawei.com ([7.182.85.71]) by frapeml500008.china.huawei.com ([7.182.85.71]) with mapi id 15.01.2507.039; Tue, 15 Apr 2025 11:28:37 +0200 To: Jonathan Cameron , Linuxarm CC: "qemu-arm@nongnu.org" , "qemu-devel@nongnu.org" , "eric.auger@redhat.com" , "peter.maydell@linaro.org" , "jgg@nvidia.com" , "nicolinc@nvidia.com" , "ddutile@redhat.com" , "berrange@redhat.com" , "nathanc@nvidia.com" , "mochs@nvidia.com" , "smostafa@google.com" , "Wangzhou (B)" , jiangkunkun , "zhangfei.gao@linaro.org" Subject: RE: [PATCH 4/5] hw/arm/virt: Add support for smmuv3 device Thread-Topic: [PATCH 4/5] hw/arm/virt: Add support for smmuv3 device Thread-Index: AQHbrehdMuAYIN1si0WJyp5C1dh1B7OkdTzg Date: Tue, 15 Apr 2025 09:28:37 +0000 Message-ID: References: <20250415081104.71708-1-shameerali.kolothum.thodi@huawei.com> <20250415081104.71708-5-shameerali.kolothum.thodi@huawei.com> <20250415102542.00007fd7@huawei.com> In-Reply-To: <20250415102542.00007fd7@huawei.com> Accept-Language: en-GB, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.203.177.241] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Received-SPF: pass client-ip=185.176.79.56; envelope-from=shameerali.kolothum.thodi@huawei.com; helo=frasgout.his.huawei.com X-Spam_score_int: -41 X-Spam_score: -4.2 X-Spam_bar: ---- X-Spam_report: (-4.2 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_MED=-2.3, RCVD_IN_MSPIKE_H2=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=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: , Reply-to: Shameerali Kolothum Thodi From: Shameerali Kolothum Thodi via Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org > -----Original Message----- > From: Jonathan Cameron > Sent: Tuesday, April 15, 2025 10:26 AM > To: Shameerali Kolothum Thodi > ; Linuxarm > > Cc: qemu-arm@nongnu.org; qemu-devel@nongnu.org; > eric.auger@redhat.com; peter.maydell@linaro.org; jgg@nvidia.com; > nicolinc@nvidia.com; ddutile@redhat.com; berrange@redhat.com; > nathanc@nvidia.com; mochs@nvidia.com; smostafa@google.com; > Wangzhou (B) ; jiangkunkun > ; Jonathan Cameron > ; zhangfei.gao@linaro.org > Subject: Re: [PATCH 4/5] hw/arm/virt: Add support for smmuv3 device >=20 > On Tue, 15 Apr 2025 09:11:03 +0100 > Shameer Kolothum wrote: >=20 > > Allow cold-plug of smmuv3 device to virt If the machine wide smmuv3 > > or a virtio-iommu is not specified. > > > > Also restrict the usage if virt <=3D 9.2. This will prevent accidently > > creating a SMMUv3 device on machines prior to 9.2 and cause failure > > on migrating to machines with same version but has a legacy smmuv3 > > device. >=20 > Hi, >=20 > As we discussed internally I'm not convinced we need to prevent this > particular > way for a user to shoot themselves in the foot. >=20 > To be a problem they have to specifically request an old machine + the > device that didn't exist for that machine, then migrate to a real old > version of QEMU. Agreed it is possible but I'm not sure we need to > prevent that particular crazy. Agree. If there is no precedence or requirement for blocking such a use cas= e I will remove that check. Thanks, Shameer