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Miller" , Jakub Kicinski , "Kirti Wankhede" , "kvm@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-pci@vger.kernel.org" , "linux-rdma@vger.kernel.org" , "netdev@vger.kernel.org" , Saeed Mahameed References: <42729adc4df649f7b3ce5dc95e66e2dc@huawei.com> From: Max Gurtovoy Message-ID: <60989aa8-4231-0cdf-47bb-1e2026bd1f17@nvidia.com> Date: Thu, 23 Sep 2021 16:55:35 +0300 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.14.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US X-Originating-IP: [172.20.187.5] X-ClientProxiedBy: HQMAIL101.nvidia.com (172.20.187.10) To DRHQMAIL107.nvidia.com (10.27.9.16) X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: f30a9f56-c5a8-4e6e-5501-08d97e99d5d6 X-MS-TrafficTypeDiagnostic: MW2PR12MB2442: X-Microsoft-Antispam-PRVS: X-MS-Oob-TLC-OOBClassifiers: OLM:8273; X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:216.228.112.32;CTRY:US;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:mail.nvidia.com;PTR:schybrid01.nvidia.com;CAT:NONE;SFS:(4636009)(46966006)(36840700001)(82310400003)(36860700001)(508600001)(70586007)(70206006)(31696002)(31686004)(426003)(54906003)(110136005)(316002)(5660300002)(86362001)(16576012)(107886003)(53546011)(4326008)(8936002)(2616005)(336012)(2906002)(16526019)(26005)(186003)(8676002)(83380400001)(7636003)(36756003)(356005)(47076005)(7416002)(43740500002);DIR:OUT;SFP:1101; X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 23 Sep 2021 13:55:43.1116 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: f30a9f56-c5a8-4e6e-5501-08d97e99d5d6 X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=43083d15-7273-40c1-b7db-39efd9ccc17a;Ip=[216.228.112.32];Helo=[mail.nvidia.com] X-MS-Exchange-CrossTenant-AuthSource: DM6NAM11FT064.eop-nam11.prod.protection.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: MW2PR12MB2442 Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org On 9/23/2021 2:17 PM, Leon Romanovsky wrote: > On Thu, Sep 23, 2021 at 10:33:10AM +0000, Shameerali Kolothum Thodi wrote: >> >>> -----Original Message----- >>> From: Leon Romanovsky [mailto:leon@kernel.org] >>> Sent: 22 September 2021 11:39 >>> To: Doug Ledford ; Jason Gunthorpe >>> Cc: Yishai Hadas ; Alex Williamson >>> ; Bjorn Helgaas ; David >>> S. Miller ; Jakub Kicinski ; Kirti >>> Wankhede ; kvm@vger.kernel.org; >>> linux-kernel@vger.kernel.org; linux-pci@vger.kernel.org; >>> linux-rdma@vger.kernel.org; netdev@vger.kernel.org; Saeed Mahameed >>> >>> Subject: [PATCH mlx5-next 2/7] vfio: Add an API to check migration state >>> transition validity >>> >>> From: Yishai Hadas >>> >>> Add an API in the core layer to check migration state transition validity >>> as part of a migration flow. >>> >>> The valid transitions follow the expected usage as described in >>> uapi/vfio.h and triggered by QEMU. >>> >>> This ensures that all migration implementations follow a consistent >>> migration state machine. >>> >>> Signed-off-by: Yishai Hadas >>> Reviewed-by: Kirti Wankhede >>> Signed-off-by: Jason Gunthorpe >>> Signed-off-by: Leon Romanovsky >>> --- >>> drivers/vfio/vfio.c | 41 +++++++++++++++++++++++++++++++++++++++++ >>> include/linux/vfio.h | 1 + >>> 2 files changed, 42 insertions(+) >>> >>> diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c >>> index 3c034fe14ccb..c3ca33e513c8 100644 >>> --- a/drivers/vfio/vfio.c >>> +++ b/drivers/vfio/vfio.c >>> @@ -1664,6 +1664,47 @@ static int vfio_device_fops_release(struct inode >>> *inode, struct file *filep) >>> return 0; >>> } >>> >>> +/** >>> + * vfio_change_migration_state_allowed - Checks whether a migration state >>> + * transition is valid. >>> + * @new_state: The new state to move to. >>> + * @old_state: The old state. >>> + * Return: true if the transition is valid. >>> + */ >>> +bool vfio_change_migration_state_allowed(u32 new_state, u32 old_state) >>> +{ >>> + enum { MAX_STATE = VFIO_DEVICE_STATE_RESUMING }; >>> + static const u8 vfio_from_state_table[MAX_STATE + 1][MAX_STATE + 1] = { >>> + [VFIO_DEVICE_STATE_STOP] = { >>> + [VFIO_DEVICE_STATE_RUNNING] = 1, >>> + [VFIO_DEVICE_STATE_RESUMING] = 1, >>> + }, >>> + [VFIO_DEVICE_STATE_RUNNING] = { >>> + [VFIO_DEVICE_STATE_STOP] = 1, >>> + [VFIO_DEVICE_STATE_SAVING] = 1, >>> + [VFIO_DEVICE_STATE_SAVING | VFIO_DEVICE_STATE_RUNNING] >>> = 1, >> Do we need to allow _RESUMING state here or not? As per the "State transitions" >> section from uapi/linux/vfio.h, > It looks like we missed this state transition. > > Thanks I'm not sure this state transition is valid. Kirti, When we would like to move from RUNNING to RESUMING ? Sameerali, can you please re-test and update if you see this transition ? > >> " * 4. To start the resuming phase, the device state should be transitioned from >> * the _RUNNING to the _RESUMING state." >> >> IIRC, I have seen that transition happening on the destination dev while testing the >> HiSilicon ACC dev migration. >> >> Thanks, >> Shameer >> >>> + }, >>> + [VFIO_DEVICE_STATE_SAVING] = { >>> + [VFIO_DEVICE_STATE_STOP] = 1, >>> + [VFIO_DEVICE_STATE_RUNNING] = 1, >>> + }, >>> + [VFIO_DEVICE_STATE_SAVING | VFIO_DEVICE_STATE_RUNNING] = { >>> + [VFIO_DEVICE_STATE_RUNNING] = 1, >>> + [VFIO_DEVICE_STATE_SAVING] = 1, >>> + }, >>> + [VFIO_DEVICE_STATE_RESUMING] = { >>> + [VFIO_DEVICE_STATE_RUNNING] = 1, >>> + [VFIO_DEVICE_STATE_STOP] = 1, >>> + }, >>> + }; >>> + >>> + if (new_state > MAX_STATE || old_state > MAX_STATE) >>> + return false; >>> + >>> + return vfio_from_state_table[old_state][new_state]; >>> +} >>> +EXPORT_SYMBOL_GPL(vfio_change_migration_state_allowed); >>> + >>> static long vfio_device_fops_unl_ioctl(struct file *filep, >>> unsigned int cmd, unsigned long arg) >>> { >>> diff --git a/include/linux/vfio.h b/include/linux/vfio.h >>> index b53a9557884a..e65137a708f1 100644 >>> --- a/include/linux/vfio.h >>> +++ b/include/linux/vfio.h >>> @@ -83,6 +83,7 @@ extern struct vfio_device >>> *vfio_device_get_from_dev(struct device *dev); >>> extern void vfio_device_put(struct vfio_device *device); >>> >>> int vfio_assign_device_set(struct vfio_device *device, void *set_id); >>> +bool vfio_change_migration_state_allowed(u32 new_state, u32 old_state); >>> >>> /* events for the backend driver notify callback */ >>> enum vfio_iommu_notify_type { >>> -- >>> 2.31.1