Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.37 as permitted sender) client-ip=23.128.96.37;
Date:   Tue, 5 Dec 2023 10:53:04 -0400
From:   Jason Gunthorpe <jgg@nvidia.com>
To:     Yan Zhao <yan.y.zhao@intel.com>
Cc:     iommu@lists.linux.dev, kvm@vger.kernel.org,
        linux-kernel@vger.kernel.org, alex.williamson@redhat.com,
        pbonzini@redhat.com, seanjc@google.com, joro@8bytes.org,
        will@kernel.org, robin.murphy@arm.com, kevin.tian@intel.com,
        baolu.lu@linux.intel.com, dwmw2@infradead.org, yi.l.liu@intel.com
Subject: Re: [RFC PATCH 12/42] iommufd: Introduce allocation data info and
 flag for KVM managed HWPT
Message-ID: <20231205145304.GE2787277@nvidia.com>
References: <20231202091211.13376-1-yan.y.zhao@intel.com>
 <20231202092113.14141-1-yan.y.zhao@intel.com>
 <20231204182928.GL1493156@nvidia.com>
 <ZW7MU4L9vybiDqZt@yzhao56-desk.sh.intel.com>
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <ZW7MU4L9vybiDqZt@yzhao56-desk.sh.intel.com>
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?PiUifFe2oiAGfW1vMqbGX6alOd8AAMW2ZxjwS81Gt0KtN8OadDYPLPtOHuKB?=
 =?us-ascii?Q?H4zX1J+63eSpydiLoi+CzdPr/jiH43tpn92imuKvUYKjqsKRDTmJpzGTk8FH?=
 =?us-ascii?Q?0UERwU8hnyB+lrT0K7y3jI9jQ/6dqgHCHmCh31DBvd57uEtngrcB4CdnRciy?=
 =?us-ascii?Q?W/Uoo5ekc7qPM63dz7bg71XtazD/Bd3GIJFZQZjWf9eDEV0o0VJ2dfwequ79?=
 =?us-ascii?Q?wGTnmYR/eClIZPBGrWCzYkIYuDGUShxx/Gg4auQd0lbLtrDc5YOyARzOj8TU?=
 =?us-ascii?Q?XpgV0X3iweEuvNKpEpn8MMw3ghlIi+On8OTmXyyCJfafvHndpwLkPcq71dI+?=
 =?us-ascii?Q?S/0cvBgRbrPyRTHupRXUK+AksfiEsXBvbs0c0DVE0OUnwI41Q/FARH8RNJe8?=
 =?us-ascii?Q?0wic6lTi/ug9sFNdNiTVNcx3RxYNNQzueHPBUx8yQrSlJWi0ShSl5kILaKSa?=
 =?us-ascii?Q?enDxjrsGID8B8kpGaK06OKySLdpZpbyzJLi5iHuRg7GMGocdgsdMFzjq5nXc?=
 =?us-ascii?Q?1lxzkByVI1anucXRrtjuBELblE0h7dBQBYoJWVfqtSeJcSPVFW2dhk7+iJ1g?=
 =?us-ascii?Q?bDzq4ZK3wl8HK2YVX9f2yPkDoseJAh0zkZE/VlySyQE7dzpHqivBZcNEcseS?=
 =?us-ascii?Q?afwjKxl6Y3GpTev2UMVrS0DXOJwJKHioE6r6L18PWFblLLpEwq9ihEBnCqib?=
 =?us-ascii?Q?mP1Axy4t9gCH/LqMj4CHRcuNglgNZi8xvvPyyFRm+f1Livwd2JzJ/o/FmqF1?=
 =?us-ascii?Q?c4hy/1oTfPrFYnJKZqYJD492+eTs342b6TCpYQj0iNqQwieU7AZ+KpGwpSmt?=
 =?us-ascii?Q?3AYatEreBRLeBs6sbWvv8AOizc+ig3bxHcG1OBrMSLw1TernX3tu5z2Ct+z+?=
 =?us-ascii?Q?UXOYEXpKB1utyX2y4xpR1eIALvkp5cLLqAm5+QdDvFqouYfoLgQgz+ySKd8H?=
 =?us-ascii?Q?eG6/Kfy8YNO2Scm2XT/d0Z/iUsXh2JmjBN/JsBBzUaV8kXFNSE7dlKTe9klw?=
 =?us-ascii?Q?Q3+O9jw5H3D5zPE+Szggcjyk5C9n2w4HIwmi7QTLlF9Zy08SHjhkhjMSyW0l?=
 =?us-ascii?Q?pl84Hq6eE5l5qyJfInr9HGm8xSP37+kT/BJjL8KO5qtYo1BcBWcDRf/wqug8?=
 =?us-ascii?Q?IR3cVvCp6S/Emk9oCjbfkM3ZqLhMScwa6IEw595NjcskpcINvOc3UEuKImkv?=
 =?us-ascii?Q?jQDMb2LwwlBL2P1mj6Yw1Z/MIvhVbHKE+ZK025+ITUt4judNVeO5DDXvGpf7?=
 =?us-ascii?Q?VHRb4+RaBNprRaQipez3PKru+Vk/8b1+4KrHGvzffO/yNBIrpqrZ+7Rb6lTa?=
 =?us-ascii?Q?rZUHfGXSpFNEXHcGoOiQK2XZpDpIqxr49ydA0UA3yUSjfP440DN3jwnMAzqb?=
 =?us-ascii?Q?Q82RKnxFE8+PFabjLrFUWNHST0WLG1e+kGsREEotvgL/idZpa42UpTH8m08h?=
 =?us-ascii?Q?3wMByw2AffQCfDYkLBVk7OQkC0kLiSuWVteg/T/iyeliXcUKRqrSFSxF0SDt?=
 =?us-ascii?Q?Aw52Gow1Y15/P9USmjWmgTqt40TOXNckI8+0V0F/Z4nrY7KCi+a3TVn4BOVO?=
 =?us-ascii?Q?A2kCtQvueDupsuAy6/UFZzEGdzdUXfO6ijEFz7VP?=
X-OriginatorOrg: Nvidia.com
X-MS-Exchange-CrossTenant-Network-Message-Id: 75ad542f-1421-4843-5aa4-08dbf5a1e348
X-MS-Exchange-CrossTenant-AuthSource: LV2PR12MB5869.namprd12.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 05 Dec 2023 14:53:05.5808
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: DwMLqLLf/Cfe26Sm5Qfrhm638WaLAxszKotEp8BdQueeKg5Ezoni0VqvfB7rnCrv
X-MS-Exchange-Transport-CrossTenantHeadersStamped: DS0PR12MB7608
X-Spam-Status: No, score=-1.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH,
        DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FORGED_SPF_HELO,
        RCVD_IN_DNSWL_BLOCKED,RCVD_IN_MSPIKE_H2,SPF_HELO_PASS,SPF_NONE,
        T_SCC_BODY_TEXT_LINE autolearn=no autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on
        lindbergh.monkeyblade.net
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org
X-Greylist: Sender passed SPF test, not delayed by milter-greylist-4.6.4 (snail.vger.email [0.0.0.0]); Tue, 05 Dec 2023 06:53:14 -0800 (PST)

