Re: [RFC v3 00/18] vfio: Adopt iommufd

[Jason Gunthorpe]

On Fri, Feb 03, 2023 at 07:03:50PM +0100, Eric Auger wrote:

> >> - vfio pci device hot reset
> > What is needed here?
> 
> we need to revisit the vfio_pci_hot_reset() implementation in hw/vfio/pci.c
> It uses VFIO_DEVICE_GET_PCI_HOT_RESET_INFO and VFIO_DEVICE_PCI_HOT_RESET
> uapis
> which retrieves/passes the list of iommu groups involved in the reset.
> The notion of group had initially disappeared from the the iommufd BE
> but I am afraid that's not that simple.

>From the kernel side I expected that the device FD would be passed in
place of the group FD and like in KVM we'd transform that into a group
and run exactly the same algorithm. The kernel cdev series should be
doing this.

So from the qemu side I would expect it to keep track of all the open
VFIO device FD and pass them all into the host rest functions when
working in cdev mode.

Jason