[Intel-gfx] [PATCH v2 10/14] vfio/pci: Reorganize VFIO_DEVICE_PCI_HOT_RESET to use the device set

[Christoph Hellwig]

On Tue, Jul 20, 2021 at 02:42:56PM -0300, Jason Gunthorpe wrote:
> Like vfio_pci_try_bus_reset() this code wants to reset all of the devices
> in the "reset group" which is the same membership as the device set.
> 
> Instead of trying to reconstruct the device set from the PCI list go
> directly from the device set's device list to execute the reset.
> 
> The same basic structure as vfio_pci_try_bus_reset() is used. The
> 'vfio_devices' struct is replaced with the device set linked list and we
> simply sweep it multiple times under the lock.
> 
> This eliminates a memory allocation and get/put traffic and another
> improperly locked test of pci_dev_driver().

Looks fine.  But oh gad is that locking scheme awful..

Signed-off-by: Christoph Hellwig <hch at lst.de>