Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Date:   Tue, 6 Jul 2021 12:59:57 -0400
From:   Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
To:     Will Deacon <will@kernel.org>
Cc:     Christoph Hellwig <hch@lst.de>,
        Robin Murphy <robin.murphy@arm.com>,
        heikki.krogerus@linux.intel.com, thomas.hellstrom@linux.intel.com,
        peterz@infradead.org, benh@kernel.crashing.org,
        joonas.lahtinen@linux.intel.com, dri-devel@lists.freedesktop.org,
        chris@chris-wilson.co.uk, grant.likely@arm.com, paulus@samba.org,
        Frank Rowand <frowand.list@gmail.com>, mingo@kernel.org,
        Stefano Stabellini <sstabellini@kernel.org>,
        Saravana Kannan <saravanak@google.com>, mpe@ellerman.id.au,
        "Rafael J . Wysocki" <rafael.j.wysocki@intel.com>,
        Bartosz Golaszewski <bgolaszewski@baylibre.com>,
        bskeggs@redhat.com, linux-pci@vger.kernel.org,
        xen-devel@lists.xenproject.org,
        Thierry Reding <treding@nvidia.com>,
        intel-gfx@lists.freedesktop.org, matthew.auld@intel.com,
        linux-devicetree <devicetree@vger.kernel.org>,
        Jianxiong Gao <jxgao@google.com>,
        Daniel Vetter <daniel@ffwll.ch>,
        maarten.lankhorst@linux.intel.com, airlied@linux.ie,
        Dan Williams <dan.j.williams@intel.com>,
        linuxppc-dev@lists.ozlabs.org, jani.nikula@linux.intel.com,
        Nathan Chancellor <nathan@kernel.org>,
        Rob Herring <robh+dt@kernel.org>, rodrigo.vivi@intel.com,
        Bjorn Helgaas <bhelgaas@google.com>,
        Claire Chang <tientzu@chromium.org>,
        boris.ostrovsky@oracle.com,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        jgross@suse.com, Nicolas Boichat <drinkcat@chromium.org>,
        Greg KH <gregkh@linuxfoundation.org>,
        Randy Dunlap <rdunlap@infradead.org>,
        Qian Cai <quic_qiancai@quicinc.com>,
        lkml <linux-kernel@vger.kernel.org>,
        "list@263.net:IOMMU DRIVERS" <iommu@lists.linux-foundation.org>,
        Jim Quinlan <james.quinlan@broadcom.com>, xypron.glpk@gmx.de,
        Tom Lendacky <thomas.lendacky@amd.com>, bauerman@linux.ibm.com
Subject: Re: [PATCH v15 06/12] swiotlb: Use is_swiotlb_force_bounce for
 swiotlb data bouncing
Message-ID: <YOSMDZmtfXEKerpf@char.us.oracle.com>
References: <20210702135856.GB11132@willie-the-truck>
 <0f7bd903-e309-94a0-21d7-f0e8e9546018@arm.com>
 <YN/7xcxt/XGAKceZ@Ryzen-9-3900X.localdomain>
 <20210705190352.GA19461@willie-the-truck>
 <20210706044848.GA13640@lst.de>
 <20210706132422.GA20327@willie-the-truck>
 <a59f771f-3289-62f0-ca50-8f3675d9b166@arm.com>
 <20210706140513.GA26498@lst.de>
 <YORsr0h7u5l9DZwh@char.us.oracle.com>
 <20210706165720.GC20750@willie-the-truck>
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20210706165720.GC20750@willie-the-truck>
