From: "Liu, Yi L" <yi.l.liu@intel.com>
To: "Tian, Kevin" <kevin.tian@intel.com>, Jason Gunthorpe <jgg@nvidia.com>
Cc: Alex Williamson <alex.williamson@redhat.com>,
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"Xu, Terrence" <terrence.xu@intel.com>
Subject: RE: [PATCH v5 09/19] vfio/pci: Allow passing zero-length fd array in VFIO_DEVICE_PCI_HOT_RESET
Date: Wed, 8 Mar 2023 07:47:23 +0000 [thread overview]
Message-ID: <DS0PR11MB75298BD3EB872C938F86C96AC3B49@DS0PR11MB7529.namprd11.prod.outlook.com> (raw)
In-Reply-To: <BN9PR11MB527616204417D92A1BEB5FDA8CB49@BN9PR11MB5276.namprd11.prod.outlook.com>
> From: Tian, Kevin <kevin.tian@intel.com>
> Sent: Wednesday, March 8, 2023 3:26 PM
>
> > From: Liu, Yi L <yi.l.liu@intel.com>
> > Sent: Tuesday, March 7, 2023 9:29 PM
> >
> > >
> > > I really prefer the 'use the iommufd option' still exist, it is so
> > > much cleaner and easier for the actual users of this API. We've lost
> > > the point by worrying about no iommu.
> >
> > Hmmm, so you are suggesting to have both the device fd approach
> > and the zero-length array approach, let user to select the best way
> > based on their wisdom. Is it? how about something like below in the
> > uapi header.
> >
> > /**
> > * VFIO_DEVICE_PCI_HOT_RESET - _IOW(VFIO_TYPE, VFIO_BASE + 13,
> > * struct vfio_pci_hot_reset)
> > *
> > * Userspace requests hot reset for the devices it uses. Due to the
> > * underlying topology, multiple devices may be affected in the reset.
> > * The affected devices may have been opened by the user or by other
> > * users or not opened yet. Only when all the affected devices are
> > * either opened by the current user or not opened by any user, should
> > * the reset request be allowed. Otherwise, this request is expected
> > * to return error. group_fds array can accept either group fds or
> > * device fds. Users using iommufd (valid fd), could also passing a
> > * zero-length group_fds array to indicate using the bound iommufd_ctx
> > * for ownership check to the affected devices that are opened.
> > *
> > * Return: 0 on success, -errno on failure.
> > */
> > struct vfio_pci_hot_reset {
> > __u32 argsz;
> > __u32 flags;
> > __u32 count;
> > __s32 group_fds[];
> > };
> >
>
> * Userspace requests hot reset for the devices it uses. Due to the
> * underlying topology, multiple devices can be affected in the reset
> * while some might be opened by another user. To avoid interference
> * the calling user must ensure all affected devices, if opened, are
> * owned by itself.
> *
> * The ownership can be proved in three ways:
> * - An array of group fds
> * - An array of device fds
> * - A zero-length array
> *
Thanks.
> * In the last case all affected devices which are opened by this user must
> * have been bound to a same iommufd_ctx.
I think we only allow it when this iommufd_ctx is valid. Is it? To
user, it means device should be bound to a positive iommufd.
