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From: Jason Gunthorpe <jgg@nvidia.com>
To: Yi Liu <yi.l.liu@intel.com>
Cc: alex.williamson@redhat.com, kevin.tian@intel.com,
	cohuck@redhat.com, eric.auger@redhat.com, nicolinc@nvidia.com,
	kvm@vger.kernel.org, mjrosato@linux.ibm.com,
	chao.p.peng@linux.intel.com, yi.y.sun@linux.intel.com,
	peterx@redhat.com, jasowang@redhat.com
Subject: Re: [RFC 07/12] vfio: Block device access via device fd until device is opened
Date: Wed, 4 Jan 2023 16:47:36 -0400	[thread overview]
Message-ID: <Y7Xl6AxA9w7IgsZ5@nvidia.com> (raw)
In-Reply-To: <20221219084718.9342-8-yi.l.liu@intel.com>

On Mon, Dec 19, 2022 at 12:47:13AM -0800, Yi Liu wrote:

> @@ -452,6 +457,11 @@ void vfio_device_close(struct vfio_device_file *df)
>  	struct vfio_device *device = df->device;
>  
>  	mutex_lock(&device->dev_set->lock);
> +	/*
> +	 * Paired with smp_load_acquire() in vfio_device_fops::ioctl/
> +	 * read/write/mmap
> +	 */
> +	smp_store_release(&df->access_granted, false);

Storing false makes no sense, it can't do anything, this function
should only be called if we are in a release function so we know that
there can't be concurrent access to access_granted.

Jason

  parent reply	other threads:[~2023-01-04 20:47 UTC|newest]

Thread overview: 44+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-12-19  8:47 [RFC 00/12] Add vfio_device cdev for iommufd support Yi Liu
2022-12-19  8:47 ` [RFC 01/12] vfio: Allocate per device file structure Yi Liu
2022-12-21  3:57   ` Tian, Kevin
2022-12-21  6:46     ` Yi Liu
2022-12-19  8:47 ` [RFC 02/12] vfio: Refine vfio file kAPIs Yi Liu
2022-12-19  8:47 ` [RFC 03/12] vfio: Accept vfio device file in the driver facing kAPI Yi Liu
2022-12-21  4:07   ` Tian, Kevin
2022-12-21  7:02     ` Yi Liu
2023-01-04 18:25     ` Jason Gunthorpe
2023-01-09  4:13       ` Tian, Kevin
2022-12-19  8:47 ` [RFC 04/12] kvm/vfio: Rename kvm_vfio_group to prepare for accepting vfio device fd Yi Liu
2022-12-19  8:47 ` [RFC 05/12] kvm/vfio: Accept vfio device file from userspace Yi Liu
2023-01-06 14:32   ` Jason Gunthorpe
2023-01-06 14:46     ` Yi Liu
2023-01-06 14:55       ` Jason Gunthorpe
2023-01-06 15:04         ` Yi Liu
2023-01-06 16:08           ` Jason Gunthorpe
2023-01-09  4:17           ` Tian, Kevin
2023-01-09  4:26             ` Yi Liu
2022-12-19  8:47 ` [RFC 06/12] vfio: Pass struct vfio_device_file * to vfio_device_open/close() Yi Liu
2022-12-21  4:10   ` Tian, Kevin
2022-12-21  7:04     ` Yi Liu
2022-12-19  8:47 ` [RFC 07/12] vfio: Block device access via device fd until device is opened Yi Liu
2022-12-21  4:18   ` Tian, Kevin
2023-01-04 20:47   ` Jason Gunthorpe [this message]
2022-12-19  8:47 ` [RFC 08/12] vfio: Add infrastructure for bind_iommufd and attach Yi Liu
2023-01-09  5:46   ` Tian, Kevin
2023-01-09 13:21     ` Jason Gunthorpe
2023-01-10  2:53       ` Tian, Kevin
2022-12-19  8:47 ` [RFC 09/12] vfio: Make vfio_device_open() exclusive between group path and device cdev path Yi Liu
2023-01-09  6:03   ` Tian, Kevin
2022-12-19  8:47 ` [RFC 10/12] vfio: Add cdev for vfio_device Yi Liu
2023-01-09  6:54   ` Tian, Kevin
2022-12-19  8:47 ` [RFC 11/12] vfio: Add ioctls for device cdev iommufd Yi Liu
2023-01-09  7:47   ` Tian, Kevin
2023-01-09 14:14     ` Jason Gunthorpe
2023-01-09 15:07       ` Yi Liu
2023-01-09 15:12         ` Jason Gunthorpe
2023-01-09 15:20           ` Yi Liu
2023-01-09 14:55     ` Yi Liu
2023-01-10  2:57       ` Tian, Kevin
2022-12-19  8:47 ` [RFC 12/12] vfio: Compile group optionally Yi Liu
2022-12-19  8:51 ` [RFC 00/12] Add vfio_device cdev for iommufd support Yi Liu
2023-01-04 15:23 ` Yi Liu

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