MIME-Version: 1.0
X-MS-Exchange-MessageSentRepresentingType: 1
Received: from char.us.oracle.com (138.3.200.56) by SA9PR13CA0164.namprd13.prod.outlook.com (2603:10b6:806:28::19) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4308.7 via Frontend Transport; Tue, 6 Jul 2021 17:00:01 +0000
X-MS-PublicTrafficType: Email
X-MS-Office365-Filtering-Correlation-Id: d90bdef9-b98b-4173-d89a-08d9409f8490
X-MS-TrafficTypeDiagnostic: BYAPR10MB3352:
X-MS-Exchange-Transport-Forked: True
X-Microsoft-Antispam-PRVS: <BYAPR10MB3352EAE5B696C84D5DB25D7B891B9@BYAPR10MB3352.namprd10.prod.outlook.com>
X-MS-Oob-TLC-OOBClassifiers: OLM:8882;
X-MS-Exchange-SenderADCheck: 1
X-Microsoft-Antispam: BCL:0;
X-Microsoft-Antispam-Message-Info: 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
X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:BYAPR10MB2999.namprd10.prod.outlook.com;PTR:;CAT:NONE;SFS:(39860400002)(136003)(396003)(376002)(346002)(366004)(86362001)(956004)(38350700002)(26005)(2906002)(66476007)(66556008)(52116002)(38100700002)(66946007)(55016002)(7366002)(6916009)(6666004)(7416002)(478600001)(186003)(7406005)(4326008)(54906003)(316002)(8936002)(5660300002)(7696005)(8676002);DIR:OUT;SFP:1101;
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?scGC9Se5Jg1HS0tFM3tWW1GGNsxDg1GUpXr0qEnbNBPaAaN9kFZpgZqIj8MP?=
 =?us-ascii?Q?DDlNMqvJOZOGvLO1B839ySjnBu/u8BK07SocW8jK0qmjmBbfzDrrNL0BZ3su?=
 =?us-ascii?Q?k7t2Gvety/UNdxAuG5PC6GK/q7HkUsjSGkr2AGdKV0xK9gpM9YwsUUYtBTJV?=
 =?us-ascii?Q?W3zZZF3g0OIWKXDnNdfT7xxIRkLVQtLyQ8Nq6GU6kpanE5lIXa/YRjjmn4Gy?=
 =?us-ascii?Q?AnR+80a/Zs5x/3yugdrxu1p6UwGDiFUq1cErU9jZTo8HgX1FHS621Fg66rF/?=
 =?us-ascii?Q?LCXsuOc+cNT+BIZHOvS40+Wumf9XIohidO46vcZGJ9Kyf435Njd+ssEM4JwZ?=
 =?us-ascii?Q?v8WZeqg1HxFwRT9PTjJMVeg4vhbLTwhr6hzF3+269Kl3CDKYxdKH/oPP7gr6?=
 =?us-ascii?Q?XCSJAEKcC5nD3UsTwwv49g/By2qVe6JOhR0HqSMln0jxBkzAK044Z+gfVIgV?=
 =?us-ascii?Q?V1EDSFQpp2K4PW77wlXiASRYLbyWiWs473OdFLUI9NlnMpqc5AWs2BP8QdvK?=
 =?us-ascii?Q?t0YS4Z5sor5vEcgcZoSQgI9pQ1y26xEK6V6B+0Vs7/Jfdygwvq3Wpichi37U?=
 =?us-ascii?Q?MG1vs9DeCPIq08keLgn7ldS+P3kAOw4A+nFJxYPCr3Wa26mvTJROOhFucRbd?=
 =?us-ascii?Q?6Twte3VY343U1rwumrFD7NVChTpvzkH/v5DnRQIWsdEazPHbEhwmhMFhog2Y?=
 =?us-ascii?Q?OtoRNIihRoM8SCPBVWzXO8Ob6wrGrvuKsTKncdtk6S1kkz3tOqz4y8VxFVbk?=
 =?us-ascii?Q?Jl1Jp/TgVjTjEYgJhPVpEmNaG7jWwIvBFIJWBVoTx7pTMBAPnIigj7jERJdz?=
 =?us-ascii?Q?at1Ii5p78N5xd2z7igdghVp40rmoqCEYgK+dUDT9MOabUL3UPUyZjpBaL8TQ?=
 =?us-ascii?Q?bHqOpw6eqt/nabCPsYEif/LoyJdG5Ylnsf7462S3bR3gGu6qeGrjAQe8b8nG?=
 =?us-ascii?Q?H1/0bWAz9nj9R2/uU9OyXR/y0zekVmgzenR2uCA/9R5ewwu+tKv6DEhDt+Bh?=
 =?us-ascii?Q?Sp7me+rATNS6umegxws6SIy+20E83ct9MJl7t0U+sGfyrcvNJgLcq4DtpeYv?=
 =?us-ascii?Q?z/0Ig+4DUTF4Zn36qTE8d+aGtjGWrSVRd/1pxtVV8ek34BSfOOeKWEN9FPmo?=