> and with this change let's rename 'group_fds' to 'fds'
Sure. It would be something like below:
struct vfio_pci_hot_reset {
__u32 argsz;
__u32 flags;
_u32 count;
union {
__s32 group_fds[0];
__s32 fds[0];
};
};
Regards,
Yi Liu
next prev parent reply other threads:[~2023-03-08 7:47 UTC|newest]
Thread overview: 128+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-27 11:11 [PATCH v5 00/19] Add vfio_device cdev for iommufd support Yi Liu
2023-02-27 11:11 ` [PATCH v5 01/19] vfio: Allocate per device file structure Yi Liu
2023-02-27 18:46 ` Jason Gunthorpe
2023-02-27 11:11 ` [PATCH v5 02/19] vfio: Refine vfio file kAPIs for KVM Yi Liu
2023-02-27 18:46 ` Jason Gunthorpe
2023-02-27 11:11 ` [PATCH v5 03/19] vfio: Accept vfio device file in the KVM facing kAPI Yi Liu
2023-02-27 18:46 ` Jason Gunthorpe
2023-02-27 11:11 ` [PATCH v5 04/19] kvm/vfio: Rename kvm_vfio_group to prepare for accepting vfio device fd Yi Liu
2023-02-27 18:47 ` Jason Gunthorpe
2023-02-27 11:11 ` [PATCH v5 05/19] kvm/vfio: Accept vfio device file from userspace Yi Liu
2023-02-27 18:47 ` Jason Gunthorpe
2023-02-27 11:11 ` [PATCH v5 06/19] vfio: Pass struct vfio_device_file * to vfio_device_open/close() Yi Liu
2023-02-27 18:47 ` Jason Gunthorpe
2023-02-27 11:11 ` [PATCH v5 07/19] vfio: Block device access via device fd until device is opened Yi Liu
2023-02-27 18:48 ` Jason Gunthorpe
2023-03-01 9:22 ` Liu, Yi L
2023-02-27 11:11 ` [PATCH v5 08/19] vfio/pci: Update comment around group_fd get in vfio_pci_ioctl_pci_hot_reset() Yi Liu
2023-02-27 18:48 ` Jason Gunthorpe
2023-02-27 11:11 ` [PATCH v5 09/19] vfio/pci: Allow passing zero-length fd array in VFIO_DEVICE_PCI_HOT_RESET Yi Liu
2023-02-27 18:22 ` Jason Gunthorpe
2023-02-28 2:31 ` Liu, Yi L
2023-03-02 6:07 ` Liu, Yi L
2023-03-02 9:55 ` Tian, Kevin
2023-03-02 12:35 ` Jason Gunthorpe
2023-03-02 14:20 ` Liu, Yi L
2023-03-03 6:36 ` Tian, Kevin
2023-03-03 16:55 ` Alex Williamson
2023-03-05 14:48 ` Liu, Yi L
2023-03-06 8:16 ` Tian, Kevin
2023-03-06 8:23 ` Tian, Kevin
2023-03-06 8:33 ` Liu, Yi L
2023-03-06 9:59 ` Liu, Yi L
2023-03-06 13:16 ` Jason Gunthorpe
2023-03-07 2:31 ` Tian, Kevin
2023-03-07 2:35 ` Liu, Yi L
2023-03-07 12:36 ` Jason Gunthorpe
2023-03-07 13:28 ` Liu, Yi L
2023-03-08 7:26 ` Tian, Kevin
2023-03-08 7:47 ` Liu, Yi L [this message]
2023-03-08 7:55 ` Tian, Kevin
2023-03-08 8:00 ` Liu, Yi L
2023-03-08 8:14 ` Tian, Kevin
2023-03-08 8:15 ` Liu, Yi L
2023-03-08 15:08 ` Jason Gunthorpe
2023-03-02 21:04 ` Alex Williamson
2023-02-27 11:11 ` [PATCH v5 10/19] vfio: Add infrastructure for bind_iommufd from userspace Yi Liu
2023-02-27 18:29 ` Jason Gunthorpe
2023-02-28 2:35 ` Liu, Yi L
2023-02-28 6:58 ` Liu, Yi L
2023-02-28 12:31 ` Jason Gunthorpe
2023-02-28 12:45 ` Liu, Yi L
2023-02-28 12:52 ` Jason Gunthorpe
2023-02-28 12:56 ` Liu, Yi L
2023-02-28 12:58 ` Jason Gunthorpe
2023-02-28 12:29 ` Jason Gunthorpe
2023-02-28 12:48 ` Liu, Yi L
