[Intel-gfx] [PATCH v4 0/9] Enhance vfio PCI hot reset for vfio cdev device

[Jiang, Yanting]

> VFIO_DEVICE_PCI_HOT_RESET requires user to pass an array of group fds to
> prove that it owns all devices affected by resetting the calling device. While for
> cdev devices, user can use an iommufd-based ownership checking model and
> invoke VFIO_DEVICE_PCI_HOT_RESET with a zero-length fd array.
> 
> This series first creates iommufd_access for noiommu devices to fill the gap for
> adding iommufd-based ownership checking model, then extends
> VFIO_DEVICE_GET_PCI_HOT_RESET_INFO to check ownership and return the
> check result and the devid of affected devices to user. In the end, extends the
> VFIO_DEVICE_PCI_HOT_RESET to accept zero-length fd array for hot-reset with
> cdev devices.
> 
> The new hot reset method and updated _INFO ioctl are tested with the below
> qemu:
> 
> https://github.com/yiliu1765/qemu/tree/iommufd_rfcv4.mig.reset.v4_var3
> (requires to test with the cdev kernel)
> 

Tested NIC passthrough on Intel platform.
Result looks good hence,
Tested-by: Yanting Jiang <yanting.jiang at intel.com>

Thanks,
Yanting