 =?us-ascii?Q?omF4tld5oAmYr4Jjn9bPuMel1A2qNDPeDWVWif+qswru6KnYpJV9RwDr8W06?=
 =?us-ascii?Q?G7JpDPfNbdKHPSsR01981ICzRVsWfLRBL+Bq1inSoTeRZePyvcaek5olgbeU?=
 =?us-ascii?Q?GhgCR/BCjMx9+rqH9+MUboZ6/eBvn1A+G7jOvB7lp1YIgfHRM3tYPx435sRf?=
 =?us-ascii?Q?p2uYqQ2IdEdocUGI/OvVOenL?=
X-OriginatorOrg: oracle.com
X-MS-Exchange-CrossTenant-Network-Message-Id: d90bdef9-b98b-4173-d89a-08d9409f8490
X-MS-Exchange-CrossTenant-AuthSource: BYAPR10MB2999.namprd10.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 06 Jul 2021 17:00:14.2584
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: 4e2c6054-71cb-48f1-bd6c-3a9705aca71b
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: zckFanMHx4+DZP0mkFA8w+J/Je1MRe1YIB1zMg75U1rDdB/71vM1KTH9RAuThBkq1D1a/ffRbEbgY+fMpFE1mQ==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: BYAPR10MB3352
X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=10037 signatures=668682
X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 spamscore=0 phishscore=0
 mlxscore=0 bulkscore=0 malwarescore=0 adultscore=0 mlxlogscore=999
 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2104190000
 definitions=main-2107060080
X-Proofpoint-GUID: MmsRRZVkZuEGZIh9CZM4MvD3gN7VIZMV
X-Proofpoint-ORIG-GUID: MmsRRZVkZuEGZIh9CZM4MvD3gN7VIZMV
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Tue, Jul 06, 2021 at 05:57:21PM +0100, Will Deacon wrote:
> On Tue, Jul 06, 2021 at 10:46:07AM -0400, Konrad Rzeszutek Wilk wrote:
> > On Tue, Jul 06, 2021 at 04:05:13PM +0200, Christoph Hellwig wrote:
> > > On Tue, Jul 06, 2021 at 03:01:04PM +0100, Robin Murphy wrote:
> > > > FWIW I was pondering the question of whether to do something along those 
> > > > lines or just scrap the default assignment entirely, so since I hadn't got 
> > > > round to saying that I've gone ahead and hacked up the alternative 
> > > > (similarly untested) for comparison :)
> > > >
> > > > TBH I'm still not sure which one I prefer...
> > > 
> > > Claire did implement something like your suggestion originally, but
> > > I don't really like it as it doesn't scale for adding multiple global
> > > pools, e.g. for the 64-bit addressable one for the various encrypted
> > > secure guest schemes.
> > 
> > Couple of things:
> >  - I am not pushing to Linus the Claire's patchset until we have a
> >    resolution on this. I hope you all agree that is a sensible way
> >    forward as much as I hate doing that.
> 
> Sure, it's a pity but we could clearly use a bit more time to get these
> just right and we've run out of time for 5.14.
> 
> I think the main question I have is how would you like to see patches for
> 5.15? i.e. as patches on top of devel/for-linus-5.14 or something else?

Yes that would be perfect. If there are any dependencies on the rc1, I
can rebase it on top of that.

> 
> Cheers,
> 
> Will