2023-02-28 12:52 ` Jason Gunthorpe
2023-02-28 13:24 ` Liu, Yi L
2023-02-27 11:11 ` [PATCH v5 11/19] vfio-iommufd: Add detach_ioas support for physical VFIO devices Yi Liu
2023-02-27 18:44 ` Jason Gunthorpe
2023-02-28 2:57 ` Liu, Yi L
2023-02-28 12:33 ` Jason Gunthorpe
2023-02-28 12:43 ` Liu, Yi L
2023-02-27 11:11 ` [PATCH v5 12/19] vfio-iommufd: Add detach_ioas for emulated " Yi Liu
2023-02-27 18:45 ` Jason Gunthorpe
2023-02-27 11:11 ` [PATCH v5 13/19] vfio: Add cdev_device_open_cnt to vfio_group Yi Liu
2023-02-27 19:20 ` Jason Gunthorpe
2023-02-27 11:11 ` [PATCH v5 14/19] vfio: Make vfio_device_open() single open for device cdev path Yi Liu
2023-02-27 18:52 ` Jason Gunthorpe
2023-02-28 3:11 ` Liu, Yi L
2023-02-28 12:33 ` Jason Gunthorpe
2023-03-01 13:58 ` Liu, Yi L
2023-02-27 11:11 ` [PATCH v5 15/19] vfio: Add cdev for vfio_device Yi Liu
2023-02-27 18:55 ` Jason Gunthorpe
2023-02-28 3:47 ` Liu, Yi L
2023-02-27 19:06 ` Jason Gunthorpe
2023-02-28 3:59 ` Liu, Yi L
2023-02-27 11:11 ` [PATCH v5 16/19] vfio: Add VFIO_DEVICE_BIND_IOMMUFD Yi Liu
2023-02-27 19:19 ` Jason Gunthorpe
2023-02-28 4:08 ` Liu, Yi L
2023-03-01 9:19 ` Liu, Yi L
2023-03-01 17:46 ` Jason Gunthorpe
2023-03-02 4:09 ` Liu, Yi L
2023-03-03 6:57 ` Liu, Yi L
2023-03-03 7:23 ` Liu, Yi L
2023-03-07 6:38 ` Tian, Kevin
2023-03-07 12:37 ` Jason Gunthorpe
2023-03-07 13:03 ` Liu, Yi L
2023-03-08 7:17 ` Tian, Kevin
2023-03-10 2:39 ` Alexey Kardashevskiy
2023-03-10 5:49 ` Liu, Yi L
2023-02-27 11:11 ` [PATCH v5 17/19] vfio: Add VFIO_DEVICE_AT[DE]TACH_IOMMUFD_PT Yi Liu
2023-02-27 18:39 ` Jason Gunthorpe
2023-02-28 2:51 ` Liu, Yi L
2023-02-28 12:32 ` Jason Gunthorpe
2023-02-28 12:42 ` Liu, Yi L
2023-02-28 12:53 ` Jason Gunthorpe
2023-02-28 13:22 ` Liu, Yi L
2023-02-28 13:25 ` Jason Gunthorpe
2023-02-28 13:36 ` Liu, Yi L
2023-02-28 13:43 ` Jason Gunthorpe
2023-02-28 14:01 ` Liu, Yi L
2023-02-28 14:38 ` Jason Gunthorpe
2023-03-01 14:04 ` Liu, Yi L
2023-03-01 17:49 ` Jason Gunthorpe
2023-03-02 3:24 ` Liu, Yi L
2023-02-27 11:11 ` [PATCH v5 18/19] vfio: Compile group optionally Yi Liu
2023-02-27 19:20 ` Jason Gunthorpe
2023-02-28 3:14 ` Liu, Yi L
2023-02-28 6:00 ` Liu, Yi L
2023-02-28 12:36 ` Jason Gunthorpe
2023-03-01 13:59 ` Liu, Yi L
2023-02-27 11:11 ` [PATCH v5 19/19] docs: vfio: Add vfio device cdev description Yi Liu
2023-02-27 19:21 ` [PATCH v5 00/19] Add vfio_device cdev for iommufd support Jason Gunthorpe
2023-02-28 3:03 ` Liu, Yi L
2023-02-28 16:58 ` Xu, Terrence
2023-03-01 2:29 ` Nicolin Chen
2023-03-01 3:44 ` Liu, Yi L
2023-03-02 9:43 ` Shameerali Kolothum Thodi
2023-03-02 23:51 ` Nicolin Chen
2023-03-03 15:01 ` Shameerali Kolothum Thodi
2023-03-04 7:00 ` Nicolin Chen
2023-03-04 8:22 ` Liu, Yi L
2023-03-08 15:54 ` Shameerali Kolothum Thodi
2023-03-14 11:38 ` Shameerali Kolothum Thodi
2023-03-15 23:22 ` Nicolin Chen
2023-03-16 7:39 ` Liu, Yi L
2023-03-03 21:29 ` Matthew Rosato
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