On Tue, Dec 05, 2023 at 03:08:03PM +0800, Yan Zhao wrote:
> On Mon, Dec 04, 2023 at 02:29:28PM -0400, Jason Gunthorpe wrote:
> > On Sat, Dec 02, 2023 at 05:21:13PM +0800, Yan Zhao wrote:
> > 
> > > @@ -413,11 +422,13 @@ struct iommu_hwpt_arm_smmuv3 {
> > >   * @IOMMU_HWPT_DATA_NONE: no data
> > >   * @IOMMU_HWPT_DATA_VTD_S1: Intel VT-d stage-1 page table
> > >   * @IOMMU_HWPT_DATA_ARM_SMMUV3: ARM SMMUv3 Context Descriptor Table
> > > + * @IOMMU_HWPT_DATA_KVM: KVM managed stage-2 page table
> > >   */
> > >  enum iommu_hwpt_data_type {
> > >  	IOMMU_HWPT_DATA_NONE,
> > >  	IOMMU_HWPT_DATA_VTD_S1,
> > >  	IOMMU_HWPT_DATA_ARM_SMMUV3,
> > > +	IOMMU_HWPT_DATA_KVM,
> > >  };
> > 
> > Definately no, the HWPT_DATA is for the *driver* - it should not be
> > "kvm".
> > 
> > Add the kvm fd to the main structure
> >
> Do you mean add a "int kvm_fd" to "struct iommu_hwpt_alloc" ?
> struct iommu_hwpt_alloc {
>         __u32 size;
>         __u32 flags;
>         __u32 dev_id;
>         __u32 pt_id;
>         __u32 out_hwpt_id;
>         __u32 __reserved;
>         __u32 data_type;
>         __u32 data_len;
>         __aligned_u64 data_uptr;
> };
> 
> Then always create the HWPT as IOMMUFD_OBJ_HWPT_KVM as long as kvm_fd > 0 ?

Yes, but 0 is a valid FD so you need to add a flag 'kvm_fd valid'

Jason