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 X-Spam-Level: X-Spam-Status: No, score=-5.3 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C340FC4167B for ; Wed, 9 Dec 2020 20:07:52 +0000 (UTC) Received: from silver.osuosl.org (smtp3.osuosl.org [140.211.166.136]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 555D523A02 for ; Wed, 9 Dec 2020 20:07:52 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 555D523A02 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by silver.osuosl.org (Postfix) with ESMTP id 06D6B204DC; Wed, 9 Dec 2020 20:07:52 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from silver.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id x1beGWad7fIj; Wed, 9 Dec 2020 20:07:50 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by silver.osuosl.org (Postfix) with ESMTP id AA84320392; Wed, 9 Dec 2020 20:07:50 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 93955C0893; Wed, 9 Dec 2020 20:07:50 +0000 (UTC) Received: from fraxinus.osuosl.org (smtp4.osuosl.org [140.211.166.137]) by lists.linuxfoundation.org (Postfix) with ESMTP id 0D9C0C013B for ; Wed, 9 Dec 2020 20:07:49 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by fraxinus.osuosl.org (Postfix) with ESMTP id EC550876E4 for ; Wed, 9 Dec 2020 20:07:48 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from fraxinus.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id pkVcaxMO_zs5 for ; Wed, 9 Dec 2020 20:07:48 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by fraxinus.osuosl.org (Postfix) with ESMTPS id 8D62B876E2 for ; Wed, 9 Dec 2020 20:07:48 +0000 (UTC) Date: Wed, 9 Dec 2020 20:07:42 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1607544468; bh=RwtPuIYol40kyDSA4Jk5Z51qfhMMaedTf5Q+9030Dtg=; h=From:To:Cc:Subject:References:In-Reply-To:From; b=WjTRYZErNqmS7HSgHfZJvcGSudj6QQ/BoaTG0mpwRSde3DtGgpDV/4KNjtqyEp4N+ 2SFusGgwv6iZgTJCRLikjacas6bF+LBJeIO0GTHgZ4EvroAXOfs4Of64brnCCAiEL/ NS4gCLeuTP+i1+ZCKXLR4nYVtPRM5cuymwlc4I/UEatT/px6/DX1ax9KzE7bxb22m0 D2BA2bOs49gRHUGRFhScPxtDW0b+fk74I1a1oBmW5xKntFJsqo1uuXPCsQPbHQGka9 x7PsjSp1nxXDMK0hxlRclxlkbHpcjvFPaN5DcSyltP56QCuHoa53NMckH935C/JDn1 FhQiUpC9ttZAw== From: Will Deacon To: Krishna Reddy Subject: Re: [PATCH v10 10/13] iommu/arm-smmu-v3: Check for SVA features Message-ID: <20201209200741.GA8992@willie-the-truck> References: <20200918101852.582559-1-jean-philippe@linaro.org> <20200918101852.582559-11-jean-philippe@linaro.org> <753bcd76c21c4ea98ef1d4e492db01f4@huawei.com> <20200924101340.GC170808@myrica> <47b244b99f284790b82b2c0a968ba830@huawei.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Cc: Jean-Philippe Brucker , Yu-Huan Hsu , Suzuki K Poulose , "catalin.marinas@arm.com" , Alistair Popple , Sachin Nikam , "fenghua.yu@intel.com" , Pritesh Raithatha , Vikram Sethi , "linux-mm@kvack.org" , "iommu@lists.linux-foundation.org" , Jason Gunthorpe , "zhangfei.gao@linaro.org" , "robin.murphy@arm.com" , "linux-arm-kernel@lists.infradead.org" X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" On Wed, Dec 09, 2020 at 07:49:09PM +0000, Krishna Reddy wrote: > > > Why is BTM mandated for SVA? I couldn't find this requirement in > > > SMMU spec (Sorry if I missed it or this got discussed earlier). But > > > if performance is the > > only concern here, > > > is it better just to allow it with a warning rather than limiting > > > SMMUs without > > BTM? > > > > It's a performance concern and requires to support multiple > > configurations, but the spec allows it. Are there SMMUs without BTM > > that need it? > > The Tegra Next Generation SOC uses arm-smmu-v3, but it doesn't have support for BTM. > Do you have plan to get your earlier patch to handle invalidate > notifications into upstream sometime soon? Is that a limitation of the SMMU implementation, the interconnect or the integration? Will _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu